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Sample records for sprint cycle training

  1. MONITORING SWIMMING SPRINT PERFORMANCE DURING A TRAINING CYCLE

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    Daniel A. Marinho

    2009-12-01

    Full Text Available The preparation for a major competition is an important concern of coaches and athletes. Therefore, the aim of this study was to evaluate the evolution in sprint performance during a training macro cycle in age-group swimmers of both genders. The sample comprised twenty four age-group swimmers (12.0 ± 0.72 years old, 41.43 ± 6.88 kg, 1.51 ± 0.09 m. The evaluations occurred during nine weeks of swimming training in the first macro cycle. During this period the subjects performed 54 training units (6 units per week. In all weeks, the performance in two trials of a 25 m front crawl all out test, with 15 min of rest, was recorded. Only the bestperformance was used to assess the effects of training. Comparisons between the first week and the following weeks were conducted using pair-sample t-test. The significance level was set at 5%. The sprint performance did not change during the first 6 weeks of preparation. In the last three weeks the performance in the 25 m front crawl test was improved when compared with the first week, although the major changes occurred at the last week of preparation.It seems that in age-group swimmers seven weeks of specific swimming training enables improving swimmer’s sprint performance, although some differences exists between male and female swimmers. Thesedata could be used by coaches to program the training season and the evolution of the load components.

  2. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

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    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K.

    2016-01-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key points In addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  3. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

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    Carolin Stangier, Thomas Abel, Julia Mierau, Wildor Hollmann, Heiko K. Strüder

    2016-03-01

    Full Text Available The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour for 8 weeks. Training intensity was determined within non-specific (cycling or running and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m and one non-specific (30s cycling or 200m running all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa and glucose (BGL 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak was significantly increased (+17%; p = 0.01 in both groups and highly correlated with the sprint performance (r = -0.71. BLa values decreased significantly (-18%, p = 0.02 after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04 in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group.

  4. Effect of sprint cycle training on activities of antioxidant enzymes in human skeletal muscle

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    Hellsten, Ylva; Apple, F. S.; Sjödin, B.

    1996-01-01

    (P anaerobic capacity in the trained muscle. The present study demonstrates that intermittent sprint cycle training that induces an enhanced capacity for anaerobic energy generation also improves......The effect of intermittent sprint cycle training on the level of muscle antioxidant enzyme protection was investigated. Resting muscle biopsies, obtained before and after 6 wk of training and 3, 24, and 72 h after the final session of an additional 1 wk of more frequent training, were analyzed...... for activities of the antioxidant enzymes glutathione peroxidase (GPX), glutathione reductase (GR), and superoxide dismutase (SOD). Activities of several muscle metabolic enzymes were determined to assess the effectiveness of the training. After the first 6-wk training period, no change in GPX, GR, or SOD...

  5. Muscle oxygen changes following Sprint Interval Cycling training in elite field hockey players.

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    Ben Jones

    Full Text Available This study examined the effects of Sprint Interval Cycling (SIT on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT. Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP and a control group (CON. The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2, tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb, total tissue haemoglobin (tHb and tissue oxygenation (TSI % were taken. In the EXP group (5.34 ± 0.14 to 5.50 ± 0.14 m.s(-1 but not the CON group (pre = 5.37 ± 0.27 to 5.39 ± 0.30 m.s(-1 significant changes were seen in the 30-15 IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (-7.59 ± 0.91 to -12.16 ± 2.70%; ΔHHb+HMb (35.68 ± 6.67 to 69.44 ± 26.48 μM.cm; and ΔHbO2+ MbO2 (-74.29 ± 13.82 to -109.36 ± 22.61 μM.cm. No significant differences were seen in ΔtHb (-45.81 ± 15.23 to -42.93 ± 16.24. NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes.

  6. Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric "Live High-Train Low"

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    Bejder, Jacob; Andersen, Andreas Breenfeldt; Buchardt, Rie

    2017-01-01

    The aim was to investigate whether 6 weeks of normobaric "Live High-Train Low" (LHTL) using altitude tents affect highly trained athletes incremental peak power, 26-km time-trial cycling performance, 3-min all-out performance, and 30-s repeated sprint ability. In a double-blinded, placebo......-controlled cross-over design, seven highly trained triathletes were exposed to 6 weeks of normobaric hypoxia (LHTL) and normoxia (placebo) for 8 h/day. LHTL exposure consisted of 2 weeks at 2500 m, 2 weeks at 3000 m, and 2 weeks at 3500 m. Power output during an incremental test, ~26-km time trial, 3-min all...... conducted in a double-blinded, placebo-controlled cross-over design do not affect power output during an incremental test, a ~26-km time-trial test, or 3-min all-out exercise in highly trained triathletes. Furthermore, 30 s of repeated sprint ability was unaltered....

  7. Sprint interval and moderate-intensity cycling training differentially affect adiposity and aerobic capacity in overweight young-adult women.

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    Higgins, Simon; Fedewa, Michael V; Hathaway, Elizabeth D; Schmidt, Michael D; Evans, Ellen M

    2016-11-01

    The purpose of the study was to examine the effects of sprint interval training (SIT) and moderate-intensity continuous cycle training (MICT), with equal estimated energy expenditure during training on body composition and aerobic capacity. Body composition measured via dual-energy X-ray absorptiometry and aerobic capacity were assessed following 6 weeks of training in previously inactive overweight/obese young women (n = 52; age, 20.4 ± 1.5 years; body mass index, 30.3 ± 4.5 kg·m -2 , 67.3% white). Training was performed in a group-exercise format that mimicked cycling classes offered by commercial fitness facilities, and included 3 weekly sessions of either 30-s "all-out" sprints followed by 4 min of active recovery (SIT), or continuous cycling at 60%-70% heart rate reserve to expend a similar amount of energy. Participants were randomized to SIT or MICT, attended a similar number of sessions (15.0 ± 1.5 sessions vs. 15.8 ± 1.9 sessions, P = 0.097) and expended a similar amount of energy (541.8 ± 104.6 kJ·session -1 vs. 553.5 ± 138.1 kJ·session -1 , P = 0.250). Without significant changes in body mass (P > 0.05), greater relative reductions occurred in SIT than in MICT in total fat mass (3.6% ± 5.6% vs. 0.6% ± 3.9%, P = 0.007), and android fat mass (6.6% ± 6.9% vs. 0.7% ± 6.5%, P = 0.002). Aerobic capacity (mL·kg -1 ·min -1 ) increased significantly following both interventions (P interval cycling reduces adiposity and increases aerobic capacity more than continuous moderate-intensity cycling of equal estimated energy expenditure in overweight/obese young women.

  8. Comparison of Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training Versus Sprint Interval Cycling.

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    Williams, Brian M; Kraemer, Robert R

    2015-12-01

    The purpose of this study was to determine the effectiveness of a novel exercise protocol we developed for kettlebell high-intensity interval training (KB-HIIT) by comparing the cardiorespiratory and metabolic responses to a standard sprint interval cycling (SIC) exercise protocol. Eight men volunteered for the study and completed 2 preliminary sessions, followed by two 12-minute sessions of KB-HIIT and SIC in a counterbalanced fashion. In the KB-HITT session, 3 circuits of 4 exercises were performed using a Tabata regimen. In the SIC session, three 30-second sprints were performed, with 4 minutes of recovery in between the first 2 sprints and 2.5 minutes of recovery after the last sprint. A within-subjects' design over multiple time points was used to compare oxygen consumption (V[Combining Dot Above]O2), respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE), caloric expenditure rate (kcal·min), and heart rate (HR) between the exercise protocols. Additionally, total caloric expenditure was compared. A significant group effect, time effect, and group × time interaction were found for V[Combining Dot Above]O2, RER, and TV, with V[Combining Dot Above]O2 being higher and TV and RER being lower in the KB-HIIT compared with the SIC. Only a significant time effect and group × time interaction were found for f, VE, kcal·min, and HR. Additionally, total caloric expenditure was found to be significantly higher during the KB-HIIT. The results of this study suggest that KB-HIIT may be more attractive and sustainable than SIC and can be effective in stimulating cardiorespiratory and metabolic responses that could improve health and aerobic performance.

  9. Selective Changes in the Mechanical Capacities of Lower-Body Muscles After Cycle-Ergometer Sprint Training Against Heavy and Light Resistances.

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    García-Ramos, Amador; Torrejón, Alejandro; Pérez-Castilla, Alejandro; Morales-Artacho, Antonio J; Jaric, Slobodan

    2018-03-01

    To explore the feasibility of the linear force-velocity (F-V) modeling approach to detect selective changes of F-V parameters (ie, maximum force [F 0 ], maximum velocity [V 0 ], F-V slope [a], and maximum power [P 0 ]) after a sprint-training program. Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F-V parameters through the application of the multiple-point method (4 resistances used for the F-V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used). Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation .80) while also being able to detect the group-specific training-related changes. Large increments of F 0 , a, and P 0 were observed in HLG compared with LLG and CG (effect size [ES] = 1.29-2.02). Moderate increments of V 0 were observed in LLG compared with HLG and CG (ES = 0.87-1.15). Short-term sprint training on a leg cycle ergometer induces specific changes in F-V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.

  10. The post-activation potentiation effect on sprint performance after combined resistance/sprint training in junior basketball players.

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    Tsimachidis, Constantinos; Patikas, Dimitrios; Galazoulas, Christos; Bassa, Eleni; Kotzamanidis, Christos

    2013-01-01

    The aim of this study was to examine the effect of a 10-week combined resistance/sprint training programme in the post-activation potentiation of sprint performance before, between and after resistance training sets. Twenty-six junior basketball players were randomly divided into a control and a combined training group. The combined training group performed a combined training programme consisting of 5 sets at 5-8 RM (Repetition Maximum) half-squats with sprints performed between each set. Post-activation potentiation was considered as the increase in sprint velocity in trials executed between and after the resistance sets compared with the sprint trial performed before the resistance sets of the respective first and last training session. For sprint evaluation the running distances 0-10 and 0-30 m were selected. The intervention increased both strength and sprint performance. No post-activation potentiation effect was observed during the first training session in either group. Post-activation potentiation appeared in the combined training group during the last training session of the intervention in both 0-10 and 0-30 m sprint. This study illustrates that post-activation potentiation effect on sprint performance in junior basketball players, who did not previously follow systematic resistance training, emerges after a 10-week resistance/sprint combined training programme.

  11. Significant molecular and systemic adaptations after repeated sprint training in hypoxia.

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    Raphael Faiss

    Full Text Available While intermittent hypoxic training (IHT has been reported to evoke cellular responses via hypoxia inducible factors (HIFs but without substantial performance benefits in endurance athletes, we hypothesized that repeated sprint training in hypoxia could enhance repeated sprint ability (RSA performed in normoxia via improved glycolysis and O(2 utilization. 40 trained subjects completed 8 cycling repeated sprint sessions in hypoxia (RSH, 3000 m or normoxia (RSN, 485 m. Before (Pre- and after (Post- training, muscular levels of selected mRNAs were analyzed from resting muscle biopsies and RSA tested until exhaustion (10-s sprint, work-to-rest ratio 1:2 with muscle perfusion assessed by near-infrared spectroscopy. From Pre- to Post-, the average power output of all sprints in RSA was increased (p<0.01 to the same extent (6% vs 7%, NS in RSH and in RSN but the number of sprints to exhaustion was increased in RSH (9.4±4.8 vs. 13.0±6.2 sprints, p<0.01 but not in RSN (9.3±4.2 vs. 8.9±3.5. mRNA concentrations of HIF-1α (+55%, carbonic anhydrase III (+35% and monocarboxylate transporter-4 (+20% were augmented (p<0.05 whereas mitochondrial transcription factor A (-40%, peroxisome proliferator-activated receptor gamma coactivator 1α (-23% and monocarboxylate transporter-1 (-36% were decreased (p<0.01 in RSH only. Besides, the changes in total hemoglobin variations (Δ[tHb] during sprints throughout RSA test increased to a greater extent (p<0.01 in RSH. Our findings show larger improvement in repeated sprint performance in RSH than in RSN with significant molecular adaptations and larger blood perfusion variations in active muscles.

  12. Development of a neuromuscular electrical stimulation protocol for sprint training.

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    Russ, David W; Clark, Brian C; Krause, Jodi; Hagerman, Fredrick C

    2012-09-01

    Sprint training is associated with several beneficial adaptations in skeletal muscle, including an enhancement of sarcoplasmic reticulum (SR) Ca(2+) release. Unfortunately, several patient populations (e.g., the elderly, those with cardiac dysfunction) that might derive great benefit from sprint exercise are unlikely to tolerate it. The purpose of this report was to describe the development of a tolerable neuromuscular electrical stimulation (NMES) protocol that induces skeletal muscle adaptations similar to those observed with sprint training. Our NMES protocol was modeled after a published sprint exercise protocol and used a novel electrode configuration and stimulation sequence to provide adequate training stimulus while maintaining subject tolerance. Nine young, healthy subjects (four men) began and completed the training protocol of the knee extensor muscles. All subjects completed the protocol, with ratings of discomfort far less than those reported in studies of traditional NMES. Training induced significant increases in SR Ca(2+) release and citrate synthase activity (~16% and 32%, respectively), but SR Ca(2+) uptake did not change. The percentage of myosin heavy chain IIx isoform was decreased significantly after training. At the whole muscle level, neither central activation nor maximum voluntary isometric contraction force were significantly altered, although isometric force did exhibit a trend toward an increase (~3%, P = 0.055). Surprisingly, the NMES training produced a significant increase in muscle cross-sectional area (~3%, P = 0.04). It seems that an appropriately designed NMES protocol can mimic many of the benefits of sprint exercise training, with a low overall time commitment and training volume. These findings suggest that NMES has the potential to bring the benefits of sprint exercise to individuals who are unable to tolerate traditional sprint training.

  13. Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.

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    Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

    2013-01-01

    Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise.

  14. Neuromuscular adjustments of the quadriceps muscle after repeated cycling sprints.

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    Olivier Girard

    Full Text Available PURPOSE: This study investigated the supraspinal processes of fatigue of the quadriceps muscle in response to repeated cycling sprints. METHODS: Twelve active individuals performed 10 × 6-s "all-out" sprints on a cycle ergometer (recovery = 30 s, followed 6 min later by 5 × 6-s sprints (recovery = 30 s. Transcranial magnetic and electrical femoral nerve stimulations during brief (5-s and sustained (30-s isometric contractions of the knee extensors were performed before and 3 min post-exercise. RESULTS: Maximal strength of the knee extensors decreased during brief and sustained contractions (~11% and 9%, respectively; P0.05. While cortical voluntary activation declined (P 40% reduced (P<0.001 following exercise. CONCLUSION: The capacity of the motor cortex to optimally drive the knee extensors following a repeated-sprint test was shown in sustained, but not brief, maximal isometric contractions. Additionally, peripheral factors were largely involved in the exercise-induced impairment in neuromuscular function, while corticospinal excitability was well-preserved.

  15. Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

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    Dæhlin, Torstein E; Haugen, Ole C; Haugerud, Simen; Hollan, Ivana; Raastad, Truls; Rønnestad, Bent R

    2017-08-01

    Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. The participants increased their 1RM squat, lean mass, and body mass (P plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players.

  16. Sprint vs. intermittent training in young female basketball players.

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    Attene, G; Pizzolato, F; Calcagno, G; Ibba, G; Pinna, M; Salernitano, G; Padulo, J

    2014-04-01

    This study aimed at comparing the effects of intermittent and repeated sprint ability training on physiological variables. Sixteen young female basketball players were randomly allocated to intermittent training (IT=8) or repeated sprint ability training (RST=8) groups. The following outcomes were measured at baseline and after 6 weeks of training: Yo-Yo intermittent recovery (Yo-Yo) and repeated sprint ability (RSA) tests. For all the variables investigated the effect of training type showed a different trend respect at current knowledge. In the RSA, best time (BT) was a significant main effect of training time (pre- vs. post-) (Ptraining type/time (P=0.03). The RST showed a decrease in BT of 3.1% (P=0.005) while the IT showed a decrease of 6.2% (Ptraining methods used in this study can be an effective training strategy for inducing anaerobic and basketball-specific training schedules. Besides, even when IT training is not done at very high speed, it can increase the maximum speed of the RSA.

  17. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

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    Gregory E. P. Pearcey

    2017-12-01

    Full Text Available Spinal cord excitability, as assessed by modulation of Hoffmann (H- reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM, sprints with sensory stimulation (SPRINT + STIM and sprints without stimulation (SPRINT. Seven participants also performed a fourth session (CONTROL, which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output

  18. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

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    Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

  19. Advancing hypoxic training in team sports: from intermittent hypoxic training to repeated sprint training in hypoxia.

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    Faiss, Raphaël; Girard, Olivier; Millet, Grégoire P

    2013-12-01

    Over the past two decades, intermittent hypoxic training (IHT), that is, a method where athletes live at or near sea level but train under hypoxic conditions, has gained unprecedented popularity. By adding the stress of hypoxia during 'aerobic' or 'anaerobic' interval training, it is believed that IHT would potentiate greater performance improvements compared to similar training at sea level. A thorough analysis of studies including IHT, however, leads to strikingly poor benefits for sea-level performance improvement, compared to the same training method performed in normoxia. Despite the positive molecular adaptations observed after various IHT modalities, the characteristics of optimal training stimulus in hypoxia are still unclear and their functional translation in terms of whole-body performance enhancement is minimal. To overcome some of the inherent limitations of IHT (lower training stimulus due to hypoxia), recent studies have successfully investigated a new training method based on the repetition of short (<30 s) 'all-out' sprints with incomplete recoveries in hypoxia, the so-called repeated sprint training in hypoxia (RSH). The aims of the present review are therefore threefold: first, to summarise the main mechanisms for interval training and repeated sprint training in normoxia. Second, to critically analyse the results of the studies involving high-intensity exercises performed in hypoxia for sea-level performance enhancement by differentiating IHT and RSH. Third, to discuss the potential mechanisms underpinning the effectiveness of those methods, and their inherent limitations, along with the new research avenues surrounding this topic.

  20. Effect of heavy back squats on repeated sprint performance in trained men.

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    Duncan, M J; Thurgood, G; Oxford, S W

    2014-04-01

    This study examined the impact of post activation potentiation on repeated sprint performance in trained Rugby Union players. Ten, male, professional Rugby Union players (mean age=25.2±5.02 years) performed 7, 30-meter sprints, separated by 25 seconds, 4 minutes following back squats (90% 1 repetition maximum) or a control condition performed in a counterbalanced order. Significant condition X sprint interactions for 10-meter (P=0.02) and 30-meter (P=0.05) indicated that times were significantly faster in the PAP condition for sprints 5, 6 and 7 across both distances. Fatigue rate was also significantly lower in the PAP condition for 10-meter (P=0.023) and 30-meter (P=0.006) sprint running speed. This study evidences that a heavy resistance exercise stimulus administered four minutes prior to repeated sprints can offset the decline in sprint performance seen during subsequent maximal sprinting over 10 and 30-meters in Rugby Union players.

  1. Effect of sprint training on resting serum irisin concentration - Sprint training once daily vs. twice every other day.

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    Tsuchiya, Yoshifumi; Ijichi, Toshiaki; Goto, Kazushige

    2016-04-01

    Exercise twice every other day has been shown to lead to increasing peroxisome proliferator receptor γ coactivator-1α (PGC-1α) expression (up-stream factor of irisin) via lowered muscle glycogen level during second of exercise compared with exercise once daily. This study determined the influence of 4weeks of sprint training (training once daily vs. twice every other day) on the serum irisin concentration. Twenty healthy males (20.9±1.3years) were assigned randomly to either the SINGLE or REPEATED group (n=10 per group). The subjects in the SINGLE group participated in a sprint training session once daily (5days per week), whereas those in the REPEATED group performed two consecutive training sessions on the same day with a 1-h rest between sessions (2-3days per week). Both groups completed 20 training sessions over 4weeks. Each training session consisted of three consecutive 30-s maximal pedaling exercises with a 10-min rest between sets. Blood samples were collected before and after training period (48h after completing the last training session). The serum irisin concentration decreased significantly after training in each group (SINGLE, 338.5±77.8 to 207.6±64.6ng/mL; REPEATED, 329.5±83.9 to 234.2±72.8ng/mL, pevery other day). Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Sprint interval and sprint continuous training increases circulating CD34+ cells and cardio-respiratory fitness in young healthy women.

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    Emma Harris

    Full Text Available The improvement of vascular health in the exercising limb can be attained by sprint interval training (SIT. However, the effects on systemic vascular function and on circulating angiogenic cells (CACs which may contribute to endothelial repair have not been investigated. Additionally, a comparison between SIT and sprint continuous training (SCT which is less time committing has not been made.12 women (22±2 yrs completed 12 sessions of either SIT (n = 6 or work-matched SCT (n = 6 on 3 days/week. Pre and post-training assessments included brachial artery endothelial function and peripheral blood analysis for CAC number (CD34+/CD34+CD45dim. CAC function was measured by migration and adhesion assays. Cardio-respiratory fitness, carotid arterial stiffness and carotid-radial and brachial-foot pulse wave velocity (PWV were also evaluated.CD34+ CACs increased following training in both groups but CD34+CD45dim did not (Pre CD34+: 40±21/105 leukocytes, Post CD34+: 56±24/105 leukocytes, main time effect p0.05.SCT involving little time commitment is comparable to SIT in increasing CD34+ cell number and [Formula: see text]. An increased mobilisation of CD34+ CACs suggests that sprint training may be an effective method to enhance vascular repair.

  3. Effects of Sprint Interval Training With Active Recovery vs. Endurance Training on Aerobic and Anaerobic Power, Muscular Strength, and Sprint Ability.

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    Sökmen, Bülent; Witchey, Ronald L; Adams, Gene M; Beam, William C

    2018-03-01

    Sökmen, B, Witchey, RL, Adams, GM, and Beam, WC. Effects of sprint interval training with active recovery vs. endurance training on aerobic and anaerobic power, muscular strength, and sprint ability. J Strength Cond Res 32(3): 624-631, 2018-This study compared sprint interval training with active recovery (SITAR) to moderate-intensity endurance training (ET) in aerobic and anaerobic power, muscular strength, and sprint time results. Forty-two recreationally active adults were randomly assigned to a SITAR or ET group. Both groups trained 3× per week for 10 weeks at 75% of V[Combining Dot Above]O2max for 30 minutes weeks 1-4, with duration increasing to 35 minutes weeks 5-7 and 40 minutes weeks 8-10. While ET ran on a 400-m track without rest for the full training session, SITAR sprinted until the 200-m mark and recovered with fast walking or light jogging the second 200 m to the finish line in 3× original sprint time. Maximal oxygen consumption (V[Combining Dot Above]O2max), anaerobic treadmill run to exhaustion at 12.5 km·h at 20% incline, isokinetic leg extension and flexion strength at 60 and 300°·s, and 50 m sprint time were determined before and after training. Results showed a significant improvement (p ≤ 0.05) in absolute and relative V[Combining Dot Above]O2max, anaerobic treadmill run, and sprint time in both groups. Only SITAR showed significant improvements in isokinetic leg extension and flexion at 300°·s and decreases in body mass (p ≤ 0.05). SITAR also showed significantly greater improvement (p ≤ 0.05) over ET in anaerobic treadmill run and 50 m sprint time. These data suggest that SITAR is a time-efficient strategy to induce rapid adaptations in V[Combining Dot Above]O2max comparable to ET with added improvements in anaerobic power, isokinetic strength, and sprint time not observed with ET.

  4. Physiological and performance changes from the addition of a sprint interval program to wrestling training.

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    Farzad, Babak; Gharakhanlou, Reza; Agha-Alinejad, Hamid; Curby, David G; Bayati, Mahdi; Bahraminejad, Morteza; Mäestu, Jarek

    2011-09-01

    Increasing the level of physical fitness for competition is the primary goal of any conditioning program for wrestlers. Wrestlers often need to peak for competitions several times over an annual training cycle. Additionally, the scheduling of these competitions does not always match an ideal periodization plan and may require a modified training program to achieve a high level of competitive fitness in a short-time frame. The purpose of this study was to examine the effects of 4 weeks of sprint-interval training (SIT) program, on selected aerobic and anaerobic performance indices, and hormonal and hematological adaptations, when added to the traditional Iranian training of wrestlers in their preseason phase. Fifteen trained wrestlers were assigned to either an experimental (EXP) or a control (CON) group. Both groups followed a traditional preparation phase consisting of learning and drilling technique, live wrestling and weight training for 4 weeks. In addition, the EXP group performed a running-based SIT protocol. The SIT consisted of 6 35-m sprints at maximum effort with a 10-second recovery between each sprint. The SIT protocol was performed in 2 sessions per week, for the 4 weeks of the study. Before and after the 4-week training program, pre and posttesting was performed on each subject on the following: a graded exercise test (GXT) to determine VO(2)max, the velocity associated with V(2)max (νVO(2)max), maximal ventilation, and peak oxygen pulse; a time to exhaustion test (T(max)) at their νVO(2)max; and 4 successive Wingate tests with a 4-minute recovery between each trial for the determination of peak and mean power output (PPO, MPO). Resting blood samples were also collected at the beginning of each pre and posttesting period, before and after the 4-week training program. The EXP group showed significant improvements in VO(2)max (+5.4%), peak oxygen pulse (+7.7%) and T(max) (+32.2%) compared with pretesting. The EXP group produced significant increases

  5. Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production.

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    Kordi, Mehdi; Goodall, Stuart; Barratt, Paul; Rowley, Nicola; Leeder, Jonathan; Howatson, Glyn

    2017-08-01

    From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The impact of dry-land sprint start training on the short track speed skating start.

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    Haug, William B; Drinkwater, Eric J; Cicero, Nicholas J; Barthell, J Anthony; Chapman, Dale W

    2017-05-05

    This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a four-week training intervention. Before and after the control and intervention periods, athletes performed three electronically timed dry-land and on-ice 14.43 m maximal sprint start efforts. The intervention consisted of two sprint sessions per week consisting of nine electronically timed 14.43 m dry-land sprint starts in addition to normal STSS training. The control period resulted in no substantial change in on-ice start performance (Mean Δ: -0.01 s, 95% Confidence Limits (CL): -0.08 to 0.05 s; Effect Size (ES): -0.05; Trivial) however, a small change was observed in dry-land start performance (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.02 s; ES: -0.49). Following brief specific dry-land sprint start training a small improvement was observed in both on-ice (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.01 s; ES: -0.33) and dry-land (Mean Δ: -0.04 s, 95% CL: -0.09 to 0.00 s; ES: -0.29) start performance. This investigation suggests STSS start performance can be improved through a brief dry-land sprint start training program.

  7. Energy compensation after sprint- and high-intensity interval training.

    Science.gov (United States)

    Schubert, Matthew M; Palumbo, Elyse; Seay, Rebekah F; Spain, Katie K; Clarke, Holly E

    2017-01-01

    Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE). This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI) and decreases in non-exercise physical activity (NEPA). We examined the degree of energy compensation in healthy young men and women in response to interval training. Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1) completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography) and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100%) and low (high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  8. Effects of Plyometric and Sprint Training on Physical and Technical Skill Performance in Adolescent Soccer Players.

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    Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos

    2015-07-01

    To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.

  9. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint

    Directory of Open Access Journals (Sweden)

    Shaun M. Phillips, Scott Findlay, Mykolas Kavaliauskas, Marie Clare Grant

    2014-06-01

    Full Text Available The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD age: 23.1 (3.0 years, height: 1.83 (0.07 m, body mass (BM: 86.3 (13.5 kg completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg-1 BM resistance. Eight participants achieved a greater peak power output (PPO in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg-1, p 0.05. No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint.

  10. Acute responses of circulating microRNAs to low-volume sprint interval cycling

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    Shu Fang eCui

    2015-10-01

    Full Text Available Low-volume high-intensity interval training is an efficient and practical method of inducing physiological responses in various tissues to develop physical fitness and may also change the expression of circulating microRNAs (miRNAs. The purpose of the present study was to examine whether miRNAs for muscle, heart, somatic tissue and metabolism were affected by 30-s intervals of intensive sprint cycling. We also examined the relationship of these miRNAs to conventional biochemical and performance indices. Eighteen healthy young males performed sprint interval cycling. Circulating miRNAs in plasma were detected using TaqMan-based quantitative PCR and normalized to Let-7d/g/i. In addition, we determined the levels of insulin-like growth factor-I, testosterone and cortisol, and anaerobic capacity. Compared to plasma levels before exercise muscle-specific miR-1 (0.12 ± 0.02 vs. 0.09 ± 0.02, miR-133a (0.46 ± 0.10 vs. 0.31 ± 0.06 and miR-133b (0.19 ± 0.02 vs. 0.10 ± 0.01 decreased (all P < 0.05, while miR-206 and miR-499 remained unchanged. The levels of metabolism related miR-122 (0.62 ± 0.07 vs. 0.34 ± 0.03 and somatic tissues related miR-16 (1.74 ± 0.27 vs. 0.94 ± 0.12 also decreased (both P < 0.05. The post-exercise IGF-1 and cortisol concentrations were significantly increased, while testosterone concentrations did not. Plasma levels of miR-133b correlated to peak power (r = 0.712, P = 0.001 and miR-122 correlated to peak power ratio (r = 0.665, P = 0.003. In conclusion sprint exercise provokes genetic changes for RNA related to specific muscle or metabolism related miRNAs suggesting that miR-133b and miR-122 may be potential useful biomarkers for actual physiological strain or anaerobic capacity. Together, our findings on the circulating miRNAs may provide new insight into the physiological responses that are being performed during exercise and delineate mechanisms by which exercise confers distinct phenotypes and improves performance.

  11. Six Sessions of Sprint Interval Training Improves Running Performance in Trained Athletes.

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    Koral, Jerome; Oranchuk, Dustin J; Herrera, Roberto; Millet, Guillaume Y

    2018-03-01

    Koral, J, Oranchuk, DJ, Herrera, R, and Millet, GY. Six sessions of sprint interval training improves running performance in trained athletes. J Strength Cond Res 32(3): 617-623, 2018-Sprint interval training (SIT) is gaining popularity with endurance athletes. Various studies have shown that SIT allows for similar or greater endurance, strength, and power performance improvements than traditional endurance training but demands less time and volume. One of the main limitations in SIT research is that most studies were performed in a laboratory using expensive treadmills or ergometers. The aim of this study was to assess the performance effects of a novel short-term and highly accessible training protocol based on maximal shuttle runs in the field (SIT-F). Sixteen (12 male, 4 female) trained trail runners completed a 2-week procedure consisting of 4-7 bouts of 30 seconds at maximal intensity interspersed by 4 minutes of recovery, 3 times a week. Maximal aerobic speed (MAS), time to exhaustion at 90% of MAS before test (Tmax at 90% MAS), and 3,000-m time trial (TT3000m) were evaluated before and after training. Data were analyzed using a paired samples t-test, and Cohen's (d) effect sizes were calculated. Maximal aerobic speed improved by 2.3% (p = 0.01, d = 0.22), whereas peak power (PP) and mean power (MP) increased by 2.4% (p = 0.009, d = 0.33) and 2.8% (p = 0.002, d = 0.41), respectively. TT3000m was 6% shorter (p training in the field significantly improved the 3,000-m run, time to exhaustion, PP, and MP in trained trail runners. Sprint interval training in the field is a time-efficient and cost-free means of improving both endurance and power performance in trained athletes.

  12. Energy compensation after sprint- and high-intensity interval training.

    Directory of Open Access Journals (Sweden)

    Matthew M Schubert

    Full Text Available Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE. This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI and decreases in non-exercise physical activity (NEPA. We examined the degree of energy compensation in healthy young men and women in response to interval training.Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1 completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100% and low (< 100% levels of energy compensation were assessed. Linear regressions were utilized to determine associations between energy compensation and ΔVO2max, ΔEI, ΔNEPA, and Δresting metabolic rate.Very large individual differences in energy compensation were noted. In comparison to individuals with low levels of compensation, individuals with high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p < 0.001 and ΔNEPA (p < 0.001.Considerable variation exists in response to short-term, low dose interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  13. Reductions in Sprint Paddling Ability and Countermovement Jump Performance After Surfing Training.

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    Secomb, Josh L; Sheppard, Jeremy M; Dascombe, Ben J

    2015-07-01

    The present study aimed to determine whether any meaningful change in a surfer's sprint paddling ability and countermovement jump (CMJ) performance developed after a 2-hour surfing training session and also whether any physical demands of the surfing session were related to the resultant changes in the capacities. Fifteen competitive male surfing athletes (age, 22.1 ± 3.9 years; height, 175.4 ± 6.4 cm; body mass, 72.5 ± 7.7 kg) performed a 2-hour surfing training session, with 15-m sprint paddle and CMJ trials performed both before and after the surfing session. Pre- to posttesting measures were analyzed using magnitude-based inferences. Likely declines were observed in the velocity achieved at the 5-, 10-, and 15-m splits of the 15-m sprint paddle, as well as peak velocity. Similarly, likely declines were calculated for CMJ peak force, relative peak force, and jump height. Furthermore, large correlations were calculated between presurfing session peak velocity and the change in 5, 10, 15 m, and peak velocity of the 15-m sprint paddle and total distance covered, wave riding bouts, and success rate. Surfing athletes and coaches may need to consider implementing shorter duration training sessions to reduce the decline in sprint paddling ability and CMJ performance. Furthermore, surfing athletes should possess highly developed sprint paddling ability because this may allow them to undertake a greater workload and catch more waves, which will increase the opportunity for technical refinement of maneuvers and skill acquisition.

  14. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint.

    Science.gov (United States)

    Phillips, Shaun M; Findlay, Scott; Kavaliauskas, Mykolas; Grant, Marie Clare

    2014-05-01

    The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO) mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD) age: 23.1 (3.0) years, height: 1.83 (0.07) m, body mass (BM): 86.3 (13.5) kg) completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin) solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA) solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg(-1) BM resistance. Eight participants achieved a greater peak power output (PPO) in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg(-1), p 0.05). No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint. Key pointsThe paper demonstrates that repeated administration of a carbohydrate mouth rinse can significantly improve peak power output during a single 30 second cycle sprint.The ergogenic effect of the carbohydrate mouth rinse may relate to the duration of exposure of the oral cavity to the mouth rinse, and associated greater stimulation of oral carbohydrate receptors.The significant increase in peak power output with the carbohydrate mouth rinse may come at a relative cost for the remainder of the sprint, evidenced by non-significantly lower mean power output and a greater fatigue index in the carbohydrate vs. placebo trial.Serial administration of a carbohydrate mouth rinse may be beneficial for

  15. Sprint cycling performance is maintained with short-term contrast water immersion.

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    Crampton, David; Donne, Bernard; Egaña, Mikel; Egana, Mikel; Warmington, Stuart A

    2011-11-01

    Given the widespread use of water immersion during recovery from exercise, we aimed to investigate the effect of contrast water immersion on recovery of sprint cycling performance, HR and, blood lactate. Two groups completed high-intensity sprint exercise before and after a 30-min randomized recovery. The Wingate group (n = 8) performed 3 × 30-s Wingate tests (4-min rest periods). The repeated intermittent sprint group (n = 8) cycled for alternating 30-s periods at 40% of predetermined maximum power and 120% maximum power, until exhaustion. Both groups completed three trials using a different recovery treatment for each trial (balanced randomized application). Recovery treatments were passive rest, 1:1 contrast water immersion (2.5 min of cold (8°C) to 2.5 min of hot (40°C)), and 1:4 contrast water immersion (1 min of cold to 4 min of hot). Blood lactate and HR were recorded throughout, and peak power and total work for pre- and postrecovery Wingate performance and exercise time and total work for repeated sprinting were recorded. Recovery of Wingate peak power was 8% greater after 1:4 contrast water immersion than after passive rest, whereas both contrast water immersion ratios provided a greater recovery of exercise time (∼ 10%) and total work (∼ 14%) for repeated sprinting than for passive rest. Blood lactate was similar between trials. Compared with passive rest, HR initially declined more slowly during contrast water immersion but increased with each transition to a cold immersion phase. These data support contrast water immersion being effective in maintaining performance during a short-term recovery from sprint exercise. This effect needs further investigation but is likely explained by cardiovascular mechanisms, shown here by an elevation in HR upon each cold immersion.

  16. Sex Comparison of Knee Extensor Size, Strength and Fatigue Adaptation to Sprint Interval Training.

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    Bagley, Liam; Al-Shanti, Nasser; Bradburn, Steven; Baig, Osamah; Slevin, Mark; McPhee, Jamie S

    2018-03-12

    Regular sprint interval training (SIT) improves whole-body aerobic capacity and muscle oxidative potential, but very little is known about knee extensor anabolic or fatigue resistance adaptations, or whether effects are similar for males and females. The purpose of this study was to compare sex-related differences in knee extensor size, torque-velocity relationship and fatigability adaptations to 12 weeks SIT. Sixteen males and fifteen females (mean (SEM) age: 41 (±2.5) yrs) completed measurements of total body composition assessed by DXA, quadriceps muscle cross-sectional area (CSAQ) assessed by MRI, the knee extensor torque-velocity relationship (covering 0 - 240°·sec) and fatigue resistance, which was measured as the decline in torque from the first to the last of 60 repeated concentric knee extensions performed at 180°·sec. SIT consisted of 4 x 20 second sprints on a cycle ergometer set at an initial power output of 175% of power at VO2max, three times per week for 12 weeks. CSAQ increased by 5% (p=0.023) and fatigue resistance improved 4.8% (p=0.048), with no sex differences in these adaptations (sex comparisons: p=0.140 and p=0.282, respectively). Knee extensor isometric and concentric torque was unaffected by SIT in both males and females (p>0.05 for all velocities). 12 weeks SIT, totalling 4 minutes very intense cycling per week, significantly increased fatigue resistance and CSAQ similarly in males and females, but did not significantly increase torque in males or females. These results suggest that SIT is a time-effective training modality for males and females to increase leg muscle size and fatigue resistance.

  17. Shuttle-Run Sprint Training in Hypoxia for Youth Elite Soccer Players: A Pilot Study

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    Hannes Gatterer

    2014-12-01

    Full Text Available The purposes of the present study were to investigate if a shuttle-run sprint training performed in a normobaric hypoxia chamber of limited size (4.75x2.25m is feasible, in terms of producing the same absolute training load, when compared to training in normoxia, and b if such training improves the repeated sprint ability (RSA and the Yo-Yo intermittent recovery (YYIR test outcome in young elite soccer players. Players of an elite soccer training Centre (age: 15.3 ± 0.5 years, height: 1.73 ± 0.07 m, body mass: 62.6 ± 6.6 kg were randomly assigned to a hypoxia or a normoxia training group. Within a 5-week period, players, who were not informed about the hypoxia intervention, performed at least 7 sessions of identical shuttle-run sprint training either in a normal training room (FiO2 = 20.95% or in a hypoxic chamber (FiO2 = 14.8%; approximately 3300m, both equipped with the same floor. Each training session comprised 3 series of 5x10s back and forth sprints (4.5m performed at maximal intensity. Recovery time between repetitions was 20s and between series 5min. Before and after the training period the RSA (6 x 40m shuttle sprint with 20 s rest between shuttles and the YYIR test were performed. The size of the chamber did not restrict the training intensity of the sprint training (both groups performed approximately 8 shuttles during 10s. Training in hypoxia resulted in a lower fatigue slope which indicates better running speed maintenance during the RSA test (p = 0.024. YYIR performance increased over time (p = 0.045 without differences between groups (p > 0.05. This study showed that training intensity of the shuttle-run sprint training was not restricted in a hypoxic chamber of limited size which indicates that such training is feasible. Furthermore, hypoxia compared to normoxia training reduced the fatigue slope during the RSA test in youth soccer players.

  18. Effect of squatting on sprinting performance and repeated exposure to complex training in male rugby players.

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    Comyns, Thomas M; Harrison, Andrew J; Hennessy, Liam K

    2010-03-01

    This study was undertaken to examine the effect of a heavy weight training exercise on sprinting performance and on the effect of repeated exposure to a complex training protocol. Eleven male rugby union players (age 20.9 +/- 3.1 years) participated in the study, which involved 5 separate testing sessions. Back squat 3 repetition maximum (3RM) was established in session 1. Sessions 2-5 were identical and involved the subjects completing a 30-m sprint before and after a 3RM back squat protocol. Four minutes of rest was given between the back squatting and the posttest 30-m sprint. All sprint trials were measured with a laser measurement device (LAVEG, Jenoptik, Jena, Germany). Sprint time and instantaneous, average, and maximum velocity were the dependent variables. The criterion for significance was set at an alpha level of p > or = 0.05. No significant improvement was evident for any of the testing sessions (p > or = 0.05). In session 1, there was a significant increase in 30-m time and a significant reduction in average 30-m velocity and maximum velocity (p benefits in sprinting may not have been realized because of intra and intersubject variations in sprint technique. The session x phase interaction revealed a significant improvement in the pre to posttest changes in instantaneous velocity at 20 m (p = 0.035) and 30 m (p = 0.036) from session 1 to session 4. This indicates that the rugby players may be able to learn to apply the potentiation effects of complex training. From a practical perspective, players may need repeated exposure to this training modality to gain benefit from it, and this should be reflected in program planning.

  19. Effects of a contrast training programme on jumping, sprinting and agility performance of prepubertal basketball players.

    Science.gov (United States)

    Latorre Román, Pedro Ángel; Villar Macias, Francisco Javier; García Pinillos, Felipe

    2018-04-01

    The purpose of this study was to examine the effects of a 10 week contrast training (CT) programme (isometric + plyometric) on jumping, sprinting abilities and agility performance in prepubertal basketball players. Fifty-eight children from a basketball academy (age: 8.72 ± 0.97 years; body mass index: 17.22 ± 2.48 kg/m 2 ) successfully completed the study. Participants were randomly assigned to experimental groups (EG, n = 30) and control groups (CG, n = 28). The CT programme was included in the experimental group's training sessions - twice a week - as part of their usual weekly training regime. This programme included 3 exercises: 1 isometric and 2 plyometric. Jumping, sprinting and agility performance were assessed before and after the training programme. Significant differences were found in posttest between EG and CG in sprint and T-test: EG showed better results than CG. Furthermore, there were significant differences in posttest-pretest between EG and CG in squat jump, countermovement jump, drop jump, sprint and T-test with the EG showing better results than CG. The CT programme led to increases in vertical jump, sprint and agility levels, so that the authors suggest that prepubertal children exhibit high muscular strength trainability.

  20. A comparison of assisted, resisted, and common plyometric training modes to enhance sprint and agility performance.

    Science.gov (United States)

    Khodaei, Kazem; Mohammadi, Abbas; Badri, Neda

    2017-10-01

    The purpose of this study was to compare the effect of assisted, resisted and common plyometric training modes to enhance sprint and agility performance. Thirty active young males (age 20.67±1.12, height 174.83±4.69, weight 63.45±7.51) volunteered to participate in this study that 24 completed testing. The participants were randomly assigned into different groups: assisted, resisted and common plyometric exercises groups. Plyometric training involved three sessions per week for 4 weeks. The volume load of plyometric training modes was equated between the groups. The posttest was performed after 48 hours of the last training session. Between-group differences were analyzed with the ANCOVA and LSD post-hoc tests, and within-group differences were analyzed by a paired t-test. The findings of the present study indicated that 0-10-m, 20-30-m sprint time and the Illinois Agility Test time significantly decreased in the assisted and resisted plyometrics modes compared to the common plyometric training mode (P≤0.05). Also, the 0-10-m, 0-30-m sprint time and agility T-test time was significantly reduced with resisted plyometrics modes compared to the assisted and common plyometric modes (P≤0.05). There was no significant difference in the 10-20-m sprint time among the three plyometric training modes. The results of this study demonstrated that assisted and resisted plyometrics modes with elastic bands were effective methods to improve sprint and agility performance than common plyometric training in active males. Also, the resisted plyometrics mode was superior than the assisted plyometrics mode to improving sprint and agility tasks.

  1. Low-Intensity Sprint Training With Blood Flow Restriction Improves 100-m Dash.

    Science.gov (United States)

    Behringer, Michael; Behlau, Daniel; Montag, Johannes C K; McCourt, Molly L; Mester, Joachim

    2017-09-01

    Behringer, M, Behlau, D, Montag, JCK, McCourt, ML, and Mester, J. Low-intensity sprint training with blood flow restriction improves 100-m dash. J Strength Cond Res 31(9): 2462-2472, 2017-We investigated the effects of practical blood flow restriction (pBFR) of leg muscles during sprint training on the 100-m dash time in well-trained sport students. Participants performed 6 × 100-m sprints at 60-70% of their maximal 100-m sprinting speed twice a week for 6 weeks, either with (intervention group [IG]; n = 12) or without pBFR (control group [CG]; n = 12). The 100-m dash time significantly decreased more in the IG (-0.38 ± 0.24 seconds) than in the CG (-0.16 ± 0.17 seconds). The muscle thickness of the rectus femoris increased only in the IG, whereas no group-by-time interactions were found for the muscle thickness of the biceps femoris and the biceps brachii. The maximal isometric force, measured using a leg press, did not change in either group. However, the rate of force development improved in the IG. Growth hormone, testosterone, insulin-like growth factor 1, and cortisol concentrations did not significantly differ between both groups at any measurement time point (pre, 1 minute, 20 minutes, 120 minutes, and 24 hours after the 6 all-out sprints of the first training session). The muscle damage marker h-FABP increased significantly more in the CG than in the IG. The pBFR improved the 100-m dash time significantly more than low-intensity sprint interval training alone. Other noted benefits of training with pBFR were a decreased level of muscle damage, a greater increase of the rectus femoris muscle thickness, and a higher rate of force development. However, the tested hormones were unable to explain the additional beneficial effects.

  2. Effects of Repeated-Sprint Training in Hypoxia on Sea-Level Performance: A Meta-Analysis.

    Science.gov (United States)

    Brocherie, Franck; Girard, Olivier; Faiss, Raphaël; Millet, Grégoire P

    2017-08-01

    Repeated-sprint training in hypoxia (RSH) is a recent intervention regarding which numerous studies have reported effects on sea-level physical performance outcomes that are debated. No previous study has performed a meta-analysis of the effects of RSH. We systematically reviewed the literature and meta-analyzed the effects of RSH versus repeated-sprint training in normoxia (RSN) on key components of sea-level physical performance, i.e., best and mean (all sprint) performance during repeated-sprint exercise and aerobic capacity (i.e., maximal oxygen uptake [[Formula: see text

  3. The effects of acute creatine supplementation on multiple sprint cycling and running performance in rugby players.

    Science.gov (United States)

    Ahmun, Robert P; Tong, Richard J; Grimshaw, Paul N

    2005-02-01

    The benefits of creatine (CR) supplementation are well documented, particularly during repeated bouts of high-intensity muscular activity. Most published experiments use mass-supported (cycle ergometry) activities as a means of evaluating creatine's efficacy, therefore minimizing any possible adverse effects of increased body mass associated with CR supplementation. This study aims to use both mass-supported and mass-dependent activities to assess the effectiveness of acute CR supplementation on a group of highly trained rugby players. A randomized, double-blind, crossover research design was utilized, with subjects receiving 20 g.d(-1) x 5 d of both CR and a glucose placebo (PL). Subjects were assessed via 10 x 6-second Wingate test and a 10 x 40-m sprint test on separate days, presupplementation and postsupplementation. A 28-d washout period separated the two treatments. No significant treatment (p > 0.05) or treatment by test interaction effects (p > 0.05) were observed for peak or minimum power output (W), peak or minimum running velocity (m.s(-1)), or fatigue index (%). No significant differences (p > 0.05) were found postsupplementation for body mass and percentage body fat. Although statistical significance was not achieved for any of the measured parameters, there were small improvements in performance that may be of benefit to rugby players.

  4. Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults: A Randomized Controlled Trial.

    Science.gov (United States)

    Prieske, Olaf; Krüger, Tom; Aehle, Markus; Bauer, Erik; Granacher, Urs

    2018-01-01

    Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST ( n = 10, 23 ± 3 years), a TPT ( n = 9, 23 ± 3 years), or a passive control group ( n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45-60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5% for RST [90%CI: (-1.1%;10.1%), d = 1.23] and 2.6% for TPT [90%CI: (0.4%;4.8%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to -6.3% for RST [90%CI: (-11.4%;-1.1%), d = 1.45) and -2.7% for TPT [90%CI: (-4.2%;-1.2%), d = 2.36]. Finally, effects for change

  5. Sprint Running Performance and Technique Changes in Athletes During Periodized Training: An Elite Training Group Case Study.

    Science.gov (United States)

    Bezodis, Ian N; Kerwin, David G; Cooper, Stephen-Mark; Salo, Aki I T

    2017-11-15

    To understand how training periodization influences sprint performance and key step characteristics over an extended training period in an elite sprint training group. Four sprinters were studied during five months of training. Step velocities, step lengths and step frequencies were measured from video of the maximum velocity phase of training sprints. Bootstrapped mean values were calculated for each athlete for each session and 139 within-athlete, between-session comparisons were made with a repeated measures ANOVA. As training progressed, a link in the changes in velocity and step frequency was maintained. There were 71 between-session comparisons with a change in step velocity yielding at least a large effect size (>1.2), of which 73% had a correspondingly large change in step frequency in the same direction. Within-athlete mean session step length remained relatively constant throughout. Reductions in step velocity and frequency occurred during training phases of high volume lifting and running, with subsequent increases in step velocity and frequency happening during phases of low volume lifting and high intensity sprint work. The importance of step frequency over step length to the changes in performance within a training year was clearly evident for the sprinters studied. Understanding the magnitudes and timings of these changes in relation to the training program is important for coaches and athletes. The underpinning neuro-muscular mechanisms require further investigation, but are likely explained by an increase in force producing capability followed by an increase in the ability to produce that force rapidly.

  6. Effect of sprint training: training once daily versus twice every second day.

    Science.gov (United States)

    Ijichi, Toshiaki; Hasegawa, Yuta; Morishima, Takuma; Kurihara, Toshiyuki; Hamaoka, Takafumi; Goto, Kazushige

    2015-01-01

    This study compared training adaptations between once daily (SINGLE) and twice every second day (REPEATED) sprint training, with same number of training sessions. Twenty physically active males (20.9 ± 1.3 yr) were assigned randomly to the SINGLE (n = 10) or REPEATED (n = 10) group. The SINGLE group trained once per day (5 days per week) for 4 weeks (20 sessions in total). The REPEATED group conducted two consecutive training sessions on the same day, separated by a rest period of 1 h (2-3 days per week) for 4 weeks (20 sessions in total). Each training session consisted of three consecutive 30-s maximal pedalling sets with a 10-min rest between sets. Before and after the training period, the power output during two bouts of 30-s maximal pedalling, exercise duration during submaximal pedalling and resting muscle phosphocreatine (PCr) levels were evaluated. Both groups showed significant increases in peak and mean power output during the two 30-s bouts of maximal pedalling after the training period (P every second day improved OBLA during endurance exercise more than the same training once daily.

  7. The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans

    DEFF Research Database (Denmark)

    Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels

    2016-01-01

    To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific V...

  8. Pulmonary O2 uptake on-kinetics in endurance- and sprint-trained master athletes.

    Science.gov (United States)

    Berger, N J A; Rittweger, J; Kwiet, A; Michaelis, I; Williams, A G; Tolfrey, K; Jones, A M

    2006-12-01

    The purpose of this study was to characterise the VO2 kinetic response to moderate intensity cycle exercise in endurance-trained (END) and sprint or power-trained (SPR) track and field master athletes ranging in age from 45 to 85 years. We hypothesised that the time constant (tau) describing the Phase II VO2 on-response would be smaller in the END compared to the SPR athletes, and that the tau would become greater with increasing age in both groups. Eighty-four master athletes who were competing at either the British or European Veteran Athletics Championships acted as subjects, and were classified as either END (800 m - marathon; n = 41), or SPR (100 - 400 m and field events; n = 43) specialists. Subjects completed two 6 minute "step" transitions to a work rate of moderate intensity on a cycle ergometer and pulmonary gas exchange was measured breath-by-breath. Analysis of variance revealed that SPR athletes had slower VO2 on-kinetics (i.e., greater tau) compared to END athletes at each of the age groups studied: 46 - 55 yrs (END: 25 +/- 6 vs. SPR: 36 +/- 9 s; p kinetics became slower with advancing age in the SPR athletes (p kinetics in SPR compared to END master athletes is consistent both with differences in physiology (e.g., muscle fibre type, oxidative/glycolytic capacity) and training between these specialist athletes. Master END athletes have similar tau values to their younger counterparts (approximately 25 s) suggesting that participation in endurance exercise training limits the slowing of VO2 on-kinetics with age in this population.

  9. Coffee and Caffeine Ingestion Have Little Effect on Repeated Sprint Cycling in Relatively Untrained Males

    Directory of Open Access Journals (Sweden)

    Neil Clarke

    2016-08-01

    Full Text Available The present study investigated the effect of ingesting caffeine-dose-matched anhydrous caffeine or coffee on the performance of repeated sprints. Twelve recreationally active males (mean ± SD age: 22 ± 2 years, height: 1.78 ± 0.07 m, body mass: 81 ± 16 kg completed eighteen 4 s sprints with 116 s recovery on a cycle ergometer on four separate occasions in a double-blind, randomised, counterbalanced crossover design. Participants ingested either 3 mg·kg−1 of caffeine (CAF, 0.09 g·kg−1 coffee, which provided 3 mg·kg−1 of caffeine (COF, a taste-matched placebo beverage (PLA, or a control condition (CON 45 min prior to commencing the exercise protocol. Peak and mean power output and rating of perceived exertion (RPE were recorded for each sprint. There were no significant differences in peak power output (CAF: 949 ± 199 W, COF: 949 ± 174 W, PLA: 971 ± 149 W and CON: 975 ± 170 W; p = 0.872; η P 2 = 0.02 or mean power output (CAF: 873 ± 172 W, COF: 862 ± 44 W, PLA: 887 ± 119 W and CON: 892 ± 143 W; p = 0.819; η P 2 = 0.03 between experimental conditions. Mean RPE was similar for all trials (CAF: 11 ± 2, COF: 11 ± 2, PLA: 11 ± 2 and CON: 11 ± 2; p = 0.927; η P 2 = 0.01. Neither the ingestion of COF or CAF improved repeated sprint cycling performance in relatively untrained males.

  10. The combination of plyometric and balance training improves sprint and shuttle run performances more often than plyometric-only training with children.

    Science.gov (United States)

    Chaouachi, Anis; Othman, Aymen Ben; Hammami, Raouf; Drinkwater, Eric J; Behm, David G

    2014-02-01

    Because balance is not fully developed in children and studies have shown functional improvements with balance only training studies, a combination of plyometric and balance activities might enhance static balance, dynamic balance, and power. The objective of this study was to compare the effectiveness of plyometric only (PLYO) with balance and plyometric (COMBINED) training on balance and power measures in children. Before and after an 8-week training period, testing assessed lower-body strength (1 repetition maximum leg press), power (horizontal and vertical jumps, triple hop for distance, reactive strength, and leg stiffness), running speed (10-m and 30-m sprint), static and dynamic balance (Standing Stork Test and Star Excursion Balance Test), and agility (shuttle run). Subjects were randomly divided into 2 training groups (PLYO [n = 14] and COMBINED [n = 14]) and a control group (n = 12). Results based on magnitude-based inferences and precision of estimation indicated that the COMBINED training group was considered likely to be superior to the PLYO group in leg stiffness (d = 0.69, 91% likely), 10-m sprint (d = 0.57, 84% likely), and shuttle run (d = 0.52, 80% likely). The difference between the groups was unclear in 8 of the 11 dependent variables. COMBINED training enhanced activities such as 10-m sprints and shuttle runs to a greater degree. COMBINED training could be an important consideration for reducing the high velocity impacts of PLYO training. This reduction in stretch-shortening cycle stress on neuromuscular system with the replacement of balance and landing exercises might help to alleviate the overtraining effects of excessive repetitive high load activities.

  11. Short- or long-rest intervals during repeated-sprint training in soccer?

    Science.gov (United States)

    Iaia, F. Marcello; Fiorenza, Matteo; Larghi, Luca; Alberti, Giampietro; Millet, Grégoire P.; Girard, Olivier

    2017-01-01

    The present study compared the effects of two repeated-sprint training (RST) programs, differing in duration of the between-sprint rest intervals, on various soccer-related exercise performances. For 5 weeks during the competitive season, twenty-nine young trained male soccer players either replaced two of their habitual fitness conditioning sessions with RST characterized by short (5–15; n = 9) or long (5–30; n = 10) rest intervals, or served as control (n = 10). The 5–15 and 5–30 protocols consisted of 6 repetitions of 30-m (~5 s) straight-line sprints interspersed with 15 s or 30 s of passive recovery, respectively. 5–15 improved 200-m sprint time (2.0±1.5%; pRecovery Test Level 2 increased following 5–15 (11.4±5.0%; psoccer players, RST over a 5-week in-season period is an efficient means to simultaneously develop different components of fitness relevant to match performance, with different benefits induced by shorter compared to longer rest intervals. PMID:28199402

  12. Oxidative stress response in trained men following repeated squats or sprints.

    Science.gov (United States)

    Bloomer, Richard J; Falvo, Michael J; Fry, Andrew C; Schilling, Brian K; Smith, Webb A; Moore, Christopher A

    2006-08-01

    The purpose of this investigation was to measure the oxidative stress response to similarly matched work bouts of squat and sprint exercise. Twelve anaerobically trained men performed six 10-s sprints and, on a separate occasion, repeated barbell squats to approximately equal the amount of work performed during the sprints. Blood lactate, heart rate, and perceived exertion was measured before and following each exercise bout. Muscle soreness, muscle force, and creatine kinase activity was determined preexercise and through 48 h of recovery. Desmin cytoskeletal protein was determined via muscle biopsy of the vastus lateralis before and at 24 h following each exercise. Plasma protein carbonyls (PC) and malondialdehyde (MDA) were measured as biomarkers of oxidative stress. Heart rate and perceived exertion was not different between exercise sessions (P > 0.05), although lactate was higher following sprinting compared with squatting (P = 0.002). Muscle soreness was greater for squatting than sprinting (P = 0.003) and reached a peak immediately postexercise for both sessions (P = 0.0003). Muscle force was unaffected by either exercise session (P > 0.05), and creatine kinase activity was elevated to a similar extent following both sessions. Desmin-negative fibers were virtually nonexistent after either exercise bout, indicating no loss of this cytoskeletal protein. Neither PC nor MDA was affected by the exercise (P > 0.05). These results suggest that in anaerobically trained men, the oxidative stress and muscle injury response to similarly matched anaerobic exercise bouts is minimal, and not different between exercise modes. Furthermore, when compared with previous literature on untrained subjects, the response is significantly attenuated, possibly because of adaptations occurring as a result of chronic, strenuous anaerobic training.

  13. Five Weeks of Sprint and High-Intensity Interval Training Improves Paddling Performance in Adolescent Surfers.

    Science.gov (United States)

    Farley, Oliver R L; Secomb, Josh L; Parsonage, Joanna R; Lundgren, Lina E; Abbiss, Chris R; Sheppard, Jeremy M

    2016-09-01

    Farley, ORL, Secomb, JL, Parsonage, JR, Lundgren, LE, Abbiss, CR, and Sheppard, JM. Five weeks of sprint and high-intensity interval training improves paddling performance in adolescent surfers. J Strength Cond Res 30(9): 2446-2452, 2016-The purpose of our study was to examine the effects of sprint interval training (SIT; 10 seconds) and high-intensity interval training (HIT; 30 seconds) on surfing athletes paddling performance (400-m time trial and repeat-sprint paddle performance). Twenty-four competitive adolescent surfers (19 male, 5 female; age = 14.4 ± 1.3 years, mass: 50.1 ± 10.7 kg, and stature: 159.9 ± 10.3 cm) were assigned to perform either 5 weeks of SIT and HIT. Participants completed a repeated-sprint paddle ability test (RSPT, 15-m surfboard sprint paddle initiated every 40 seconds × 10 bouts) and 400-m endurance surfboard paddle time trial before and after training. High-intensity interval training decreased the total time to complete the 400 m by 15.8 ± 16.1 seconds (p = 0.03), and SIT decreased the total time to complete the RSPT by 6.5 ± 4.3 seconds (p = 0.02). Fatigue index during the RSPT (first-slowest effort) was lower after HIT and SIT (p ≤ 0.001 and p = 0.02, respectively). There were no significant differences in performance changes in the 400 m (total time) and RSPT (total time, fastest 15 m time, and peak velocity) between HIT and SIT. Our study indicates that HIT and SIT may be implemented to the training program of surfers to improve aerobic and repeat-sprint paddle ability, both of which are identified as key aspects of the sport. In addition, these findings indicate that 400-m paddle and RSPT can discriminate between aerobic and anaerobic training adaptations, with aerobic gains likely from HIT and anaerobic gains from SIT.

  14. Adaptive Changes After 2 Weeks of 10-s Sprint Interval Training With Various Recovery Times

    Directory of Open Access Journals (Sweden)

    Robert A. Olek

    2018-04-01

    Full Text Available Purpose: The aim of this study was to compare the effect of applying two different rest recovery times in a 10-s sprint interval training session on aerobic and anaerobic capacities as well as skeletal muscle enzyme activities.Methods: Fourteen physically active but not highly trained male subjects (mean maximal oxygen uptake 50.5 ± 1.0 mlO2·kg−1·min−1 participated in the study. The training protocol involved a series of 10-s sprints separated by either 1-min (SIT10:1 or 4-min (SIT10:4 of recovery. The number of sprints progressed from four to six over six sessions separated by 1–2 days rest. Pre and post intervention anthropometric measurements, assessment of aerobic, anaerobic capacity and muscle biopsy were performed. In the muscle samples maximal activities of citrate synthase (CS, 3-hydroxyacylCoA dehydrogenase (HADH, carnitine palmitoyl-transferase (CPT, malate dehydrogenase (MDH, and its mitochondrial form (mMDH, as well as lactate dehydrogenase (LDH were determined. Analysis of variance was performed to determine changes between conditions.Results: Maximal oxygen uptake improved significantly in both training groups, by 13.6% in SIT10:1 and 11.9% in SIT10:4, with no difference between groups. Wingate anaerobic test results indicated main effect of time for total work, peak power output and mean power output, which increased significantly and similarly in both groups. Significant differences between training groups were observed for end power output, which increased by 10.8% in SIT10:1, but remained unchanged in SIT10:4. Both training protocols induced similar increase in CS activity (main effect of time p < 0.05, but no other enzymes.Conclusion: Sprint interval training protocols induce metabolic adaptation over a short period of time, and the reduced recovery between bouts may attenuate fatigue during maximal exercise.

  15. REPEATED SPRINT ABILITY AND RECOVERY PERIOD: COMPARISON OF TRAINED AND UNTRAINED INDIVIDUALS

    OpenAIRE

    Sultan

    2016-01-01

    The purpose of the study was to investigate the effects of training both in repeated sprint ability (RSA) and during the recovery after sprint. Soccer players playing in regional amateur league (n=14, age: 21.86±2.35 years, height: 180.14±4.54 cm, body mass: 72.57±5.03 kg, training age: 8.71±1.86 years) and students from faculty of sport sciences that played soccer in the past (n=13, age: 23.77±2.65 years, height: 178.54±4.67 cm, body mass: 74.54±10.52 kg) participated in this study as traine...

  16. A comparison of maximal squat strength and 5-, 10-, and 20-meter sprint times, in athletes and recreationally trained men.

    Science.gov (United States)

    Comfort, Paul; Bullock, Nathan; Pearson, Stephen J

    2012-04-01

    The purpose of this study was to identify whether there was a relationship between relative strength during a 1 repetition maximum (1RM) back squat and 5-, 10-, and 20-m sprint performances in both trained athletes and recreationally trained individuals. Professional rugby league players (n = 24) and recreationally trained individuals (n = 20) participated in this investigation. Twenty-meter sprint time and 1RM back squat strength, using free weights, were assessed on different days. There were no significant (p ≥ 0.05) differences between the well-trained and recreationally trained groups for 5-m sprint times. In contrast, the well-trained group's 10- and 20-m sprint times were significantly quicker (p = 0.004; p = 0.002) (1.78 + 0.06 seconds; 3.03 + 0.09 seconds) compared with the recreationally trained group (1.84 + 0.07 seconds; 3.13 + 0.11 seconds). The athletes were significantly stronger (170.63 + 21.43 kg) than the recreationally trained individuals (135.45 + 30.07 kg) (p = 0.01); however, there were no significant differences (p > 0.05) in relative strength between groups (1.78 + 0.27 kg/kg; 1.78 + 0.33 kg/kg, respectively). Significant negative correlations were found between 5-m sprint time and relative squat strength (r = -0.613, power = 0.96, p = 0.004) and between relative squat strength and 10- and 20-m sprint times in the recreationally trained group (r = -0.621, power = 0.51, p = 0.003; r = -0.604, power = 0.53, p = 0.005, respectively). These results, indicating that relative strength, are important for initial sprint acceleration in all athletes but more strongly related to sprint performance over greater distances in recreationally trained individuals.

  17. Effects of four weeks of repeated sprint training on physiological indices in futsal players

    Directory of Open Access Journals (Sweden)

    Paulo Cesar do Nascimento

    2014-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p91   The aim of this study was to investigate the effects of short repeated-sprint ability (RSA training on the neuromuscular and physiological indices in U17 futsal players during the competitive period. Fourteen players were divided into two groups: intervention group (n = 8 and control group (n = 6. Both groups performed a repeated maximal sprint test (40-m MST, intermittent shuttle-running test (Carminatti’s test and vertical jumps before and after the training period. The intervention group was submitted to an additional four-week repeated sprints program, twice a week, while the control group maintained their normal training routine. There was no significant interaction between time and groups for all variables analysed (p > 0.05. However, a significant main effect was observed for time (p < 0.01 indicating an increase on speed at heart rate deflection point (VHRDP and the continuous jump performance while the peak lactate (40m-LACpeak and sprint decrement decreased after training, in both groups. Still, based on effect sizes (ES the greater changes with practical relevance were verified for intervention group in important variables such as peak velocity (ES = 0,71, VHRDP (ES = 0,83 and 40m-LACpeak (ES = 1,00. This study showed that RSA-based and normal training routine are equally effective in producing changes in the analysed variables during a short period of intervention. However, the effect size suggests that four weeks of RSA training would be a minimum time that could induce the first changes of futsal player’s physical fitness.

  18. Improvements in Attention and Cardiac Autonomic Modulation After a 2-Weeks Sprint Interval Training Program: A Fidelity Approach

    Directory of Open Access Journals (Sweden)

    Arilson F. M. de Sousa

    2018-03-01

    Full Text Available This study aimed to: (1 investigate the influence of a 2-weeks sprint interval training (SIT program on aerobic capacity, cardiac autonomic control, and components of attention in young healthy university students; and (2 to ascertain whether training fidelity would influence these adaptations. One hundred and nine participants were divided into an experimental (EG and control (CG groups. The EG performed a SIT program that consisted of 6 sessions of 4 × 30 s “all-out” efforts on a cycle ergometer, interspersed with active rests of 4 min. The criterion for fidelity was achieving >90% of estimated maximum heart rate (HR during sprint bouts. After analyses, the EG was divided into HIGH (n = 26 and LOW (n = 46 fidelity groups. Components of attention were assessed using the Attention Network Test (ANT. Aerobic capacity (VO2max was estimated while the sum of skinfolds was determined. Autonomic control of HR was assessed by means of HR variability (HRV and HR complexity at rest and during ANT. Both HIGH and LOW significantly increased aerobic capacity, vagal modulation before and during ANT, and executive control, and decreased body fatness after SIT (p < 0.05. However, only participants from HIGH showed an increase in HR complexity and accuracy in ANT when compared to LOW (p < 0.05. Two weeks of SIT improved executive control, body fatness, aerobic fitness, and autonomic control in university students with better results reported in those individuals who exhibited high fidelity.

  19. Sprinting performance and resistance based training interventions: A systematic review with meta-analysis

    OpenAIRE

    Bolger, Richard; Kenny, Ian; Lyons, Mark; Harrison, Andrew J.

    2014-01-01

    peer-reviewed Introduction Much of the research which focuses on improving sprinting performance has been carried out with team sport athletes or endurance athletes (Berryman, Maurel, & Bosquet, 2010; Esteve-Lanao, Rhea, Fleck, & Lucia, 2008; Hanon, Bernard, Rabate, & Claire, 2012; Rhea, Kenn, & Dermody, 2009; Shalfawi, Haugen, Jakobsen, Enoksen, & T??nnessen, 2013; West et al., 2013). There is little consensus with the prescription of resistance based training within this body of resea...

  20. Four weeks of running sprint interval training improves cardiorespiratory fitness in young and middle-aged adults.

    Science.gov (United States)

    Willoughby, Taura N; Thomas, Matthew P L; Schmale, Matthew S; Copeland, Jennifer L; Hazell, Tom J

    2016-01-01

    The purpose of this study was to determine the effectiveness of a 4-week running sprint interval training protocol to improve both aerobic and anaerobic fitness in middle-aged adults (40-50 years) as well as compare the adaptations to younger adults (20-30 years). Twenty-eight inactive participants - 14 young 20-30-year-olds (n = 7 males) and 14 middle-aged 40-50-year-olds (n = 5 males) - completed 4 weeks of running sprint interval training (4 to 6, 30-s "all-out" sprints on a curved, self-propelled treadmill separated by 4 min active recovery performed 3 times per week). Before and after training, all participants were assessed for maximal oxygen consumption (VO2max), 2000 m time trial performance, and anaerobic performance on a single 30-s sprint. There were no interactions between group and time for any tested variable, although training improved relative VO2max (young = 3.9, middle-aged = 5.2%; P < 0.04), time trial performance (young = 5.9, middle-aged = 8.2%; P < 0.001), peak sprint speed (young = 9.3, middle-aged = 2.2%; P < 0.001), and average sprint speed (young = 6.8, middle-aged = 11.6%; P < 0.001) in both young and middle-aged groups from pre- to post-training on the 30-s sprint test. The current study demonstrates that a 4-week running sprint interval training programme is equally effective at improving aerobic and anaerobic fitness in younger and middle-aged adults.

  1. TO COMPARE THE EFFECTS OF SPRINT AND PLYOMETRIC TRAINING PROGRAM ON ANAEROBIC POWER AND AGILITY IN COLLEGIATE MALE FOOTBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    K. Vadivelan

    2015-06-01

    Full Text Available Background: Football is the world’s most popular game and is played by men, women and children of all ages and levels of ability. Success as a player requires an appropriate mixture of mental, physical, technical and tactical ability. Many decisive moments are defined by anaerobic activities such as sprinting, jumping & contests for the football. Agility is an ability of the neuromuscular system to coordinate explosive changes of direction of an individual and/or multiple body segments in all planes of motion. Plyometric Training has been advocated for sports that require the athletes to have explosive power and agility. Similarly previous sprint training studies have shown improvement in the dynamic athletic lower body performance. Advanced technique such as plyometric training protocol has proven more effective but not much studies have been done to assess its effectiveness over Plyometric Training, namely Lower Body Power and Agility Methods: A total of 30 collegiate football players were taken with a mean age of 21.5 with a standard deviation of one. They were randomized into two groups (Group A – Sprint Training & Group B – Plyometric Training. Each group consist of 15 players were selected based on their selection criteria. Informed consent was obtained from the subjects. The study was conducted for six weeks (12 sessions with both the Groups. Evolution parameters are vertical jump height, 40 yard dash, illinois agility Test. Results: Independent t test was used to analysis data. On comparing VJH, Plyometric Training shows (49.26 which have the higher mean value is more effective than Sprint Training (44.93.On comparing Anaerobic power Plyometric Training shows (4150.8 which has the higher Mean value is more effective than Sprint Training (3782.4, on comparing 40 yard dash Plyometric Training shows (5.335 which has the lower Mean value is more effective than Sprint Training (5.490. Illinois Agility Test Plyometric Training shows (15

  2. The Effects of Sprint Interval vs. Continuous Endurance Training on Physiological and Metabolic Adaptations in Young Healthy Adults

    Directory of Open Access Journals (Sweden)

    Nalcakan Gulbin Rudarli

    2014-12-01

    Full Text Available The purpose of this study was to compare the effects of sprint interval training (SIT and continuous endurance training (CET on selected anthropometric, aerobic, and anaerobic performance indices as well as the blood lipid profile, inflammatory and muscle damage markers in healthy young males. Fifteen recreationally active male volunteers (age: 21.7 ±2.2 years, body mass: 83.0 ±8.0 kg, body height: 1.82 ±0.05 m were divided into two groups according to their initial VO2max levels. Training programs were conducted 3 times per week for 7 weeks. The SIT program consisted of 4-6 Wingate anaerobic sprints with a 4.5 min recovery, while CET consisted of 30-50 min cycling at 60% VO2max. Biochemical, anthropometric and fitness assessments were performed both pre and post-intervention. Significant improvements in VO2max, anaerobic power and capacity, and VO2 utilization during the submaximal workout and significant decreases in body fat and in waist circumference after the intervention occurred in both SIT and CET groups. Significantly greater gross efficiency was measured in the CET group. No differences in the lipid profile or serum levels of inflammatory, myocardial and skeletal muscle damage markers were observed after the training period. The study results agree with the effectiveness of a 30 s all-out training program with a reduced time commitment for anthropometric, aerobic and anaerobic adaptation and eliminate doubts about its safety as a model.

  3. Cold-water immersion after training sessions: Effects on fiber type-specific adaptations in muscle K+ transport proteins to sprint-interval training in men.

    Science.gov (United States)

    Christiansen, Danny; Bishop, David John; Broatch, James R; Bangsbo, Jens; McKenna, Michael John; Murphy, Robyn M

    2018-05-10

    Effects of regular use of cold-water immersion (CWI) on fiber type-specific adaptations in muscle K + transport proteins to intense training, along with their relationship to changes in mRNA levels after the first training session, were investigated in humans. Nineteen recreationally-active men (24{plus minus}6 y, 79.5{plus minus}10.8 kg, 44.6{plus minus}5.8 mL∙kg -1 ∙min -1 ) completed six weeks of sprint-interval cycling either without (passive rest; CON) or with training sessions followed by CWI (15 min at 10{degree sign}C; COLD). Muscle biopsies were obtained before and after training to determine abundance of Na + ,K + -ATPase isoforms (α 1-3 , β 1-3 ) and FXYD1, and after recovery treatments (+0h and +3h) on the first day of training to measure mRNA content. Training increased (ptraining (p>0.05). CWI after each session did not influence responses to training (p>0.05). However, α 2 mRNA increased after the first session in COLD (+0h, p0.05). In both conditions, α 1 and β 3 mRNA increased (+3h; p 0.05) after the first session. In summary, Na + ,K + -ATPase isoforms are differently regulated in type I and II muscle fibers by sprint-interval training in humans, which for most isoforms do not associate with changes in mRNA levels after the first training session. CWI neither impairs nor improves protein adaptations to intense training of importance for muscle K + regulation.

  4. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    OpenAIRE

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 �� 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval du...

  5. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    OpenAIRE

    Lukas Cipryan, Gerhard Tschakert, Peter Hofmann

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval dur...

  6. Maturation-related adaptations in running speed in response to sprint training in youth soccer players.

    Science.gov (United States)

    Moran, Jason; Parry, Dave A; Lewis, Ieuan; Collison, Jay; Rumpf, Michael C; Sandercock, Gavin R H

    2018-05-01

    This study investigated the effects of a previously recommended dose of sprint training (ST) in young male soccer players of differing maturity status. Quasi-experimental design. Male soccer players from two professional academies were divided into Pre-PHV (Training: n=12; Control: n=13) and Mid-PHV (Training: n=7; Control=10) groups. The training groups completed 16 sprints of 20m with 90s recovery, once per week for 8weeks. Between-group effect sizes (ES) were substantially larger in Pre-PHV (10m [1.54, CI: 0.74-2.23]; 20m [1.49, CI: 0.75-2.23]; 5-10-5 [0.92, CI: 0.23-1.61]) than in Mid-PHV (10m [-0.00, CI: -0.81 to 0.81]; 20m [-0.12, CI: -0.93 to 0.69]; 5-10-5 [-0.41, CI: -1.22 to 0.41]). Within-group effects demonstrated a similar, though less accentuated, trend which revealed ST to be effective in both Pre-PHV (10m [0.44, CI: -0.24 to 1.12]; 20m [0.45, CI: -0.23 to 1.13]; 5-10-5 [0.69, CI: 0.00-1.38]) and Mid-PHV (10m [0.51, CI: -0.38 to 1.40]; 20m [0.33, CI: -0.56 to 1.21]; 5-10-5 [0.43, CI: -0.46 to 1.32]). ST, in the amount of 16 sprints over 20m with a 90s rest, may be more effective in Pre-PHV youths than in Mid-PHV youths. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Effects of sprint interval training and body weight reduction on power to weight ratio in experienced cyclists.

    Science.gov (United States)

    Lunn, William R; Finn, Joan A; Axtell, Robert S

    2009-07-01

    The purpose of this study was to determine the effect of supramaximal sprint interval training (SIT), body weight reduction, and a combination of both treatments on peak and average anaerobic power to weight ratio (PPOan:Wt, APOan:Wt) by manipulating peak and average anaerobic power output (PPOan, APOan) and body weight (BW) in experienced cyclists. Participants (N = 34, age = 38.0 +/- 7.1 years) were assigned to 4 groups for a 10-week study. One group performed twice-weekly SIT sessions on a cycle ergometer while maintaining body weight (SIT). A second group did not perform SIT but intentionally reduced body weight (WR). A third group simultaneously performed SIT sessions and reduced body weight (SIT+WR). A control group cycled in their normal routine and maintained body weight (CON). The 30-second Wingate Test assessed pretest and posttest POan:Wt scores. There was a significant mean increase (p weight (kg) decreased significantly in WR and SIT + WR (80.3 +/- 13.7 to 75.3 +/- 11.9 and 78.9 +/- 10.8 to 73.4 +/- 10.8, respectively). The results demonstrate that cyclists can use SIT sessions and body weight reduction as singular training interventions to effect significant increases in anaerobic power to weight ratio, which has been correlated to enhanced aerobic cycling performance. However, the treatments were not effective as combined interventions, as there was no significant change in either PPOan:Wt or APOan:Wt in SIT + WR.

  8. Fatigue during maximal sprint cycling: unique role of cumulative contraction cycles.

    Science.gov (United States)

    Tomas, Aleksandar; Ross, Emma Z; Martin, James C

    2010-07-01

    Maximal cycling power has been reported to decrease more rapidly when performed with increased pedaling rates. Increasing pedaling rate imposes two constraints on the neuromuscular system: 1) decreased time for muscle excitation and relaxation and 2) increased muscle shortening velocity. Using two crank lengths allows the effects of time and shortening velocity to be evaluated separately. We conducted this investigation to determine whether the time available for excitation and relaxation or the muscle shortening velocity was mainly responsible for the increased rate of fatigue previously observed with increased pedaling rates and to evaluate the influence of other possible fatiguing constraints. Seven trained cyclists performed 30-s maximal isokinetic cycling trials using two crank lengths: 120 and 220 mm. Pedaling rate was optimized for maximum power for each crank length: 135 rpm for the 120-mm cranks (1.7 m x s(-1) pedal speed) and 109 rpm for the 220-mm cranks (2.5 m x s(-1) pedal speed). Power was recorded with an SRM power meter. Crank length did not affect peak power: 999 +/- 276 W for the 120-mm crank versus 1001 +/- 289 W for the 220-mm crank. Fatigue index was greater (58.6% +/- 3.7% vs 52.4% +/- 4.8%, P < 0.01), and total work was less (20.0 +/- 1.8 vs 21.4 +/- 2.0 kJ, P < 0.01) with the higher pedaling rate-shorter crank condition. Regression analyses indicated that the power for the two conditions was most highly related to cumulative work (r2 = 0.94) and to cumulative cycles (r2 = 0.99). These results support previous findings and confirm that pedaling rate, rather than pedal speed, was the main factor influencing fatigue. Our novel result was that power decreased by a similar increment with each crank revolution for the two conditions, indicating that each maximal muscular contraction induced a similar amount of fatigue.

  9. Effects of inspiratory muscle training on respiratory function and repetitive sprint performance in wheelchair basketball players.

    Science.gov (United States)

    Goosey-Tolfrey, V; Foden, E; Perret, C; Degens, H

    2010-07-01

    There is considerable evidence that respiratory muscle training improves pulmonary function, quality of life and exercise performance in healthy athletic populations. The benefits for wheelchair athletes are less well understood. Therefore, in the present study, influence of inspiratory muscle training (IMT) on respiratory function and repetitive propulsive sprint performance in wheelchair basketball players was examined. Using a placebo-controlled design, 16 wheelchair athletes were divided to an experimental (IMT; n=8) or placebo (sham-IMT; n=8) group based on selective grouping criteria. 30 dynamic breaths were performed by the IMT group twice daily at a resistance equivalent to 50% maximum inspiratory pressure (MIP), and 60 slow breaths were performed by the sham-IMT group once a day at 15% MIP for a period of 6 weeks. In the IMT group, both MIP and maximum expiratory pressure (17% and 23%, respectively; ptraining device suggested "less breathlessness" and "less tightness in the chest during the training". Although there was no improvement in sprint performance, an improved respiratory muscle function and quality of life were reported by participants in both the IMT and sham-IMT groups.

  10. The effects of maturation on jumping ability and sprint adaptations to plyometric training in youth soccer players.

    Science.gov (United States)

    Asadi, Abbas; Ramirez-Campillo, Rodrigo; Arazi, Hamid; Sáez de Villarreal, Eduardo

    2018-04-03

    The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = -0.58; -0.66), and 20-m sprint with ball (ES = -0.44; -0.8; -0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.

  11. Acute effect of a complex training protocol of back squats on 30-m sprint times of elite male military athletes.

    Science.gov (United States)

    Ojeda, Álvaro Huerta; Ríos, Luis Chirosa; Barrilao, Rafael Guisado; Serrano, Pablo Cáceres

    2016-03-01

    [Purpose] The aim of this study was to determine the acute effect temporal of a complex training protocol on 30 meter sprint times. A secondary objective was to evaluate the fatigue indexes of military athletes. [Subjects and Methods] Seven military athletes were the subjects of this study. The variables measured were times in 30-meter sprint, and average power and peak power of squats. The intervention session with complex training consisted of 4 sets of 5 repetitions at 30% 1RM + 4 repetitions at 60% 1RM + 3 repetitions of 30 meters with 120-second rests. For the statistical analysis repeated measures of ANOVA was used, and for the post hoc analysis, student's t-test was used. [Results] Times in 30 meter sprints showed a significant reduction between the control set and the four experimental sets, but the average power and peak power of squats did not show significant changes. [Conclusion] The results of the study show the acute positive effect of complex training, over time, in 30-meter sprint by military athletes. This effect is due to the post activation potentiation of the lower limbs' muscles in the 30 meters sprint.

  12. A PRACTICAL MODEL OF LOW-VOLUME HIGH-INTENSITY INTERVAL TRAINING INDUCES PERFORMANCE AND METABOLIC ADAPTATIONS THAT RESEMBLE 'ALL-OUT' SPRINT INTERVAL TRAINING

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    Mahdi Bayati

    2011-09-01

    Full Text Available Recently, a novel type of high-intensity interval training known as sprint interval training has demonstrated increases in aerobic and anaerobic performance with very low time commitment. However, this type of training program is unpractical for general populations. The present study compared the impact of a low-volume high-intensity interval training to a "all-out" sprint interval training. Twenty-four active young males were recruited and randomized into three groups: (G1: 3-5 cycling bouts × 30-s all-out with 4 min recovery; G2: 6- 10 cycling bouts × 125% Pmax with 2 min recovery and a non-trained control group. They all performed a VO2max test, a time to exhaustion at Pmax (Tmax and a Wingate test before and after the intervention. Capillary blood lactate was taken at rest, 3, and 20 min after the Wingate trial. Training was performed 3 sessions per week for 4 weeks. In G1, significant improvements (p < 0.05 following training were found in VO2max (9.6%, power at VO2max (12.8%, Tmax (48.4%, peak power output (10.3% and mean power output (17.1%. In G2, significant improvements following training were found in VO2max (9.7%, power at VO2max (16.1%, Tmax (54.2%, peak power output (7.4%; p < 0.05, but mean power output did not change significantly. Blood lactate recovery (20th min significantly decreased in G1 and G2 when compared with pre-testing and the CON group (p < 0.05. In conclusion, the results of the current study agree with earlier work demonstrating the effectiveness of 30-s all-out training program to aerobic and anaerobic adaptations. Of substantial interest is that the low volume high intensity training provides similar results but involves only half the intensity with double the repetitions

  13. Within-cycle characteristics of the wheelchair push in sprinting on a wheelchair ergometer

    NARCIS (Netherlands)

    Veeger, DirkJan (H. E. J.); van der Woude, L H; Rozendal, R H

    To investigate power output and torque production in wheelchair sprinting, six able-bodied subjects performed nine 20-s sprint tests on a stationary wheelchair ergometer (load 0-8 kg). Ergometer data were analyzed and combined with kinematic data and surface electromyography. Of all power and torque

  14. SPRINT-INTERVAL TRAINING INDUCES HEAT SHOCK PROTEIN 72 IN RAT SKELETAL MUSCLES

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    Yuji Ogura

    2006-06-01

    Full Text Available Previous studies have demonstrated that endurance exercise training increases the level of heat shock proteins (HSPs in skeletal muscles. However, little attention has been drawn to the effects of high intensity-short duration exercise, or sprint- interval training (SIT on HSP72 level in rat skeletal muscles. This study performed to test the hypothesis that the SIT would induce the HSP72 in fast and slow skeletal muscles of rats. Young male Wistar rats (8 weeks old were randomly assigned to a control (CON or a SIT group (n = 8/group. Animals in the SIT group were trained (1 min/sprint, 6~10 sets/day and 5~6 days/week on a treadmill for 9 weeks. After the training period, HSP72 levels in the plantaris (fast and soleus (slow muscles were analyzed by Western blotting method. Enzyme activities (hexokinase, phosphofructokinase and citrate synthase and histochemical properties (muscle fiber type compositions and cross sectional area in both muscles were also determined. The SIT resulted in significantly (p < 0.05 higher levels of HSP72 in both the plantaris and soleus muscles compared to the CON group, with the plantaris producing a greater HSP72 increase than the soleus (plantaris; 550 ± 116%, soleus; 26 ± 8%, p < 0.05. Further, there were bioenergetic improvements, fast-to-slow shift of muscle fiber composition and hypertrophy in the type IIA fiber only in the plantaris muscle. These findings indicate that the SIT program increases HSP72 level of the rat hindlimb muscles, and the SIT-induced accumulation of HSP72 differs between fast and slow muscles

  15. High-intensity cycle interval training improves cycling and running performance in triathletes.

    Science.gov (United States)

    Etxebarria, Naroa; Anson, Judith M; Pyne, David B; Ferguson, Richard A

    2014-01-01

    Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.

  16. Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment.

    Directory of Open Access Journals (Sweden)

    Jenna B Gillen

    Full Text Available We investigated whether sprint interval training (SIT was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training (MICT. SIT involved 1 minute of intense exercise within a 10-minute time commitment, whereas MICT involved 50 minutes of continuous exercise per session.Sedentary men (27±8y; BMI = 26±6kg/m2 performed three weekly sessions of SIT (n = 9 or MICT (n = 10 for 12 weeks or served as non-training controls (n = 6. SIT involved 3x20-second 'all-out' cycle sprints (~500W interspersed with 2 minutes of cycling at 50W, whereas MICT involved 45 minutes of continuous cycling at ~70% maximal heart rate (~110W. Both protocols involved a 2-minute warm-up and 3-minute cool-down at 50W.Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both. Insulin sensitivity index (CSI, determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002 and MICT (5.0±3.3 to 6.7±5.0 x 10-4 min-1 [μU/mL]-1, p = 0.013 (p<0.05. Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001. The corresponding changes in the control group were small for VO2peak (p = 0.99, CSI (p = 0.63 and CS (p = 0.97.Twelve weeks of brief intense interval exercise improved indices of cardiometabolic health to the same extent as traditional endurance training in sedentary men, despite a five-fold lower exercise volume and time commitment.

  17. Training loads of female canoeing youth national team in sprint competitions

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    Cieslicka Miroslawa.

    2012-12-01

    Full Text Available Introduction Long-term training process need precise, scientific management, based on recognition indicators of fitness preparation, technical, mental health status of the player. Control is treated as a collection of information allowing to organize rational technological solution. Verification should provide high reliability and information of the test results, what is achieved by standardizing test conditions, sets of samples used in any of the disciplines and measurement techniques. Objective The objective was to calculate the training loads of female canoeing youth national team (sprint. In addition, attempts to answer the following questions: What was the structure of the annual training plans and whether it is consistent with the theory of training canoeist?; What was the pace and direction of changes in the volume of work within each group of training? Materials and methods The study used records of logs implementation training loads what competitors have done in the years 2009 to 2010. The analysis included data on training loads and boot. The loads presented as the number of kilometers completed during each season training and during each period of the season and in arbitrary units. Results and conclusions Based on the collected material research analysed training of female canoeing youth national team both in terms of its subject, as well as temporary structures. Every aspect of fitness requires adequate time, necessary to make adaptive changes. Therefore, it is necessary to vary the time required for development. Comparing the training load can be seen that in 2009 competitors have done more work in the run-up than in 2010, but much smaller loads can be seen in 2009 during start season comparing the training load during startup in 2010.

  18. The Effect of High-Intensity Interval Cycling Sprints Subsequent to Arm-Curl Exercise on Upper-Body Muscle Strength and Hypertrophy.

    Science.gov (United States)

    Kikuchi, Naoki; Yoshida, Shou; Okuyama, Mizuki; Nakazato, Koichi

    2016-08-01

    Kikuchi, N, Yoshida, S, Okuyama, M, and Nakazato, K. The effect of high-intensity interval cycling sprints subsequent to arm-curl exercise on upper-body muscle strength and hypertrophy. J Strength Cond Res 30(8): 2318-2323, 2016-The purpose of this study was to examine whether lower limb sprint interval training (SIT) after arm resistance training (RT) influences training response of arm muscle strength and hypertrophy. Twenty men participated in this study. We divided subjects into RT group (n = 6) and concurrent training group (CT, n = 6). The RT program was designed to induce muscular hypertrophy (3 sets × 10 repetitions [reps] at 80% 1 repetition maximum [1RM] of arm-curl exercise) and was performed in an 8-week training schedule performed 3 times per week on nonconsecutive days. Subjects assigned to the CT group performed identical protocols as strength training and modified SIT (4 sets of 30-s maximal effort, separated in 4 m 30-s rest intervals) on the same day. Pretest and posttest maximal oxygen consumption (V[Combining Dot Above]O2max), muscle cross-sectional area (CSA), and 1RM were measured. Significant increase in V[Combining Dot Above]O2max from pretest to posttest was observed in the CT group (p = 0.010, effect size [ES] = 1.84) but not in the RT group (p = 0.559, ES = 0.35). Significant increase in CSA from pretest to posttest was observed in the RT group (p = 0.030, ES = 1.49) but not in the CT group (p = 0.110, ES = 1.01). Significant increase in 1RM from pretest to posttest was observed in the RT group (p = 0.021, ES = 1.57) but not in the CT group (p = 0.065, ES = 1.19). In conclusion, our data indicate that concurrent lower limb SIT interferes with arm muscle hypertrophy and strength.

  19. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s), long HIIT (3min) and constant load exercise (CE). The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇O2, RER) and metabolic (lactate) variables as well as the post-exercise changes (up to 3 h) in the heart rate variability, inflammation (interleukin-6, leucocytes) and muscle damage (creatine kinase, myoglobin) were monitored. Endurance athletes performed exercise interventions with moderately (CE) or largely (both HIIT modes) higher mean V̇O2. These differences were trivial/small when V̇O2 was expressed as a percentage of V̇O2max. Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes. Key points The manner in which each training background (endurance vs. sprint) influences the response to HIIT is not well known. Despite the identical exercise intensity in relative terms, endurance

  20. Similar inflammatory responses following sprint interval training performed in hypoxia and normoxia

    Directory of Open Access Journals (Sweden)

    Alan James Richardson

    2016-08-01

    Full Text Available Sprint interval training (SIT is an efficient intervention capable of improving aerobic capacity and exercise performance. This experiment aimed to determine differences in training adaptations and the inflammatory responses following 2 weeks of SIT (30s maximal work, 4 min recovery; 4-7 repetitions performed in normoxia or hypoxia. Forty-two untrained participants [(mean ± SD, age 21 ±1 yrs, body mass 72.1 ±11.4 kg and height 173 ±10 cm] were equally and randomly assigned to one of three groups; control (CONT; no training, n = 14, normoxic (NORM; SIT in FiO2: 0.21, n = 14 and normobaric hypoxic (HYP; SIT in FiO2: 0.15, n = 14. Participants completed a V̇O2peak test, a time to exhaustion (TTE trial (power = 80% V̇O2peak and had haematological [haemoglobin (Hb, haematocrit (Hct] and inflammatory markers [interleukin-6 (IL-6, tumor necrosis factor-α (TNFα] measured in a resting state, pre and post SIT. V̇O2peak (mL.kg-1.min-1 improved in HYP (+11.9% and NORM (+9.8%, but not CON (+0.9%. Similarly TTE improved in HYP (+32.2% and NORM (+33.0%, but not CON (+3.4% whilst the power at the anaerobic threshold (AT; W.kg-1 also improved in HYP (+13.3% and NORM (+8.0%, but not CON (-0.3%. AT (mL.kg-1.min-1 improved in HYP (+9.5%, but not NORM (+5% or CON (-0.3%. No between group change occurred in 30 s sprint performance or Hb and Hct. IL-6 increased in HYP (+17.4% and NORM (+20.1%, but not CON (+1.2% respectively. TNF-α increased in HYP (+10.8% NORM (+12.9% and CON (+3.4%.SIT in HYP and NORM increased VO2peak, power at AT and TTE performance in untrained individuals, improvements in AT occurred only when SIT was performed in HYP. Increases in IL-6 and TNFα reflect a training induced inflammatory response to SIT; hypoxic conditions do not exacerbate this.

  1. Comparative Effects of In-Season Full-Back Squat, Resisted Sprint Training, and Plyometric Training on Explosive Performance in U-19 Elite Soccer Players.

    Science.gov (United States)

    de Hoyo, Moises; Gonzalo-Skok, Oliver; Sañudo, Borja; Carrascal, Claudio; Plaza-Armas, Jose R; Camacho-Candil, Fernando; Otero-Esquina, Carlos

    2016-02-01

    The aim of this study was to analyze the effects of 3 different low/moderate load strength training methods (full-back squat [SQ], resisted sprint with sled towing [RS], and plyometric and specific drills training [PLYO]) on sprinting, jumping, and change of direction (COD) abilities in soccer players. Thirty-two young elite male Spanish soccer players participated in the study. Subjects performed 2 specific strength training sessions per week, in addition to their normal training sessions for 8 weeks. The full-back squat protocol consisted of 2-3 sets × 4-8 repetitions at 40-60% 1 repetition maximum (∼ 1.28-0.98 m · s(-1)). The resisted sprint training was compounded by 6-10 sets × 20-m loaded sprints (12.6% of body mass). The plyometric and specific drills training was based on 1-3 sets × 2-3 repetitions of 8 plyometric and speed/agility exercises. Testing sessions included a countermovement jump (CMJ), a 20-m sprint (10-m split time), a 50-m (30-m split time) sprint, and COD test (i.e., Zig-Zag test). Substantial improvements (likely to almost certainly) in CMJ (effect size [ES]: 0.50-0.57) and 30-50 m (ES: 0.45-0.84) were found in every group in comparison to pretest results. Moreover, players in PLYO and SQ groups also showed substantial enhancements (likely to very likely) in 0-50 m (ES: 0.46-0.60). In addition, 10-20 m was also improved (very likely) in the SQ group (ES: 0.61). Between-group analyses showed that improvements in 10-20 m (ES: 0.57) and 30-50 m (ES: 0.40) were likely greater in the SQ group than in the RS group. Also, 10-20 m (ES: 0.49) was substantially better in the SQ group than in the PLYO group. In conclusion, the present strength training methods used in this study seem to be effective to improve jumping and sprinting abilities, but COD might need other stimulus to achieve positive effects.

  2. The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans

    Science.gov (United States)

    Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels; Larsen, Filip J.; Schiffer, Tomas A.; Willis, Sarah J.; Gelabert-Rebato, Miriam; Perez-Valera, Mario; Boushel, Robert; Calbet, Jose A. L.; Holmberg, Hans-Christer

    2016-01-01

    To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4–6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO2peak and Wmax increased 3–11% after training, with a more pronounced change in the arms (P training, VO2 during the two Wingate tests was increased by 52 and 6% for the arms and legs, respectively (P intensity, HR, VO2, VCO2, VE, and Vt were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling (P = 0.017). The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO2 for the arms was enhanced more by training, reducing the O2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms and legs is enhancement of aerobic energy production. However, with their higher proportion of fast muscle fibers, the arms exhibit greater plasticity. PMID:27746738

  3. Effects of dry-land vs. resisted- and assisted-sprint exercises on swimming sprint performances.

    Science.gov (United States)

    Girold, Sébastien; Maurin, Didier; Dugué, Benoit; Chatard, Jean-Claude; Millet, Grégoire

    2007-05-01

    This study was undertaken to compare the effects of dry-land strength training with a combined in-water resisted- and assisted-sprint program in swimmer athletes. Twenty-one swimmers from regional to national level participated in this study. They were randomly assigned to 3 groups: the strength (S) group that was involved in a dry-land strength training program where barbells were used, the resisted- and assisted-sprint (RAS) group that got involved in a specific water training program where elastic tubes were used to generate resistance and assistance while swimming, and the control (C) group which was involved in an aerobic cycling program. During 12 weeks, the athletes performed 6 training sessions per week on separate days. All of them combined the same aerobic dominant work for their basic training in swimming and running with their specific training. Athletes were evaluated 3 times: before the training program started, after 6 weeks of training, and at the end of the training program. The outcome values were the strength of the elbow flexors and extensors evaluated using an isokinetic dynamometer, and the speed, stroke rate, stroke length, and stroke depth observed during a 50-meter sprint. No changes were observed after 6 weeks of training. At the end of the training period, we observed significant increases in swimming velocity, and strength of elbow flexors and extensors both in the S and RAS groups. However, stroke depth decreased both in the S and RAS groups. Stroke rate increased in the RAS but not in the S group. However, no significant differences in the swimming performances between the S and RAS groups were observed. No significant changes occurred in C. Altogether, programs combining swimming with dry-land strength or with in-water resisted- and assisted-sprint exercises led to a similar gain in sprint performance and are more efficient than traditional swimming training methods alone.

  4. Validity and reliability of the look Keo power pedal system for measuring power output during incremental and repeated sprint cycling.

    Science.gov (United States)

    Sparks, S Andy; Dove, Benjamin; Bridge, Craig A; Midgely, Adrian W; McNaughton, Lars R

    2015-01-01

    Power meters have traditionally been integrated into the crank set, but several manufacturers have designed new systems located elsewhere on the bike, such as inside the pedals. This study aimed to determine the validity and reliability of the Keo power pedals during several laboratory cycling tasks. Ten active male participants (mean ± SD age 34.0 ± 10.6 y, height 1.77 ± 0.04 m, body mass 76.5 ± 10.7 kg) familiar with laboratory cycling protocols completed this study. Each participant was required to complete 2 laboratory cycling trials on an SRM ergometer (SRM, Germany) that was also fitted with the Keo power pedals (Look, France). The trials consisted of an incremental test to exhaustion followed by 10 min rest and then three 10-s sprint tests separated by 3 min of cycling at 100 W. Over power ranges of 75 to 1147 W, the Keo power-pedal system produced typical error values of 0.40, 0.21, and 0.21 for the incremental, sprint, and combined trials, respectively, compared with the SRM. Mean differences of 21.0 and 18.6 W were observed between trials 1 and 2 with the Keo system in the incremental and combined protocols, respectively. In contrast, the SRM produced differences of 1.3 and 0.6 W for the same protocols. The power data from the Keo power pedals should be treated with some caution given the presence of mean differences between them and the SRM. Furthermore, this is exacerbated by poorer reliability than that of the SRM power meter.

  5. Effect of Different Training Methods on Stride Parameters in Speed Maintenance Phase of 100-m Sprint Running.

    Science.gov (United States)

    Cetin, Emel; Hindistan, I Ethem; Ozkaya, Y Gul

    2018-05-01

    Cetin, E, Hindistan, IE, Ozkaya, YG. Effect of different training methods on stride parameters in speed maintenance phase of 100-m sprint running. J Strength Cond Res 32(5): 1263-1272, 2018-This study examined the effects of 2 different training methods relevant to sloping surface on stride parameters in speed maintenance phase of 100-m sprint running. Twenty recreationally active students were assigned into one of 3 groups: combined training (Com), horizontal training (H), and control (C) group. Com group performed uphill and downhill training on a sloping surface with an angle of 4°, whereas H group trained on a horizontal surface, 3 days a week for 8 weeks. Speed maintenance and deceleration phases were divided into distances with 10-m intervals, and running time (t), running velocity (RV), step frequency (SF), and step length (SL) were measured at preexercise, and postexercise period. After 8 weeks of training program, t was shortened by 3.97% in Com group, and 2.37% in H group. Running velocity also increased for totally 100 m of running distance by 4.13 and 2.35% in Com, and H groups, respectively. At the speed maintenance phase, although t and maximal RV (RVmax) found to be statistically unaltered during overall phase, t was found to be decreased, and RVmax was preceded by 10 m in distance in both training groups. Step length was increased at 60-70 m, and SF was decreased at 70-80 m in H group. Step length was increased with concomitant decrease in SF at 80-90 m in Com group. Both training groups maintained the RVmax with a great percentage at the speed maintenance phase. In conclusion, although both training methods resulted in an increase in running time and RV, Com training method was more prominently effective method in improving RV, and this improvement was originated from the positive changes in SL during the speed maintaining phase.

  6. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes.

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-06-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s), long HIIT (3min) and constant load exercise (CE). The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇ O 2 , RER) and metabolic (lactate) variables as well as the post-exercise changes (up to 3 h) in the heart rate variability, inflammation (interleukin-6, leucocytes) and muscle damage (creatine kinase, myoglobin) were monitored. Endurance athletes performed exercise interventions with moderately (CE) or largely (both HIIT modes) higher mean V̇ O 2 . These differences were trivial/small when V̇ O 2 was expressed as a percentage of V̇ O 2max . Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes.

  7. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    Directory of Open Access Journals (Sweden)

    Lukas Cipryan, Gerhard Tschakert, Peter Hofmann

    2017-06-01

    Full Text Available The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years participating in endurance (n = 8 or sprint (n = 8 sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s, long HIIT (3min and constant load exercise (CE. The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇O2, RER and metabolic (lactate variables as well as the post-exercise changes (up to 3 h in the heart rate variability, inflammation (interleukin-6, leucocytes and muscle damage (creatine kinase, myoglobin were monitored. Endurance athletes performed exercise interventions with moderately (CE or largely (both HIIT modes higher mean V̇O2. These differences were trivial/small when V̇O2 was expressed as a percentage of V̇O2max. Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes.

  8. The effect of 8-week plyometric training on leg power, jump and sprint performance in female soccer players.

    Science.gov (United States)

    Ozbar, Nurper; Ates, Seda; Agopyan, Ani

    2014-10-01

    The aim of this study was to determine the effect of 8-week plyometric training (PT) on the leg power and jump and sprint performance in female soccer players. Eighteen female soccer players from Women Second League (age = 18.2 ± 2.3 years, height = 161.3 ± 5.4 cm, body mass = 56.6 ± 7.2 kg) were randomly assigned to control (n = 9) and plyometric (n = 9) groups. Both groups continued together with regular technical and tactical soccer training for 4 days a week. Additionally, the plyometric group underwent PT for 8 weeks, 1 day per week, 60-minute session duration. During the 8-week period, the control group was hindered from any additional conditioning training. All players' jumps (triple hop, countermovement jump, and standing broad jump), running speed (20 m), and peak power were evaluated before and after 8 weeks. No significant difference was found between the groups at pretest variables (p > 0.05). Significant improvements were found in the posttest of both the groups (p ≤ 0.05), except for 20-m sprint test in the control group (p > 0.05). Triple hop distance, countermovement jump, standing broad jump, peak power, and 20-m sprint test values were all significantly improved in the plyometric group, compared with the control group (p ≤ 0.05). We concluded that short duration PT is an improved important component of athletic performance in female soccer players. The results indicate that safe, effective, and alternative PT can be useful to strength and conditioning coaches, especially during competition season where less time is available for training.

  9. Effect of 8 weeks sprint interval training on serum levels of Adiponectin and insulin in overweight children

    Directory of Open Access Journals (Sweden)

    Abdolreza Kazemi

    2016-04-01

    Full Text Available Background: Scientific studies demonstrated that decreased blood Adiponectin level is associated with insulin resistance in obesity. Also it is well documented that exercise training exerts beneficial effects on obesity but there is few study regarding beneficial effects of sprint Interval training (SIT on childhood obesity. This study was intended to investigate the effect of SIT on serum levels of Adiponectin and insulin in overweight children. Material and Methods: In this study thirty-two obese boy (BMI=27 were randomly assigned to sprint Interval Training (SIT (N=16 and control group(C (N=16. Training protocol consisted of 30s and 90s all-out running that performed 3 sessions per week for 8 weeks. Blood samples were measured by ELISA analysis. Data were analyzed using Independent sample t-test. Results: 8 weeks SIT increase serum levels of Adiponectin (P=0.028 and decrease insulin level (P=0.00. This change was directly related to decrease in values of BMI (P=0.01, total cholesterol (P=0.00 and body weight (P=0.02, but significant change in serum levels of HDL (P=0.50, LDL (P=0.17 and TG (P=0.60 wasn’t observed. Conclusion: These findings suggest that SIT may ameliorate the metabolic abnormalities associated with obesity in children probably through elevation of serum Adiponectin level.

  10. Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

    Science.gov (United States)

    Marián, Vanderka; Katarína, Longová; Dávid, Olasz; Matúš, Krčmár; Simon, Walker

    2016-01-01

    The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, psquats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term. Key points Jump squat exercise is one of many exercises to develop explosive strength that has been the focus of several researches, while the load used during the training seem to be an important factor that affects training outcomes. Experimental group improved performance in all assessed parameters, such as Fmax, RFD100, CMJ, SJ and 50 m sprint time. However, improvements in CMJ and SJ were recorded after the entire power training period and thereafter plateau occurred. The portable FitroDyne could serve as a valuable device to individualize the load that maximizes mean power output and visual feedback can be provided to athletes during the training. PMID:27803628

  11. The effect of milk on recovery from repeat-sprint cycling in female team-sport athletes.

    Science.gov (United States)

    Rankin, Paula; Lawlor, Michael J; Hills, Frank A; Bell, Phillip G; Stevenson, Emma J; Cockburn, Emma

    2018-02-01

    The consumption of milk following eccentric exercise attenuates the effects of muscle damage in team-sport athletes. However, participation in team sport involves both concentric-eccentric loading and metabolic stress. Therefore, the aim of this study was to investigate the effects of postexercise milk consumption on recovery from a cycling protocol designed to simulate the metabolic demands of team sport. Ten female team-sport athletes participated in a randomised crossover investigation. Upon completion of the protocol participants consumed 500 mL of milk (MILK) or 500 mL of an energy-matched carbohydrate (CHO) drink. Muscle function (peak torque, rate of force development, countermovement jump, 20-m sprint), muscle soreness and tiredness, serum creatine kinase, high-sensitivity C-reactive protein, and measures of oxidative stress (protein carbonyls and reduced glutathione/oxidized glutathione (GSH/GSSG) ratio) were determined at pre-exercise and 24 h, 48 h, and 72 h postexercise. MILK had a possible beneficial effect in attenuating losses in peak torque (180°/s) from baseline to 24 h (3.2% ± 7.8% vs. -6.2% ± 7.5%, MILK vs. CHO) and a possible beneficial effect in minimising soreness (baseline-48 h; baseline-72 h) and tiredness (baseline-24 h; baseline-72 h). There was no change in oxidative stress following the exercise protocol, though a likely benefit of milk was observed for GSH/GSSG ratio at baseline-24 h (0.369 ×/÷ 1.89, 1.103 ×/÷ 3.96, MILK vs. CHO). MILK had an unclear effect on all other variables. Consumption of 500 mL of milk after repeat sprint cycling had little to no benefit in minimising losses in peak torque or minimising increases in soreness and tiredness and had no effect on serum markers of muscle damage and inflammation.

  12. Effect of tapering after a period of high-volume sprint interval training on running performance and muscular adaptations in moderately trained runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Kvorning, Thue

    2018-01-01

    The effect of tapering following a period of high-volume sprint interval training (SIT) and a basic volume of aerobic training on performance and muscle adaptations in moderately trained runners was examined. Eleven (8 males, 3 females) runners (maximum oxygen uptake (VO2-max): 56.8±2.9 mL·min(-1...... running test at 90% of vVO2-max to exhaustion (RRT). In addition, a biopsy from m. vastus lateralis was obtained at rest. Performance during RRT was better (P... at 60% of vVO2-max was lower (P

  13. Changes in Sprint and Jump Performances After Traditional, Plyometric, and Combined Resistance Training in Male Youth Pre- and Post-Peak Height Velocity.

    Science.gov (United States)

    Lloyd, Rhodri S; Radnor, John M; De Ste Croix, Mark B A; Cronin, John B; Oliver, Jon L

    2016-05-01

    The purpose of this study was to compare the effectiveness of 6-week training interventions using different modes of resistance (traditional strength, plyometric, and combined training) on sprinting and jumping performances in boys before and after peak height velocity (PHV). Eighty school-aged boys were categorized into 2 maturity groups (pre- or post-PHV) and then randomly assigned to (a) plyometric training, (b) traditional strength training, (c) combined training, or (d) a control group. Experimental groups participated in twice-weekly training programs for 6 weeks. Acceleration, maximal running velocity, squat jump height, and reactive strength index data were collected pre- and postintervention. All training groups made significant gains in measures of sprinting and jumping irrespective of the mode of resistance training and maturity. Plyometric training elicited the greatest gains across all performance variables in pre-PHV children, whereas combined training was the most effective in eliciting change in all performance variables for the post-PHV cohort. Statistical analysis indicated that plyometric training produced greater changes in squat jump and acceleration performances in the pre-PHV group compared with the post-PHV cohort. All other training responses between pre- and post-PHV cohorts were not significant and not clinically meaningful. The study indicates that plyometric training might be more effective in eliciting short-term gains in jumping and sprinting in boys who are pre-PHV, whereas those who are post-PHV may benefit from the additive stimulus of combined training.

  14. Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

    Directory of Open Access Journals (Sweden)

    Vanderka Marián, Longová Katarína, Olasz Dávid, Krčmár Matúš, Walker Simon

    2016-09-01

    Full Text Available The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax and rate of force development over 100ms (RFD100, countermovement jump (CMJ and squat jump (SJ height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg were divided into experimental (EXP; n = 36 and control (CON, n = 32 groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions. Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, p<0.001, and from mid- to post-training (Δ ~4%, p < 0.001 in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Δ ~3.5%, p < 0.05 was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Δ ~27%, p < 0.001, as well as from mid- to post-training (Δ ~17%, p < 0.01 were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Δ ~10%, ~15%, respectively, p < 0.001 but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid-training (Δ -1%, p < 0.05, and from mid- to post-training (Δ -1.9%, p < 0.001 in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.

  15. The physiological mechanisms of performance enhancement with sprint interval training differ between the upper and lower extremities in humans.

    Directory of Open Access Journals (Sweden)

    Christoph Zinner

    2016-09-01

    Full Text Available To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6x30-sec all-out sprints (SIT with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-sec Wingate tests with 4-min recovery, muscle efficiency and time-trial performance (TT, 5-min all-out were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO2peak and Wmax increased 3-11% after training, with a more pronounced change in the arms (P < 0.05. Gross efficiency improved for the arms (+8.8%, P < 0.05, but not the legs (-0.6%. Wingate peak and mean power outputs improved similarly for the arms and legs, as did TT performance. After training, VO2 during the two Wingate tests was increased by 52% and 6% for the arms and legs, respectively (P < 0.001. In the case of the arms, VO2 was higher during the first than second Wingate test (64% vs. 44%, P < 0.05. During the TT, relative exercise intensity, HR, VO2, VCO2, VE, and Vt were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling (P = 0.017. The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO2 for the arms was enhanced more by training, reducing the O2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms

  16. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-01-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pvolleyball players. Future studies should evaluate differential program effects in less experienced and younger players. Key points Plyometric- and skill-based-conditioning resulted in improvements in jumping and throwing capacities, but plyometric training additionally induced positive changes in anthropometrics and sprint-capacity The changes induced by plyometric training were larger in magnitude than those achieved by skill-based conditioning. The higher intensity together with possibility of more accurate adjustment of training load in plyometric training are probably the most important determinant of such differential influence. It is likely that the skill-based conditioning program did not result in changes of higher magnitude because of the players’ familiarity with volleyball-related skills. PMID:29238253

  17. Sprint performance and propulsion asymmetries on an ergometer in trained high- and low-point wheelchair rugby players.

    Science.gov (United States)

    Goosey-Tolfrey, V L; Vegter, R J K; Mason, B S; Paulson, T A W; Lenton, J P; van der Scheer, J W; van der Woude, L H V

    2018-05-01

    The purpose of this study was to examine the propulsion asymmetries of wheelchair athletes while sprinting on an instrumented, dual-roller ergometer system. Eighteen experienced wheelchair rugby players (8 low point (LP) (class ≤1.5) and 10 high point (HP) (class ≥2.0)) performed a 15-second sprint in their sports wheelchair on the instrumented ergometer. Asymmetry was defined as the difference in distance and power output (PO) between left and right sides when the best side reached 28 m. Propulsion techniques were quantified based on torque and velocity data. HP players covered an average 3 m further than the LP players (P = .002) and achieved faster sprint times than LP players (6.95 ± 0.89 vs 8.03 ± 0.68 seconds, P = .005) and at the time the best player finished (5.96 seconds). Higher peak POs (667 ± 108 vs 357 ± 78 W, P = .0001) and greater peak speeds that were also evident were for HP players (4.80 ± 0.71 vs 4.09 ± 0.45 m/s, P = .011). Greater asymmetries were found in HP players for distance (1.86 ± 1.43 vs 0.70 ± 0.65 m, P = .016), absolute peak PO (P = .049), and speed (0.35 ± 0.25 vs 0.11 ± 0.10 m/s, P = .009). Although HP players had faster sprint times over 28 m (achieved by a higher PO), high standard deviations show the heterogeneity within the two groups (eg, some LP players were better than HP players). Quantification of asymmetries is important not only for classifiers but also for sports practitioners wishing to improve performance as they could be addressed through training and/or wheelchair configuration. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Effects of an In-season Plyometric Training Program on Repeated Change of Direction and Sprint Performance in the Junior Soccer Player.

    Science.gov (United States)

    Hammami, Mehréz; Negra, Yassine; Aouadi, Ridha; Shephard, Roy J; Chelly, Mohamed Souhaiel

    2016-12-01

    Hammami, M, Negra, Y, Aouadi, R, Shephard, RJ, and Chelly, MS. Effects of an in-season plyometric training program on repeated change of direction and sprint performance in the junior soccer player. J Strength Cond Res 30(12): 3312-3320, 2016-We aimed to determine the gains in explosive movements of male junior soccer players induced by incorporating an 8-week plyometric training program (PTP) into a standard soccer conditioning regimen 5 months after the beginning of the competitive season. Our hypothesis was that PTP would enhance explosive movements, and thus sprint running, repeated shuttle sprint ability (RSSA), agility and the ability to make repeated changes of direction (RCOD). A group of junior soccer players were randomly divided into 2 groups: an experimental group (E, n = 15, age 15.7 ± 0.2 years) and a control group (C, n = 13, age 15.8 ± 0.2 years). The participants in E and C performed training exercises and matches together, but for an 8-week period in the latter part of the season, the experimental group replaced a part of the normal regimen (the tactical session) by a biweekly course of PTP (hurdle and drop jumps). Two familiarization sessions were held 2 weeks before definitive testing. The ability of the players was assessed by 3 agility tests (a sprint test with 180° turns, a 9-3-6-3-9 m sprint with backward and forward running, and a four 5-m sprint test with turns); 2 repeated sprint tests (RSSA and RCOD); and running times over 5-, 10-, 20-, 30-, and 40-m distances. Participants in E showed gains relative to C in sprint times (p ≤ 0.05 for 5, 10, and 20 m), and 2 of 3 the RCOD parameters (RCOD best, p ≤ 0.001; RCOD total, p ≤ 0.05). However, with the pattern of plyometric training that we adopted, and perhaps because participants were in good initial physical condition, the agility and RSSA test scores remained unchanged. Nevertheless, we conclude that our PTP can be commended to junior soccer players as a means of improving

  19. Enhanced 400-m sprint performance in moderately trained participants by a 4-day alkalizing diet: a counterbalanced, randomized controlled trial.

    Science.gov (United States)

    Limmer, Mirjam; Eibl, Angi Diana; Platen, Petra

    2018-05-31

    Sodium bicarbonate (NaHCO 3 ) is an alkalizing agent and its ingestion is used to improve anaerobic performance. However, the influence of alkalizing nutrients on anaerobic exercise performance remains unclear. Therefore, the present study investigated the influence of an alkalizing versus acidizing diet on 400-m sprint performance, blood lactate, blood gas parameters, and urinary pH in moderately trained adults. In a randomized crossover design, eleven recreationally active participants (8 men, 3 women) aged 26.0 ± 1.7 years performed one trial under each individual's unmodified diet and subsequently two trials following either 4 days of an alkalizing (BASE) or acidizing (ACID) diet. Trials consisted of 400-m runs at intervals of 1 week on a tartan track in a randomized order. We found a significantly lower 400-m performance time for the BASE trial (65.8 ± 7.2 s) compared with the ACID trial (67.3 ± 7.1 s; p = 0.026). In addition, responses were significantly higher following the BASE diet for blood lactate (BASE: 16.3 ± 2.7; ACID: 14.4 ± 2.1 mmol/L; p = 0.32) and urinary pH (BASE: 7.0 ± 0.7; ACID: 5.5 ± 0.7; p = 0.001). We conclude that a short-term alkalizing diet may improve 400-m performance time in moderately trained participants. Additionally, we found higher blood lactate concentrations under the alkalizing diet, suggesting an enhanced blood or muscle buffer capacity. Thus, an alkalizing diet may be an easy and natural way to enhance 400-m sprint performance for athletes without the necessity of taking artificial dietary supplements.

  20. Effects of in-season short-term aerobic and high-intensity interval training program on repeated sprint ability and jump performance in handball players.

    Science.gov (United States)

    Hermassi, Souhail; Ingebrigtsen, Jørgen; Schwesig, René; Fieseler, Georg; Delank, Karl-Stefan; Chamari, Karim; Shephard, Roy J; Chelly, Mohamed-Souhaiel

    2018-01-01

    This study examined the effects of a 7-week in-season aerobic and high-intensity interval-training program on performance tests linked to successful handball play (e.g., repeated sprint and jumping ability). Thirty participants (age 17.0±1.2 years, body mass 81.1±3.4 kg, height 1.82±0.07 m) performed a Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), a squat (SJ) and a Countermovement Jump Test (CMJ), as well as a repeated Sprint Ability Test (RSA). From this, maximal aerobic speed (MAS, reached at the end of the Yo-Yo IR1), jumping ability, best time in a single sprint trial (RSAbest), total time (RSATT) and the performance decrement (RSAdec) during all sprints were calculated. Later, subjects were randomly assigned to a control group (CG; N.=15) performing their normal training schedule (5 weekly sessions of ~90 minutes of handball training) or an experimental group (EG; N.=15). The EG performed two 30 min sessions per week of high-intensity aerobic exercises at 100-130% of MAS in addition to their normal training schedule. A significant improvement in MAS (d=4.1), RSAbest (d=1.9), RSATT (d=1.5) and RSAdec (d=2.3) after the training period was demonstrated. Also, significant interaction effects (time x group) were found for all parameters as the EG significantly improved performances in all tests after training. The greatest interaction effects were observed in MAS (η2=0.811) and CMJ (η2=0.759). No relevant changes in test performances were found in the CG (mean d=-0.02). These results indicate that individually speed-controlled aerobic and interval training is effective for improving specific handball performance.

  1. The Effects of Caffeine, Taurine, or Caffeine-Taurine Coingestion on Repeat-Sprint Cycling Performance and Physiological Responses.

    Science.gov (United States)

    Warnock, Rory; Jeffries, Owen; Patterson, Stephen; Waldron, Mark

    2017-11-01

    To investigate the effects of caffeine (C), taurine (T), caffeine and taurine coingestion (C +T), or placebo (P) on repeated Wingate cycling performance and associated physiological responses. Seven male team-sport players participated in a randomized, single-blind, crossover study, where they completed 3 Wingate tests, each separated by 2 min, an hour after ingesting: C (5 mg/kg body mass [BM]), T (50 mg/kg BM), C +T (5 mg/kg BM + 50 mg/kg BM), or P (5 mg/kg BM) in a gelatin capsule. Performance was measured on an ergometer, and blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP), and rate pressure product (RPP) were measured at rest (presupplement), baseline (1 h postsupplement), and during and after exercise. Magnitude-based inferences revealed that all of the supplements increased (small to moderate, likely to very likely) mean peak power (MPP), peak power (PP), and mean power (MP) compared to P, with greater MPP, PP, and MP in T compared to C (small, possible). Intrasprint fatigue index (%FI Intra ) was greater in T compared to P and C (moderate, likely), and %FI Inter was lower in T compared to C (small, possible). C and C +T increased HR, MAP, and RPP compared to P and T at baseline (moderate to very large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint. T elicited greater improvements in performance compared to P, C, or C +T while reducing the typical chronotropic and pressor effects of C.

  2. Sprint performance and propulsion asymmetries on an ergometer in trained high- and low-point wheelchair rugby players

    NARCIS (Netherlands)

    Goosey-Tolfrey, Victoria L; Vegter, Riemer J K; Mason, Barry S; Paulson, Thomas A W; Lenton, John P; van der Scheer, Jan W; van der Woude, Lucas H V

    The purpose of this study was to examine the propulsion asymmetries of wheelchair athletes while sprinting on an instrumented, dual-roller ergometer system. Eighteen experienced wheelchair rugby players (8 low point (LP) (class 1.5) and 10 high point (HP) (class 2.0)) performed a 15-second sprint in

  3. Solar Sprint

    Science.gov (United States)

    Tabor, Richard; Anderson, Stephen

    2007-01-01

    In the "Solar Sprint" activity, students design, test, and race a solar-powered car built with Legos. The use of ratios is incorporated to simulate the actual work of scientists and engineers. This method encourages fourth-grade students to think about multiple variables and stimulates their curiosity when an activity doesn't come out as…

  4. Repeated supra-maximal sprint cycling with and without sodium bicarbonate supplementation induces endothelial microparticle release.

    Science.gov (United States)

    Kirk, Richard J; Peart, Daniel J; Madden, Leigh A; Vince, Rebecca V

    2014-01-01

    Under normal homeostatic conditions, the endothelium releases microparticles (MPs), which are known to increase under stressful conditions and in disease states. CD105 (endoglin) and CD106 (vascular cell adhesion molecule-1) are expressed on the surface of endothelial cells and increased expression in response to stress may be observed. A randomised-controlled double-blinded study aimed to examine the use of endothelial MPs as a marker for the state of one's endothelium, as well as whether maintaining acid-base homeostasis affects the release of these MPs. This study tested seven healthy male volunteers, who completed a strenuous cycling protocol, with venous blood analysed for CD105+ and CD106+ MPs by flow cytometry at regular intervals. Prior to each trial participants consumed either 0.3 g·kg(-1) body mass of sodium bicarbonate (NaHCO3), or 0.045 g·kg(-1) body mass of sodium chloride (NaCl). A significant rise in endothelial CD105+ MPs and CD106+ MPs (p<0.05) was observed at 90 min post-exercise. A significant trend was shown for these MPs to return to resting levels 180 min post-exercise in both groups. No significance was found between experimental groups, suggesting that maintaining acid-base variables closer to basal levels has little effect upon the endothelial stress response for this particular exercise mode. In conclusion, strenuous exercise is accompanied by MP release and the endothelium is able to rapidly recover in healthy individuals, whilst maintaining acid-base homeostasis does not attenuate the MP release from the endothelium after exercise.

  5. EFFECTS OF COMBINED FOOT/ANKLE ELECTROMYOSTIMULATION AND RESISTANCE TRAINING ON THE IN-SHOE PLANTAR PRESSURE PATTERNS DURING SPRINT IN YOUNG ATHLETES

    Directory of Open Access Journals (Sweden)

    François Fourchet

    2011-06-01

    Full Text Available Several studies have already reported that specific foot/ankle muscle reinforcement strategies induced strength and joint position sense performance enhancement. Nevertheless the effects of such protocols on sprint performance and plantar loading distribution have not been addressed yet. The objective of the study is to investigate the influence of a 5-wk foot/ankle strength training program on plantar loading characteristics during sprinting in adolescent males. Sixteen adolescent male athletes of a national training academy were randomly assigned to either a combined foot/ankle electromyostimulation and resistance training (FAST or a control (C group. FAST consisted of foot medial arch and extrinsic ankle muscles reinforcement exercises, whereas C maintained their usual training routine. Before and after training, in-shoe loading patterns were measured during 30-m running sprints using pressure sensitive insoles (right foot and divided into nine regions for analysis. Although sprint times remained unchanged in both groups from pre- to post- training (3.90 ± 0.32 vs. 3.98 ± 0.46 s in FAST and 3.83 ± 0.42 vs. 3.81 ± 0.44 s in C, changes in force and pressure appeared from heel to forefoot between FAST and C. In FAST, mean pressure and force increased in the lateral heel area from pre- to post- training (67.1 ± 44.1 vs. 82.9 ± 28.6 kPa [p = 0.06]; 25.5 ± 17.8 vs. 34.1 ± 14.3 N [p = 0.05] and did not change in the medial forefoot (151.0 ± 23.2 vs. 146.1 ± 30.0 kPa; 142.1 ± 29.4 vs. 136.0 ± 33.8; NS. Mean area increased in FAST under the lateral heel from pre- to post- (4.5 ± 1.3 vs. 5.7 ± 1.6 cm2 [p < 0.05] and remained unchanged in C (5.5 ± 2.8 vs. 5.0 ± 3.0 cm2. FAST program induced significant promising lateral and unwanted posterior transfer of the plantar loads without affecting significantly sprinting performance

  6. Effects of In-Season Explosive Strength Training on Maximal Leg Strength, Jumping, Sprinting, and Intermittent Aerobic Performance in Male Handball Athletes.

    Science.gov (United States)

    Hermassi, Souhail; Chelly, Mohamed Souhaiel; Fieseler, Georg; Bartels, Thomas; Schulze, Stephan; Delank, Karl-Stefan; Shephard, Roy J; Schwesig, René

    2017-09-01

    Background  Team handball is an intense ball sport with specific requirements on technical skills, tactical understanding, and physical performance. The ability of handball players to develop explosive efforts (e. g. sprinting, jumping, changing direction) is crucial to success. Objective  The purpose of this pilot study was to examine the effects of an in-season high-intensity strength training program on the physical performance of elite handball players. Materials and methods  Twenty-two handball players (a single national-level Tunisian team) were randomly assigned to a control group (CG; n = 10) or a training group (TG; n = 12). At the beginning of the pilot study, all subjects performed a battery of motor tests: one repetition maximum (1-RM) half-squat test, a repeated sprint test [6 × (2 × 15 m) shuttle sprints], squat jumps, counter movement jumps (CMJ), and the Yo-Yo intermittent recovery test level 1. The TG additionally performed a maximal leg strength program twice a week for 10 weeks immediately before engaging in regular handball training. Each strength training session included half-squat exercises to strengthen the lower limbs (80 - 95 % of 1-RM, 1 - 3 repetitions, 3 - 6 sets, 3 - 4 min rest between sets). The control group underwent no additional strength training. The motor test battery was repeated at the end of the study interventions. Results  In the TG, 3 parameters (maximal strength of lower limb: η² = 0.74; CMJ: η² = 0.70, and RSA best time: η² = 0.25) showed significant improvements, with large effect sizes (e. g. CMJ: d = 3.77). A reduction in performance for these same 3 parameters was observed in the CG (d = -0.24). Conclusions  The results support our hypothesis that additional strength training twice a week enhances the maximal strength of the lower limbs and jumping or repeated sprinting performance. There was no evidence of shuttle sprints ahead of regular

  7. Effects of small-sided games and high-intensity interval training on aerobic and repeated sprint performance and peripheral muscle oxygenation changes in elite junior basketball players.

    Science.gov (United States)

    Delextrat, A; Gruet, M; Bieuzen, F

    2018-03-06

    The aim of the current study was to compare the effects of 6 weeks of small-sided game (SSG) and high-intensity interval training (HIIT) on aerobic fitness and muscle oxygenation during a repeated sprint (RS) sequence in elite male junior basketball players. Twenty participants (14.3 ± 0.5 years; 176.8 ± 12.5 cm; 74.5 ± 9.8 kg) performed pre- and post-tests interspersed by 6-weeks of SSG or HIIT training. Testing sessions consisted of the 30-15 Intermittent Fitness Test and a RS sequence (two bouts of 15-s). During RS, muscle oxygenation parameters (tissue saturation index (TSI, %), post-sprint muscle reoxygenation rate) were measured by near-infrared spectroscopy (NIRS). The results showed that both training interventions similarly improved maximal aerobic speed (VIFT, 3.4 and 4.1%, respectively for HIIT and SSG, Ptraining interventions also resulted in a greater ΔTSI during the second sprint (47.8% to 114%, Ptrainings are applicable methodologies to improve in-season aerobic and anaerobic fitness capacities in junior basketball players.

  8. Bases of technique of sprinting

    Directory of Open Access Journals (Sweden)

    Valeriy Druz

    2015-06-01

    Full Text Available Purpose: to determine the biomechanical consistent patterns of a movement of a body providing the highest speed of sprinting. Material and Methods: the analysis of scientific and methodical literature on the considered problem, the anthropometrical characteristics of the surveyed contingent of sportsmen, the analysis of high-speed shootings of the leading runners of the world. Results: the biomechanical bases of technique of sprinting make dispersal and movement of the general center of body weight of the sportsman on a parabolic curve in a start phase taking into account the initial height of its stay in a pose of a low start. Its further movement happens on a cycloidal trajectory which is formed due to a pendulum movement of the extremities creating the lifting power which provides flight duration more in a running step, than duration of a basic phase. Conclusions: the received biomechanical regularities of technique of sprinting allow increasing the efficiency of training of sportsmen in sprinting.

  9. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning

    Directory of Open Access Journals (Sweden)

    Bahri Gjinovci, Kemal Idrizovic, Ognjen Uljevic, Damir Sekulic

    2017-12-01

    Full Text Available There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg, who participated in plyometric- (n = 21, or skill-based-conditioning-program (n = 20. Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM, countermovement jump (CMJ, standing broad jump (SBJ, medicine ball throw, (MBT and 20-m sprint (S20M. All tests were assessed at the study baseline (pre- and at the end of the 12-week programs (post-testing. Two-way ANOVA for repeated measurements showed significant (p<0.05 “Group x Time” effects for all variables but body-height. Plyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes, and improved their performance in S20M (moderate ES; 8%, MBT (very large ES; 25%, CMJ (large ES; 27%, and SBJ (moderate ES; 8%. Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%, SBJ (small ES; 3%, and MBT (large ES; 9%. The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  10. Plyometric Training Improves Sprinting, Jumping and Throwing Capacities of High Level Female Volleyball Players Better Than Skill-Based Conditioning.

    Science.gov (United States)

    Gjinovci, Bahri; Idrizovic, Kemal; Uljevic, Ognjen; Sekulic, Damir

    2017-12-01

    There is an evident lack of studies on the effectiveness of plyometric- and skill-based-conditioning in volleyball. This study aimed to evaluate effects of 12-week plyometric- and volleyball-skill-based training on specific conditioning abilities in female volleyball players. The sample included 41 high-level female volleyball players (21.8 ± 2.1 years of age; 1.76 ± 0.06 cm; 60.8 ± 7.0 kg), who participated in plyometric- (n = 21), or skill-based-conditioning-program (n = 20). Both programs were performed twice per week. Participants were tested on body-height, body-mass (BM), countermovement jump (CMJ), standing broad jump (SBJ), medicine ball throw, (MBT) and 20-m sprint (S20M). All tests were assessed at the study baseline (pre-) and at the end of the 12-week programs (post-testing). Two-way ANOVA for repeated measurements showed significant (pPlyometric group significantly reduced body-mass (trivial effect size [ES] differences; 1% average pre- to post-measurement changes), and improved their performance in S20M (moderate ES; 8%), MBT (very large ES; 25%), CMJ (large ES; 27%), and SBJ (moderate ES; 8%). Players involved in skill-based-conditioning significantly improved CMJ (large ES; 18%), SBJ (small ES; 3%), and MBT (large ES; 9%). The changes which occurred between pre- and post-testing were more inter-correlated in plyometric-group. Although both training-modalities induced positive changes in jumping- and throwing-capacities, plyometric-training is found to be more effective than skill-based conditioning in improvement of conditioning capacities of female senior volleyball players. Future studies should evaluate differential program effects in less experienced and younger players.

  11. Living at high altitude in combination with sea-level sprint training increases hematological parameters but does not improve performance in rats.

    Science.gov (United States)

    Martinez-Bello, Vladimir Essau; Sanchis-Gomar, Fabian; Nascimento, Ana Lucia; Pallardo, Federico V; Ibañez-Sania, Sandra; Olaso-Gonzalez, Gloria; Calbet, Jose Antonio; Gomez-Cabrera, Mari Carmen; Viña, Jose

    2011-06-01

    The regimen of aerobic training at sea level with recovery at high altitude has been used by athletes to improve performance. However, little is known about the effects of hypoxia when combined with sprint interval training on performance. The aim of the present study was to determine the effect of a "living high-sprint training low" strategy on hemoglobin, hematocrit and erythropoietin levels in rats. We also wanted to test whether the addition of a hypoxic stress to the program of daily treadmill running at high speeds induces expressional adaptations in skeletal muscle and affects performance. The protein content of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), cytochrome C, pyruvate dehydrogenase kinase (PDK1), heat shock protein 70 (HSP70), manganese superoxide dismutase (MnSOD) and citrate synthase activity were determined in different muscle fiber types in our animals (red and white gastrocnemius muscle). We also determined the maximal aerobic velocity (MAV) before and after the training period. A total of 24 male Wistar rats (3 month old) were randomly divided into four experimental groups: the normoxic control group (n = 6), the normoxic trained group (n = 6), the hypoxic control group (12 h pO(2) 12%/12 h pO(2) 21%) (n = 6) and the hypoxic trained group (12 h pO(2) 12%/12 h pO(2) 21%). Living in normobaric hypoxia condition for 21 days significantly increased hemoglobin, hematocrit and erythropoietin levels in both the rest and the trained groups. The trained animals (normoxia and hypoxia) significantly increased their maximal aerobic velocity. No changes were found in the skeletal muscle in PGC-1α, cytochrome C, PDK1, HSP70, MnSOD protein content and in the citrate synthase activity in any experimental group. Regardless of whether it is combined with sprint interval training or not, after 21 days of living at high altitude we found a significant increase in the hematological values determined in our study. However, contrary to

  12. Sex differences in the effects of 12 weeks sprint interval training on body fat mass and the rates of fatty acid oxidation and VO2max during exercise.

    Science.gov (United States)

    Bagley, Liam; Slevin, Mark; Bradburn, Steven; Liu, Donghui; Murgatroyd, Chris; Morrissey, George; Carroll, Michael; Piasecki, Mathew; Gilmore, William S; McPhee, Jamie S

    2016-01-01

    The purpose of this study was to examine whether very short duration, very high intensity sprint interval training (SIT) leads to loss of body fat mass in association with improvements to VO 2 max and fatty acid oxidation, and to assess the extent of sex dimorphism in these physiological responses. A total of 24 men and 17 women (mean (SEM) age: 39 (±2) years; body mass index 24.6 (0.6)) completed measurements of the maximal rate of oxygen uptake (VO 2 max) and fatty acid oxidation (FATmax). Body fat and lean mass were measured by dual emission x-ray absorptiometry, and fasting blood lipid, glucose and insulin profiles were assessed before and after training. SIT consisted of 4×20 s sprints on a cycle ergometer at approximately 175% VO 2 max, three times per week for 12 weeks. Fat mass decreased by 1.0 kg, although men lost statistically significantly more fat than women both when expressed in Kg and as % body fat. VO 2 max increased by around 9%, but women improved VO 2 max significantly more than men. FATmax improved by around 13%, but fasting plasma glucose, insulin, total triglyceride, total cholesterol and high-density lipoprotein (HDL) did not change after training, while low-density lipoprotein decreased by 8% (p=0.028) and the HDL:Total Cholesterol ratio improved by 6%. There were no sex differences in these metabolic responses to training. These results show lower body fat %, and higher rates of fatty acid oxidation and VO 2 max after 12 weeks of training for just 4 min per week. Notably, women improved VO 2 max more than men, while men lost more fat than women.

  13. Sex differences in the effects of 12 weeks sprint interval training on body fat mass and the rates of fatty acid oxidation and VO2max during exercise

    Science.gov (United States)

    Bagley, Liam; Slevin, Mark; Bradburn, Steven; Liu, Donghui; Murgatroyd, Chris; Morrissey, George; Carroll, Michael; Piasecki, Mathew; Gilmore, William S; McPhee, Jamie S

    2016-01-01

    Background The purpose of this study was to examine whether very short duration, very high intensity sprint interval training (SIT) leads to loss of body fat mass in association with improvements to VO2max and fatty acid oxidation, and to assess the extent of sex dimorphism in these physiological responses. Methods A total of 24 men and 17 women (mean (SEM) age: 39 (±2) years; body mass index 24.6 (0.6)) completed measurements of the maximal rate of oxygen uptake (VO2max) and fatty acid oxidation (FATmax). Body fat and lean mass were measured by dual emission x-ray absorptiometry, and fasting blood lipid, glucose and insulin profiles were assessed before and after training. SIT consisted of 4×20 s sprints on a cycle ergometer at approximately 175% VO2max, three times per week for 12 weeks. Results Fat mass decreased by 1.0 kg, although men lost statistically significantly more fat than women both when expressed in Kg and as % body fat. VO2max increased by around 9%, but women improved VO2max significantly more than men. FATmax improved by around 13%, but fasting plasma glucose, insulin, total triglyceride, total cholesterol and high-density lipoprotein (HDL) did not change after training, while low-density lipoprotein decreased by 8% (p=0.028) and the HDL:Total Cholesterol ratio improved by 6%. There were no sex differences in these metabolic responses to training. Conclusions These results show lower body fat %, and higher rates of fatty acid oxidation and VO2max after 12 weeks of training for just 4 min per week. Notably, women improved VO2max more than men, while men lost more fat than women. PMID:27900150

  14. Improvement of Repeated-Sprint Ability and Horizontal-Jumping Performance in Elite Young Basketball Players With Low-Volume Repeated-Maximal-Power Training.

    Science.gov (United States)

    Gonzalo-Skok, Oliver; Tous-Fajardo, Julio; Arjol-Serrano, José Luis; Suarez-Arrones, Luis; Casajús, José Antonio; Mendez-Villanueva, Alberto

    2016-05-01

    To examine the effects of a low-volume repeated-power-ability (RPA) training program on repeated-sprint and change-of- direction (COD) ability and functional jumping performance. Twenty-two male elite young basketball players (age 16.2 ± 1.2 y, height 190.0 ± 10.0 cm, body mass 82.9 ± 10.1 kg) were randomly assigned either to an RPA-training group (n = 11) or a control group (n = 11). RPA training consisted of leg-press exercise, twice a week for 6 wk, of 1 or 2 blocks of 5 sets × 5 repetitions with 20 s of passive recovery between sets and 3 min between blocks with the load that maximized power output. Before and after training, performance was assessed by a repeated-sprint-ability (RSA) test, a repeated-COD-ability test, a hop for distance, and a drop jump followed by tests of a double unilateral hop with the right and left legs. Within-group and between-groups differences showed substantial improvements in slowest (RSAs) and mean time (RSAm) on RSA; best, slowest and mean time on repeated-COD ability; and unilateral right and left hop in the RPA group in comparison with control. While best time on RSA showed no improvement in any group, there was a large relationship (r = .68, 90% CI .43;.84) between the relative decrement in RSAm and RSAs, suggesting better sprint maintenance with RPA training. The relative improvements in best and mean repeated-COD ability were very largely correlated (r = .89, 90% CI .77;.94). Six weeks of lowvolume (4-14 min/wk) RPA training improved several physical-fitness tests in basketball players.

  15. Isolated core training improves sprint performance in national-level junior swimmers.

    Science.gov (United States)

    Weston, Matthew; Hibbs, Angela E; Thompson, Kevin G; Spears, Iain R

    2015-03-01

    To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming. Twenty national-level junior swimmers (10 male and 10 female, 16±1 y, 171±5 cm, 63±4 kg) participated in the study. Group allocation (intervention [n=10], control [n=10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function. Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (-2.0%; 90% confidence interval -3.8 to -0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1-16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7-33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction. This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance.

  16. Effects of In-Season Short-term Plyometric Training Program on Sprint and Jump Performance of Young Male Track Athletes.

    Science.gov (United States)

    Chelly, Mohamed Souhaiel; Hermassi, Souhail; Shephard, Roy J

    2015-08-01

    We studied the effect of supplementing normal in-season training by a 10-week lower limb plyometric training program (hurdle and depth jumping), examining measures of competitive potential (peak power output [PP], sprint running velocity, squat jump [SJ], countermovement jump [CMJ], drop jump [DJ], and lower limb muscle volume). The subjects (27 male track athletes, aged 11.9 ± 1.0 years; body mass: 39.1 ± 6.1 kg; height: 1.56 ± 0.02 m; body fat: 12.8 ± 4.4%) were randomly assigned between a control (normal training) group (C; n = 13) and an experimental group (E; n = 14) who also performed plyometric training 3 times per week. A force-velocity ergometer test determined PP and SJ, and an Optojump apparatus evaluated CMJ height and DJ (height and power). A multiple-5-bound test assessed horizontal jumping, and video-camera analyses over a 40-m sprint yielded velocities for the first step (VS), the first 5 m (V5m), and between 35 and 40 m (Vmax). Leg muscle volume was estimated anthropometrically. Experimental group showed gains relative to C in SJ height (p plyometric training improved important components of athletic performance relative to standard in-season training in young runners.

  17. Effects of Pre - Season Short - Term Daily Undulating Periodized Training on Muscle Strength and Sprint Performance of Under - 20 Soccer Players

    Directory of Open Access Journals (Sweden)

    Charles Ricardo L OPES

    2015-06-01

    Full Text Available The aim of this study was to evaluate the effects of daily undulating training periodization designed for maximal lower limb muscle strength and sprint performance in under - 20 soccer players. Twenty - four male athletes (age = 19.1 ± 1.2 yr; mass = 71.1 ± 6. 8 kg; height = 178.0 ± 0.1 cm participated in four weeks of a daily undulating periodized (DUP training soccer program. During the pre - and post - training periods the subjects performed a one repetition maximum (1 RM half back squat test and a 15 - meter s print. Significant training - induced changes were observed in sprint times (pre = 2.38 ± 0.01 s; post = 2.31 ± 0.02 s and 1 RM tests (pre = 107.0 ± 2.0 kg; post = 128.0 ± 2.2 kg. These results indicate that a DUP program is efficient in promoting positive neuromuscular adaptations in soccer players, even with a short - term preseason training period.

  18. Regulators of human white adipose browning: evidence for sympathetic control and sexual dimorphic responses to sprint interval training.

    Directory of Open Access Journals (Sweden)

    Rebecca L Scalzo

    Full Text Available The conversion of white adipose to the highly thermogenic beige adipose tissue has been proposed as a potential strategy to counter the unfavorable consequences of obesity. Three regulators of this conversion have recently emerged but information regarding their control is limited, and contradictory. We present two studies examining the control of these regulators. Study 1: In 10 young men, the plasma concentrations of irisin and fibroblast growth factor 21 (FGF21 were determined prior to and during activation of the sympathetic nervous system via hypoxic gas breathing (FIO2 = 0.11. The measurements were performed twice, once with and once without prior/concurrent sympathetic inhibition via transdermal clonidine administration. FGF21 was unaffected by basal sympathetic inhibition (338±113 vs. 295±80 pg/mL; P = 0.43; mean±SE, but was increased during hypoxia mediated sympathetic activation (368±135; this response was abrogated (P = 0.035 with clonidine (269±93. Irisin was unaffected by sympathetic inhibition and/or hypoxia (P>0.21. Study 2: The plasma concentration of irisin and FGF21, and the skeletal muscle protein content of fibronectin type III domain containing 5 (FNDC5 was determined in 19 young adults prior to and following three weeks of sprint interval training (SIT. SIT decreased FGF21 (338±78 vs. 251±36; P = 0.046 but did not affect FNDC5 (P = 0.79. Irisin was decreased in males (127±18 vs. 90±23 ng/mL; P = 0.045 and increased in females (139±14 vs. 170±18. Collectively, these data suggest a potential regulatory role of acute sympathetic activation pertaining to the browning of white adipose; further, there appears to be a sexual dimorphic response of irisin to SIT.

  19. Influence of training intensity on adaptations in acid/base transport proteins, muscle buffer capacity, and repeated-sprint ability in active men.

    Science.gov (United States)

    McGinley, Cian; Bishop, David J

    2016-12-01

    McGinley C, Bishop DJ. Influence of training intensity on adaptations in acid/base transport proteins, muscle buffer capacity, and repeated-sprint ability in active men. J Appl Physiol 121: 1290-1305, 2016. First published October 14, 2016; doi:10.1152/japplphysiol.00630.2016-This study measured the adaptive response to exercise training for each of the acid-base transport protein families, including providing isoform-specific evidence for the monocarboxylate transporter (MCT)1/4 chaperone protein basigin and for the electrogenic sodium-bicarbonate cotransporter (NBCe)1. We investigated whether 4 wk of work-matched, high-intensity interval training (HIIT), performed either just above the lactate threshold (HIITΔ20; n = 8), or close to peak aerobic power (HIITΔ90; n = 8), influenced adaptations in acid-base transport protein abundance, nonbicarbonate muscle buffer capacity (βm in vitro ), and exercise capacity in active men. Training intensity did not discriminate between adaptations for most proteins measured, with abundance of MCT1, sodium/hydrogen exchanger (NHE) 1, NBCe1, carbonic anhydrase (CA) II, and CAXIV increasing after 4 wk, whereas there was little change in CAIII and CAIV abundance. βm in vitro also did not change. However, MCT4 protein content only increased for HIITΔ20 [effect size (ES): 1.06, 90% confidence limits × / ÷ 0.77], whereas basigin protein content only increased for HIITΔ90 (ES: 1.49, × / ÷ 1.42). Repeated-sprint ability (5 × 6-s sprints; 24 s passive rest) improved similarly for both groups. Power at the lactate threshold only improved for HIITΔ20 (ES: 0.49; 90% confidence limits ± 0.38), whereas peak O 2 uptake did not change for either group. Detraining was characterized by the loss of adaptations for all of the proteins measured and for repeated-sprint ability 6 wk after removing the stimulus of HIIT. In conclusion, 4 wk of HIIT induced improvements in each of the acid-base transport protein families, but, remarkably, a 40

  20. Poorer Intermittent Sprints Performance in Ramadan-Fasted Muslim Footballers despite Controlling for Pre-Exercise Dietary Intake, Sleep and Training Load

    Science.gov (United States)

    Aziz, Abdul Rashid; Che Muhamad, Ahmad Munir; Roslan, Siti Raifana; Ghulam Mohamed, Nazirah; Singh, Rabindarjeet; Chia, Michael Yong Hwa

    2017-01-01

    This study examines the effects of Ramadan fasting on sprint performance during prolonged intermittent exercise in trained Muslim footballers, under controlled pre-exercise conditions. A within-group, cross-over study design with two non-fasted or Control trials performed before (i.e., CON1) and after (CON2) the Ramadan month, and with the Ramadan-fasted (RAM) trials performed within the Ramadan month. After familiarization, 14 players completed a modified 60-min (4 × 15-min exercise blocks interspersed with 3-min intervals) of the Loughborough Intermittent Shuttle Test (mLIST) of fixed speeds of walking, jogging, running, but with all-out effort sprints. During the interval periods, capillary blood glucose and blood lactate measures were taken, rectal and skin temperatures were recorded and maximal voluntary isometric contractions (MVIC) of the dominant leg and hand-grip were performed to provide some indication to the cause(s) of ‘fatigue’ during exercise. Players were provided with standardized 24-h pre-packed meals prior to all trials. Sleep hours were objectively assessed and perceived training loads were monitored and these were equivalent between RAM and CON trials. Sprint times throughout mLIST were significantly faster in both CON1 and CON2 as compared to RAM trials (all P performance in RAM was observed as early as during the first 15-min of the mLIST. Blood markers, MVIC and thermoregulatory results were not substantially different between both CON and RAM trials. In conclusion, despite similarities in dietary intake, sleeping hours and training loads between conditions, results still indicate that Ramadan fasting had an adverse effect on prolonged intermittent performance. Nocebo effects plays a dominant role during exercise in the Ramadan-fasted state. PMID:29910364

  1. Poorer Intermittent Sprints Performance in Ramadan-Fasted Muslim Footballers despite Controlling for Pre-Exercise Dietary Intake, Sleep and Training Load

    Directory of Open Access Journals (Sweden)

    Abdul Rashid Aziz

    2017-01-01

    Full Text Available This study examines the effects of Ramadan fasting on sprint performance during prolonged intermittent exercise in trained Muslim footballers, under controlled pre-exercise conditions. A within-group, cross-over study design with two non-fasted or Control trials performed before (i.e., CON1 and after (CON2 the Ramadan month, and with the Ramadan-fasted (RAM trials performed within the Ramadan month. After familiarization, 14 players completed a modified 60-min (4 × 15-min exercise blocks interspersed with 3-min intervals of the Loughborough Intermittent Shuttle Test (mLIST of fixed speeds of walking, jogging, running, but with all-out effort sprints. During the interval periods, capillary blood glucose and blood lactate measures were taken, rectal and skin temperatures were recorded and maximal voluntary isometric contractions (MVIC of the dominant leg and hand-grip were performed to provide some indication to the cause(s of ‘fatigue’ during exercise. Players were provided with standardized 24-h pre-packed meals prior to all trials. Sleep hours were objectively assessed and perceived training loads were monitored and these were equivalent between RAM and CON trials. Sprint times throughout mLIST were significantly faster in both CON1 and CON2 as compared to RAM trials (all P < 0.017; d = small to moderate, and this poorer performance in RAM was observed as early as during the first 15-min of the mLIST. Blood markers, MVIC and thermoregulatory results were not substantially different between both CON and RAM trials. In conclusion, despite similarities in dietary intake, sleeping hours and training loads between conditions, results still indicate that Ramadan fasting had an adverse effect on prolonged intermittent performance. Nocebo effects plays a dominant role during exercise in the Ramadan-fasted state.

  2. Training development in Juzbado's Fuel Cycle Facility

    International Nuclear Information System (INIS)

    Perez, A.; Cunado, E.; Ortiz, D.

    2003-01-01

    In Juzbado's fuel cycle facility, because of the special activities developed, training is a very important issues. Training has been evolved, due to changes on the standards applicable each moment, and also due to the technological resources available. Both aspects have resulted in an evolution of the documents referred to training, such as training programs procedures, Radiation Protection Manual as well as the teaching methods. In the report we are going to present, we will show more precisely the changes that take place, referring to the different training methods used, present training sanitations, and the improvements already planned in training subjects as well as tools used, accomplishing with the legislation and improving in our effort of a better assimilation of the necessary knowledge. (Author)

  3. Effects of coffee and caffeine anhydrous on strength and sprint performance.

    Science.gov (United States)

    Trexler, Eric T; Smith-Ryan, Abbie E; Roelofs, Erica J; Hirsch, Katie R; Mock, Meredith G

    2016-09-01

    Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300 mg flat dose; yielding 3-5 mg/kg bodyweight), COF (8.9 g; 303 mg caffeine), or placebo (PLA; 3.8 g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p = .04), but not PLA (p = .99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p > .05). There were no sprint × treatment interactions for PP or TW (p > .05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.

  4. Short-Term Effects of Combined High-Intensity Strength and Sprint Interval Training on Anthropometric Characteristics and Physical Performance of Elite Team Handball Players.

    Science.gov (United States)

    Hermassi, Souhail; Chelly, Mohamed Souhail; Fieseler, Georg; Bartels, Thomas; Schulze, Stephan; Delank, Karl-Stefan; Shepard, Roy J; Schwesig, René

    2017-12-01

    Muscular strength and speed are critical physical factors in determining the technical and tactical skills of elite team handball players. This study thus investigated the effect of high-intensity muscular strength and sprint interval training (SIT) on lower limb explosive performance and anthropometric characteristics in 22 male handball athletes aged 20.2 ± 0.1 years. A training group (TG, n = 12) and a control group (CG, n = 10) were followed over 8 weeks parallel to regular handball training. The TG received combined additional high-intensity muscular strength and interval training twice per week during this period. The muscular training was comprised of 3 - 4 sets of 70 - 85 % of 1-RM (repetition maximum) of dynamic back half squat exercise; followed immediately by a short sprint program with 4, 5, and 6 maximal intensity repetitions of 30 m runs. Strength (1-RM of the half back-squat and bench press), first step (V1S), first 5 m (V5 m), squat jumps (SJ), counter movement jumps (CMJ) and the Modified Agility Test (MAT) were tested at the beginning and end of the study. Significant interaction effects (group × time) were observed for all parameters (η² range: 0.531 (MAT) to 0.829 (First 5 m)). All 10 parameters showed relevant intervention effects (d> 0.5) in the TG (highest intervention effect: CMJ: d = 4.05), the mean effect size being d = 1.85. In contrast, scores for the CG either remained unchanged or decreased (d = -0.24). We conclude that combined high-intensity strength and sprint interval training during the competitive season should be recommended to elite male handball players as a means of improving handball-related performance characteristics without compromising other critical aspects of the individual's performance. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Muscle activity in sprinting: a review.

    Science.gov (United States)

    Howard, Róisín M; Conway, Richard; Harrison, Andrew J

    2018-03-01

    The use of electromyography (EMG) is widely recognised as a valuable tool for enhancing the understanding of performance drivers and potential injury risk in sprinting. The timings of muscle activations relative to running gait cycle phases and the technology used to obtain muscle activation data during sprinting are of particular interest to scientists and coaches. This review examined the main muscles being analysed by surface EMG (sEMG), their activations and timing, and the technologies used to gather sEMG during sprinting. Electronic databases were searched using 'Electromyography' OR 'EMG' AND 'running' OR 'sprinting'. Based on inclusion criteria, 18 articles were selected for review. While sEMG is widely used in biomechanics, relatively few studies have used sEMG in sprinting due to system constraints. The results demonstrated a focus on the leg muscles, with over 70% of the muscles analysed in the upper leg. This is consistent with the use of tethered and data logging EMG systems and many sprints being performed on treadmills. Through the recent advances in wireless EMG technology, an increase in the studies on high velocity movements such as sprinting is expected and this should allow practitioners to perform the analysis in an ecologically valid environment.

  6. The effect of sprinting after each set of heavy resistance training on the running speed and jumping performance of young basketball players.

    Science.gov (United States)

    Tsimahidis, Konstantinos; Galazoulas, Christos; Skoufas, Dimitrios; Papaiakovou, Georgios; Bassa, Eleni; Patikas, Dimitrios; Kotzamanidis, Christos

    2010-08-01

    The purpose of this study was to investigate the effect of a 10-week heavy resistance combined with a running training program on the strength, running speed (RS), and vertical jump performance of young basketball players. Twenty-six junior basketball players were equally divided in 2 groups. The control (CON) group performed only technical preparation and the group that followed the combined training program (CTP) performed additionally 5 sets of 8-5 repetition maximum (RM) half squat with 1 30-m sprint after each set. The evaluation took place before training and after the 5th and 10th weeks of training. Apart from the 1RM half squat test, the 10- and 30-m running time was measured using photocells and the jump height (squat, countermovement jump, and drop jump) was estimated taking into account the flight time. The 1RM increased by 30.3 +/- 1.5% at the 10th week of training for the CTP group (p 0.05). In general, all measured parameters showed a statistically significant increase after the 5th and 10th weeks (p 0.05). This suggests that the applied CTP is beneficial for the strength, RS, and jump height of young basketball players. The observed adaptations in the CTP group could be attributed to learning factors and to a more optimal transfer of the strength gain to running and jumping performance.

  7. The Effects of a 6-Week Strength Training on Critical Velocity, Anaerobic Running Distance, 30-M Sprint and Yo-Yo Intermittent Running Test Performances in Male Soccer Players.

    Science.gov (United States)

    Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando

    2016-01-01

    The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (psoccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.

  8. Jumping and Hopping in Elite and Amateur Orienteering Athletes and Correlations to Sprinting and Running

    DEFF Research Database (Denmark)

    Hébert-Losier, Kim; Jensen, Kurt; Holmberg, Hans-Christer

    2014-01-01

    PURPOSE: Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlatio...... and rapid generation of high relative maximal forces, especially vertically. These functional measures were more closely related to sprinting and/or running abilities, indicating benefits of lower-body training in orienteering.......PURPOSE: Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlations...... with sprinting and/or running have been examined in orienteering athletes. METHODS: We investigated squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), and hopping performed by 8 elite and 8 amateur male foot-orienteering athletes (29 ± 7 y, 183 ± 5 cm, 73 ± 7 kg) and possible correlations...

  9. Effects of Sprint versus High-Intensity Aerobic Interval Training on Cross-Country Mountain Biking Performance: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Allan Inoue

    Full Text Available The current study compared the effects of high-intensity aerobic training (HIT and sprint interval training (SIT on mountain biking (MTB race simulation performance and physiological variables, including peak power output (PPO, lactate threshold (LT and onset of blood lactate accumulation (OBLA.Sixteen mountain bikers (mean ± SD: age 32.1 ± 6.4 yr, body mass 69.2 ± 5.3 kg and VO2max 63.4 ± 4.5 mL∙kg(-1∙min(-1 completed graded exercise and MTB performance tests before and after six weeks of training. The HIT (7-10 x [4-6 min--highest sustainable intensity / 4-6 min-CR100 10-15] and SIT (8-12 x [30 s--all-out intensity / 4 min--CR100 10-15] protocols were included in the participants' regular training programs three times per week.Post-training analysis showed no significant differences between training modalities (HIT vs. SIT in body mass, PPO, LT or OBLA (p = 0.30 to 0.94. The Cohen's d effect size (ES showed trivial to small effects on group factor (p = 0.00 to 0.56. The interaction between MTB race time and training modality was almost significant (p = 0.08, with a smaller ES in HIT vs. SIT training (ES = -0.43. A time main effect (pre- vs. post-phases was observed in MTB race performance and in several physiological variables (p = 0.001 to 0.046. Co-variance analysis revealed that the HIT (p = 0.043 group had significantly better MTB race performance measures than the SIT group. Furthermore, magnitude-based inferences showed HIT to be of likely greater benefit (83.5% with a lower probability of harmful effects (0.8% compared to SIT.The results of the current study suggest that six weeks of either HIT or SIT may be effective at increasing MTB race performance; however, HIT may be a preferable strategy.ClinicalTrials.gov NCT01944865.

  10. Effects of Sprint versus High-Intensity Aerobic Interval Training on Cross-Country Mountain Biking Performance: A Randomized Controlled Trial.

    Science.gov (United States)

    Inoue, Allan; Impellizzeri, Franco M; Pires, Flávio O; Pompeu, Fernando A M S; Deslandes, Andrea C; Santos, Tony M

    2016-01-01

    The current study compared the effects of high-intensity aerobic training (HIT) and sprint interval training (SIT) on mountain biking (MTB) race simulation performance and physiological variables, including peak power output (PPO), lactate threshold (LT) and onset of blood lactate accumulation (OBLA). Sixteen mountain bikers (mean ± SD: age 32.1 ± 6.4 yr, body mass 69.2 ± 5.3 kg and VO2max 63.4 ± 4.5 mL∙kg(-1)∙min(-1)) completed graded exercise and MTB performance tests before and after six weeks of training. The HIT (7-10 x [4-6 min--highest sustainable intensity / 4-6 min-CR100 10-15]) and SIT (8-12 x [30 s--all-out intensity / 4 min--CR100 10-15]) protocols were included in the participants' regular training programs three times per week. Post-training analysis showed no significant differences between training modalities (HIT vs. SIT) in body mass, PPO, LT or OBLA (p = 0.30 to 0.94). The Cohen's d effect size (ES) showed trivial to small effects on group factor (p = 0.00 to 0.56). The interaction between MTB race time and training modality was almost significant (p = 0.08), with a smaller ES in HIT vs. SIT training (ES = -0.43). A time main effect (pre- vs. post-phases) was observed in MTB race performance and in several physiological variables (p = 0.001 to 0.046). Co-variance analysis revealed that the HIT (p = 0.043) group had significantly better MTB race performance measures than the SIT group. Furthermore, magnitude-based inferences showed HIT to be of likely greater benefit (83.5%) with a lower probability of harmful effects (0.8%) compared to SIT. The results of the current study suggest that six weeks of either HIT or SIT may be effective at increasing MTB race performance; however, HIT may be a preferable strategy. ClinicalTrials.gov NCT01944865.

  11. EFFECTS OF A SAND RUNNING SURFACE ON THE KINEMATICS OF SPRINTING AT MAXIMUM VELOCITY

    Directory of Open Access Journals (Sweden)

    P E Alcaraz

    2011-05-01

    Full Text Available Performing sprints on a sand surface is a common training method for improving sprint-specific strength. For maximum specificity of training the athlete’s movement patterns during the training exercise should closely resemble those used when performing the sport. The aim of this study was to compare the kinematics of sprinting at maximum velocity on a dry sand surface to the kinematics of sprinting on an athletics track. Five men and five women participated in the study, and flying sprints over 30 m were recorded by video and digitized using biomechanical analysis software. We found that sprinting on a sand surface was substantially different to sprinting on an athletics track. When sprinting on sand the athletes tended to ‘sit’ during the ground contact phase of the stride. This action was characterized by a lower centre of mass, a greater forward lean in the trunk, and an incomplete extension of the hip joint at take-off. We conclude that sprinting on a dry sand surface may not be an appropriate method for training the maximum velocity phase in sprinting. Although this training method exerts a substantial overload on the athlete, as indicated by reductions in running velocity and stride length, it also induces detrimental changes to the athlete’s running technique which may transfer to competition sprinting.

  12. Sled Towing Acutely Decreases Acceleration Sprint Time.

    Science.gov (United States)

    Wong, Megan A; Dobbs, Ian J; Watkins, Casey M; Barillas, Saldiam R; Lin, Anne; Archer, David C; Lockie, Robert G; Coburn, Jared W; Brown, Lee E

    2017-11-01

    Wong, MA, Dobbs, IJ, Watkins, C, Barillas, SR, Lin, A, Archer, DC, Lockie, RG, Coburn, JW, and Brown, LE. Sled towing acutely decreases acceleration sprint time. J Strength Cond Res 31(11): 3046-3051, 2017-Sled towing is a common form of overload training in sports to develop muscular strength for sprinting. This type of training leads to acute and chronic outcomes. Acute training potentially leads to postactivation potentiation (PAP), which is when subsequent muscle performance is enhanced after a preload stimulus. The purpose of this study was to determine differences between rest intervals after sled towing on acute sprint speed. Twenty healthy recreationally trained men (age = 22.3 ± 2.4 years, height = 176.95 ± 5.46 cm, mass = 83.19 ± 11.31 kg) who were currently active in a field sport twice a week for the last 6 months volunteered to participate. A maximal 30-meter (m) baseline (BL) body mass (BM) sprint was performed (with splits at 5, 10, 20, and 30 m) followed by 5 visits where participants sprinted 30 m towing a sled at 30% BM then rested for 2, 4, 6, 8, or 12 minutes. They were instructed to stand still during rest times. After the rest interval, they performed a maximal 30-m post-test BM sprint. Analysis of variance (ANOVA) revealed that post sled tow BM sprint times (4.47 ± 0.21 seconds) were less than BL times (4.55 ± 0.18 seconds) on an individualized rest interval basis. A follow-up 2 × 4 ANOVA showed that this decrease occurred only in the acceleration phase over the first 5 m (BL = 1.13 ± 0.08 seconds vs. Best = 1.08 ± 0.08 seconds), which may be the result of PAP and the complex relationship between fatigue and potentiation relative to the intensity of the sled tow and the rest interval. Therefore, coaches should test their athletes on an individual basis to determine optimal rest time after a 30-m 30% BM sled tow to enhance acute sprint speed.

  13. The acute effects of heavy back and front squats on speed during forty-meter sprint trials.

    Science.gov (United States)

    Yetter, Mike; Moir, Gavin L

    2008-01-01

    The purpose of the present study was to investigate the effects of performing heavy back squats (HBS) and heavy front squats (HFS) on the average speed during each 10-m interval of 40-m sprint trials. In a randomized, cross-over design, 10 strength-trained men performed a HBS, HFS, or control treatment before performing three 40-m sprint trials separated by 3 minutes. The HBS and HFS treatments consisted of performing parallel back or front squats with 30%, 50%, and 70% of the subject's 1 repetition maximum after 5 minutes of cycling. The control treatment consisted of cycling for 5 minutes. The sprint trials were performed 4 minutes after completing the HBS, HFS, or control treatments. Significant increases in speed were found during the 10- to 20-m interval for the HBS compared with the control treatment (mean difference, 0.12 m x s(-1); 95% likely range, 0.05-0.18 m x s(-1); P = 0.001). During the 30- to 40-m interval, HBS produced significantly greater speeds compared with the HFS treatment (mean difference, 0.24 m x s(-1); 95% likely range, 0.02-0.45 m x s(-1); P = 0.034) and the control treatment (mean difference, 0.18 m x s(-1); 95% likely range, 0.03-0.32 m x s(-1); P = 0.021). The differing effects of the treatments may reflect different levels of muscular activation or different mechanical aspects of the squat exercises. Similarly, the multidimensional nature of sprint running means that other specific exercises may confer improvements in sprinting performance during other intervals. It is suggested that coaches could incorporate HBS into the warm-up procedure of athletes to improve sprinting performance.

  14. Effects of 18-week in-season heavy-resistance and power training on throwing velocity, strength, jumping, and maximal sprint swim performance of elite male water polo players.

    Science.gov (United States)

    Ramos Veliz, Rafael; Requena, Bernardo; Suarez-Arrones, Luis; Newton, Robert U; Sáez de Villarreal, Eduardo

    2014-04-01

    We examined the effects of 18 weeks of strength and high-intensity training on key sport performance measures of elite male water polo (WP) players. Twenty-seven players were randomly assigned to 2 groups, control (in-water training only) and strength group, (strength training sessions [twice per week] + in-water training). In-water training was conducted 5 d·wk. Twenty-meter maximal sprint swim, maximal dynamic strength 1-repetition maximum (1RM) for upper bench press (BP) and lower full squat (FS) body, countermovement jump (CMJ), and throwing velocity were measured before and after the training. The training program included upper and lower body strength and high-intensity exercises (BP, FS, military press, pull-ups, CMJ loaded, and abs). Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the control group; however, meaningful improvement was found in all variables in the experimental group: CMJ (2.38 cm, 6.9%, effect size [ES] = 0.48), BP (9.06 kg, 10.53%, ES = 0.66), FS (11.06 kg, 14.21%, ES = 0.67), throwing velocity (1.76 km·h(-1), 2.76%, ES = 0.25), and 20-m maximal sprint swim (-0.26 seconds, 2.25%, ES = 0.29). Specific strength and high-intensity training in male WP players for 18 weeks produced a positive effect on performance qualities highly specific to WP. Therefore, we propose modifications to the current training methodology for WP players to include strength and high-intensity training for athlete preparation in this sport.

  15. Effect of Spinning Cycling Training on Body Composition in Women

    Science.gov (United States)

    Kaya, Fatih; Nar, Dilek; Erzeybek, Mustafa Said

    2018-01-01

    In this study the effects of a 6 week spinning cycling training on the body composition of women were investigated. Twelve sedentary women (32-47 years old) voluntarily participated in this study. The 6-week training program consisted of exercise sessions on 3 days per week. The intensity of the training program that was kept low in the beginning…

  16. The comparison of quadriceps muscle strength between sprint runner and normal un-trained individuals (Determined by Kin-Com

    Directory of Open Access Journals (Sweden)

    Talebian Moghaddam S "

    2002-08-01

    Full Text Available Introduction: It is suggested that quadriceps muscle has an important role in stability & mobility of Knee joint in athletics and normal individuals; therefore, the purpose of this study was evaluation of the strength in Power Athletics (PA and Normal Un-trained Individuals (NUI groups. Methods and Materials: 31 Females (20 NUI & 11 PA participated in this study. For measuring the strength, each individual performed 5 continuous concentric-eccentric maximal contraction at angular velocities of 90°/s, 135°/s. Twenty five percent of each individual (Maximum Voluntary Isometric Contraction MVIC was determined and used as Pre-load force. Results: Averages concentric & eccentric torques were greater in PA group in comparison with NUI group. The significant difference (P<0.02 existed between PA and NUI groups. Average concentric torques of quadriceps muscle decreased (with increasing of speed from 90°/s to 135°/s and average eccentric torques increased. Average eccentric torques were greater (P<0.01 in PA & NUI groups in comparison with average concentric torques. Conclusion: PA group strength was greater in comparison with NUI group. This is possibly due to the type of muscle fibers in this group have (greater type II fibers. Accordingly, it is critical to consider the role of eccentric exercise in PA group for preventing sport injury.

  17. Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting.

    Science.gov (United States)

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2018-06-01

    This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.

  18. Relationships between ground reaction impulse and sprint acceleration performance in team sport athletes.

    Science.gov (United States)

    Kawamori, Naoki; Nosaka, Kazunori; Newton, Robert U

    2013-03-01

    Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

  19. Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 2).

    Science.gov (United States)

    Attene, Giuseppe; Laffaye, Guillaume; Chaouachi, Anis; Pizzolato, Fabio; Migliaccio, Gian Mario; Padulo, Johnny

    2015-01-01

    The aim of this study was to compare the training effects based on repeated sprint ability (RSA) (with one change of direction) with an intensive repeated sprint ability (IRSA) (with two changes of direction) on jump performance and aerobic fitness. Eighteen male basketball players were assigned to repeated sprint ability and intensive repeated sprint ability training groups (RSAG and IRSAG). RSA, IRSA, squat jump (SJ), countermovement jump (CMJ) and Yo-Yo intermittent recovery level 1 test were assessed before and after four training weeks. The RSA and IRSA trainings consisted of three sets of six sprints (first two weeks) and eight sprints (second two weeks) with 4-min sets recovery and 20-s of sprints recovery. Four weeks of training led to an overall improvement in most of the measures of RSA, but little evidence of any differences between the two training modes. Jump performance was enhanced: CMJ of 7.5% (P training with one/two changes of direction promotes improvements in both RSA and IRSA respectively but the better increase on jump performance shown a few changes on sprint and endurance performances.

  20. Training report of the FBR cycle training facility in 2004FY

    International Nuclear Information System (INIS)

    Watanabe, Toshio; Sasaki, Kazuichi; Sawada, Makoto; Ohtsuka, Jirou

    2004-07-01

    The FBR cycle training facility consists of sodium handling training facility and maintenance training facility, and is being contributed to train for the operators and maintenance workers of the prototype fast breeder reactor 'Monju'. So far, some training courses have been added to the both training courses of sodium handling technologies maintenance technologies in every year in order to carry out be significant training for preparation of Monju restarting. As encouragement of the sodium handling technology training in 2003FY, the sodium heat transfer basic course was equipped as the 9th sodium handling training course with the aims of learning basic principal technology regarding sodium heat transfer. While, for the maintenance training course, a named 'Monju Systems Learning Training Course', which aims to learn necessary knowledge as the engineers related Monju development, was provided newly in this year as an improvement concerned the maintenance course. In 2003FY, nine sodium handling technology training courses were carried out total 33 times and 235 trainees took part in those training courses. Also, nine training courses concerning the maintenance technology held 15 times and total 113 trainees participated. On the other hand, the 4th special lecture related sodium technology by France sodium school instructor was held on Mar. 15-17 and 34 trainees participated. Consequently, a cumulative trainees since October in 2000 opened the FBR cycle training facility reached to 1,236 so far. (author)

  1. Factors that Influence the Performance of Elite Sprint Cross-Country Skiers.

    Science.gov (United States)

    Hébert-Losier, Kim; Zinner, Christoph; Platt, Simon; Stöggl, Thomas; Holmberg, Hans-Christer

    2017-02-01

    -country skiers: at the start of the race, at any given point when required (e.g., when being challenged by a competitor), and in the final section of each heat. Although high skiing speed is suggested to rely primarily on high cycle rates, longer cycle lengths are commonly observed in faster skiers. In addition, faster skiers rely on different technical strategies when approaching peak speeds, employ more effective techniques, and use better coordinated movements to optimize generation of propulsive force from the resultant ski and pole forces. Strong uphill technique is critical to race performance since uphill segments are the most influential on race outcomes. A certain strength level is required, although more does not necessarily translate to superior sprint skiing performance, and sufficient strength-endurance capacities are also of importance to minimize the impact and accumulation of fatigue during repeated heats. Lastly, higher lean mass does appear to benefit sprint skiers' performance, with no clear advantage conferred via body height and mass. Generalization of findings from one study to the next is challenging considering the array of experimental tasks, variables defining performance, fundamental differences between skiing techniques, and evolution of sprint skiing competitions. Although laboratory-based measures can effectively assess on-snow skiing performance, conclusions drawn from roller-skiing investigations might not fully apply to on-snow skiing performance. A low number of subjects were females (only 17 %), warranting further studies to better understand this population. Lastly, more training studies involving high-level elite sprint skiers and investigations pertaining to the ability of skiers to maintain high-sprint speeds at the end of races are recommended to assist in understanding and improving high-level sprint skiing performance, and resilience to fatigue. Successful sprint cross-country skiing involves well-developed aerobic and anaerobic

  2. Caffeine Alters Blood Potassium and Catecholamine Concentrations but not the Perception of Pain and Fatigue with a 1 km Cycling Sprint

    Directory of Open Access Journals (Sweden)

    Dean M. Cordingley

    2016-07-01

    Full Text Available Background: Caffeine has been used by some athletes to improve short-term high-intensity exercise performance; however, the literature is equivocal. Objectives: The objective of this study was to investigate the effects of caffeine on plasma potassium and catecholamine concentrations, pain and fatigue perception, to determine whether potassium ion handling and altered perception related to the central nervous system are associated with enhanced performance during a 1 km cycling time trial.  Methods: Thirteen well trained men with a mean age of 27 ± 6 yrs (body mass: 76.4 ± 6.4 kg, height: 180 ± 7 cm, and max: 57.5 ± 4.6 ml·kg-1·min-1 were recruited.  Participants were randomized to a caffeine (5 mg·kg-1 or a placebo condition using a double blind, cross over design.  Results: Caffeine had no significant effects on the 1 km time-trial performance indicators of time (82.1 ± 2.4 vs. 81.9 ± 3.9s, peak (633.0 ± 83.6 vs. 638.7 ± 110.1 watts or average power (466.0 ± 37.3 vs. 467.5 ± 59.9 watts; caffeine and placebo conditions respectively.  In addition, caffeine had no significant effect on oxygen consumption ( (4.11 ± 0.24 vs 4.06 ± 0.29 L,the perception of pain (5.6 ± 2.4 vs. 5.5 ± 2.6 or fatigue (7.1 ± 1.8 vs.7.1 ± 1.8: caffeine and placebo conditions respectively.  There was a significantly greater increase in post-exercise blood lactate (p<0.05 and catecholamines (p<0.05 as well as a lower pre-exercise blood potassium concentration (p<0.05 in the caffeine condition. Conclusions: The results suggest that caffeine can enhance certain metabolic parameters, but these changes were unable to augment short-distance (1km, high-intensity cycling performance. Keywords: ergogenic, anaerobic exercise, performance, oxygen consumption

  3. Sprint's Social Media Ninja Program: A Model for Teaching Consumer Relations

    Science.gov (United States)

    Gilliland, Rebecca A.

    2017-01-01

    This study reviews the application of a new training model, Sprint's Social Media Ninja program, an innovative approach to using new media to initiate change. Sprint recognized change management must occur from employee ambassadors to relevant audiences including consumers and other employees. By teaching volunteer employees the strategic message…

  4. The Effect of Concurrent Plyometric Training Versus Submaximal Aerobic Cycling on Rowing Economy, Peak Power, and Performance in Male High School Rowers.

    Science.gov (United States)

    Egan-Shuttler, Julian D; Edmonds, Rohan; Eddy, Cassandra; O'Neill, Veronica; Ives, Stephen J

    2017-12-01

    Plyometric training has been shown to increase muscle power, running economy, and performance in athletes. Despite its use by rowing coaches, it is unknown whether plyometrics might improve rowing economy or performance. The purpose was to determine if plyometric training, in conjunction with training on the water, would lead to improved rowing economy and performance. Eighteen male high school rowers were assigned to perform 4 weeks of either plyometric training (PLYO, n = 9) or steady-state cycling below ventilatory threshold (endurance, E, n = 9), for 30 min prior to practice on the water (matched for training volume) 3 days per week. Rowing performance was assessed through a 500-m rowing time trial (TT) and peak rowing power (RP), while rowing economy (RE) was assessed by measuring the oxygen cost over four work rates (90, 120, 150, and 180 W). Rowing economy was improved in both PLYO and E (p  0.05). Finally, RP was moderately higher in the PLYO group post-training (E 569 ± 75 W, PLYO 629 ± 51 W, ES = 0.66) CONCLUSIONS: In a season when the athletes performed no rowing sprint training, 4 weeks of plyometric training improved the 500-m rowing performance and moderately improved peak power. This increase in performance may have been mediated by moderate improvements in rowing power, but not economy, and warrants further investigation.

  5. Title IV Cash Management Life Cycle Training. Participant's Guide.

    Science.gov (United States)

    Department of Education, Washington, DC.

    This participant's guide includes: "Introduction: Welcome to Cash Management Life Cycle Training"; "Module 1: Review of Cash Management Principles" (cash management overview and activity); "Module 2: Common Origination and Disbursement (COD) System Overview" (e.g., full participants and phase-in participants, COD…

  6. Cycle Training Using Implanted Neural Prostheses: Team Cleveland.

    Science.gov (United States)

    McDaniel, John; Lombardo, Lisa M; Foglyano, Kevin M; Marasco, Paul D; J Triolo, Ronald

    2017-12-05

    Recently our laboratory team focused on training five individuals with complete spinal cord injuries for an overground FES bike race in the 2016 Cybathlon held in Zurich Switzerland. A unique advantage team Cleveland had over other teams was the use of implanted pulse generators that provide more selective activation of muscles compared to standard surface stimulation. The advancements in muscle strength and endurance and ultimately cycling power our pilots made during this training period helped propel our competing pilot to win gold at the Cybathlon and allowed our pilots to ride their bikes outside within their communities. Such positive outcomes has encouraged us to further explore more widespread use of FES overground cycling as a rehabilitative tool for those with spinal cord injuries. This review will describes our approach to this race including information on the pilots, stimulation strategy, bike details and training program.

  7. Cycle Training Using Implanted Neural Prostheses: Team Cleveland

    Directory of Open Access Journals (Sweden)

    John McDaniel

    2017-12-01

    Full Text Available Recently our laboratory team focused on training five individuals with complete spinal cord injuries for an overground FES bike race in the 2016 Cybathlon held in Zurich Switzerland. A unique advantage team Cleveland had over other teams was the use of implanted pulse generators that provide more selective activation of muscles compared to standard surface stimulation. The advancements in muscle strength and endurance and ultimately cycling power our pilots made during this training period helped propel our competing pilot to win gold at the Cybathlon and allowed our pilots to ride their bikes outside within their communities. Such positive outcomes has encouraged us to further explore more widespread use of FES overground cycling as a rehabilitative tool for those with spinal cord injuries. This review will describes our approach to this race including information on the pilots, stimulation strategy, bike details and training program.

  8. The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

    Science.gov (United States)

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos Mª; del Campo-Vecino, Juan; Alonso-Curiel, Dionisio

    2013-01-01

    The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photo-cells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=−2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=−1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=−1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=−1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers. PMID:23717361

  9. Performance changes and relationship between vertical jump measures and actual sprint performance in elite sprinters with visual impairment throughout a Parapan American games training season

    Science.gov (United States)

    Loturco, Irineu; Winckler, Ciro; Kobal, Ronaldo; Cal Abad, Cesar C.; Kitamura, Katia; Veríssimo, Amaury W.; Pereira, Lucas A.; Nakamura, Fábio Y.

    2015-01-01

    The aims of this study were to estimate the magnitude of variability and progression in actual competitive and field vertical jump test performances in elite Paralympic sprinters with visual impairment in the year leading up to the 2015 Parapan American Games, and to investigate the relationships between loaded and unloaded vertical jumping test results and actual competitive sprinting performance. Fifteen Brazilian Paralympic sprinters with visual impairment attended seven official competitions (four national, two international and the Parapan American Games 2015) between April 2014 and August 2015, in the 100- and 200-m dash. In addition, they were tested in five different periods using loaded (mean propulsive power [MPP] in jump squat [JS] exercise) and unloaded (squat jump [SJ] height) vertical jumps within the 3 weeks immediately prior to the main competitions. The smallest important effect on performances was calculated as half of the within-athlete race-to-race (or test-to-test) variability and a multiple regression analysis was performed to predict the 100- and 200-m dash performances using the vertical jump test results. Competitive performance was enhanced during the Parapan American Games in comparison to the previous competition averages, overcoming the smallest worthwhile enhancement in both the 100- (0.9%) and 200-m dash (1.43%). In addition, The SJ and JS explained 66% of the performance variance in the competitive results. This study showed that vertical jump tests, in loaded and unloaded conditions, could be good predictors of the athletes' sprinting performance, and that during the Parapan American Games the Brazilian team reached its peak competitive performance. PMID:26594181

  10. Performance changes and relationship between vertical jump measures and actual sprint performance in elite sprinters with visual impairment throughout a Parapan American games training season

    Directory of Open Access Journals (Sweden)

    Irineu eLoturco

    2015-11-01

    Full Text Available The aims of this study were to estimate the magnitude of variability and progression in actual competitive and field vertical jump test performances in elite Paralympic sprinters with visual impairment in the year leading up to the 2015 Parapan American Games, and to investigate the relationships between loaded and unloaded vertical jumping test results and actual competitive sprinting performance. Fifteen Brazilian Paralympic sprinters with visual impairment attended seven official competitions (four national, two international and the Parapan American Games 2015 between April 2014 and August 2015, in the 100- and 200-m dash. In addition, they were tested in five different periods using loaded (mean propulsive power [MPP] in jump squat [JS] exercise and unloaded (squat jump [SJ] height vertical jumps within the 3 weeks immediately prior to the main competitions. The smallest important effect on performances was calculated as half of the within-athlete race-to-race (or test-to-test variability and a multiple regression analysis was performed to predict the 100- and 200-m dash performances using the vertical jump test results. Competitive performance was enhanced during the Parapan American Games in comparison to the previous competition averages, overcoming the smallest worthwhile enhancement in both the 100- (0.9% and 200-m dash (1.43%. In addition, The SJ and JS explained 66% of the performance variance in the competitive results. This study showed that vertical jump tests, in loaded and unloaded conditions, could be good predictors of the athletes’ sprinting performance, and that during the Parapan American Games the Brazilian team reached its peak competitive performance.

  11. Postactivation potentiation of sprint acceleration performance using plyometric exercise.

    Science.gov (United States)

    Turner, Anthony P; Bellhouse, Sam; Kilduff, Liam P; Russell, Mark

    2015-02-01

    Postactivation potentiation (PAP), an acute and temporary enhancement of muscular performance resulting from previous muscular contraction, commonly occurs after heavy resistance exercise. However, this method of inducing PAP has limited application to the precompetition practices (e.g., warm-up) of many athletes. Very few studies have examined the influence of plyometric activity on subsequent performance; therefore, we aimed to examine the influence of alternate-leg bounding on sprint acceleration performance. In a randomized crossover manner, plyometric-trained men (n = 23) performed seven 20-m sprints (with 10-m splits) at baseline, ∼15 seconds, 2, 4, 8, 12, and 16 minutes after a walking control (C) or 3 sets of 10 repetitions of alternate-leg bounding using body mass (plyometric, P) and body mass plus 10% (weighted plyometric, WP). Mean sprint velocities over 10 and 20 m were similar between trials at baseline. At ∼15 seconds, WP impaired 20-m sprint velocity by 1.4 ± 2.5% when compared with C (p = 0.039). Thereafter, 10- and 20-m sprint velocities improved in WP at 4 minutes (10 m: 2.2 ± 3.1%, p = 0.009; 20 m: 2.3 ± 2.6%, p = 0.001) and 8 minutes (10 m: 2.9 ± 3.6%, p = 0.002; 20 m: 2.6 ± 2.8%, p = 0.001) compared with C. Improved 10-m sprint acceleration performance occurred in P at 4 minutes (1.8 ± 3.3%, p = 0.047) relative to C. Therefore, sprint acceleration performance is enhanced after plyometric exercise providing adequate recovery is given between these activities; however, the effects may differ according to whether additional load is applied. This finding presents a practical method to enhance the precompetition practices of athletes.

  12. High performance image processing of SPRINT

    Energy Technology Data Exchange (ETDEWEB)

    DeGroot, T. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    This talk will describe computed tomography (CT) reconstruction using filtered back-projection on SPRINT parallel computers. CT is a computationally intensive task, typically requiring several minutes to reconstruct a 512x512 image. SPRINT and other parallel computers can be applied to CT reconstruction to reduce computation time from minutes to seconds. SPRINT is a family of massively parallel computers developed at LLNL. SPRINT-2.5 is a 128-node multiprocessor whose performance can exceed twice that of a Cray-Y/MP. SPRINT-3 will be 10 times faster. Described will be the parallel algorithms for filtered back-projection and their execution on SPRINT parallel computers.

  13. Bicycle Trains, Cycling, and Physical Activity: A Pilot Cluster RCT.

    Science.gov (United States)

    Mendoza, Jason A; Haaland, Wren; Jacobs, Maya; Abbey-Lambertz, Mark; Miller, Josh; Salls, Deb; Todd, Winifred; Madding, Rachel; Ellis, Katherine; Kerr, Jacqueline

    2017-10-01

    Increasing children's cycling to school and physical activity are national health goals. The objective was to conduct an RCT of a bicycle train program to assess impact on students' school travel mode and moderate-to-vigorous physical activity (MVPA). Pilot cluster RCT with randomization at the school level and N=54 participants. Fourth-fifth graders from four public schools serving low-income families in Seattle, WA in 2014 with analyses in 2015-2016. All participants were provided and fitted with bicycles, safety equipment (helmets, locks, and lights), and a 2- to 3-hour bicycle safety course. The intervention was a bicycle train offered daily (i.e., students volunteered to cycle with study staff to and from school). Time 1 assessments occurred prior to randomization. Time 2 assessments occurred after 3-5 weeks of the intervention (i.e., during Weeks 4-6 of the intervention period). The primary outcome was the percentage of daily commutes to school by cycling measured by validated survey. MVPA, measured by accelerometry and GPS units and processed by machine learning algorithms, was a secondary outcome. For two separate adjusted repeated measures linear mixed effects models in which students (N=54) were nested within schools (N=4), intervention participants had: (1) an absolute increase in mean percentage of daily commutes by cycling of 44.9%, (95% CI=26.8, 63.0) and (2) an increase in mean MVPA of 21.6 minutes/day, (95% CI=8.7, 34.6) from Time 1 to Time 2 compared with controls. A pilot bicycle train intervention increased cycling to school and daily MVPA in the short term among diverse, inner-city elementary school students. The bicycle train intervention appears promising and warrants further experimental trials among large, diverse samples with longer follow-up. This study is registered at www.clinicaltrials.gov NCT02006186. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Comparison of step-by-step kinematics in repeated 30m sprints in female soccer players.

    Science.gov (United States)

    van den Tillaar, Roland

    2018-01-04

    The aim of this study was to compare kinematics in repeated 30m sprints in female soccer players. Seventeen subjects performed seven 30m sprints every 30s in one session. Kinematics were measured with an infrared contact mat and laser gun, and running times with an electronic timing device. The main findings were that sprint times increased in the repeated sprint ability test. The main changes in kinematics during the repeated sprint ability test were increased contact time and decreased step frequency, while no change in step length was observed. The step velocity increased in almost each step until the 14, which occurred around 22m. After this, the velocity was stable until the last step, when it decreased. This increase in step velocity was mainly caused by the increased step length and decreased contact times. It was concluded that the fatigue induced in repeated 30m sprints in female soccer players resulted in decreased step frequency and increased contact time. Employing this approach in combination with a laser gun and infrared mat for 30m makes it very easy to analyse running kinematics in repeated sprints in training. This extra information gives the athlete, coach and sports scientist the opportunity to give more detailed feedback and help to target these changes in kinematics better to enhance repeated sprint performance.

  15. Load training athletes specializing in race to 100 meter hurdles in its annual training cycle

    Directory of Open Access Journals (Sweden)

    Radosław Muszkieta

    2016-10-01

    Full Text Available The aim of the study was to provide an annual macrocycle preparation of athletes specializing in the 100 meters hurdles. A detailed discussion of the structure and analyze loads in individual periods of the annual training cycle. And the analysis and discussion of the variables of training athletes Marlene Morton, who allowed her to win the bronze medal Polish Youth Championships in Bialystok. The study was conducted based on a detailed analysis of the training diary kept by the athlete, the coach and the daily interview with the coach conducting Arthur Kohutek. They were presented various training periods and analyzed periods and sub-periods. In the summary they presented the conclusions that can be helpful when planning the burden for athletes who specialize in racing gossip.

  16. Repeated-Sprint Sequences During Female Soccer Matches Using Fixed and Individual Speed Thresholds.

    Science.gov (United States)

    Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Rosseti, Marcelo; Moura, Felipe A; Bradley, Paul S

    2017-07-01

    Nakamura, FY, Pereira, LA, Loturco, I, Rosseti, M, Moura, FA, and Bradley, PS. Repeated-sprint sequences during female soccer matches using fixed and individual speed thresholds. J Strength Cond Res 31(7): 1802-1810, 2017-The main objective of this study was to characterize the occurrence of single sprint and repeated-sprint sequences (RSS) during elite female soccer matches, using fixed (20 km·h) and individually based speed thresholds (>90% of the mean speed from a 20-m sprint test). Eleven elite female soccer players from the same team participated in the study. All players performed a 20-m linear sprint test, and were assessed in up to 10 official matches using Global Positioning System technology. Magnitude-based inferences were used to test for meaningful differences. Results revealed that irrespective of adopting fixed or individual speed thresholds, female players produced only a few RSS during matches (2.3 ± 2.4 sequences using the fixed threshold and 3.3 ± 3.0 sequences using the individually based threshold), with most sequences composing of just 2 sprints. Additionally, central defenders performed fewer sprints (10.2 ± 4.1) than other positions (fullbacks: 28.1 ± 5.5; midfielders: 21.9 ± 10.5; forwards: 31.9 ± 11.1; with the differences being likely to almost certainly associated with effect sizes ranging from 1.65 to 2.72), and sprinting ability declined in the second half. The data do not support the notion that RSS occurs frequently during soccer matches in female players, irrespective of using fixed or individual speed thresholds to define sprint occurrence. However, repeated-sprint ability development cannot be ruled out from soccer training programs because of its association with match-related performance.

  17. Effects of synchronous versus asynchronous mode of propulsion on wheelchair basketball sprinting.

    Science.gov (United States)

    Faupin, Arnaud; Borel, Benoit; Meyer, Christophe; Gorce, Philippe; Watelain, Eric

    2013-11-01

    This study aimed to first investigate synchronous (SYN) versus asynchronous (ASY) mode of propulsion and, second, investigate the wheel camber effects on sprinting performance as well as temporal parameters. Seven wheelchair basketball players performed four maximal eight-second sprints on a wheelchair ergometer. They repeated the test according to two modes of propulsion (SYN and ASY) and two wheel cambers (9° and 15°). The mean maximal velocity and push power output was greater in the synchronous mode compared to the asynchronous mode for both camber angles. However, the fluctuation in the velocity profile is inferior for ASY versus SYN mode for both camber angles. Greater push time/cycle time (Pt/Ct) and arm frequency (AF) for synchronous mode versus asynchronous mode and inversely, lesser Ct and rest time (Rt) values for the synchronous mode, for which greater velocity were observed. SYN mode leads to better performance than ASY mode in terms of maximal propulsion velocity. However, ASY propulsion allows greater continuity of the hand-rim force application, reducing fluctuations in the velocity profile. The camber angle had no effect on ASY and SYN mean maximal velocity and push power output. The study of wheelchair propulsion strategies is important for better understanding physiological and biomechanical impacts of wheelchair propulsion for individuals with disabilities. From a kinematical point of view, this study highlights synchronous mode of propulsion to be more efficient, with regards to mean maximal velocity reaching during maximal sprinting exercises. Even if this study focuses on well-trained wheelchair athletes, results from this study could complement the knowledge on the physiological and biomechanical adaptations to wheelchair propulsion and therefore, might be interesting for wheelchair modifications for purposes of rehabilitation.

  18. Increases in lower-body strength transfer positively to sprint performance: a systematic review with meta-analysis.

    Science.gov (United States)

    Seitz, Laurent B; Reyes, Alvaro; Tran, Tai T; Saez de Villarreal, Eduardo; Haff, G Gregory

    2014-12-01

    Although lower-body strength is correlated with sprint performance, whether increases in lower-body strength transfer positively to sprint performance remain unclear. This meta-analysis determined whether increases in lower-body strength (measured with the free-weight back squat exercise) transfer positively to sprint performance, and identified the effects of various subject characteristics and resistance-training variables on the magnitude of sprint improvement. A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE and PubMed databases, and references of original studies and reviews were searched for further relevant studies. The analysis comprised 510 subjects and 85 effect sizes (ESs), nested with 26 experimental and 11 control groups and 15 studies. There is a transfer between increases in lower-body strength and sprint performance as indicated by a very large significant correlation (r = -0.77; p = 0.0001) between squat strength ES and sprint ES. Additionally, the magnitude of sprint improvement is affected by the level of practice (p = 0.03) and body mass (r = 0.35; p = 0.011) of the subject, the frequency of resistance-training sessions per week (r = 0.50; p = 0.001) and the rest interval between sets of resistance-training exercises (r = -0.47; p ≤ 0.001). Conversely, the magnitude of sprint improvement is not affected by the athlete's age (p = 0.86) and height (p = 0.08), the resistance-training methods used through the training intervention, (p = 0.06), average load intensity [% of 1 repetition maximum (RM)] used during the resistance-training sessions (p = 0.34), training program duration (p = 0.16), number of exercises per session (p = 0.16), number of sets per exercise (p = 0.06) and number of repetitions per set (p = 0.48). Increases in lower-body strength transfer positively to sprint performance. The magnitude of sprint improvement is affected by numerous subject characteristics and resistance-training

  19. High-Intensity Cycling Training: The Effect of Work-to-Rest Intervals on Running Performance Measures.

    Science.gov (United States)

    Kavaliauskas, Mykolas; Aspe, Rodrigo R; Babraj, John

    2015-08-01

    The work-to-rest ratio during cycling-based high-intensity interval training (HIT) could be important in regulating physiological and performance adaptations. We sought to determine the effectiveness of cycling-based HIT with different work-to-rest ratios for long-distance running. Thirty-two long-distance runners (age: 39 ± 8 years; sex: 14 men, 18 women; average weekly running training volume: 25 miles) underwent baseline testing (3-km time-trial, V[Combining Dot Above]O2peak and time to exhaustion, and Wingate test) before a 2-week matched-work cycling HIT of 6 × 10-second sprints with different rest periods (30 seconds [R30], 80 seconds [R80], 120 seconds [R120], or control). Three-kilometer time trial was significantly improved in the R30 group only (3.1 ± 4.0%, p = 0.04), whereas time to exhaustion was significantly increased in the 2 groups with a lower work-to-rest ratio (R30 group 6.4 ± 6.3%, p = 0.003 vs. R80 group 4.4 ± 2.7%, p = 0.03 vs. R120 group 1.9 ± 5.0%, p = 0.2). However, improvements in average power production were significantly greater with a higher work-to-rest ratio (R30 group 0.3 ± 4.1%, p = 0.8 vs. R80 group 4.6 ± 4.2%, p = 0.03 vs. R120 group 5.3 ± 5.9%, p = 0.02), whereas peak power significantly increased only in the R80 group (8.5 ± 8.2%, p = 0.04) but not in the R30 group (4.3 ± 6.1%, p = 0.3) or in the R120 group (7.1 ± 7.9%, p = 0.09). Therefore, cycling-based HIT is an effective way to improve running performance, and the type and magnitude of adaptation is dependent on the work-to-rest ratio.

  20. Effects of electric stimulation-assisted cycling training in people with chronic stroke

    NARCIS (Netherlands)

    Janssen, T.W.J.; Beltman, J.M.; Elich, P.; Koppe, P.A.; Konijnenbelt, H.; de Haan, A.; Gerrits, K.H.L.

    2008-01-01

    Janssen TW, Beltman JM, Elich P, Koppe PA, Konijnenbelt H, de Haan A, Gerrits KH. Effects of electric stimulation-assisted cycling training in people with chronic stroke. Objective: To evaluate whether leg cycling training in subjects with chronic stroke can improve cycling performance, aerobic

  1. The effects of precompetition massage on the kinematic parameters of 20-m sprint performance.

    Science.gov (United States)

    Fletcher, Iain M

    2010-05-01

    The purpose of this study was to investigate what effect precompetition massage has on short-term sprint performance. Twenty male collegiate games players, with a minimum training/playing background of 3 sessions per week, were assigned to a randomized, counter-balanced, repeated-measures designed experiment used to analyze 20-m sprints performance. Three discrete warm-up modalities, consisting of precompetition massage, a traditional warm-up, and a precompetition massage combined with a traditional warm-up were used. Massage consisted of fast, superficial techniques designed to stimulate the main muscle groups associated with sprint running. Twenty-meter sprint performance and core temperature were assessed post warm-up interventions. Kinematic differences between sprints were assessed through a 2-dimensional computerized motion analysis system (alpha level p velocity were found to be significantly greater in the warm-up and massage combined with warm-up modalities when compared to massage alone. No significant differences were demonstrated in any measures when the warm-up and massage and warm-up combined conditions were compared. Massage as a preperformance preparation strategy seems to decrease 20-m sprint performance when compared to a traditional warm-up, although its combination with a normal active warm-up seems to have no greater benefit then active warm-up alone. Therefore, massage use prior to competition is questionable because it appears to have no effective role in improving sprint performance.

  2. Does Vibration Warm-up Enhance Kinetic and Temporal Sprint Parameters?

    Science.gov (United States)

    Cochrane, D J; Cronin, M J; Fink, P W

    2015-08-01

    The aim of this study was to investigate the efficacy of vibration warm-up to enhance sprint performance. 12 males involved in representative team sports performed 4 warm-up conditions in a randomised order performed at least 24 h apart; VbX warm-up (VbX-WU); Neural activation warm-up (Neu-WU); Dynamic warm-up (Dyn-WU) and Control (No VbX). Participants completed 5 m sprint at 30 s, 2:30 min and 5 min post warm-up where sprint time, kinetics, and temporal components were recorded. There was no significant (p>0.05) main effect or interaction effect between the split sprint times of 1 m, 2.5 m, and 5 m. There was a condition effect where vertical mean force was significantly higher (p0.05) main and interaction effects in sprint kinetic and temporal parameters existed. Overall, all 4 warm-up conditions produced comparable results for sprint performance, and there was no detrimental effect on short-duration sprint performance using VbX-WU. Therefore, VbX could be useful for adding variety to the training warm-up or be included into the main warm-up routine as a supplementary modality. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Correlation between explosive strength, aerobic power and repeated sprint ability in elite basketball players.

    Science.gov (United States)

    Stojanovic, M D; Ostojic, S M; Calleja-González, J; Milosevic, Z; Mikic, M

    2012-08-01

    The aim of this study was to examine the relationship between explosive strength and aerobic power with basketball-specific repeated sprint ability in elite male basketball players. Twenty-four elite basketball players (age 22.2±3.4 years, height 197.1±6.2 cm, weight 95.7±8.8 kg; training experience 11.0±3.1 years; mean±SD), participated in the study. Subjects performed countermovement jump (CMJ) test and incremental pseudo-ramp test protocol with measured CMJ height and VO2max, respectively. Specific repeated sprint ability (RSA) test was conducted, with total sprinting time (summation of 10 sprint times - RSAtot) and sprint decrement (fatigue index - RSAFI) calculated. Significant decrements in sprint performance from the eight 30-m sprint (Pbasketball players. It seems that coaches and strength and conditioning professionals should devote additional time for explosive strength development in elite basketball players during preparatory period to enhance RSA performance.

  4. Cycling in the African American Community : safety training guidelines and findings.

    Science.gov (United States)

    2013-08-01

    This report is a program users manual for the Cycling in the African American Community (CAAC) safety training intervention. The CAAC safety training intervention was designed to nudge more African Americans, who are often beginning cyclists...

  5. Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance.

    Science.gov (United States)

    Beaven, C Martyn; Maulder, Peter; Pooley, Adrian; Kilduff, Liam; Cook, Christian

    2013-06-01

    Our purpose was to examine the effectiveness of carbohydrate and caffeine mouth rinses in enhancing repeated sprint ability. Previously, studies have shown that a carbohydrate mouth rinse (without ingestion) has beneficial effects on endurance performance that are related to changes in brain activity. Caffeine ingestion has also demonstrated positive effects on sprint performance. However, the effects of carbohydrate or caffeine mouth rinses on intermittent sprints have not been examined previously. Twelve males performed 5 × 6-s sprints interspersed with 24 s of active recovery on a cycle ergometer. Twenty-five milliliters of either a noncaloric placebo, a 6% glucose, or a 1.2% caffeine solution was rinsed in the mouth for 5 s prior to each sprint in a double-blinded and balanced cross-over design. Postexercise maximal heart rate and perceived exertion were recorded, along with power measures. A second experiment compared a combined caffeine-carbohydrate rinse with carbohydrate only. Compared with the placebo mouth rinse, carbohydrate substantially increased peak power in sprint 1 (22.1 ± 19.5 W; Cohen's effect size (ES), 0.81), and both caffeine (26.9 ± 26.9 W; ES, 0.71) and carbohydrate (39.1 ± 25.8 W; ES, 1.08) improved mean power in sprint 1. Experiment 2 demonstrated that a combination of caffeine and carbohydrate improved sprint 1 power production compared with carbohydrate alone (36.0 ± 37.3 W; ES, 0.81). We conclude that carbohydrate and (or) caffeine mouth rinses may rapidly enhance power production, which could have benefits for specific short sprint exercise performance. The ability of a mouth-rinse intervention to rapidly improve maximal exercise performance in the absence of fatigue suggests a central mechanism.

  6. Simulation of aperiodic bipedal sprinting.

    Science.gov (United States)

    Celik, Huseyin; Piazza, Stephen J

    2013-08-01

    Synthesis of legged locomotion through dynamic simulation is useful for exploration of the mechanical and control variables that contribute to efficient gait. Most previous simulations have made use of periodicity constraints, a sensible choice for investigations of steady-state walking or running. Sprinting from rest, however, is aperiodic by nature and this aperiodicity is central to the goal of the movement, as performance is determined in large part by a rapid acceleration phase early in the race. The purpose of this study was to create a novel simulation of aperiodic sprinting using a modified spring-loaded inverted pendulum (SLIP) biped model. The optimal control problem was to find the set of controls that minimized the time for the model to run 20 m, and this problem was solved using a direct multiple shooting algorithm that converts the original continuous time problem into piecewise discrete subproblems. The resulting nonlinear programming problem was solved iteratively using a sequential quadratic programming method. The starting point for the optimizer was an initial guess simulation that was a slow alternating-gait "jogging" simulation developed using proportional-derivative feedback to control trunk attitude, swing leg angle, and leg retraction and extension. The optimized aperiodic sprint simulation solution yielded a substantial improvement in locomotion time over the initial guess (2.79 s versus 6.64 s). Following optimization, the model produced forward impulses at the start of the sprint that were four times greater than those of the initial guess simulation, producing more rapid acceleration. Several gait features demonstrated in the optimized sprint simulation correspond to behaviors of human sprinters: forward trunk lean at the start; straightening of the trunk during acceleration; and a dive at the finish. Optimization resulted in reduced foot contact times (0.065 s versus 0.210 s), but contact times early in the optimized

  7. Telemonitoring of home exercise cycle training in patients with COPD

    Directory of Open Access Journals (Sweden)

    Franke KJ

    2016-11-01

    Full Text Available Karl-Josef Franke,1,2 Ulrike Domanski,1 Maik Schroeder,1 Volker Jansen,3 Frank Artmann,4 Uwe Weber,5 Rainer Ettler,6 Georg Nilius1,2 1Department of Pneumology and Critical Care Medicine, Helios Klinik Ambrock, Hagen, 2Witten/Herdecke University, Witten, 3Lung Practice Jansen, Menden, 4Aeroprax Wuppertal, Wuppertal, 5Lung Practice Witten, Witten, 6Lung Practice Ettler, Hagen, Germany Background: Regular physical activity is associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD. Interventions to reduce time spent in sedentary behavior could improve outcomes. The primary purpose was to investigate the impact of telemonitoring with supportive phone calls on daily exercise times with newly established home exercise bicycle training. The secondary aim was to examine the potential improvement in health-related quality of life and physical activity compared to baseline. Methods: This prospective crossover-randomized study was performed over 6 months in stable COPD patients. The intervention phase (domiciliary training with supporting telephone calls and the control phase (training without phone calls were randomly assigned to the first or the last 3 months. In the intervention phase, patients were called once a week if they did not achieve a real-time monitored daily cycle time of 20 minutes. Secondary aims were evaluated at baseline and after 3 and 6 months. Health-related quality of life was measured by the COPD Assessment Test (CAT, physical activity by the Godin Leisure Time Exercise Questionnaire (GLTEQ. Results: Of the 53 included patients, 44 patients completed the study (forced expiratory volume in 1 second 47.5%±15.8% predicted. In the intervention phase, daily exercise time was significantly higher compared to the control phase (24.2±9.4 versus 19.6±10.3 minutes. Compared to baseline (17.6±6.1, the CAT-score improved in the intervention phase to 15.3±7.6 and in the control phase to 15.7±7.3

  8. Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.

    Science.gov (United States)

    Ozaki, Hayao; Loenneke, J P; Thiebaud, R S; Abe, T

    2015-03-01

    Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.

  9. Push Characteristics in Wheelchair Court Sport Sprinting

    NARCIS (Netherlands)

    van der Slikke, Rienk M A; Berger, Monique; Bregman, Daan; Veeger, Dirkjan

    2016-01-01

    Short sprints are important components of most wheelchair court sports, since being faster than the opponent often determines keeping ball possession or not. Sprinting capacity is best measured during a field test, allowing the athlete to freely choose push strategies adapted to their own wheelchair

  10. Push characteristics in wheelchair court sport sprinting

    NARCIS (Netherlands)

    van der Slikke, R.M.A.; Berger, Monique; Bregman, D.J.J.; Veeger, H.E.J.; van der Helm, FCT; Jansen, AJ

    2016-01-01

    Short sprints are important components of most wheelchair court sports, since being faster than the opponent often determines keeping ball possession or not. Sprinting capacity is best measured during a field test, allowing the athlete to freely choose push strategies adapted to their own

  11. Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

    Science.gov (United States)

    Wyland, Timothy P; Van Dorin, Joshua D; Reyes, G Francis Cisco

    2015-11-01

    Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

  12. Lateral Squats Significantly Decrease Sprint Time in Collegiate Baseball Athletes

    Directory of Open Access Journals (Sweden)

    Jason B. White

    2016-03-01

    Full Text Available The purpose was to examine the effect of prior performance of dumbbell lateral squats (DBLS on an agility movement-into-a-sprint (AMS test. Twelve collegiate, resistance-trained, baseball athletes participated in three sessions separated by three days. Session One consisted of AMS baseline test, DBLS 5-RM test, and experimental protocol familiarization. Subjects were randomly assigned the protocol order for Sessions Two and Three, which consisted of warm up followed by 1-min sitting (no-DBLS or performing the DBLS for 1 × 5 repetitions @ 5RM for each leg. Four minutes of slow recovery walking preceded the AMS test, which consisted of leading off a base and waiting for a visual stimulus. In reaction to stimulus, subjects exerted maximal effort while moving to the right by either pivoting or drop stepping and sprinting for 10 yards (yd. In Session Three, subjects switched protocols (DBLS, no-DBLS. Foot contact time (FCT, stride frequency (SF, stride length (SL, and 10-yd sprint time were measured. There were no differences between conditions for FCT, SF, or SL. Differences existed between DBLS (1.85 ± 0.09 s and no-DBLS (1.89 ± 0.10 s for AMS (p = 0.03. Results from the current study support the use of DBLS for performance enhancement prior to performing the AMS test.

  13. The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes.

    Science.gov (United States)

    Paulson, Sally; Braun, William A

    2011-06-01

    The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes. The aim of this investigation was to compare the acute effects of parachute-resisted (PR) sprinting on selected kinematic variables. Twelve collegiate sprinters (mean age 19.58 ± 1.44 years, mass 69.32 ± 14.38 kg, height 1.71 ± 9.86 m) ran a 40-yd dash under 2 conditions: PR sprint and sprint without a parachute (NC) that were recorded on a video computer system (60 Hz). Sagittal plane kinematics of the right side of the body was digitized to calculate joint angles at initial ground contact (IGC) and end ground contact (EGC), ground contact (GC) time, stride rate (SR), stride length (SL), and the times of the 40-yd dashes. The NC 40-yd dash time was significantly faster than the PR trial (p 0.05). This study suggests that PR sprinting does not acutely affect GC time, SR, SL and upper extremity or lower extremity joint angles during weight acceptance (IGC) in collegiate sprinters. However, PR sprinting increased shoulder flexion by 23.5% at push-off and decreased speed by 4.4%. While sprinting with the parachute, the athlete's movement patterns resembled their mechanics during the unloaded condition. This indicates the external load caused by PR did not substantially overload the runner, and only caused a minor change in the shoulder during push-off. This sports-specific training apparatus may provide coaches with another method for training athletes in a sports-specific manner without causing acute changes to running mechanics.

  14. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

    Directory of Open Access Journals (Sweden)

    Martínez-Valencia María Asunción

    2015-06-01

    Full Text Available Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak, a peak rate of force development (RFDpeak and time to RFD (TRFD in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001 in sprint times (20 and 30 m sprint for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01. Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

  15. Determining friction and effective loading for sled sprinting.

    Science.gov (United States)

    Cross, Matt R; Tinwala, Farhan; Lenetsky, Seth; Samozino, Pierre; Brughelli, Matt; Morin, Jean-Benoit

    2017-11-01

    Understanding the impact of friction in sled sprinting allows the quantification of kinetic outputs and the effective loading experienced by the athlete. This study assessed changes in the coefficient of friction (µ k ) of a sled sprint-training device with changing mass and speed to provide a means of quantifying effective loading for athletes. A common sled equipped with a load cell was towed across an athletics track using a motorised winch under variable sled mass (33.1-99.6 kg) with constant speeds (0.1 and 0.3 m · s -1 ), and with constant sled mass (55.6 kg) and varying speeds (0.1-6.0 m · s -1 ). Mean force data were analysed, with five trials performed for each condition to assess the reliability of measures. Variables were determined as reliable (ICC > 0.99, CV friction-force and speed/coefficient of friction relationships well fitted with linear (R 2  = 0.994-0.995) and quadratic regressions (R 2  = 0.999), respectively (P friction values determined at two speeds, and the range in values from the quadratic fit (µ k  = 0.35-0.47) suggested µ k and effective loading were dependent on instantaneous speed on athletics track surfaces. This research provides a proof-of-concept for the assessment of friction characteristics during sled towing, with a practical example of its application in determining effective loading and sled-sprinting kinetics. The results clarify effects of friction during sled sprinting and improve the accuracy of loading applications in practice and transparency of reporting in research.

  16. The effects of passive leg press training on jumping performance, speed, and muscle power.

    Science.gov (United States)

    Liu, Chiang; Chen, Chuan-Shou; Ho, Wei-Hua; Füle, Róbert János; Chung, Pao-Hung; Shiang, Tzyy-Yuang

    2013-06-01

    Passive leg press (PLP) training was developed based on the concepts of the stretch-shortening cycle (SSC) and the benefits of high muscle contraction velocity. Passive leg press training enables lower limb muscle groups to apply a maximum downward force against a platform moved up and down at high frequency by an electric motor. Thus, these muscle groups accomplished both concentric and eccentric isokinetic contractions in a passive, rapid, and repetitive manner. This study investigates the effects of 10 weeks of PLP training at high and low movement frequencies have on jumping performance, speed, and muscle power. The authors selected 30 college students who had not performed systematic resistance training in the previous 6 months, including traditional resistance training at a squat frequency of 0.5 Hz, PLP training at a low frequency of 0.5 Hz, and PLP training at a high frequency of 2.5 Hz, and randomly divided them into 3 groups (n = 10). The participants' vertical jump, drop jump, 30-m sprint performance, explosive force, and SSC efficiency were tested under the same experimental procedures at pre- and post-training. Results reveal that high-frequency PLP training significantly increased participants' vertical jump, drop jump, 30-m sprint performance, instantaneous force, peak power, and SSC efficiency (p training (p training significantly increased participants' vertical jump, 30-m sprint performance, instantaneous force, and peak power (p training only increased participants' 30-m sprint performance and peak power (p training at high movement frequency. A PLP training machine powered by an electrical motor enables muscles of the lower extremities to contract faster compared with voluntary contraction. Therefore, muscle training with high contraction velocity is one of the main methods of increasing muscle power. Passive leg press training is a unique method for enhancing jump performance, speed, and muscle power.

  17. Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

    Science.gov (United States)

    Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

    2015-03-01

    Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

  18. Baseline strength can influence the ability of salivary free testosterone to predict squat and sprinting performance.

    Science.gov (United States)

    Crewther, Blair T; Cook, Christian J; Gaviglio, Chris M; Kilduff, Liam P; Drawer, Scott

    2012-01-01

    The objective of this study was to determine if salivary free testosterone can predict an athlete's performance during back squats and sprints over time and the influence baseline strength on this relationship. Ten weight-trained male athletes were divided into 2 groups based on their 1 repetition maximum (1RM) squats, good squatters (1RM > 2.0 × body weight, n = 5) and average squatters (1RM squat 1RM and 10-m sprint times on 10 separate occasions over a 40-day period. A saliva sample was collected before testing and assayed for free testosterone and cortisol. The pooled testosterone correlations were strong and significant in the good squatters (r = 0.92 for squats, r = -0.87 for sprints, p squats, r = -0.18 for sprints). Cortisol showed no significant correlations with 1RM squat and 10-m sprint performance, and no differences were identified between the 2 squatting groups. In summary, these results suggest that free testosterone is a strong individual predictor of squat and sprinting performance in individuals with relatively high strength levels but a poor predictor in less strong individuals. This information can assist coaches, trainers, and performance scientists working with stronger weight-trained athletes, for example, the preworkout measurement of free testosterone could indicate likely training outcomes or a readiness to train at a certain intensity level, especially if real-time measurements are made. Our results also highlight the need to separate group and individual hormonal data during the repeated testing of athletes with variable strength levels.

  19. Induced moment due to perpendicular field cycling in trained ...

    Indian Academy of Sciences (India)

    in trained exchange bias system. AMITESH PAUL1,∗ and S ... in a phenomenological picture takes the form of a unidirectional magnetic anisotropy, is known as exchange ..... [19] C V Haesendonck, private communication. Pramana – J. Phys.

  20. Peak oxygen uptake in a sprint interval testing protocol vs. maximal oxygen uptake in an incremental testing protocol and their relationship with cross-country mountain biking performance.

    Science.gov (United States)

    Hebisz, Rafał; Hebisz, Paulina; Zatoń, Marek; Michalik, Kamil

    2017-04-01

    In the literature, the exercise capacity of cyclists is typically assessed using incremental and endurance exercise tests. The aim of the present study was to confirm whether peak oxygen uptake (V̇O 2peak ) attained in a sprint interval testing protocol correlates with cycling performance, and whether it corresponds to maximal oxygen uptake (V̇O 2max ) determined by an incremental testing protocol. A sample of 28 trained mountain bike cyclists executed 3 performance tests: (i) incremental testing protocol (ITP) in which the participant cycled to volitional exhaustion, (ii) sprint interval testing protocol (SITP) composed of four 30 s maximal intensity cycling bouts interspersed with 90 s recovery periods, (iii) competition in a simulated mountain biking race. Oxygen uptake, pulmonary ventilation, work, and power output were measured during the ITP and SITP with postexercise blood lactate and hydrogen ion concentrations collected. Race times were recorded. No significant inter-individual differences were observed in regards to any of the ITP-associated variables. However, 9 individuals presented significantly increased oxygen uptake, pulmonary ventilation, and work output in the SITP compared with the remaining cyclists. In addition, in this group of 9 cyclists, oxygen uptake in SITP was significantly higher than in ITP. After the simulated race, this group of 9 cyclists achieved significantly better competition times (99.5 ± 5.2 min) than the other cyclists (110.5 ± 6.7 min). We conclude that mountain bike cyclists who demonstrate higher peak oxygen uptake in a sprint interval testing protocol than maximal oxygen uptake attained in an incremental testing protocol demonstrate superior competitive performance.

  1. Space Radiation Intelligence System (SPRINTS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NextGen Federal Systems proposes an innovative SPace Radiation INTelligence System (SPRINTS) which provides an interactive and web-delivered capability that...

  2. Estimation of tensile force in the hamstring muscles during overground sprinting.

    Science.gov (United States)

    Ono, T; Higashihara, A; Shinohara, J; Hirose, N; Fukubayashi, T

    2015-02-01

    The purpose of this study was to identify the period of the gait cycle during which the hamstring muscles were likely injured by estimating the magnitude of tensile force in each muscle during overground sprinting. We conducted three-dimensional motion analysis of 12 male athletes performing overground sprinting at their maximal speed and calculated the hamstring muscle-tendon length and joint angles of the right limb throughout a gait cycle during which the ground reaction force was measured. Electromyographic activity during sprinting was recorded for the biceps femoris long head, semitendinosus, and semimembranosus muscles of ipsilateral limb. We estimated the magnitude of tensile force in each muscle by using the length change occurred in the musculotendon and normalized electromyographic activity value. The study found a quick increase of estimated tensile force in the biceps femoris long head during the early stance phase of the gait cycle during which the increased hip flexion angle and ground reaction force occurred at the same time. This study provides quantitative data of tensile force in the hamstring muscles suggesting that the biceps femoris long head muscle is susceptible to a strain injury during the early stance phase of the sprinting gait cycle. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males

    Directory of Open Access Journals (Sweden)

    Orem Ihsan

    2009-04-01

    Full Text Available Abstract Background Recent research has indicated that short term administration of glycine propionyl-L-carnitine (GPLC significantly elevates levels of nitric oxide metabolites at rest and in response to reactive hyperaemia. However, no scientific evidence exists that suggests such supplementation enhances exercise performance in healthy, trained individuals. The purpose of this study was to examine the effects of GPLC on the performance of repeated high intensity stationary cycle sprints with limited recovery periods in resistance trained male subjects. Methods In a double-blind, placebo-controlled, cross-over design, twenty-four male resistance trained subjects (25.2 ± 3.6 years participated in two test sessions separated by one week. Testing was performed 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose (PL, in randomized order. The exercise testing protocol consisted of five 10-second Wingate cycle sprints separated by 1-minute active recovery periods. Peak (PP and mean values (MP of sprint power output and percent decrement of power (DEC were determined per bout and standardized relative to body masss. Heart rate (HR and blood lactate (LAC were measured prior to, during and following the five sprint bouts. Results Significant main effects (p Conclusion These findings indicate that short-term oral supplementation of GPLC can enhance peak power production in resistance trained males with significantly less LAC accumulation.

  4. Establishing a Practical Treadmill Sprint as an Alternative to the Wingate Anaerobic Test

    Science.gov (United States)

    McKie, Greg L.; Islam, Hashim; Townsend, Logan K.; Howe, Greg J.; Hazell, Tom J.

    2018-01-01

    This study examined the validity and reliability of a 30-second running sprint test using two non-motorized treadmills compared to the established Wingate Anaerobic Test. Twenty-four participants completed three sessions in a randomized order on a: (1) manual mode treadmill (Woodway); (2) specialized interval training treadmill (HiTrainer); and…

  5. Ground Reaction Force and Cadence during Stationary Running Sprint in Water and on Land.

    Science.gov (United States)

    Fontana, H de Brito; Ruschel, C; Haupenthal, A; Hubert, M; Roesler, H

    2015-06-01

    This study was aimed at analyzing the cadence (Cadmax) and the peak vertical ground reaction force (Fymax) during stationary running sprint on dry land and at hip and chest level of water immersion. We hypothesized that both Fymax and Cadmax depend on the level of immersion and that differences in Cadmax between immersions do not affect Fymax during stationary sprint. 32 subjects performed the exercise at maximum cadence at each immersion level and data were collected with force plates. The results show that Cadmax and Fymax decrease 17 and 58% from dry land to chest immersion respectively, with no effect of cadence on Fymax. While previous studies have shown similar neuromuscular responses between aquatic and on land stationary sprint, our results emphasize the differences in Fymax between environments and levels of immersion. Additionally, the characteristics of this exercise permit maximum movement speed in water to be close to the maximum speed on dry land. The valuable combination of reduced risk of orthopedic trauma with similar neuromuscular responses is provided by the stationary sprint exercise in water. The results of this study support the rationale behind the prescription of stationary sprinting in sports training sessions as well as rehabilitation programs. © Georg Thieme Verlag KG Stuttgart · New York.

  6. The Effect of Acceleration Sprint and Zig-zag Drill Combination to Increase Students’ Speed and Agility

    Science.gov (United States)

    Bana, O.; Mintarto, E.; Kusnanik, N. W.

    2018-01-01

    The purpose of this research is to analyze the following factors: (1) how far the effect of exercise acceleration sprint on the speed and agility (2) how much influence the zig-zag drill combination to the speed and agility (3) and is there any difference between the effects of exercise acceleration sprint and practice zig-zag drill combination of the speed and agility. This research is quantitative with quasi-experimental approach. The design of this study is matching only design.This study was conducted on 33 male students who take part in extracurricular and divided into 3 groups with 11 students in each group. Group 1 was given training of acceleration sprint, group 2 was given zig-zag training combination drills of conventional and exercises for group 3, for 8 weeks. The data collection was using sprint 30 meter to test the speed and agility t-test to test agility. Data were analyzed using t-test and analysis of variance. The conclusion of the research is (1) there is a significant effect of exercise acceleration sprint for the speed and agility, (2) there is a significant influence combination zig-zag drills, on speed and agility (3) and exercise acceleration sprint have more effect on the speed and agility.

  7. Comparison of ergometer- and track-based testing in junior track-sprint cyclists. Implications for talent identification and development.

    Science.gov (United States)

    Tofari, Paul J; Cormack, Stuart J; Ebert, Tammie R; Gardner, A Scott; Kemp, Justin G

    2017-10-01

    Talent identification (TID) and talent development (TDE) programmes in track sprint cycling use ergometer- and track-based tests to select junior athletes and assess their development. The purpose of this study was to assess which tests are best at monitoring TID and TDE. Ten male participants (16.2 ± 1.1 year; 178.5 ± 6.0 cm and 73.6 ± 7.6 kg) were selected into the national TID squad based on initial testing. These tests consisted of two 6-s maximal sprints on a custom-built ergometer and 4 maximal track-based tests (2 rolling and 2 standing starts) using 2 gear ratios. Magnitude-based inferences and correlation coefficients assessed changes following a 3-month TDE programme. Training elicited meaningful improvements (80-100% likely) in all ergometer parameters. The standing and rolling small gear, track-based effort times were likely and very likely (3.2 ± 2.4% and 3.3 ± 1.9%, respectively) improved by training. Stronger correlations between ergometer- and track-based measures were very likely following training. Ergometer-based testing provides a more sensitive tool than track-based testing to monitor changes in neuromuscular function during the early stages of TDE. However, track-based testing can indicate skill-based improvements in performance when interpreted with ergometer testing. In combination, these tests provide information on overall talent development.

  8. Cycling for Transportation in Sao Paulo City: Associations with Bike Paths, Train and Subway Stations.

    Science.gov (United States)

    Florindo, Alex Antonio; Barrozo, Ligia Vizeu; Turrell, Gavin; Barbosa, João Paulo Dos Anjos Souza; Cabral-Miranda, William; Cesar, Chester Luiz Galvão; Goldbaum, Moisés

    2018-03-21

    Cities that support cycling for transportation reap many public health benefits. However, the prevalence of this mode of transportation is low in Latin American countries and the association with facilities such as bike paths and train/subway stations have not been clarified. We conducted a cross-sectional analysis of the relationship between bike paths, train/subway stations and cycling for transportation in adults from the city of Sao Paulo. We used data from the Sao Paulo Health Survey ( n = 3145). Cycling for transportation was evaluated by a questionnaire and bike paths and train/subway stations were geocoded using the geographic coordinates of the adults' residential addresses in 1500-m buffers. We used multilevel logistic regression, taking account of clustering by census tract and households. The prevalence of cycling for transportation was low (5.1%), and was more prevalent in males, singles, those active in leisure time, and in people with bicycle ownership in their family. Cycling for transportation was associated with bike paths up to a distance of 500 m from residences (OR (Odds Ratio) = 2.54, 95% CI (Confidence interval) 1.16-5.54) and with the presence of train/subway stations for distances >500 m from residences (OR = 2.07, 95% CI 1.10-3.86). These results are important to support policies to improve cycling for transportation in megacities such as Sao Paulo.

  9. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement.

    Science.gov (United States)

    Yin, Chieh; Hsueh, Ya-Hsin; Yeh, Chun-Yu; Lo, Hsin-Chang; Lan, Yi-Ting

    2016-01-01

    Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS), which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI) between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p = 0.046) and in force plate the stand balance has also improved by 0.29 (p = 0.031); thus both methods show the significant difference.

  10. A Virtual Reality-Cycling Training System for Lower Limb Balance Improvement

    Directory of Open Access Journals (Sweden)

    Chieh Yin

    2016-01-01

    Full Text Available Stroke survivors might lose their walking and balancing abilities, but many studies pointed out that cycling is an effective means for lower limb rehabilitation. However, during cycle training, the unaffected limb tends to compensate for the affected one, which resulted in suboptimal rehabilitation. To address this issue, we present a Virtual Reality-Cycling Training System (VRCTS, which senses the cycling force and speed in real-time, analyzes the acquired data to produce feedback to patients with a controllable VR car in a VR rehabilitation program, and thus specifically trains the affected side. The aim of the study was to verify the functionality of the VRCTS and to verify the results from the ten stroke patients participants and to compare the result of Asymmetry Ratio Index (ARI between the experimental group and the control group, after their training, by using the bilateral pedal force and force plate to determine any training effect. The results showed that after the VRCTS training in bilateral pedal force it had improved by 0.22 (p=0.046 and in force plate the stand balance has also improved by 0.29 (p=0.031; thus both methods show the significant difference.

  11. Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

    Science.gov (United States)

    Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

    2017-11-01

    Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Model training across multiple breeding cycles significantly improves genomic prediction accuracy in rye (Secale cereale L.).

    Science.gov (United States)

    Auinger, Hans-Jürgen; Schönleben, Manfred; Lehermeier, Christina; Schmidt, Malthe; Korzun, Viktor; Geiger, Hartwig H; Piepho, Hans-Peter; Gordillo, Andres; Wilde, Peer; Bauer, Eva; Schön, Chris-Carolin

    2016-11-01

    Genomic prediction accuracy can be significantly increased by model calibration across multiple breeding cycles as long as selection cycles are connected by common ancestors. In hybrid rye breeding, application of genome-based prediction is expected to increase selection gain because of long selection cycles in population improvement and development of hybrid components. Essentially two prediction scenarios arise: (1) prediction of the genetic value of lines from the same breeding cycle in which model training is performed and (2) prediction of lines from subsequent cycles. It is the latter from which a reduction in cycle length and consequently the strongest impact on selection gain is expected. We empirically investigated genome-based prediction of grain yield, plant height and thousand kernel weight within and across four selection cycles of a hybrid rye breeding program. Prediction performance was assessed using genomic and pedigree-based best linear unbiased prediction (GBLUP and PBLUP). A total of 1040 S 2 lines were genotyped with 16 k SNPs and each year testcrosses of 260 S 2 lines were phenotyped in seven or eight locations. The performance gap between GBLUP and PBLUP increased significantly for all traits when model calibration was performed on aggregated data from several cycles. Prediction accuracies obtained from cross-validation were in the order of 0.70 for all traits when data from all cycles (N CS  = 832) were used for model training and exceeded within-cycle accuracies in all cases. As long as selection cycles are connected by a sufficient number of common ancestors and prediction accuracy has not reached a plateau when increasing sample size, aggregating data from several preceding cycles is recommended for predicting genetic values in subsequent cycles despite decreasing relatedness over time.

  13. Effects of plyometric training volume and training surface on explosive strength.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Andrade, David C; Izquierdo, Mikel

    2013-10-01

    The purpose of this study is to examine the effects of different volume and training surfaces during a short-term plyometric training program on neuromuscular performance. Twenty-nine subjects were randomly assigned to 4 groups: control group (CG, n = 5), moderate volume group (MVG, n = 9, 780 jumps), moderate volume hard surface group (MVGHS, n = 8, 780 jumps), and high volume group (HVG, n = 7, 1,560 jumps). A series of tests were performed by the subjects before and after 7 weeks of plyometric training. These tests were measurement of maximum strength (5 maximum repetitions [5RMs]), drop jumps (DJs) of varying heights (20, 40, and 60 cm), squat and countermovement jumps (SJ and CMJ, respectively), timed 20-m sprint, agility, body weight, and height. The results of the present study suggest that high training volume leads to a significant increase in explosive performance that requires fast stretch-shortening cycle (SSC) actions (such as DJ and sprint) in comparison to what is observed after a moderate training volume regimen. Second, when plyometric training is performed on a hard training surface (high-impact reaction force), a moderate training volume induces optimal stimulus to increase explosive performance requiring fast SSC actions (e.g., DJ), maximal dynamic strength enhancement, and higher training efficiency. Thus, a finding of interest in the study was that after 7 weeks of plyometric training, performance enhancement in maximal strength and in actions requiring fast SSC (such as DJ and sprint) were dependent on the volume of training and the surface on which it was performed. This must be taken into account when using plyometric training on different surfaces.

  14. Autonomic modulations of heart rate variability are associated with sports injury incidence in sprint swimmers.

    Science.gov (United States)

    Lima-Borges, Dayanne S; Martinez, Paula F; Vanderlei, Luiz Carlos M; Barbosa, Fernando S S; Oliveira-Junior, Silvio A

    2018-03-28

    Young athletes' participation in competitive sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of overtraining and sports injuries. Since these issues are poorly understood, this study analyzed heart rate variability, stress/recovery relationship, and sports injury incidence during a training macrocycle of young sprint and endurance swimmers. Thirty teenage swimmers (aged 12 to 17 years) were divided into two groups as follows: Sprint (n = 17) and Endurance (n = 13). Subjects were evaluated over 20 weeks, based on the following three schedules: general, specific, and competitive. In addition to heart rate variability and sports injury incidence, the Recovery-Stress-Questionnaire of Athletes was used to analyse stress/recovery states in athletes. All procedures were developed at the initial moment and at the end of each periodization step. The Sprint group presented a reduced standard deviation of normal-normal beats (73.0 ± 6.6 vs. 54.1 ± 3.5 ms; p sports injury than the Endurance group (0.0214 ± 0.0068 vs. 0.0136 ± 0.0050 cases/1000 hours). Sprint training was associated with progressive activation of the sympathetic nervous system as well as a higher incidence of sports injury in comparison to endurance swimming during a training macrocycle.

  15. Development of repeated sprint ability in talented youth basketball players.

    Science.gov (United States)

    te Wierike, Sanne C M; de Jong, Mark C; Tromp, Eveline J Y; Vuijk, Pieter J; Lemmink, Koen A P M; Malina, Robert M; Elferink-Gemser, Marije T; Visscher, Chris

    2014-04-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14-19 years of age (16.1 ± 1.7 years). Players were observed on 6 occasions during the 2008-09 and 2009-10 seasons. Three following basketball-specific field tests were administered on each occasion: the shuttle sprint test for RSA, the vertical jump for lower body explosive strength (power), and the interval shuttle run test for interval endurance capacity. Height and weight were measured; body composition was estimated (percent fat, lean body mass). Multilevel modeling of RSA development curve was used with 32 players (16.0 ± 1.7 years) who had 2 or more observations. The 16 players (16.1 ± 1.8 years) measured on only 1 occasion were used as a control group to evaluate the appropriateness of the model. Age, lower body explosive strength, and interval endurance capacity significantly contributed to RSA (p ≤ 0.05). Repeated sprint ability improved with age from 14 to 17 years (p ≤ 0.05) and reached a plateau at 17-19 years. Predicted RSA did not significantly differ from measured RSA in the control group (p ≥ 0.05). The results suggest a potentially important role for the training of lower body explosive strength and interval endurance capacity in the development of RSA among youth basketball players. Age-specific reference values for RSA of youth players may assist basketball coaches in setting appropriate goals for individual players.

  16. Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting.

    Science.gov (United States)

    Requena, Bernardo; García, Inmaculada; Requena, Francisco; de Villarreal, Eduardo Sáez-Sáez; Cronin, John B

    2011-08-01

    The purpose of this study was to quantify the magnitude of the relationship between vertical jumping and maximal sprinting at different distances with performance in the traditional and ballistic concentric squat exercise in well-trained sprinters. Twenty-one men performed 2 types of barbell squats (ballistic and traditional) across different loads with the aim of determining the maximal peak and average power outputs and 1 repetition maximum (1RM) values. Moreover, vertical jumping (countermovement jump test [CMJ]) and maximal sprints over 10, 20, 30, 40, 60, and 80 m were also assessed. In respect to 1RM in traditional squat, (a) no significant correlation was found with CMJ performance; (b) positive strong relationships (p ballistic and traditional squat exercises (r = 0.53-0.90); (c) negative significant correlations (r = -0.49 to -0.59, p ballistic or traditional squat exercises. Sprint time at 20 m was only related to ballistic and traditional squat performance when power values were expressed in relative terms. Moderate significant correlations (r = -0.39 to -0.56, p ballistic and traditional squat exercises. Sprint times at 60 and 80 m were mainly related to ballistic squat power outputs. Although correlations can only give insights into associations and not into cause and effect, from this investigation, it can be seen that traditional squat strength has little in common with CMJ performance and that relative 1RM and power outputs for both squat exercises are statistically correlated to most sprint distances underlying the importance of strength and power to sprinting.

  17. The recovery of repeated-sprint exercise is associated with PCr resynthesis, while muscle pH and EMG amplitude remain depressed.

    Directory of Open Access Journals (Sweden)

    Alberto Mendez-Villanueva

    Full Text Available The physiological equivalents of power output maintenance and recovery during repeated-sprint exercise (RSE remain to be fully elucidated. In an attempt to improve our understanding of the determinants of RSE performance we therefore aimed to determine its recovery following exhaustive exercise (which affected intramuscular and neural factors concomitantly with those of intramuscular concentrations of adenosine triphosphate [ATP], phosphocreatine [PCr] and pH values and electromyography (EMG activity (a proxy for net motor unit activity changes. Eight young men performed 10, 6-s all-out sprints on a cycle ergometer, interspersed with 30 s of recovery, followed, after 6 min of passive recovery, by five 6-s sprints, again interspersed by 30 s of passive recovery. Biopsies of the vastus lateralis were obtained at rest, immediately after the first 10 sprints and after 6 min of recovery. EMG activity of the vastus lateralis was obtained from surface electrodes throughout exercise. Total work (TW, [ATP], [PCr], pH and EMG amplitude decreased significantly throughout the first ten sprints (P<0.05. After 6 min of recovery, TW during sprint 11 recovered to 86.3±7.7% of sprint 1. ATP and PCr were resynthesized to 92.6±6.0% and 85.3±10.3% of the resting value, respectively, but muscle pH and EMG amplitude remained depressed. PCr resynthesis was correlated with TW done in sprint 11 (r = 0.79, P<0.05 and TW done during sprints 11 to 15 (r = 0.67, P<0.05. There was a ∼2-fold greater decrease in the TW/EMG ratio in the last five sprints (sprint 11 to 15 than in the first five sprints (sprint 1 to 5 resulting in a disproportionate decrease in mechanical power (i.e., TW in relation to EMG. Thus, we conclude that the inability to produce power output during repeated sprints is mostly mediated by intramuscular fatigue signals probably related with the control of PCr metabolism.

  18. Effect of ischemic preconditioning on land-based sprinting in team-sport athletes.

    Science.gov (United States)

    Gibson, Neil; White, James; Neish, Mhari; Murray, Andrew

    2013-11-01

    The study aimed to assess whether exposure to ischemic preconditioning (IPC) in a trained population would affect land-based maximal sprinting performance over 30 m. Twenty-five well-trained participants regularly involved in invasion-type team-sport events were recruited to take part in a randomized crossover study design. Participants underwent both an IPC and a placebo treatment involving 3 periods of 5-min occlusion applied unilaterally (3 × 5-min occlusion to each leg) at either 220 mmHg or 50 mmHg, respectively. Each period of occlusion was followed by 5 min of reperfusion. After treatment, 3 maximal sprints over a distance of 30 m were undertaken from a standing start interspersed with 1-min recovery. Split times were recorded at 10, 20, and 30 m. No significant effects of the IPC treatment were observed on sprint speed (P split timings; however, a small and negative effect was observed in female participants. Calculated effect sizes of the treatment were found to be trivial (swimming, further research is required to elucidate whether this is the case over distances associated with land-based events in track and field or in events reliant on repeated-sprint ability.

  19. Effect of formoterol, a long-acting β2-adrenergic agonist, on muscle strength and power output, metabolism and fatigue during maximal sprinting in men

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Backer, Vibeke

    2016-01-01

    The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE) m......L min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured...

  20. GHG-emissions for cars with different power trains over the whole life cycle

    Energy Technology Data Exchange (ETDEWEB)

    Roeder, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The method of life-cycle assessment (LCA) has been applied to cars with different power trains. As an example, the results for greenhouse gas (GHG) emissions are presented. They show possibilities and limits for the reduction of these emissions in the transportation sector by means of advanced technology. (author) 2 figs., 4 refs.

  1. Menstrual Cycle Effects on Anaerobic Power, Muscular Strength, and Muscular Endurance in Trained and Untrained Females.

    Science.gov (United States)

    Rosenburg, Beth S.; And Others

    A study determined if anaerobic power, isometric strength, and isometric endurance are affected by the menstrual cycle and if endurance trained females and untrained females are affected in the same manner on these performance parameters. Subjects were healthy, normally menstruating females, ages 18-34 years who were classified as either trained…

  2. A seven day running training period increases basal urinary hepcidin levels as compared to cycling

    NARCIS (Netherlands)

    Sim, M.; Dawson, B.; Landers, G.J.; Swinkels, D.W.; Tjalsma, H.; Wiegerinck, E.T.G.; Trinder, D.; Peeling, P.

    2014-01-01

    BACKGROUND: This investigation compared the effects of an extended period of weight-bearing (running) vs. non-weight-bearing (cycling) exercise on hepcidin production and its implications for iron status. METHODS: Ten active males performed two separate exercise training blocks with either running

  3. Insulin Responsiveness in Metabolic Syndrome after Eight Weeks of Cycle Training

    Science.gov (United States)

    Stuart, Charles A.; South, Mark A.; Lee, Michelle L.; McCurry, Melanie P.; Howell, Mary E. A.; Ramsey, Michael W.; Stone, Michael H.

    2013-01-01

    Introduction Insulin resistance in obesity is decreased after successful diet and exercise. Aerobic exercise training alone was evaluated as an intervention in subjects with the metabolic syndrome. Methods Eighteen non-diabetic, sedentary subjects, eleven with the metabolic syndrome, participated in eight weeks of increasing intensity stationary cycle training. Results Cycle training without weight loss did not change insulin resistance in metabolic syndrome subjects or sedentary control subjects. Maximal oxygen consumption (VO2max), activated muscle AMP-dependent kinase, and muscle mitochondrial marker ATP synthase all increased. Strength, lean body mass, and fat mass did not change. Activated mammalian target of rapamycin was not different after training. Training induced a shift in muscle fiber composition in both groups but in opposite directions. The proportion of 2x fibers decreased with a concomitant increase in 2a mixed fibers in the control subjects, but in metabolic syndrome, 2x fiber proportion increased and type 1 fibers decreased. Muscle fiber diameters increased in all three fiber types in metabolic syndrome subjects. Muscle insulin receptor expression increased in both groups and GLUT4 expression increased in the metabolic syndrome subjects. Excess phosphorylation of insulin receptor substrate-1 (IRS-1) at Ser337 in metabolic syndrome muscle tended to increase further after training in spite of a decrease in total IRS-1. Conclusion In the absence of weight loss, cycle training of metabolic syndrome subjects resulted in enhanced mitochondrial biogenesis, and increased expression of insulin receptors and GLUT4 in muscle, but did not decrease the insulin resistance. The failure for the insulin signal to proceed past IRS-1 tyrosine phosphorylation may be related to excess serine phosphorylation at IRS-1 Ser337 and this is not ameliorated by eight weeks of endurance exercise training. PMID:23669880

  4. An Automatic Identification Procedure to Promote the use of FES-Cycling Training for Hemiparetic Patients

    Directory of Open Access Journals (Sweden)

    Emilia Ambrosini

    2014-01-01

    Full Text Available Cycling induced by Functional Electrical Stimulation (FES training currently requires a manual setting of different parameters, which is a time-consuming and scarcely repeatable procedure. We proposed an automatic procedure for setting session-specific parameters optimized for hemiparetic patients. This procedure consisted of the identification of the stimulation strategy as the angular ranges during which FES drove the motion, the comparison between the identified strategy and the physiological muscular activation strategy, and the setting of the pulse amplitude and duration of each stimulated muscle. Preliminary trials on 10 healthy volunteers helped define the procedure. Feasibility tests on 8 hemiparetic patients (5 stroke, 3 traumatic brain injury were performed. The procedure maximized the motor output within the tolerance constraint, identified a biomimetic strategy in 6 patients, and always lasted less than 5 minutes. Its reasonable duration and automatic nature make the procedure usable at the beginning of every training session, potentially enhancing the performance of FES-cycling training.

  5. Can FES-augmented active cycling training improve locomotion in post-acute elderly stroke patients?

    Directory of Open Access Journals (Sweden)

    Elisabetta Peri

    2016-06-01

    Full Text Available Recent studies advocated the use of active cycling coupled with functional electrical stimulation to induce neuroplasticity and enhance functional improvements in stroke adult patients. The aim of this work was to evaluate whether the benefits induced by such a treatment are superior to standard physiotherapy. A single-blinded randomized controlled trial has been performed on post-acute elderly stroke patients. Patients underwent FES-augmented cycling training combined with voluntary pedaling or standard physiotherapy. The intervention consisted of fifteen 30-minutes sessions carried out within 3 weeks. Patients were evaluated before and after training, through functional scales, gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy group. Sixteen patients completed the training. After treatment, a general improvement of all clinical scales was obtained for both groups. Only the mechanical efficiency highlighted a group effect in favor of the experimental group. Although a group effect was not found for any other cycling or gait parameters, the experimental group showed a higher percentage of change with respect to the control group (e.g. the gait velocity was improved of 35.4% and 25.4% respectively, and its variation over time was higher than minimal clinical difference for the experimental group only. This trend suggests that differences in terms of motor recovery between the two groups may be achieved increasing the training dose. In conclusion, this study, although preliminary, showed that FES-augmented active cycling training seems to be effective in improving cycling and walking ability in post-acute elderly stroke patients. A higher sample size is required to confirm results.

  6. Approaches to realization of year cycle of Iraq football players’ sport training

    Directory of Open Access Journals (Sweden)

    Sadek Drevel Khalaf

    2015-10-01

    Full Text Available Purpose: to substantiate ways of increase of Iraq football players’ training process effectiveness, depending on calendar of events. Material: analysis of technical-tactic actions was conducted by quantitative and qualitative characteristics of football players in every match. The analysis was presented by mean indicators of matches of the first (n=15 and second (n=15 rounds of championships of Iraq premier league 2011-2014. Results: we realized conception of periodization of Iraq elite football players’ sport training. Specific conditions of periodization of Iraq sportsmen’s training have been worked out and substantiated. Scientific-methodic basis of perfection of Iraq football players’ training process management has been formed. On the base of heuristic simulation we formulated algorithm of realization of Iraq premier league football players’ year cycle training. It is recommended to use higher and more significant loads with correlation 50% and 30% from total scope of training sessions. Conclusions: On principles of rational combination we built hierarchy of macro-cycles’ structural components, combined in single, formed year cycle during long term competition season.

  7. Swimming and cycling overloaded training in triathlon has no effect on running kinematics and economy.

    Science.gov (United States)

    Palazzetti, S; Margaritis, I; Guezennec, C Y

    2005-04-01

    The aim of the study was to verify whether an overloaded training (OT) in triathlon deteriorates running kinematics (RK) and running economy (RE). Thirteen well-trained male long-distance triathletes (age: 28.1 +/- 4.3 yrs; V.O (2max): 65.0 +/- 3.1 ml O (2) . min (-1) . kg (-1)) were divided into two groups: completed an individualized OT program (OG; n = 7) or maintained a normal level of training (NT) (CG; n = 6) for a duration of 3 weeks. Every week, each triathlete completed a standardized questionnaire to quantify the influence of training loads on mood state. To reach OT, total training load (h . 3 wk (-1)) was increased by 24 %; swimming and cycling total volumes were increased by 46 and 57 %, respectively, but the distance run was not modified in order to limit the risk of injuries. RK and RE were determined on treadmill test at 12 km . h (-1) before and after the 3 weeks. The 3-week swimming and cycling OT in triathlon was sufficiently stressful to alter mood state but not to deteriorate the running kinematics and economy parameters in our previously well-trained male long-distance triathletes.

  8. Acute Effects of Plyometric Intervention—Performance Improvement and Related Changes in Sprinting Gait Variability.

    Science.gov (United States)

    Maćkała, Krzysztof; Fostiak, Marek

    2015-07-01

    The purpose of this study was to examine the effect of a short high-intensity plyometric program on the improvement of explosive power of lower extremities and sprint performance as well as changes in sprinting stride variability in male sprinters. Fourteen healthy male sprinters (mean ± SD: age: 18.07 ± 0.73 years, body mass: 73 ± 9.14 kg, height: 180.57 ± 8.16 cm, and best 100 m: 10.89 ± 0.23) participated in the experiment. The experimental protocol included vertical jumping such as squat jump, countermovement jump, and horizontal jumps; standing long jump and standing triple jumps to assess lower-body power, maximal running velocity; a 20-m flying start sprint that evaluated variability of 10 running steps and 60-m starting block sprint. All analyzed parameters were obtained using the new technology of OptoJump-Microgate (OptoJump, Italy). The short-term plyometric training program significantly increased the explosive power of lower extremities, both vertical and horizontal jumping improvement. However, the vertical jumps increased much more than the horizontal. The 20-m improvements were derived from an increase of stride frequency from 4.31 to 4.39 Hz because of a decrease of ground contact time from 138 to 133 milliseconds. This did not translate into step length changes. Therefore, the significantly increased frequency of stride (1.8%), which is a specific expression of ground contact time reduction during support phase, resulted in an increase of speed. The training volume of 2 weeks (with 6 sessions) using high-intensity (between 180 and 250 jumps per session) plyometric exercises can be recommended as the short-term strategy that will optimize one's probability of reaching strong improvements in explosive power and sprint velocity performance.

  9. Consecutive days of cold water immersion: effects on cycling performance and heart rate variability.

    Science.gov (United States)

    Stanley, Jamie; Peake, Jonathan M; Buchheit, Martin

    2013-02-01

    We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cycling with post-exercise cold water immersion (CWI) or passive recovery (PAS). In a crossover design, 11 cyclists completed two separate 3-day training blocks (120 min cycling per day, 66 maximal sprints, 9 min time trialling [TT]), followed by 2 days of recovery-based training. The cyclists recovered from each training session by standing in cold water (10 °C) or at room temperature (27 °C) for 5 min. Mean power for sprints, total TT work and HR were assessed during each session. Resting vagal-HRV (natural logarithm of square-root of mean squared differences of successive R-R intervals; ln rMSSD) was assessed after exercise, after the recovery intervention, during sleep and upon waking. CWI allowed better maintenance of mean sprint power (between-trial difference [90 % confidence limits] +12.4 % [5.9; 18.9]), cadence (+2.0 % [0.6; 3.5]), and mean HR during exercise (+1.6 % [0.0; 3.2]) compared with PAS. ln rMSSD immediately following CWI was higher (+144 % [92; 211]) compared with PAS. There was no difference between the trials in TT performance (-0.2 % [-3.5; 3.0]) or waking ln rMSSD (-1.2 % [-5.9; 3.4]). CWI helps to maintain sprint performance during consecutive days of training, whereas its effects on vagal-HRV vary over time and depend on prior exercise intensity.

  10. Improved Function and Reduced Pain after Swimming and Cycling Training in Patients with Osteoarthritis.

    Science.gov (United States)

    Alkatan, Mohammed; Baker, Jeffrey R; Machin, Daniel R; Park, Wonil; Akkari, Amanda S; Pasha, Evan P; Tanaka, Hirofumi

    2016-03-01

    Arthritis and its associated joint pain act as significant barriers for adults attempting to perform land-based physical activity. Swimming can be an ideal form of exercise for patients with arthritis. Yet there is no information on the efficacy of regular swimming exercise involving patients with arthritis. The effect of a swimming exercise intervention on joint pain, stiffness, and physical function was evaluated in patients with osteoarthritis (OA). Using a randomized study design, 48 sedentary middle-aged and older adults with OA underwent 3 months of either swimming or cycling exercise training. Supervised exercise training was performed for 45 min/day, 3 days/week at 60-70% heart rate reserve for 12 weeks. The Western Ontario and McMaster Universities Arthritis Index was used to measure joint pain, stiffness, and physical limitation. After the exercise interventions, there were significant reductions in joint pain, stiffness, and physical limitation accompanied by increases in quality of life in both groups (all p swimming and cycling training. Regular swimming exercise reduced joint pain and stiffness associated with OA and improved muscle strength and functional capacity in middle-aged and older adults with OA. Additionally, the benefits of swimming exercise were similar to the more frequently prescribed land-based cycling training. clinicaltrials.gov NCT01836380.

  11. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training

    Directory of Open Access Journals (Sweden)

    Martin eBehrens

    2015-05-01

    Full Text Available Previously published studies on the effect of short-term endurance training on the neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after eight weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms and isometric maximum voluntary contraction of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave, peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that the endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue

  12. Effectiveness of cycle fit, a 6-week training program for novice cyclers, on increasing physical activity: a controlled study.

    NARCIS (Netherlands)

    Ooms, L.; Veenhof, C.

    2014-01-01

    Introduction: In the Netherlands, National Sports Federations were funded to develop “easily accessible” sporting programs aimed at inactive population groups. Cycle Fit, a 6-week training program for novice cyclers (i.e. mountain biking, race cycling), developed by the Dutch Cycle Federation, is

  13. Effects of the Nordic Hamstring exercise on sprint capacity in male football players: a randomized controlled trial.

    Science.gov (United States)

    Ishøi, Lasse; Hölmich, Per; Aagaard, Per; Thorborg, Kristian; Bandholm, Thomas; Serner, Andreas

    2018-07-01

    This assessor-blinded, randomized controlled superiority trial investigated the efficacy of the 10-week Nordic Hamstring exercise (NHE) protocol on sprint performance in football players. Thirty-five amateur male players (age: 17-26 years) were randomized to a do-as-usual control group (CG; n = 17) or to 10-weeks of supervised strength training using the NHE in-season (IG; n = 18). A repeated-sprint test, consisting of 4 × 6 10 m sprints, with 15 s recovery period between sprints and 180 s between sets, was conducted to evaluate total sprint time as the primary outcome. Secondary outcomes were best 10 m sprint time (10mST) and sprint time during the last sprint (L10mST). Additionally, peak eccentric hamstring strength (ECC-P HS ) and eccentric hamstring strength capacity (ECC-CAP HS ) were measured during the NHE. Ten players were lost to follow-up, thus 25 players were analyzed (CG n = 14; IG n = 11). Between-group differences in mean changes were observed in favor of the IG for sprint performance outcomes; TST (-0.649 s, p = 0.056, d = 0.38), 10mST (-0.047 s, p = 0.005, d = 0.64) and L10mST (-0.052 s, p = 0.094, d = 0.59), and for strength outcomes; ECC-P HS (62.3 N, p = 0.006, d = 0.92), and ECC-CAP HS (951 N, p = 0.005, d = 0.95). In conclusion, the NHE showed small-to-medium improvements in sprint performance and large increases in peak eccentric hamstring strength and capacity. NCT02674919.

  14. Isometric strength training lowers the O2 cost of cycling during moderate-intensity exercise.

    Science.gov (United States)

    Zoladz, Jerzy A; Szkutnik, Zbigniew; Majerczak, Joanna; Grandys, Marcin; Duda, Krzysztof; Grassi, Bruno

    2012-12-01

    The effect of maximal voluntary isometric strength training of knee extensor muscles on pulmonary V'O(2) on-kinetics, the O(2) cost of cycling and peak oxygen uptake (V'O(2peak)) in humans was studied. Seven healthy males (mean ± SD, age 22.3 ± 2.0 years, body weight 75.0 ± 9.2 kg, V'O(2peak) 49.5 ± 3.8 ml kg(-1) min(-1)) performed maximal isometric strength training lasting 7 weeks (4 sessions per week). Force during maximal voluntary contraction (MVC) increased by 15 % (P Strength training resulted in a significant decrease (by ~7 %; P Isometric strength training rapidly (i.e., after 1 week) decreases the O(2) cost of cycling during moderate-intensity exercise, whereas it does not affect the amplitude of the slow component of the V'O(2) on-kinetics during heavy-intensity exercise. Isometric strength training can have beneficial effects on performance during endurance events.

  15. Education and training in LCA and life-cycle thinking experience and needs

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Bey, Niki; Hauschild, Michael Zwicky

    2003-01-01

    . The target group for the educational offers are students of both short and long term higher education, primarily engineering students of various disciplines. However, teaching within LCA and life cycle thinking also takes place in curricula for designers, architects and production technicians. The target...... group for the training are in most cases companies, and participants are in mostly employees from the environmental department, but there are also offers for governmental authorities and unemployed. Both education and further training mainly convey qualifications on a "knowing about"-level in the form...

  16. Relationship Between Jumping Ability, Agility and Sprint Performance of Elite Young Basketball Players: A Field-Test Approach

    Directory of Open Access Journals (Sweden)

    Abbas Asadi

    2016-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p177   The purpose of this study was to determine the relationships between sprint, agility and jump performance of elite young basketball players. Sixteen elite national level young male basketball players participated in this study. The jumping ability of each player was determined using countermovement jump (CMJ, and broad long jump (BLJ. The agility T test (TT and Illinois agility test (IAT were assessed to determine the agility, and 20-m sprint time was also measured to determine sprint performance. The results of Pearson Product Moment Correlation analysis indicated moderate correlation between training age and IAT (r = -0.57; p = 0.021. Strong correlations were found between CMJ and BLJ (r = 0.71; p = 0.002, and between TT and IAT (r = 0.70; p = 0.002. Similarly, 20-m sprint time was strong correlated with CMJ (r = -0.61; p = 0.011, BLJ (r = -0.76; p = 0.001, TT (r = 0.77; p = 0.001, and IAT (r = 0.68; p = 0.003. In addition, CMJ was strongly correlated with TT (r = -0.60; p = 0.013, and IAT (r = -0.64; p = 0.007, and also strong correlation between BLJ with TT (r = -0.85; p = 0.001 and IAT (r = -0.76; p = 0.001. The findings of the present study indicated significant correlation between sprint and agility, jumping ability and sprint performance and between jumping ability and agility performance in basketball players. Therefore, the results suggest that sprint, agility and jumping ability share common physiological and biomechanical determinants.

  17. Mechanics of the human hamstring muscles during sprinting.

    Science.gov (United States)

    Schache, Anthony G; Dorn, Tim W; Blanch, Peter D; Brown, Nicholas A T; Pandy, Marcus G

    2012-04-01

    An understanding of hamstring mechanics during sprinting is important for elucidating why these muscles are so vulnerable to acute strain-type injury. The purpose of this study was twofold: first, to quantify the biomechanical load (specifically, musculotendon strain, velocity, force, power, and work) experienced by the hamstrings across a full stride cycle; and second, to determine how these parameters differ for each hamstring muscle (i.e., semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BF), biceps femoris short head (BF)). Full-body kinematics and ground reaction force data were recorded simultaneously from seven subjects while sprinting on an indoor running track. Experimental data were integrated with a three-dimensional musculoskeletal computer model comprised of 12 body segments and 92 musculotendon structures. The model was used in conjunction with an optimization algorithm to calculate musculotendon strain, velocity, force, power, and work for the hamstrings. SM, ST, and BF all reached peak strain, produced peak force, and formed much negative work (energy absorption) during terminal swing. The biomechanical load differed for each hamstring muscle: BF exhibited the largest peak strain, ST displayed the greatest lengthening velocity, and SM produced the highest peak force, absorbed and generated the most power, and performed the largest amount of positive and negative work. As peak musculotendon force and strain for BF, ST, and SM occurred around the same time during terminal swing, it is suggested that this period in the stride cycle may be when the biarticular hamstrings are at greatest injury risk. On this basis, hamstring injury prevention or rehabilitation programs should preferentially target strengthening exercises that involve eccentric contractions performed with high loads at longer musculotendon lengths.

  18. Effects of Cycling vs. Running Training on Endurance Performance in Preparation for Inline Speed Skating.

    Science.gov (United States)

    Stangier, Carolin; Abel, Thomas; Hesse, Clemens; Claen, Stephanie; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-06-01

    Winter weather conditions restrict regular sport-specific endurance training in inline speed skating. As a result, this study was designed to compare the effects of cycling and running training programs on inline speed skaters' endurance performance. Sixteen (8 men, 8 women) high-level athletes (mean ± SD 24 ± 8 years) were randomly assigned to 1 of 2 groups (running and cycling). Both groups trained twice a week for 8 weeks, one group on a treadmill and the other on a cycle ergometer. Training intensity and duration was individually calculated (maximal fat oxidation: ∼52% of V[Combining Dot Above]O2peak: 500 kcal per session). Before and after the training intervention, all athletes performed an incremental specific (inline speed skating) and 1 nonspecific (cycling or running) step test according to the group affiliation. In addition to blood lactate concentration, oxygen uptake (V[Combining Dot Above]O2), ventilatory equivalent (VE/V[Combining Dot Above]O2), respiratory exchange ratio (RER), and heart rate were measured. The specific posttest revealed significantly increased absolute V[Combining Dot Above]O2peak values (2.9 ± 0.4, 3.4 ± 0.7, p = 0.01) and submaximal V[Combining Dot Above]O2 values (p ≤ 0.01). VE/V[Combining Dot Above]O2 and RER significantly decreased at maximal (46.6 ± 6.6, 38.5 ± 3.4, p = 0.005; 1.1 ± 0.03, 1.0 ± 0.04, p = 0.001) and submaximal intensities (p ≤ 0.04). None of the analysis revealed a significant group effect (p ≥ 0.15). The results indicate that both cycling vs. running exercise at ∼52% of V[Combining Dot Above]O2peak had a positive effect on the athletes' endurance performance. The increased submaximal V[Combining Dot Above]O2 values indicate a reduction in athletes' inline speed skating technique. Therefore, athletes would benefit from a focus on technique training in the subsequent period.

  19. Effect of visual biofeedback cycling training on gait in patients with multiple sclerosis.

    Science.gov (United States)

    Hochsprung, A; Granja Domínguez, A; Magni, E; Escudero Uribe, S; Moreno García, A

    2017-09-06

    Gait alterations are present in a high percentage of patients with multiple sclerosis (MS). They appear from early stages of the disease and can limit patients' capacity to perform basic activities of daily living, affecting their quality of life. Visual biofeedback cycling training appears to be a useful tool in treating these impairments. This study aims to evaluate the short-term effect of visual biofeedback cycling training on gait in patients with MS. A total of 61 patients with mild to moderate MS were randomly assigned to a control group and an intervention group. The intervention group received visual biofeedback cycling training (MOTOmed viva2 system) once per week for 3 months, and a home exercise program. The control group only received the home exercise program. Both groups were evaluated using the GAITRite ® Walkway gait assessment system before the intervention, during the first month of the programme, and after the intervention. In the intervention group, the analysis revealed statistically significant differences between Functional Ambulation Profile (FAP) scores before and during the intervention (P=.014), and before and after the intervention (P=.002). A statistically significant improvement was observed in step length in the intervention group between pre- and post-intervention scores (P=.001) and between first-month and post-intervention scores (P=.004). Visual biofeedback cycling training improved specific gait parameters in the short term and appears to be a therapeutic option for gait retraining in patients with MS. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Cycle Training Increased GLUT4 and Activation of mTOR in Fast Twitch Muscle Fibers

    Science.gov (United States)

    Stuart, Charles A.; Howell, Mary E.A.; Baker, Jonathan D.; Dykes, Rhesa J.; Duffourc, Michelle M.; Ramsey, Michael W.; Stone, Michael H.

    2009-01-01

    Purpose To determine if cycle training of sedentary subjects would increase the expression of the principle muscle glucose transporters, six volunteers completed six weeks of progressively increasing intensity stationary cycle cycling. Methods In vastus lateralis muscle biopsies, changes in expression of GLUT1, GLUT4, GLUT5, and GLUT12 were compared using quantitative immunoblots with specific protein standards. Regulatory pathway components were evaluated by immunoblots of muscle homogenates and immunohistochemistry of microscopic sections. Results GLUT1 was unchanged, GLUT4 increased 66%, GLUT12 increased 104%, and GLUT5 decreased 72%. A mitochondrial marker (cytochrome c) and regulators of mitochondrial biogenesis (PGC-1α and phospho-AMPK) were unchanged, but the muscle hypertrophy pathway component, phospho-mTOR increased 83% after the exercise program. In baseline biopsies, GLUT4 by immunohistochemical techniques was 37% greater in Type I (slow twitch, red) muscle fibers, but the exercise training increased GLUT4 expression in Type II (fast twitch, white) fibers by 50%, achieving parity with the Type I fibers. Baseline phospho-mTOR expression was 50% higher in Type II fibers and increased more in Type II fibers (62%) with training, but also increased in Type I fibers (34%). Conclusion Progressive intensity stationary cycle training of previously sedentary subjects increased muscle insulin-responsive glucose transporters (GLUT4 and GLUT12) and decreased the fructose transporter (GLUT5). The increase in GLUT4 occurred primarily in Type II muscle fibers and this coincided with activation of the mTOR muscle hypertrophy pathway. There was little impact on Type I fiber GLUT4 expression and no evidence of change in mitochondrial biogenesis. PMID:20010125

  1. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test

    Directory of Open Access Journals (Sweden)

    Diercks Ron L

    2010-05-01

    Full Text Available Abstract Background Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint test was therefore developed to measure the attentional and visual demands for repeated-sprint performance. The aims of the study were: 1 to assess test-retest reliability of the figure-of-eight sprint test, and 2 to study the attentional and visual demands for sprint performance in a non-fatigued and fatigued condition. Methods Twenty-seven healthy athletes were included in the study. To determine test-retest reliability, a subgroup of 19 athletes performed the figure-of-eight sprint test twice. The figure-of-eight sprint test consisted of nine 30-second sprints. The sprint test consisted of three test parts: sprinting without any restriction, with an attention-demanding task, and with restricted vision. Increases in sprint times with the attention-demanding task or restricted vision are reflective of the attentional and visual demands for sprinting. Intraclass correlation coefficients (ICCs and mean difference between test and retest with 95% confidence limits (CL were used to assess test-retest reliability. Repeated-measures ANOVA were used for comparisons between the sprint times and fatigue measurements of the test parts in both a non-fatigued and fatigued condition. Results The figure-of-eight sprint test showed good test-retest reliability, with ICCs ranging from 0.75 to 0.94 (95% CL: 0.40-0.98. Zero lay within the 95% CL of the mean differences, indicating that no bias existed between sprint performance at test and retest. Sprint times during the test parts with attention-demanding task (P = 0.01 and restricted vision (P Conclusions High ICCs and the absence of systematic variation indicate good test-retest reliability of the figure

  2. Abundance in proteins expressed after functional electrical stimulation cycling or arm cycling ergometry training in persons with chronic spinal cord injury.

    Science.gov (United States)

    Gorgey, Ashraf S; Graham, Zachary A; Bauman, William A; Cardozo, Christopher; Gater, David R

    2017-07-01

    Longitudinal design. The study determined the effects of two forms of exercise training on the abundance of two proteins, (glucose transporter-4 [GLUT-4], adenosine monophosphate kinase [AMPK]) involved in glucose utilization and the transcriptional coactivator that regulates the genes involved in energy metabolism and mitochondrial biogenesis (peroxisome proliferator-activated receptor (PPAR) coactivator 1 alpha [PGC-1α]), in muscles in men with chronic motor-complete spinal cord injury (SCI). Clinical trial at a Medical Center. Nine men with chronic motor-complete SCI participated in functional electrical stimulation lower extremity cycling (FES-LEC; n = 4) or arm cycling ergometer (arm-cycling ergometer [ACE]; n = 5) 5 days/week for 16 weeks. Whole body composition was measured by dual energy X-ray absorptiometry. An intravenous glucose tolerance test was performed to measure glucose effectiveness (Sg) and insulin sensitivity (Si). Muscle biopsies of the right vastus lateralis (VL) and triceps muscles were collected one week prior to and post the exercise training intervention. Neither training intervention altered body composition or carbohydrate metabolism. GLUT-4 increased by 3.8 fold in the VL after FES training and increased 0.6 fold in the triceps after ACE training. PGC-1α increased by 2.3 fold in the VL after FES training and 3.8 fold in the triceps after ACE training. AMPK increased by 3.4 fold in the VL after FES training and in the triceps after ACE training. FES-LEC and ACE training were associated with greater protein expressions in the trained muscles by effectively influencing the abundance of GLUT-4, AMPK and PGC-1α. Thus, FES-LEC training of paralyzed muscle can modulate protein expression similar to that of trained and innervated muscle.

  3. A Clustered Repeated-Sprint Running Protocol for Team-Sport Athletes Performed in Normobaric Hypoxia

    Directory of Open Access Journals (Sweden)

    Jaime Morrison, Chris McLellan, Clare Minahan

    2015-12-01

    Full Text Available The present study compared the performance (peak speed, distance, and acceleration of ten amateur team-sport athletes during a clustered (i.e., multiple sets repeated-sprint protocol, (4 sets of 4, 4-s running sprints; i.e., RSR444 in normobaric normoxia (FiO2 = 0.209; i.e., RSN with normobaric hypoxia (FiO2 = 0.140; i.e., RSH. Subjects completed two separate trials (i. RSN, ii. RSH; randomised order between 48 h and 72 h apart on a non-motorized treadmill. In addition to performance, we examined blood lactate concentration [La-] and arterial oxygen saturation (SpO2 before, during, and after the RSR444. While there were no differences in peak speed or distance during set 1 or set 2, peak speed (p = 0.04 and 0.02, respectively and distance (p = 0.04 and 0.02, respectively were greater during set 3 and set 4 of RSN compared with RSH. There was no difference in the average acceleration achieved in set 1 (p = 0.45, set 2 (p = 0.26, or set 3 (p = 0.23 between RSN and RSH; however, the average acceleration was greater in RSN than RSH in set 4 (p < 0.01. Measurements of [La-] were higher during RSH than RSN immediately after Sprint 16 (10.2 ± 2.5 vs 8.6 ± 2.6 mM; p = 0.02. Estimations of SpO2 were lower during RSH than RSN, respectively, immediately prior to the commencement of the test (89.0 ± 2.0 vs 97.2 ± 1.5 %, post Sprint 8 (78.0 ± 6.3 vs 93.8 ± 3.6 % and post Sprint 16 (75.3 ± 6.3 vs 94.5 ± 2.5 %; all p < 0.01. In summary, the RSR444 is a practical protocol for the implementation of a hypoxic repeated-sprint training intervention into the training schedules of team-sport athletes. However, given the inability of amateur team-sport athletes to maintain performance in hypoxic (FiO2 = 0.140 conditions, the potential for specific training outcomes (i.e. speed to be achieved will be compromised, thus suggesting that the RSR444 should be used with caution.

  4. SPRINT: A new parallel framework for R

    Directory of Open Access Journals (Sweden)

    Scharinger Florian

    2008-12-01

    Full Text Available Abstract Background Microarray analysis allows the simultaneous measurement of thousands to millions of genes or sequences across tens to thousands of different samples. The analysis of the resulting data tests the limits of existing bioinformatics computing infrastructure. A solution to this issue is to use High Performance Computing (HPC systems, which contain many processors and more memory than desktop computer systems. Many biostatisticians use R to process the data gleaned from microarray analysis and there is even a dedicated group of packages, Bioconductor, for this purpose. However, to exploit HPC systems, R must be able to utilise the multiple processors available on these systems. There are existing modules that enable R to use multiple processors, but these are either difficult to use for the HPC novice or cannot be used to solve certain classes of problems. A method of exploiting HPC systems, using R, but without recourse to mastering parallel programming paradigms is therefore necessary to analyse genomic data to its fullest. Results We have designed and built a prototype framework that allows the addition of parallelised functions to R to enable the easy exploitation of HPC systems. The Simple Parallel R INTerface (SPRINT is a wrapper around such parallelised functions. Their use requires very little modification to existing sequential R scripts and no expertise in parallel computing. As an example we created a function that carries out the computation of a pairwise calculated correlation matrix. This performs well with SPRINT. When executed using SPRINT on an HPC resource of eight processors this computation reduces by more than three times the time R takes to complete it on one processor. Conclusion SPRINT allows the biostatistician to concentrate on the research problems rather than the computation, while still allowing exploitation of HPC systems. It is easy to use and with further development will become more useful as more

  5. Training Intensity Distribution Over a Four-Year Cycle in Olympic Champion Rowers: Different Roads Lead to Rio.

    Science.gov (United States)

    Plews, Daniel J; Laursen, Paul B

    2017-09-27

    The purpose of this study was to compare the training intensity distribution (TID) of the undefeated world champion male rowing New Zealand (kiwi) pair over a four-year Olympic cycle, across training phases, training years, and between individuals. Training data, including heart rate and boat speed, were recorded in the athletes rowing in the same boat between March 2013 and August 2016, ending with the Rio Olympics final. Progressive exercise tests assessed first (LT 1 ) and second (LT 2 ) lactate thresholds and associated heart rates, to determine the percentage of training performed below, between and above these demarcation points. Training an average of only 12-15 h/wk throughout the Olympic cycle, the mean percent distribution of time (±SD) at each training intensity was 80.4 ± 5.5% LT 2 for Rower A and 67.3 ± 9.0% LT 2 for Rower B. Across the years 2014-2016, Rower A performed most likely more training training between LT 1 -LT 2 . Training appeared to become more polarised, with greater amounts of time spent training duration (R=0.38-0.43). Two of the world's best rowers, rowing together in the same boat with an undefeated record across an Olympic cycle, travelled markedly different "roads to Rio" within the context of their TID, with one rower displaying a polarised model of TID, and the other pyramidal. However, TID trended towards becoming more polarised in both rowers with increased training duration.

  6. Changes of explosive strength in professional basketball players after a six week training cycle with plyometric training and resistance training

    Directory of Open Access Journals (Sweden)

    Michal Lehnert

    2014-03-01

    Full Text Available BACKGROUND: Explosive strength of the lower extremities and agility are important parts of game performance in basketball. Although numerous studies have focused on the assessment of the training effect of plyometric training, studies focusing on elite players are missing. OBJECTIVE: The aim of the study was to find out what changes in explosive strength of the lower extremities take place after a 6 week strength training with plyometric exercises and resistance exercises in elite basketball players. METHODS: Elite basketball players (n = 12; age 24.71 ± 1.5 years; height 197.0 ± 7.6 cm; weight 95.8 ± 8.1 kg performed during pre-season a 6 week training program with plyometric exercises and resistance exercises which were conducted biweekly during the pre-season. The changes in explosive strength were measured by the squat jump without arms, the counter movement jump without arms, the counter movement jump free arms and the 2 step run up jump. The players participated in two measurements. The 1st (pretesting was performed on the first day of pre-season and the 2nd (posttesting was completed two days after terminating the PT programme. The differences between the average values of the monitored parameters were determined by the Wilcoxon paired test. To calculate the effect size formula according to Fritz, Morris, and Richler (2012: R = Z/√N was used. RESULTS: Analysis of intra-group changes confirmed significant differences between the two measurements in tests of vertical jump squat (Z = 2.58, p = .01, r = .75, vertical jump from the point of the swing arm (Z = 2.49, p = .01, r = .72 and vertical jump from place without the swing arm (Z = 2.75, p = .01, r = .79. In case of the two step run up jump significant differences were not found (Z = 1.60, p = .11, r = .56. Analysis of intra-individual changes showed the significant interindividual differences in the changes of the explosive power of the lower limbs after a 6 week training. The

  7. Improvement of Sprint Performance in Wheelchair Sportsmen With Caffeine Supplementation.

    Science.gov (United States)

    Graham-Paulson, Terri S; Perret, Claudio; Watson, Phil; Goosey-Tolfrey, Victoria L

    2016-03-01

    Caffeine can be beneficial during endurance and repeated-sprint exercise in able-bodied individuals performing leg or whole-body exercise. However, little evidence exists regarding its effects during upper-body exercise. This study therefore aimed to investigate the effects of caffeine on sprint (SPR) and 4-min maximal-push (PUSH) performance in wheelchair sportsmen. Using a double-blind, placebo-controlled, crossover design, 12 male wheelchair rugby players (age 30.0 ± 7.7 y, body mass 69.6 ± 15.3 kg, training 11.1 ± 3.5 h/wk) completed 2 exercise trials, separated by 7-14 d, 70 min after ingestion of 4 mg/kg caffeine (CAF) or dextrose placebo (PLA). Each trial consisted of four 4-min PUSHes and 3 sets of 3 × 20-m SPRs, each separated by 4 min rest. Participants responded to the Felt Arousal (a measure of perceived arousal), Feeling (a measure of the affective dimension of pleasure/displeasure), and rating-of-perceived-exertion (RPE) scales. Salivary caffeine secretion rates were measured. Average SPR times were faster during CAF than PLA during SPR 1 and SPR 2 (P = .037 and .016). There was no influence of supplementation on PUSHes 2-4 (P > .099); however, participants pushed significantly farther during PUSH 1 after CAF than after PLA (mean ± SD 677 ± 107 and 653 ± 118 m, P = .047). There was no influence of CAF on arousal or RPE scores (P > .132). Feeling scores improved over the course of the CAF trial only (P = .017) but did not significantly differ between trials (P > .167). Pre-warm-up (45 min postingestion) salivary CAF secretion rates were 1.05 ± 0.94 and 0.08 ± 0.05 μg/min for CAF and PLA, respectively. Acute CAF supplementation can improve both 20-m-sprint performance and a 1-off bout of short-term endurance performance in wheelchair sportsmen.

  8. Training effects induced by cycling of magnetic field in ferromagnetic rich phase-separated nanocomposite manganites

    Energy Technology Data Exchange (ETDEWEB)

    Das, Kalipada, E-mail: kalipada.das@saha.ac.in; Das, I.

    2015-12-01

    We have carried out an experimental investigation of magneto-transport and magnetic properties of charge-ordered Pr{sub 0.67}Ca{sub 0.33}MnO{sub 3} (PCMO) and ferromagnetic La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (LSMO) nanoparticles along with a nanocomposite consisting of those two types of nanoparticles. From the magneto-transport measurements, clear irreversibility is observed in the field dependence of resistance due to magnetic field cycling in the case of PCMO nanoparticles. The value of resistance increases during such a field cycling. However such an irreversibility is absent in the case of LSMO nanoparticles as well as nanocomposites. On the other hand, the magnetic measurements indicate the gradual growth of antiferromagnetic phases in all samples leading to a decrease in magnetization. These inconsistencies between magneto-transport and magnetic behaviors are attributed to the magnetic training effects. - Highlights: • The resistance value in Pr{sub 0.67}Ca{sub 0.33}MnO{sub 3} nanoparticles is found to increase owing to the magnetic field cycling. • No anomaly in resistance was found in Pr{sub 0.67}Ca{sub 0.33}MnO{sub 3}–La{sub 0.67}Sr{sub 0.33}MnO{sub 3} nanocomposite. • Magnetic measurements indicate the training effect in nanostructure compounds.

  9. International Project on Innovative Nuclear Reactors and Fuel Cycles: Introduction and Education and Training Activity

    International Nuclear Information System (INIS)

    Fesenko, G.; Kuznetsov, V.; Phillips, J.R.; Rho, K.; Grigoriev, A.; Korinny, A.; Ponomarev, A.

    2015-01-01

    The IAEA’s International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) was established in 2000 through IAEA General Conference resolution with aim to ensure that sustainable nuclear energy is available to help meet the energy needs of the 21st century. INPRO seeks to bring together technology holders, users and newcomers to consider jointly the international and national actions required for achieving desired innovations in nuclear reactors and fuel cycles, with a particular focus on sustainability and needs of developing countries. It is a mechanism for INPRO Members to collaborate on topics of joint interest. INPRO activities are undertaken in close cooperation with Member States in the following main areas: Global Scenarios, Innovations, Sustainability Assessment and Strategies, Policy and Dialogue. The paper presents short introduction in INPRO and specifically the distant Education and Training INPRO activity on important topics of nuclear energy sustainability to audiences in different Member States. These activities can support capacity building and national human resource development in the nuclear energy sector. The main benefit of such training courses and workshops is that it is not only targeted to students, but also to lecturers of technical and nuclear universities. Moreover, young professionals working at nuclear energy departments, electric utilities, energy ministries and R&D institutions can participate in such training and benefit from it. (authors)

  10. ENERGY EXPENDITURE AND HABITUAL PHYSICAL ACTIVITIES IN ADOLESCENT SPRINT ATHLETES

    Directory of Open Access Journals (Sweden)

    Dirk Aerenhouts

    2011-06-01

    Full Text Available This study aimed to assess total energy expenditure (TEE and specific habitual physical activities in adolescent sprint athletes. Two methods used to estimate TEE, an activity diary (AD and SenseWear armband (SWA, were compared. Sixteen athletes (6 girls, 10 boys, mean age 16.5 ± 1.6 yr simultaneously wore a SWA and completed an AD and food diary during one week. Basal energy expenditure as given by the SWA when taken off was corrected for the appropriate MET value using the AD. TEE as estimated by the AD and SWA was comparable (3196 ± 590 kcal and 3012 ± 518 kcal, p = 0.113 without day-to-day variations in TEE and energy expended in activities of high intensity. Daily energy intake (2569 ± 508 kcal did not match TEE according to both the AD and SWA (respectively p < 0.001 and p = 0.007. Athletes were in a supine position for a longer time on weekend days than on week days and slept longer on Sundays. Athletes reported a longer time of high-intensive physical activities in the AD than registered by the SWA on 4 out of 7 days. In addition to specific sprint activities on 3 to 7 days per week, 11 out of 16 athletes actively commuted to school where they participated in sports once or twice per week. The AD and the SWA are comparable in the estimation of TEE, which appears realistic and sustainable. The SWA offers an appropriate and objective method in the assessment of TEE, sleeping and resting in adolescent athletes on the condition that detailed information is given for the times the armband is not worn. The AD offers activity specific information but relies on the motivation, compliance and subjectivity of the individual, especially considering high-intensive intermittent training

  11. When Is a Sprint a Sprint? A Review of the Analysis of Team-Sport Athlete Activity Profile

    Directory of Open Access Journals (Sweden)

    Alice J. Sweeting

    2017-06-01

    Full Text Available The external load of a team-sport athlete can be measured by tracking technologies, including global positioning systems (GPS, local positioning systems (LPS, and vision-based systems. These technologies allow for the calculation of displacement, velocity and acceleration during a match or training session. The accurate quantification of these variables is critical so that meaningful changes in team-sport athlete external load can be detected. High-velocity running, including sprinting, may be important for specific team-sport match activities, including evading an opponent or creating a shot on goal. Maximal accelerations are energetically demanding and frequently occur from a low velocity during team-sport matches. Despite extensive research, conjecture exists regarding the thresholds by which to classify the high velocity and acceleration activity of a team-sport athlete. There is currently no consensus on the definition of a sprint or acceleration effort, even within a single sport. The aim of this narrative review was to examine the varying velocity and acceleration thresholds reported in athlete activity profiling. The purposes of this review were therefore to (1 identify the various thresholds used to classify high-velocity or -intensity running plus accelerations; (2 examine the impact of individualized thresholds on reported team-sport activity profile; (3 evaluate the use of thresholds for court-based team-sports and; (4 discuss potential areas for future research. The presentation of velocity thresholds as a single value, with equivocal qualitative descriptors, is confusing when data lies between two thresholds. In Australian football, sprint efforts have been defined as activity >4.00 or >4.17 m·s−1. Acceleration thresholds differ across the literature, with >1.11, 2.78, 3.00, and 4.00 m·s−2 utilized across a number of sports. It is difficult to compare literature on field-based sports due to inconsistencies in velocity and

  12. Energy system contributions and determinants of performance in sprint cross-country skiing

    DEFF Research Database (Denmark)

    Andersson, E; Björklund, G; Holmberg, H-C

    2017-01-01

    To improve current understanding of energy contributions and determinants of sprint-skiing performance, 11 well-trained male cross-country skiers were tested in the laboratory for VO2max , submaximal gross efficiency (GE), maximal roller skiing velocity, and sprint time-trial (STT) performance...... during the STT was predicted from the submaximal relationships for GE against velocity and incline, allowing computation of metabolic rate and O2 deficit. The skiers completed the STT in 232 ± 10 s (distributed as 55 ± 3% DP and 45 ± 3% DS) with a mean power output of 324 ± 26 W. The anaerobic energy......-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance....

  13. Human capital needs - teaching, training and coordination for nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Retegan, T.; Ekberg, C. [Department of Chemistry and Biological Engineering, Nuclear Chemistry, Chalmers University of Technology, Kemivaegen 4, 41296 Gothenburg (Sweden); John, J. [Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehova 7, 115 19 Prague 1 (Czech Republic); Nordlund, A. [Nuclear Engineering, Chalmers University of Technology, Kemivaegen 4, 41296 Gothenburg (Sweden)

    2013-07-01

    Human capital is the accumulation of competencies, knowledge, social and creativity skills and personality attributes, which are necessary to perform work so as to produce economic value. In the frame of the nuclear fuel cycle, this is of paramount importance that the right human capital exists and in Europe this is fostered by a series of integrated or directed projects. The teaching, training and coordination will be discussed in the frame of University curricula with examples from several programs, like e.g. the Master of Nuclear Engineering at Chalmers University, Sweden and two FP7 EURATOM Projects: CINCH - a project for cooperation in nuclear chemistry - and ASGARD - a research project on advanced or novel nuclear fuels and their reprocessing issues for generation IV reactors. The integration of the university curricula in the market needs but also the anchoring in the research and future fuel cycles will be also discussed, with examples from the ASGARD project. (authors)

  14. Method to generate a pulse train of few-cycle coherent radiation

    Directory of Open Access Journals (Sweden)

    Bryant Garcia

    2016-09-01

    Full Text Available We develop a method to generate a long pulse train of few-cycle coherent radiation by modulating an electron beam with a high power laser. The large energy modulation disperses the beam in a radiating undulator and leads to the production of phase-locked few-cycle coherent radiation pulses. These pulses are produced at a high harmonic of the modulating laser, and are longitudinally separated by the modulating laser wavelength. We discuss an analytical model for this scheme and investigate the temporal and spectral properties of this radiation. This model is compared with numerical simulation results using the unaveraged code Puffin. We examine various harmful effects and how they might be avoided, as well as a possible experimental realization of this scheme.

  15. Human capital needs - teaching, training and coordination for nuclear fuel cycle

    International Nuclear Information System (INIS)

    Retegan, T.; Ekberg, C.; John, J.; Nordlund, A.

    2013-01-01

    Human capital is the accumulation of competencies, knowledge, social and creativity skills and personality attributes, which are necessary to perform work so as to produce economic value. In the frame of the nuclear fuel cycle, this is of paramount importance that the right human capital exists and in Europe this is fostered by a series of integrated or directed projects. The teaching, training and coordination will be discussed in the frame of University curricula with examples from several programs, like e.g. the Master of Nuclear Engineering at Chalmers University, Sweden and two FP7 EURATOM Projects: CINCH - a project for cooperation in nuclear chemistry - and ASGARD - a research project on advanced or novel nuclear fuels and their reprocessing issues for generation IV reactors. The integration of the university curricula in the market needs but also the anchoring in the research and future fuel cycles will be also discussed, with examples from the ASGARD project. (authors)

  16. CHANGES IN THE ANAEROBIC THRESHOLD IN AN ANNUAL CYCLE OF SPORT TRAINING OF YOUNG SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Robert Śliwowski

    2013-04-01

    Full Text Available The aim of the study was to assess changes in the anaerobic threshold of young soccer players in an annual training cycle. A group of highly trained 15-18 year old players of KKS Lech Poznań were tested. The tests included an annual training macrocycle, and its individual stages resulted from the time structure of the sports training. In order to assess the level of exercise capacities of the players, a field exercise test of increasing intensity was carried out on a soccer pitch. The test made it possible to determine the 4 millimolar lactate threshold (T LA 4 mmol · l-1 on the basis of the lactate concentration in blood [LA], to establish the threshold running speed and the threshold heart rate [HR]. The threshold running speed at the level of the 4 millimolar lactate threshold was established using the two-point form of the equation of a straight line. The obtained indicators of the threshold running speed allowed for precise establishment of effort intensity used in individual training in developing aerobic endurance. In order to test the significance of differences in mean values between four dates of tests, a non-parametric Friedman ANOVA test was used. The significance of differences between consecutive dates of tests was determined using a post-hoc Friedman ANOVA test. The tests showed significant differences in values of selected indicators determined at the anaerobic threshold in various stages of an annual training cycle of young soccer players. The most beneficial changes in terms of the threshold running speed were noted on the fourth date of tests, when the participants had the highest values of 4.01 m · s-1 for older juniors, and 3.80 m · s-1 for younger juniors. This may be indicative of effective application of an individualized programme of training loads and of good preparation of teams for competition in terms of players’ aerobic endurance.

  17. Determinants of a simulated cross-country skiing sprint competition using V2 skating technique on roller skis.

    Science.gov (United States)

    Mikkola, Jussi; Laaksonen, Marko; Holmberg, Hans-Christer; Vesterinen, Ville; Nummela, Ari

    2010-04-01

    The present study investigated the performance-predicting factors of a simulated cross-country (XC) skiing sprint competition on roller skis, on a slow surface. Sixteen elite male XC skiers performed a simulated sprint competition (4 x 850 m heat with a 20-minute recovery) using V2 skating technique on an indoor tartan track. Heat velocities, oxygen consumption, and peak lactate were measured during or after the heats. Maximal skiing velocity was measured by performing a 30-m speed test. Explosive and maximal force production in the upper body was determined by bench press (BP). Subjects also performed maximal anaerobic skiing test (MAST) and the 2 x 2-km double poling (DP) test. The maximal velocity of MAST (VMAST) and velocities at 3 (V3), 5 (V5), 7 (V7) mmol.L lactate levels in MAST were determined. In the 2 x 2-km test, DP economy (VO2SUBDP) and maximal 2-km DP velocity (VDP2KM) were determined. The best single performance-predicting factors for the sprint performance were VDP2KM (r = 0.73, p < 0.01), V7 (r = 0.70, p < 0.01), and VO2SUBDP (r = -0.70, p < 0.01). Faster skiers in sprint simulation had a higher absolute VO2 (L.min) (p < 0.05-0.01) during sprint heats, and higher anaerobic skiing power (VMAST, p < 0.05) and better anaerobic skiing economy (V3, V5, V7, p < 0.05-0.001) than slower skiers. Faster skiers were also stronger in BP, with regard to both absolute (p < 0.01) and relative (p < 0.05) values. In addition, anaerobic characteristics seem to be of importance at the beginning of the XC skiing sprint competition, whereas the aerobic characteristics become more important as the XC skiing sprint competition progressed. This study indicates that sprint skiers should emphasize sport-specific upper body training, and training skiing economy at high speeds.

  18. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated

  19. Repeated Sprint Ability in Elite Water Polo Players and Swimmers and its Relationship to Aerobic and Anaerobic Performance

    Directory of Open Access Journals (Sweden)

    Yoav Meckel

    2013-12-01

    Full Text Available The purpose of this study was to determine indices of swimming repeated sprint ability (RSA in 19 elite water polo players compared to 16 elite swimmers during a repeated sprint swimming test (RST, and to examine the relationships between these indices and aerobic and anaerobic performance capabilities in both groups. Indices of RSA were determined by the ideal sprint time (IS, the total sprint time (TS, and the performance decrement (PD recorded during an 8 x 15-m swimming RST. Single long - (800-m and short-(25-m distance swim tests were used to determined indices of aerobic and anaerobic swimming capabilities, respectively. The water polo players exhibited lower RSA swimming indices, as well as lower scores in the single short and long swim distances, compared to the swimmers. Significant relationships were found between the 25- m swim results and the IS and the TS, but not the PD of both the swimmers and the water polo players. No significant relationships were found between the 800-m swim results and any of the RSA indices in either the swimmers or the water polo players. No significant relationships were found between the 25-m and the 800-m swim results in either the swimmers or the water polo players. The results indicate that swimmers posses better RSA as well as higher anaerobic and aerobic capabilities, as reflected by the single short- and long-distance swim tests, compared to water polo players. The results also indicate that, as for running and cycling, repeated sprint swim performance is strongly related to single sprint performance.

  20. Repeated high-speed activities during youth soccer games in relation to changes in maximal sprinting and aerobic speeds.

    Science.gov (United States)

    Buchheit, M; Simpson, B M; Mendez-Villanueva, A

    2013-01-01

    The aim of this study was to examine in highly-trained young soccer players whether substantial changes in either maximal sprinting speed (MSS) or maximal aerobic speed (as inferred from peak incremental test speed, V(Vam-Eval)) can affect repeated high-intensity running during games. Data from 33 players (14.5±1.3 years), who presented substantial changes in either MSS or V(Vam-Eval) throughout 2 consecutive testing periods (~3 months) were included in the final analysis. For each player, time-motion analyses were performed using a global positioning system (1-Hz) during 2-10 international club games played within 1-2 months from/to each testing period of interest (n for game analyzed=109, player-games=393, games per player per period=4±2). Sprint activities were defined as at least a 1-s run at intensities higher than 61% of individual MSS. Repeated-sprint sequences (RSS) were defined as a minimum of 2 consecutive sprints interspersed with a maximum of 60 s of recovery. Improvements in both MSS and V(Vam-Eval) were likely associated with a decreased RSS occurrence, but in some positions only (e. g., - 24% vs. - 3% for improvements in MSS in strikers vs. midfielders, respectively). The changes in the number of sprints per RSS were less clear but also position-dependent, e. g., +7 to +12% for full-backs and wingers, - 5 to - 7% for centre-backs and midfielders. In developing soccer players, changes in repeated-sprint activity during games do not necessarily match those in physical fitness. Game tactical and strategic requirements are likely to modulate on-field players' activity patterns independently (at least partially) of players' physical capacities. © Georg Thieme Verlag KG Stuttgart · New York.

  1. High-intensity sprint fatigue does not alter constant-submaximal velocity running mechanics and spring-mass behavior.

    Science.gov (United States)

    Morin, Jean-Benoit; Tomazin, Katja; Samozino, Pierre; Edouard, Pascal; Millet, Guillaume Y

    2012-04-01

    We investigated the changes in constant velocity spring-mass behavior after high intensity sprint fatigue in order to better interpret the results recently reported after ultra-long distance (ULD) exercises. Our hypothesis was that after repeated sprints (RS), subjects may likely experience losses of force such as after ULD, but the necessity to modify their running pattern to attenuate the overall impact at each step (such as after ULD) may not be present. Eleven male subjects performed four sets of five 6-s sprints with 24-s recovery between sprints and 3 min between sets, on a sprint treadmill and on a bicycle ergometer. For each session, their running mechanics and spring-mass characteristics were measured at 10 and 20 km h(-1) on an instrumented treadmill before and after RS. Two-way (period and velocity) ANOVAs showed that high-intensity fatigue did not induce any change in the constant velocity running pattern at low or high velocity, after both running and cycling RS, despite significant decreases (P < 0.001) in maximal power (-27.1 ± 8.2% after running RS and -15.4 ± 11.5 % after cycling RS) and knee extensors maximal voluntary force (-18.8 ± 6.7 % after running RS and -15.0 ± 7.6 % after cycling RS). These results bring indirect support to the hypothesis put forward in recent ULD studies that the changes in running mechanics observed after ULD are likely not related to the decrease in strength capabilities, but rather to the necessity for subjects to adopt a protective running pattern.

  2. Changes in Muscle Strength in U19 Soccer Players During an Annual Training Cycle

    Directory of Open Access Journals (Sweden)

    Lehnert Michal

    2014-10-01

    Full Text Available The aim of the study was to investigate the seasonal variation in isokinetic strength of the knee flexors and extensors, and conventional (H/QCONV and functional (H/QFUNC hamstring to quadriceps strength ratios in highly trained adolescent soccer players. The players (n=11; age 17.8±0.3 were measured at the end of the competitive season (autumn, at the beginning and the end of pre-season (winter and during the sixth week of a new competitive season. Isokinetic peak torque (concentric and eccentric was measured at 60°•s-1 in a sitting position with the hip flexed at 100°. The testing range of motion was set from 10 - 90° of knee flexion. The players performed a set of five maximum repetitions for both the dominant and non-dominant leg. Statistically significant differences (p<0.001 between the four seasonal measurements were noted for peak torque of the dominant leg knee flexors in concentric muscle action only. A post hoc analysis revealed a statistically significant increase in peak torque from the 1st to the 4th measurement (p<0.001; d=0.692 and from the 2nd to the 4th (p<0.01; d=0.564. The differences in the changes of peak torque of the knee flexors and extensors depending on type of muscle action and tendencies found in the H/Q ratios throughout the annual training cycle indicate that strength assessment of the knee flexors and extensors and their balance throughout the annual training cycle could be beneficial for elite male adolescent soccer players both in terms of performance and risk of injury.

  3. Differences in activation properties of the hamstring muscles during overground sprinting.

    Science.gov (United States)

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2015-09-01

    The purpose of this study was to quantify activation of the biceps femoris (BF) and medial hamstring (MH) during overground sprinting. Lower-extremity kinematics and electromyography (EMG) of the BF and MH were recorded in 13 male sprinters performing overground sprinting at maximum effort. Mean EMG activity was calculated in the early stance, late stance, mid-swing, and late-swing phases. Activation of the BF was significantly greater during the early stance phase than the late stance phase (p<0.01). Activation of the BF muscle was significantly lower during the first half of the mid-swing phase than the other phases (p<0.05). The MH had significantly greater EMG activation relative to its recorded maximum values compared to that for the BF during the late stance (p<0.05) and mid-swing (p<0.01) phases. These results indicate that the BF shows high activation before and after foot contact, while the MH shows high activation during the late stance and mid-swing phases. We concluded that the activation properties of the BF and MH muscles differ within the sprinting gait cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Relationship between lower limbs kinematic variables and effectiveness of sprint during maximum velocity phase.

    Science.gov (United States)

    Struzik, Artur; Konieczny, Grzegorz; Grzesik, Kamila; Stawarz, Mateusz; Winiarski, Sławomir; Rokita, Andrzej

    2015-01-01

    The aim of the study was to determine the relationships between time of running over a 15-25 m section of a 30-meter run along a straight line and changes in the angle and angular velocity observed in ankle, knee and hip joints. Therefore, the authors attempted to answer the question of whether a technique of lower limbs movement during the phase of sprint maximum velocity significantly correlates with the time of running over this section. A group of 14 young people from the Lower Silesia Voivodeship Team participated in the experiment. A Fusion Smart Speed System was employed for running time measurements. The kinematic data were recorded using Noraxon MyoMotion system. There were observed statistically significant relationships between sprint time over a section from 15 to 25 m and left hip rotation (positive) and between this time and left and right ankle joint dorsi-plantar flexion (negative). During the maximum velocity phase of a 30 m sprint, the effect of dorsi-plantar flexion performed in the whole range of motion was found to be beneficial. This can be attributed to the use of elastic energy released in the stride cycle. Further, hip rotation should be minimized, which makes the stride aligned more along a line of running (a straight line) instead of from side to side.

  5. Adipose tissue extracts plasma ammonia after sprint exercise in women and men

    DEFF Research Database (Denmark)

    Esbjörnsson, Mona; Bülow, Jens; Norman, Barbara

    2006-01-01

    This study evaluates a possible contribution of adipose tissue to the elimination of plasma ammonia (NH(3)) after high-intensity sprint exercise. In 14 healthy men and women, repeated blood samples for plasma NH(3) analyses were obtained from brachial artery and from a subcutaneous abdominal vein......) with glutamate resulting in its conversion to glutamine. Adipose tissue may thus play an important physiological role in eliminating plasma NH(3) and thereby reducing the risk of NH(3) intoxication after high-intensity exercise.......This study evaluates a possible contribution of adipose tissue to the elimination of plasma ammonia (NH(3)) after high-intensity sprint exercise. In 14 healthy men and women, repeated blood samples for plasma NH(3) analyses were obtained from brachial artery and from a subcutaneous abdominal vein...... before and after three repeated 30-s cycle sprints separated by 20 min of recovery. Biopsies from subcutaneous abdominal adipose tissue were obtained and analyzed for glutamine and glutamate content. After exercise, both arterial and abdominal venous plasma NH(3) concentrations were lower in women than...

  6. Paralympic Sprint Performance Between 1992 and 2012.

    Science.gov (United States)

    Grobler, Lara; Ferreira, Suzanne; Terblanche, Elmarie

    2015-11-01

    The Paralympic Games have undergone many changes since their inception in 1960, one being the advances made in running-specific prostheses (RSPs) for track athletes with lower-limb amputations. To investigate the sprinting-performance changes in athletes with lower-limb amputations since 1992 to assess whether the influence of developments in RSP technology is evident. The results of the Olympic and Paralympic Games ranging between 1992 and 2012 for the 100-m and 200-m were collected, and performance trends, percentage change in performance, and competition density (CD) were calculated. The results indicate that the greatest performance increases were seen in athletes with lower-limb amputations (T42 = 26%, T44 = 14%). These performance improvements were greater than for Olympic athletes (Paralympic athletes from other selected classes (Paralympic sprint performances, RSP technology has played a noteworthy role in the progression of performances of athletes with amputations. It is also hypothesized that the difference in the performance improvements between the T42 and T44 classes is due to the level of disability and therefore the extent to which technology is required to enable locomotion. It is evident that RSP technology has played a significant role in the progression of performances in athletes with lower-limb amputations.

  7. Repeated Sprint Ability in Young Basketball Players (Part 2): The Chronic Effects of Multidirection and of One Change of Direction Are Comparable in Terms of Physiological and Performance Responses.

    Science.gov (United States)

    Attene, Giuseppe; Nikolaidis, Pantelis T; Bragazzi, Nicola L; Dello Iacono, Antonio; Pizzolato, Fabio; Zagatto, Alessandro M; Dal Pupo, Juliano; Oggianu, Marcello; Migliaccio, Gian M; Mannucci Pacini, Elena; Padulo, Johnny

    2016-01-01

    The aim of this study was to examine the effects of a 5-week training program, consisting of repeated 30-m sprints, on two repeated sprint ability (RSA) test formats: one with one change of direction (RSA) and the other with multiple changes of direction (RSM). Thirty-six young male and female basketball players (age 16.1 ± 0.9 years), divided into two experimental groups, were tested for RSA, RSM, squat jump, counter-movement jump, and the Yo-Yo Intermittent Recovery-Level-1 (Yo-Yo IR1) test, before and after a 4-week training program and 1 week of tapering. One group performed 30-m sprints with one change of direction (RSA group, RSAG), whereas the other group performed multidirectional 30-m sprints (RSM group, RSMG). Both groups improved in all scores in the post-intervention measurements (P basketball players, but have a different psycho-physiological impact.

  8. How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing–Stance Transition

    Science.gov (United States)

    SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU

    2015-01-01

    ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288

  9. How joint torques affect hamstring injury risk in sprinting swing-stance transition.

    Science.gov (United States)

    Sun, Yuliang; Wei, Shutao; Zhong, Yunjian; Fu, Weijie; Li, Li; Liu, Yu

    2015-02-01

    The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases.

  10. Influence of physical development on start and countermovement jump performance in adolescent sprint athletes.

    Science.gov (United States)

    Aerenhouts, D; Debaere, S; Hagman, F; Van Gheluwe, B; Delecluse, C; Clarys, P

    2013-02-01

    The aim of the present study was to describe the effect of physical changes during adolescence on sprint start and countermovement jump (CMJ) performance. Twenty-eight girls and 25 boys (15.0±1.6 and 14.7±1.9 years at start respectively) were measured twice with a one year interval. Anthropometric data allowed skeletal muscle mass (SMM) estimation. Athletes performed a 10m sprint tracked from behind by a laser sensor, with starting blocks measuring propulsion forces. CMJ's were performed on a Kistler force plate. Between the two measurement occasions both genders increased in body height, weight and SMM. In girls and boys, impulse during the push-off, block leaving velocity and times at 5 and 10 m improved significantly. In both genders CMJ absolute power increased but not power.kg-1. Only in boys a higher CMJ was registered on occasion 2. For both genders on both occasions, impulse during the push-off correlated with body weight, SMM and CMJ power (r from .46 to .84), and in boys also with CMJ height and CMJ power.kg-1 (r from 0.43 to 0.76). Boys showed CMJ height and power to correlate with 5 and 10 m times (r from -0.42 to -0.79) and with block leaving velocity, however only on the first data collection (r=0.61 and 0.59, respectively). Sprint start performance is only partly related to muscular development and CMJ could predict start performance in boys only. Sprint start and CMJ rely on technical skills and, therefore, increasing muscularity should be accompanied with sufficient specific training to allow an optimal transfer to start performance.

  11. Effect of cluster set warm-up configurations on sprint performance in collegiate male soccer players.

    Science.gov (United States)

    Nickerson, Brett S; Mangine, Gerald T; Williams, Tyler D; Martinez, Ismael A

    2018-06-01

    The purpose of this study was to determine if back squat cluster sets (CS) with varying inter-repetition rest periods would potentiate greater sprint performance compared with a traditional set parallel back squat in collegiate soccer players. Twelve collegiate male soccer players (age, 21.0 ± 2.0 years; height, 180.0 ± 9.0 cm; body mass, 79.0 ± 9.5 kg) performed a 20-m sprint prior to a potentiation complex and at 1, 4, 7, and 10 min postexercise on 3 separate, randomized occasions. On each occasion, the potentiation complex consisted of 1 set of 3 repetitions at 85% 1-repetition maximum (1RM) for the traditional parallel back squat. However, on 1 occasion the 3-repetition set was performed in a traditional manner (i.e., continuously), whereas on the other 2 occasions, 30s (CS 30 ) and 60 s (CS 60 ) of rest were allotted between each repetition. Repeated-measures ANOVA revealed greater (p = 0.022) mean barbell velocity on CS 60 compared with the traditional set. However, faster (p < 0.040) 20-m sprint times were observed for CS 30 (3.15 ± 0.16 s) compared with traditional (3.20 ± 0.17 s) only at 10 min postexercise. No other differences were observed. These data suggest that a single cluster set of 3 repetitions with 30-s inter-repetition rest periods at 85% 1RM acutely improves 20-m sprinting performance. Strength and conditioning professionals and their athletes might consider its inclusion during the specific warm-up to acutely improve athletic performance during the onset (≤10 min) of training or competition.

  12. The inquisitive inspector: Reflections on the nuclear fuel cycle and proliferation pathways training course

    International Nuclear Information System (INIS)

    Burrows, B.; Howsley, R.; Andrew, G.; Fortakov, V.; Nilsson, A.

    1999-01-01

    Amongst the many lessons to be learnt from the Iraqi experience is the intrinsic value of utilising individuals who are well informed in fuel cycle technologies and who possess keen powers of observation. The safeguards strengthening measures of increased access and increased information now set the scene for IAEA inspectors to wear two hats; the traditional role of inspecting declared nuclear materials and the more inquisitive role of probing for and recognising indicators of undeclared activities. The key to unlocking any enquiring potential is the provision of training to increase the awareness of fuel cycle indicators especially those which lie on the more sensitive pathways that a proliferator may follow. In 1994, the IAEA formulated a task for such training, which was subsequently sponsored by the Department of Trade and Industry (DTI) under the United Kingdom Safeguards R and D Support Programme to the IAEA. Experts from the UK have worked closely with the IAEA to develop an intensive one week course entitled 'The Nuclear Fuel Cycle and Proliferation Pathways'. Following trial running, the course went into 'active operation' in 1996 and has been universally well received by the course participants. This paper describes the course development, the objectives, the syllabus, the use of audio-visual material and the evaluation of the effectiveness of the course. The training is very intensive and challenging; as a new course its content is still evolving and being adjusted in the light of feedback from participants. From the outset it was necessary to recognise the balance between increasing observation and being educational on critical technologies. The course therefore, is strongly focused on the indicators of 'what' activities rather than the 'how' of a particular proliferation pathway. The course is in line with and in support of what was the IAEA Programme '93+2' Task 5 for increased information analysis. As to the impact the course has on its participants

  13. Is Soleus Muscle-Tendon-Unit Behavior Related to Ground-Force Application During the Sprint Start?

    Science.gov (United States)

    Schrödter, Erik; Brüggemann, Gert-Peter; Willwacher, Steffen

    2017-04-01

    To describe the stretch-shortening behavior of ankle plantar-flexing muscle-tendon units (MTUs) during the push-off in a sprint start. Fifty-four male (100-m personal best: 9.58-12.07 s) and 34 female (100-m personal best: 11.05-14.00 s) sprinters were analyzed using an instrumented starting block and 2-dimensional high-speed video imaging. Analysis was performed separately for front and rear legs, while accounting for block obliquities and performance levels. The results showed clear signs of a dorsiflexion in the upper ankle joint (front block 15.8° ± 7.4°, 95% CI 13.2-18.2°; rear block 8.0° ± 5.7°, 95% CI 6.4-9.7°) preceding plantar flexion. When observed in their natural block settings, the athletes' block obliquity did not significantly affect push-off characteristics. It seems that the stretch-shortening-cycle-like motion of the soleus MTU has an enhancing influence on push-off force generation. This study provides the first systematic observation of ankle-joint stretch-shortening behavior for sprinters of a wide range of performance levels. The findings highlight the importance of reactive-type training for the improvement of starting performance. Nonetheless, future studies need to resolve the independent contributions of tendinous and muscle-fascicle structures to overall MTU performance.

  14. Pareto-Optimal Model Selection via SPRINT-Race.

    Science.gov (United States)

    Zhang, Tiantian; Georgiopoulos, Michael; Anagnostopoulos, Georgios C

    2018-02-01

    In machine learning, the notion of multi-objective model selection (MOMS) refers to the problem of identifying the set of Pareto-optimal models that optimize by compromising more than one predefined objectives simultaneously. This paper introduces SPRINT-Race, the first multi-objective racing algorithm in a fixed-confidence setting, which is based on the sequential probability ratio with indifference zone test. SPRINT-Race addresses the problem of MOMS with multiple stochastic optimization objectives in the proper Pareto-optimality sense. In SPRINT-Race, a pairwise dominance or non-dominance relationship is statistically inferred via a non-parametric, ternary-decision, dual-sequential probability ratio test. The overall probability of falsely eliminating any Pareto-optimal models or mistakenly returning any clearly dominated models is strictly controlled by a sequential Holm's step-down family-wise error rate control method. As a fixed-confidence model selection algorithm, the objective of SPRINT-Race is to minimize the computational effort required to achieve a prescribed confidence level about the quality of the returned models. The performance of SPRINT-Race is first examined via an artificially constructed MOMS problem with known ground truth. Subsequently, SPRINT-Race is applied on two real-world applications: 1) hybrid recommender system design and 2) multi-criteria stock selection. The experimental results verify that SPRINT-Race is an effective and efficient tool for such MOMS problems. code of SPRINT-Race is available at https://github.com/watera427/SPRINT-Race.

  15. Gender differences in the physiological responses and kinematic behaviour of elite sprint cross-country skiers.

    Science.gov (United States)

    Sandbakk, Oyvind; Ettema, Gertjan; Leirdal, Stig; Holmberg, Hans-Christer

    2012-03-01

    Gender differences in performance by elite endurance athletes, including runners, track cyclists and speed skaters, have been shown to be approximately 12%. The present study was designed to examine gender differences in physiological responses and kinematics associated with sprint cross-country skiing. Eight male and eight female elite sprint cross-country skiers, matched for performance, carried out a submaximal test, a test of maximal aerobic capacity (VO(2max)) and a shorter test of maximal treadmill speed (V (max)) during treadmill roller skiing utilizing the G3 skating technique. The men attained 17% higher speeds during both the VO(2max) and the V (max) tests (P differences that were reduced to 9% upon normalization for fat-free body mass. Furthermore, the men exhibited 14 and 7% higher VO(2max) relative to total and fat-free body mass, respectively (P gender groups. At the same absolute speed, men employed 11% longer cycles at lower rates, and at peak speed, 21% longer cycle lengths (P gender differences in performance and VO(2max) than those reported for comparable endurance sports. These differences reflect primarily the higher VO(2max) and lower percentage of body fat in men, since no gender differences in the ability to convert metabolic rate into work rate and speed were observed. With regards to kinematics, the gender difference in performance was explained by cycle length, not by cycle rate.

  16. High-efficiency intracavity second-harmonic enhancement for a few-cycle laser pulse train

    International Nuclear Information System (INIS)

    Cai, Yi; Xu, Shixiang; Zeng, Xuanke; Zou, Da; Li, Jingzhen

    2012-01-01

    This paper presents an intracavity second-harmonic (SH) enhancement technology without the need of input impedance-matching for optimal coupling between the cavity and its input frequency comb. More than 10% SH energy conversion efficiency is available, thus the power of the SH frequency comb can be enhanced beyond 100 relative to single-pass SH generation. Compared with a conventional passive enhancing cavity, for the purpose of high power enhancement, our scheme can operate at much lower finesse and thus broader bandwidth so that it can support several-optical-cycle pulses more easily. If they have the same finesse, both methods perform with similar operating stability. The results show that our novel design is suitable for some applications which need a short wavelength, high intensity, and ultra-broad bandwidth pulse train. (paper)

  17. Characteristics of sprint performance in college football players.

    Science.gov (United States)

    Brechue, William F; Mayhew, Jerry L; Piper, Fontaine C

    2010-05-01

    To investigate sprinting strategy, acceleration and velocity patterns were determined in college football players (n = 61) during performance of a 9.1-, 36.6-, and 54.9-m sprints. Acceleration and velocity were determined at 9.1-m intervals during each sprint. Lower-body strength and power were evaluated by 1 repetition maximum (1-RM) squat, power clean, jerk, vertical jump, standing long jump, and standing triple jump. Sprint times averaged 1.78 +/- 0.11 seconds (9.1 m), 5.18 +/- 0.35 seconds (36.6 m), and 7.40 +/- 0.53 seconds. Acceleration peaked at 9.1 m (2.96 +/- 0.44 m x s(-2)), was held constant at 18.3 m (3.55 +/- 0.0.94 m x s(-2)), and was negative at 27.4 m (-1.02 +/- 0.72 m x s(-2)). Velocity peaked at 18.3 m (8.38 +/- 0.65 m x s(-2)) and decreased slightly, but significantly at 27.4 m (7.55 +/- 0.66 m x s(-2)), associated with the negative acceleration. Measures of lower-body strength were significantly related to acceleration, velocity, and sprint performance only when corrected for body mass. Lower-body strength/BM and power correlated highest with 36.6-m time (rs = -0.55 to -0.80) and with acceleration (strength r = 0.67-0.49; power r = 0.73-0.81) and velocity (strength r = 0.68-0.53; power r = 0.74-0.82) at 9.1 m. Sprint times and strength per body mass were significantly lower in lineman compared with linebackers-tight ends and backs. The acceleration and velocity patterns were the same for each position group, and differences in sprint time were determined by the magnitude of acceleration and velocity at 9.1 and 18.3 m. Sprint performance in football players is determined by a rapid increase in acceleration (through 18.3 m) and a high velocity maintained throughout the sprint and is independent of position played. The best sprint performances (independent of sprint distance) appear to be related to the highest initial acceleration (through 18.3 m) and highest attained and maintained velocity. Strength relative to body mass and power appears to

  18. Training-specific muscle architecture adaptation after 5-wk training in athletes.

    Science.gov (United States)

    Blazevich, Anthony J; Gill, Nicholas D; Bronks, Roger; Newton, Robert U

    2003-12-01

    This study examined changes in the muscle size, muscle architecture, strength, and sprint/jump performances of concurrently training athletes during 5 wk of "altered" resistance training (RT). Eight female and 15 male athletes performed 4 wk of sprint, jump, and resistance training in addition to their sports training (standardization) before adopting one of three different programs for 5 wk: 1) squat lift training (SQ, N = 8) with sprint/jump training; 2) forward hack squat training (FHS, N = 7) with sprint/jump training; or 3) sprint/jump training only (SJ, N = 8). Muscle size, fascicle angle, and fascicle length of the vastus lateralis (VL) and rectus femoris (RF) muscles (using ultrasound procedures) as well as 20-m sprint run, vertical jump, and strength performance changes were examined. A small increase in VL fascicle angle in SQ and FHS was statistically different to the decrease in SJ subjects (P < 0.05 at distal, P < 0.1 at proximal). VL fascicle length increased for SJ only (P < 0.05 at distal, P < 0.1 at proximal) and increased in RF in SQ subjects (P < 0.05). Muscle thickness of VL and RF increased in all training groups (P < 0.05) but only at proximal sites. There were no between-group differences in squat, forward hack squat, or isokinetic strength performances, or in sprint or jump performances, despite improvements in some of the tests across the groups. Significant muscle size and architectural adaptations can occur in concurrently training athletes in response to a 5-wk training program. These adaptations were possibly associated with the force and velocity characteristics of the training exercises but not the movement patterns. Factors other than, or in addition to, muscle architecture must mediate changes in strength, sprint, and jump performance.

  19. Moderate, but not vigorous, intensity exercise training reduces C-reactive protein.

    Science.gov (United States)

    Fedewa, Michael V; Hathaway, Elizabeth D; Higgins, Simon; Forehand, Ronald L; Schmidt, Michael D; Evans, Ellen M

    2018-06-01

    Sprint interval cycle training is a contemporary popular mode of training but its relative efficacy, under conditions of matched energy expenditure, to reduce risk factors for cardiometabolic disease is incompletely characterised, especially in young women. The purpose of this investigation was to determine the relative efficacy of six weeks of moderate-intensity cycling (MOD-C) and vigorous sprint-interval cycling (VIG-SIC) on lipid profile, insulin (INS) and insulin resistance using the homeostatic model assessment (HOMA-IR) and C-reactive protein (CRP) in inactive, overweight/obese (OW/OB) young women. Participants (BMI ≥25 kg/m 2 , waist circumference ≥88 cm) were randomly assigned to MOD-C (20-30 min at 60-70% of heart rate reserve(HRR)) or VIG-SIC (5-7 repeated bouts 30-second maximal effort sprints, followed by four minutes of active recovery) supervised training three days/week for six weeks, with each group matched on energy expenditure. Adiposity (%Fat) was measured using dual x-ray absorptiometry. Forty-four participants (20.4 ± 1.6 years, 65.9% Caucasian, 29.8 ± 4.1 kg/m 2 ) were included in the analysis. The improvement in CRP observed in the MOD-C group was larger than the VIG-C group (p = .034). Overall, high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) levels improved following training (p  .05). These results indicate MOD-C training may be more effective in reducing CRP than VIG-SIC.

  20. Giving students the run of sprinting models

    Science.gov (United States)

    Heck, André; Ellermeijer, Ton

    2009-11-01

    A biomechanical study of sprinting is an interesting task for students who have a background in mechanics and calculus. These students can work with real data and do practical investigations similar to the way sports scientists do research. Student research activities are viable when the students are familiar with tools to collect and work with data from sensors and video recordings and with modeling tools for comparing simulation and experimental results. This article describes a multipurpose system, named COACH, that offers a versatile integrated set of tools for learning, doing, and teaching mathematics and science in a computer-based inquiry approach. Automated tracking of reference points and correction of perspective distortion in videos, state-of-the-art algorithms for data smoothing and numerical differentiation, and graphical system dynamics based modeling are some of the built-in techniques that are suitable for motion analysis. Their implementation and their application in student activities involving models of running are discussed.

  1. Comparison of between-training-sessions recovery strategies for world-class BMX pilots.

    Science.gov (United States)

    Marquet, Laurie-Anne; Hausswirth, Christophe; Hays, Arnaud; Vettoretti, Fabrice; Brisswalter, Jeanick

    2015-03-01

    To assess the impact of between-training-sessions recovery strategies (passive [PAS], active [ACT], cold-water immersion [CWI], and ingestion of a recovery drink [NUTR]) on maximal cycling performance, perceptions of delayed-onset muscle soreness (DOMS), and fatigue in world-class BMX riders. Eleven elite BMX athletes, members of the French national team (top country in the 2011 international ranking, 4 medals at the 2012 World Championships, top European country), participated in the study, which involved standardized training periods. Athletes performed 3 maximal-sprint power tests: the first day of the week before the training session and before and after training on the third day of the week (D3). The recovery strategy was randomly assigned to each participant on day 2 immediately after the last training period of the day. Perceptions of DOMS and general fatigue were recorded on D3. After training on D3, the decrease in maximal-sprint power (Pmax) was significantly greater for PAS than with CWI (P=.02) and NUTR (P=.018). Similar results were found with ACT (vs CWI P=.044, and vs NUTR P=.042). Self-reported DOMS and fatigue were significantly greater after PAS than after other strategies. For elite BMX riders, between training days, nutritional and/or CWI recovery strategies appear to be best for reducing muscle fatigue and increasing the capacity to withstand the training schedule.

  2. The effects of 16 weeks of intensive cycling training on seminal oxidants and antioxidants in male road cyclists.

    Science.gov (United States)

    Maleki, Behzad Hajizadeh; Tartibian, Bakhtyar; Vaamonde, Diana

    2014-07-01

    To examine the effects of 16 weeks of intensive cycling training on seminal reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC) in male road cyclists. Repeated measures design. The Exercise Physiology Laboratory of the Urmia University. Twenty-four healthy nonprofessional male road cyclists (aged 17-26 years) participated in this study. All subjects participated in 16 weeks of intensive cycling training. The semen samples were collected, respectively, at baseline (T1), immediately (T2), 12 (T3), and 24 (T4) hours after the last training session in week 8; immediately (T5), 12 (T6), and 24 (T7) hours after the last training session in week 16; and 7 (T8) and 30 (T9) days after the last training session in week 16. Total antioxidant capacity and SOD were measured by colorimetric assay. The levels of ROS were measured by a chemiluminescence assay. Malondialdehyde levels were measured by thiobarbituric acid reactive substance assay. Catalase was measured by monitoring the initial rate of disappearance of hydrogen peroxide (initial concentration 10 mM) at 240 nm. The levels of seminal ROS and MDA increased (P < 0.008) and remained high after 30 days of recovery. The levels of seminal SOD, catalase, and TAC decreased (P < 0.008) and remained low after 30 days of recovery (P < 0.008). Sixteen weeks of intensive cycling training may have deleterious consequences for spermatozoa and hence may affect sperm healthy parameters in male cyclists.

  3. Performance and Metabolic Demand of a New Repeated-Sprint Ability Test in Basketball Players: Does the Number of Changes of Direction Matter?

    Science.gov (United States)

    Zagatto, Alessandro M; Ardigò, Luca P; Barbieri, Fabio A; Milioni, Fabio; Dello Iacono, Antonio; Camargo, Bruno H F; Padulo, Johnny

    2017-09-01

    Zagatto, AM, Ardigò, LP, Barbieri, FA, Milioni, F, Dello Iacono, A, Camargo, BHF, and Padulo, J. Performance and metabolic demand of a new repeated-sprint ability test in basketball players: does the number of changes of direction matter? J Strength Cond Res 31(9): 2438-2446, 2017-This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 × 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (V[Combining Dot Above]O2) and posttest blood lactate concentration [La] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands.

  4. A sled push stimulus potentiates subsequent 20-m sprint performance.

    Science.gov (United States)

    Seitz, Laurent B; Mina, Minas A; Haff, G Gregory

    2017-08-01

    The objective of this study was to examine the potentiating effects of performing a single sprint-style sled push on subsequent unresisted 20m sprint performance. Randomized crossover design. Following a familiarization session, twenty rugby league players performed maximal unresisted 20m sprints before and 15s, 4, 8 and 12min after a single sled push stimulus loaded with either 75 or 125% body mass. The two sled push conditions were performed in a randomized order over a one-week period. The fastest sprint time recorded before each sled push was compared to that recorded at each time point after to determine the post-activation potentiation (PAP) effect. After the 75% body mass sled push, sprint time was 0.26±1.03% slower at the 15s time point (effect size [ES]=0.07) but faster at the 4 (-0.95±2.00%; ES=-0.22), 8 (-1.80±1.43%; ES=-0.42) and 12 (-1.54±1.54%; ES=-0.36)min time points. Sprint time was slower at all the time points after the 125% body mass sled (1.36±2.36%-2.59±2.90%; ESs=0.34-0.64). Twenty-meter sprint performance is potentiated 4-12min following a sled push loaded with 75% body mass while it is impaired after a 125% body mass sled. These results are of great importance for coaches seeking to potentiate sprint performance with the sled push exercise. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. EFFECT OF ENERGY EXPENDITURE AND TRAINING STATUS ON LEPTIN RESPONSE TO SUB-MAXIMAL CYCLING

    Directory of Open Access Journals (Sweden)

    Anissa Bouassida

    2009-06-01

    Full Text Available We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR and 7 untrained (UTR subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP. Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively. [Lep] was related to body fat percentage and body fat mass in TR (r = 0. 84, p < 0.05 and r = 0.93, p < 0.01 and in UTR (r = 0.89, p < 0.01 and r = 0.92, p < 0. 01, respectively. [Lep] did not change significantly during both protocols for both groups but was lower (p < 0.05 in all sampling in TR when compared to UTR. Plasma [I] decreased (p < 0.01 and [GH] increased (p < 0.01 significantly during both SP and PP and these hormones remained lower (I: p < 0.01 and higher (GH: p < 0.01 than pre-exercise levels after a 2-h recovery period, returning to base-line at 24-h recovery. Plasma [La] increased (p < 0.01 during both protocols for TR and UTR. There was no significant change in [C] and [G] during and after both protocols for all subjects. It is concluded that 1 leptin is not sensitive to acute short or prolonged sub-maximal exercises (with energy expenditure under 800 kcal in volleyball/ anaerobically trained athletes as in untrained subjects, 2 volleyball athletes showed significantly lower resting and exercise leptin response with respect to untrained subjects and 3 it appears that in these anaerobically trained athletes leptin response to exercise is more sensitive to the level of

  6. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players.

    Science.gov (United States)

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-11-22

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 - 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  7. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

    Directory of Open Access Journals (Sweden)

    Wieczorek Marta

    2015-12-01

    Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  8. Proposal for the revision of the Background Questionnaire on education and training for the 2nd cycle of PIAAC

    NARCIS (Netherlands)

    Allen, James; Massing, Natascha; Schneider, Silke; van der Velden, Rolf

    2017-01-01

    In this report, we provide suggestions for improving the way in which education is surveyed in PIAAC. We critically assess how the concepts of educational attainment, educational pathways and non-formal training were measured in the first cycle, and suggest improvements in how these can be measured

  9. Effect of biofeedback cycling training on functional recovery and walking ability of lower extremity in patients with stroke

    Directory of Open Access Journals (Sweden)

    Huei-Ching Yang

    2014-01-01

    Full Text Available This study aimed to investigate the effectiveness of biofeedback cycling training on lower limb functional recovery, walking endurance, and walking speed for patients with chronic stroke. Thirty-one patients with stroke (stroke onset >3 months were randomly assigned into two groups using a crossover design. One group (N = 16; mean: 53.6 ± 10.3 years underwent conventional rehabilitation and cycling training (30 minutes/time, 5 times per week for 4 weeks, followed by only conventional rehabilitation for another 4 weeks. The other group (N = 15; mean: 54.5 ± 8.0 years underwent the same training in reverse order. The bike used in this biofeedback cycling training was the MOTOmed viva2 Movement Trainer. Outcome measures included the lower extremity subscale of Fugl-Meyer assessment (LE-FMA, the 6-minute walk test (6MWT, the 10-meter walk test (10MWT, and the modified Ashworth scale (MAS. All participants were assessed at the beginning of the study, at the end of the 4th week, and at the end of the 8th week. Thirty participants completed the study, including the cycling training interventions and all assessments. The results showed that improvements in the period with cycling training were significantly better than the noncycling period in the LE-FMA (p < 0.05, 6MWT (p < 0.001, 10MWT (p < 0.001, and MAS (p < 0.001 scores. No significant carryover effects were observed. The improvements on outcome measures were significantly different between the cycling period and the noncycling period after adjusting for potential confounding factors in the multivariate analysis of variance (p < 0.001. The study result indicates that the additional 4-week biofeedback cycling training could lead to improved LE functional recovery, walking endurance, and speed for patients with chronic stroke.

  10. Isometric Mid-Thigh Pull Performance Is Associated With Athletic Performance And Sprinting Kinetics In Division I Men And Women's Basketball Players.

    Science.gov (United States)

    Townsend, Jeremy R; Bender, David; Vantrease, William; Hudy, John; Huet, Kevin; Williamson, Cassie; Bechke, Emily; Serafini, Paul; Mangine, Gerald T

    2017-07-31

    To examine the relationships between isometric mid-thigh pull (IMTP) force, athletic performance measures, and sprint kinetics in Division I men's and women's basketball players. Twenty-three (male = 8, female = 15) division 1 basketball players completed a maximal 20-m sprint trial while tethered to a device which provided kinetic feedback (peak and average sprinting power, velocity and force). Additionally, one repetition-maximal (1RM) front squat, 1RM hang clean, vertical jump height, and agility (pro-agility and lane agility) tests were performed. Rate of force development (RFD) at 50ms, 100ms, 150ms, 200ms and 250ms of IMTP, as well as peak force (PF) were also collected. Pearson product-moment correlation analysis was used to examine the relationships between these measures. Significant (p training.

  11. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males

    DEFF Research Database (Denmark)

    Babraj, John A; Vollaard, Niels B J; Keast, Cameron

    2009-01-01

    BACKGROUND: Traditional high volume aerobic exercise training reduces cardiovascular and metabolic disease risk but involves a substantial time commitment. Extremely low volume high-intensity interval training (HIT) has recently been demonstrated to produce improvements to aerobic function...... cycle sprints per session). Aerobic performance (250-kJ self-paced cycling time trial), and glucose, insulin and NEFA responses to a 75-g oral glucose load (oral glucose tolerance test; OGTT) were determined before and after training. RESULTS: Following 2 weeks of HIT, the area under the plasma glucose......, to substantially improve insulin action in young sedentary subjects is remarkable. This novel time-efficient training paradigm can be used as a strategy to reduce metabolic risk factors in young and middle aged sedentary populations who otherwise would not adhere to time consuming traditional aerobic exercise...

  12. Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance.

    Science.gov (United States)

    Boyett, James C; Giersch, Gabrielle E W; Womack, Christopher J; Saunders, Michael J; Hughey, Christine A; Daley, Hannah M; Luden, Nicholas D

    2016-10-14

    This project was designed to assess the effects of time of day and training status on the benefits of caffeine supplementation for cycling performance. Twenty male subjects (Age, 25 years; Peak oxygen consumption, 57 mL·kg -1 ·min -1 ) were divided into tertiles based on training levels, with top and bottom tertiles designated as 'trained' ( n = 7) and 'untrained' ( n = 7). Subjects completed two familiarization trials and four experimental trials consisting of a computer-simulated 3-km cycling time trial (TT). The trials were performed in randomized order for each combination of time of day (morning and evening) and treatment (6mg/kg of caffeine or placebo). Magnitude-based inferences were used to evaluate all treatment effects. For all subjects, caffeine enhanced TT performance in the morning (2.3% ± 1.7%, 'very likely') and evening (1.4% ± 1.1%, 'likely'). Both untrained and trained subjects improved performance with caffeine supplementation in the morning (5.5% ± 4.3%, 'likely'; 1.0% ± 1.7%, 'likely', respectively), but only untrained subjects rode faster in the evening (2.9% ± 2.6%, 'likely'). Altogether, our observations indicate that trained athletes are more likely to derive ergogenic effects from caffeine in the morning than the evening. Further, untrained individuals appear to receive larger gains from caffeine in the evening than their trained counterparts.

  13. Low dose creatine supplementation enhances sprint phase of 400 meters swimming performance.

    Science.gov (United States)

    Anomasiri, Wilai; Sanguanrungsirikul, Sompol; Saichandee, Pisut

    2004-09-01

    This study demonstrated the effect of low dose creatine supplement (10 g. per day) on the sprinting time in the last 50 meters of 400 meters swimming competition, as well as the effect on exertion. Nineteen swimmers in the experimental group received creatine monohydrate 5 g with orange solution 15 g, twice per day for 7 days and nineteen swimmers in the control group received the same quantity of orange solution. The results showed that the swimmers who received creatine supplement lessened the sprinting time in the last 50 meters of 400 meters swimming competition than the control group. (p<0.05). The results of Wingate test (anaerobic power, anaerobic capacity and fatigue index) compared between pre and post supplementation. There was significant difference at p<0.05 in the control group from training effect whereas there was significant difference at p<0.000 from training effect and creatine supplement in the experiment group. Therefore, the creatine supplement in amateur swimmers in the present study enhanced the physical performance up to the maximum capacity.

  14. The effects of hybrid cycle training in inactive people with long-term spinal cord injury : design of a multicenter randomized controlled trial

    NARCIS (Netherlands)

    Bakkum, Arjan J. T.; de Groot, Sonja; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

    2013-01-01

    Purpose: Physical activity in people with long-term spinal cord injury (SCI) is important to stay fit and healthy. The purpose of this study is to evaluate the effects of hybrid cycle training (hand cycling in combination with functional electrical stimulation-induced leg cycling) on fitness,

  15. Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance

    Directory of Open Access Journals (Sweden)

    James C. Boyett

    2016-10-01

    Full Text Available This project was designed to assess the effects of time of day and training status on the benefits of caffeine supplementation for cycling performance. Twenty male subjects (Age, 25 years; Peak oxygen consumption, 57 mL·kg−1·min−1 were divided into tertiles based on training levels, with top and bottom tertiles designated as ‘trained’ (n = 7 and ‘untrained’ (n = 7. Subjects completed two familiarization trials and four experimental trials consisting of a computer-simulated 3-km cycling time trial (TT. The trials were performed in randomized order for each combination of time of day (morning and evening and treatment (6mg/kg of caffeine or placebo. Magnitude-based inferences were used to evaluate all treatment effects. For all subjects, caffeine enhanced TT performance in the morning (2.3% ± 1.7%, ‘very likely’ and evening (1.4% ± 1.1%, ‘likely’. Both untrained and trained subjects improved performance with caffeine supplementation in the morning (5.5% ± 4.3%, ‘likely’; 1.0% ± 1.7%, ‘likely’, respectively, but only untrained subjects rode faster in the evening (2.9% ± 2.6%, ‘likely’. Altogether, our observations indicate that trained athletes are more likely to derive ergogenic effects from caffeine in the morning than the evening. Further, untrained individuals appear to receive larger gains from caffeine in the evening than their trained counterparts.

  16. The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

    Directory of Open Access Journals (Sweden)

    Matthew R. Lowery

    2018-04-01

    Full Text Available Background/objective: The relationship between ventilatory threshold (VT1, VT2 and repeated-sprint ability (RSA in competitive male ice hockey players was investigated. Methods: Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope. Participants performed an on-ice repeated shift (RSA test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec. Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2 and RSA (first gate, second gate, and total course decrement. Results: Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P < 0.05, second gate (r = −0.58; P < 0.001 and total course decrement (r = −0.42; P < 0.05. Conclusion: The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA. Keywords: Athletes, Aerobic capacity, Fatigue, Sprint decrement

  17. International inventory of training facilities in nuclear power and its fuel cycle

    International Nuclear Information System (INIS)

    1977-01-01

    Because the development of trained manpower is important for full use of nuclear power, the International Atomic Energy Agency has compiled this first inventory of training facilities and programs. It is based on information submitted by Member States and received up to 31 January 1977. The inventory is arranged by country, type of training organization, and by subject

  18. The Effects of Muscular Fatigue on the Kinetics of Sprint Running.

    Science.gov (United States)

    Sprague, Paul; Mann, Ralph V.

    1983-01-01

    To compare the kinematic and kinetic effects of fatigue on the biomechanics of sprint running, male subjects were filmed performing a short maximal exertion sprint and a long fatiguing sprint. Observable differences in the productive muscular activity of the better and the poorer sprinters occurred during the ground-phase of their strides.…

  19. The effect of hamstring flexibility on peak hamstring muscle strain in sprinting

    Directory of Open Access Journals (Sweden)

    Xianglin Wan

    2017-09-01

    Conclusion: A potential for hamstring injury exists during the late swing phase of sprinting. Peak hamstring muscle strains in sprinting are negatively correlated to hamstring flexibility across individuals. The magnitude of peak muscle strains is different among hamstring muscles in sprinting, which may explain the different injury rate among hamstring muscles.

  20. Coherent lidar modulated with frequency stepped pulse trains for unambiguous high duty cycle range and velocity sensing in the atmosphere

    DEFF Research Database (Denmark)

    Lindelöw, Per Jonas Petter; Mohr, Johan Jacob

    2007-01-01

    Range unambiguous high duty cycle coherent lidars can be constructed based on frequency stepped pulse train modulation, even continuously emitting systems could be envisioned. Such systems are suitable for velocity sensing of dispersed targets, like the atmosphere, at fast acquisition rates....... The lightwave synthesized frequency sweeper is a suitable generator yielding fast pulse repetition rates and stable equidistant frequency steps. Theoretical range resolution profiles of modulated lidars are presented....

  1. High Speed Running and Sprinting Profiles of Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Miñano-Espin Javier

    2017-08-01

    Full Text Available Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD = 536, External Defenders (ED = 491, Central Midfielders (CM = 544, External Midfielders (EM = 233, and Forwards (F = 278. Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France. A repeated measures analysis of variance (ANOVA was performed for distances covered at different intensities (sprinting (>24.0 km/h and high-speed running (21.1-24.0 km/h and the number of sprints (21.1-24.0 km/h and >24.0 km/h during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p 0.01 from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.

  2. Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

    Science.gov (United States)

    Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

    2013-09-30

    Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

  3. Carbohydrate mouth rinse does not improve repeated sprint performance

    Directory of Open Access Journals (Sweden)

    Leandro Ricardo Altimari

    2013-09-01

    Full Text Available The objective of this study was to evaluate the effect of a carbohydrate mouth rinse on the repeated sprint ability (RSA of young soccer players. Nine youth soccer players (15.0 ± 1.5 years; 60.7 ± 4.84 kg; 1.72 ± 0.05 m; 20.5 ± 1.25 kg/m2 were selected. The athletes were submitted to an RSA test consisting of six sprints of 40 m (going/return = 20 m + 20 m, separated by 20 s of passive recovery, under three experimental conditions: carbohydrate mouth rinse (CHO or placebo (PLA and control (CON. The mouth rinses containing CHO or PLA were administered 5 min and immediately before the beginning of the test in doses of 100 mL. The best sprint time (RSAbest, mean sprint time (RSAmean, and drop-off in sprint performance (fatigue index were determined for the different treatments. One-not identify significant differences (p> 0.05 in RSAbest (CHO way ANOVA for repeated measures did = 7.30 ± 0.31 s; PLA = 7.30 ± 0.30 s; CON = 7.26 ±0.16 s, RSA mean (CHO = 7.71 ± 0.30 s; PLA = 7.71 ± 0.25 s; CON = 7.66 ± 0.24s, or fatigue index (CHO = 5.58 ± 2.16%; PLA = 5.77 ± 3.04%; CON = 5.55 ±3.72%. The results suggest that a carbohydrate mouth rinse does not improve the repeated sprint performance of young soccer players.

  4. Isometric Mid-Thigh Pull Correlates With Strength, Sprint, and Agility Performance in Collegiate Rugby Union Players.

    Science.gov (United States)

    Wang, Ran; Hoffman, Jay R; Tanigawa, Satoru; Miramonti, Amelia A; La Monica, Michael B; Beyer, Kyle S; Church, David D; Fukuda, David H; Stout, Jeffrey R

    2016-11-01

    Wang, R, Hoffman, JR, Tanigawa, S, Miramonti, AA, La Monica, MB, Beyer, KS, Church, DD, Fukuda, DH, and Stout, JR. Isometric mid-thigh pull correlates with strength, sprint, and agility performance in collegiate rugby union players. J Strength Cond Res 30(11): 3051-3056, 2016-The purpose of this investigation was to examine the relationships between isometric mid-thigh pull (IMTP) force and strength, sprint, and agility performance in collegiate rugby union players. Fifteen members of a champion-level university's club rugby union team (mean ± SD: 20.67 ± 1.23 years, 1.78 ± 0.06 m, and 86.51 ± 14.18 kg) participated in this investigation. One repetition maximum (1RM) squat, IMTP, speed (40 m sprint), and agility (proagility test and T-test) were performed during 3 separate testing sessions. Rate of force development (RFD) and force output at 30, 50, 90, 100, 150, 200, and 250 milliseconds of IMTP, as well as the peak value were determined. Pearson product-moment correlation analysis was used to examine the relationships between these measures. Performance in the 1RM squat was significantly correlated to the RFD between 90 and 250 milliseconds from the start of contraction (r's ranging from 0.595 to 0.748), and peak force (r = 0.866, p ≤ 0.05). One repetition maximum squat was also correlated to force outputs between 90 and 250 milliseconds (r's ranging from 0.757 to 0.816, p ≤ 0.05). Sprint time over the first 5 m in the 40 m sprint was significantly (p ≤ 0.05) correlated with peak RFD (r = -0.539) and RFD between 30 and 50 milliseconds (r's = -0.570 and -0.527, respectively). Time for the proagility test was correlated with peak RFD (r = -0.523, p ≤ 0.05) and RFD between 30 and 100 milliseconds (r's ranging from -0.518 to -0.528, p's strength, agility, and sprint performance. Future studies should examine IMTP as a potential tool to monitor athletic performance during the daily training of rugby union players.

  5. A High Intensity Interval Training (HIIT)-Based Running Plan Improves Athletic Performance by Improving Muscle Power.

    Science.gov (United States)

    García-Pinillos, Felipe; Cámara-Pérez, Jose C; Soto-Hermoso, Víctor M; Latorre-Román, Pedro Á

    2017-01-01

    García-Pinillos, F, Cámara-Pérez, JC, Soto-Hermoso, VM, and Latorre-Román, PÁ. A High Intensity Interval Training (HIIT)-based running plan improves athletic performance by improving muscle power. J Strength Cond Res 31(1): 146-153, 2017-This study aimed to examine the effect of a 5-week high-intensity intermittent training (HIIT)-based running plan on athletic performance and to compare the physiological and neuromuscular responses during a sprint-distance triathlon before and after the HIIT period. Thirteen triathletes were matched into 2 groups: the experimental group (EG) and the control group (CG). The CG was asked to maintain their normal training routines, whereas the EG maintained only their swimming and cycling routines and modified their running routine. Participants completed a sprint-distance triathlon before (pretest) and after (posttest) the intervention period. In both pretest and posttest, the participants performed 4 jumping tests: before the race (baseline), postswim, postcycling, and postrun. Additionally, heart rate was monitored (HRmean), whereas rate of perceived exertion (RPE) and blood lactate accumulation (BLa) were registered after the race. No significant differences (p ≥ 0.05) between groups were found before HIIT intervention (at pretest). Significant group-by-training interactions were found in vertical jumping ability and athletic performance: the EG improved jumping performance (∼6-9%, p ≤ 0.05, effect size (ES) > 0.7), swimming performance (p = 0.013, ES = 0.438), and running time (p = 0.001, ES = 0.667) during the competition, whereas the CG remained unchanged (p ≥ 0.05, ES HIIT-based running plan combined with the high training volumes of these triathletes in swimming and cycling improved athletic performance during a sprint-distance triathlon. This improvement may be due to improved neuromuscular characteristics that were transferred into improved muscle power and work economy.

  6. High intensity interval and moderate continuous cycle training in a physical education programme improves health-related fitness in young females.

    Science.gov (United States)

    Mazurek, K; Zmijewski, P; Krawczyk, K; Czajkowska, A; Kęska, A; Kapuściński, P; Mazurek, T

    2016-06-01

    The aim of the study was to investigate the effects of eight weeks of regular physical education classes supplemented with high intensity interval cycle exercise (HIIE) or continuous cycle exercises of moderate intensity (CME). Forty-eight collegiate females exercising in two regular physical education classes per week were randomly assigned to two programmes (HIIE; n = 24 or CME; n = 24) of additional (one session of 63 minutes per week) physical activity for 8 weeks. Participants performed HIIE comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active recovery pedalling with intensity 65%-75% HRmax or performed CME corresponding to 65%-75% HRmax. Before and after the 8-week programmes, anthropometric data and aero- and anaerobic capacity were measured. Two-way ANOVA revealed a significant time main effect for VO2max (p body mass not changing significantly (p = 0.59; +0.4% in HIIE and -0.1% in CME). A significant main time effect was found for relative fat mass (FM) and fat-free mass (FFM) (p body composition than physical education classes supplemented with HIIE sessions. In contrast to earlier, smaller trials, similar improvements in aerobic capacity were observed following physical activity with additional HIIE or CME sessions.

  7. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress.

    Directory of Open Access Journals (Sweden)

    Olivier Girard

    Full Text Available Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C and CON (25°C conditions.Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting.Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001 and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05 temperatures, together with thermal comfort (P<0.001 were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001 and contact time (+3.2±2.4%; P<0.01 higher in HOT for the mean of sets 1-3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001, with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06. Mean vertical (-2.6±5.5%; P<0.01, horizontal (-9.1±4.4%; P<0.001 and resultant ground reaction forces (-3.0±2.8%; P<0.01 along with vertical stiffness (-12.9±2.3%; P<0.001 and leg stiffness (-8.4±2.7%; P<0.01 decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001, with lower propulsive power values in set 2 (-6.6%; P<0.05 in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise.Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations.

  8. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

    Science.gov (United States)

    Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

    2017-01-01

    Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

  9. Changes in Muscle and Cerebral Deoxygenation and Perfusion during Repeated Sprints in Hypoxia to Exhaustion

    Directory of Open Access Journals (Sweden)

    Sarah J. Willis

    2017-10-01

    Full Text Available During supramaximal exercise, exacerbated at exhaustion and in hypoxia, the circulatory system is challenged to facilitate oxygen delivery to working tissues through cerebral autoregulation which influences fatigue development and muscle performance. The aim of the study was to evaluate the effects of different levels of normobaric hypoxia on the changes in peripheral and cerebral oxygenation and performance during repeated sprints to exhaustion. Eleven recreationally active participants (six men and five women; 26.7 ± 4.2 years, 68.0 ± 14.0 kg, 172 ± 12 cm, 14.1 ± 4.7% body fat completed three randomized testing visits in conditions of simulated altitude near sea-level (~380 m, FIO2 20.9%, ~2000 m (FIO2 16.5 ± 0.4%, and ~3800 m (FIO2 13.3 ± 0.4%. Each session began with a 12-min warm-up followed by two 10-s sprints and the repeated cycling sprint (10-s sprint: 20-s recovery test to exhaustion. Measurements included power output, vastus lateralis, and prefrontal deoxygenation [near-infrared spectroscopy, delta (Δ corresponds to the difference between maximal and minimal values], oxygen uptake, femoral artery blood flow (Doppler ultrasound, hemodynamic variables (transthoracic impedance, blood lactate concentration, and rating of perceived exertion. Performance (total work, kJ; −27.1 ± 25.8% at 2000 m, p < 0.01 and −49.4 ± 19.3% at 3800 m, p < 0.001 and pulse oxygen saturation (−7.5 ± 6.0%, p < 0.05 and −18.4 ± 5.3%, p < 0.001, respectively decreased with hypoxia, when compared to 400 m. Muscle Δ hemoglobin difference ([Hbdiff] and Δ tissue saturation index (TSI were lower (p < 0.01 at 3800 m than at 2000 and 400 m, and lower Δ deoxyhemoglobin resulted at 3800 m compared with 2000 m. There were reduced changes in peripheral [Δ[Hbdiff], ΔTSI, Δ total hemoglobin ([tHb

  10. Structure of a year cycle of athletes training in aerobics (woman with various psychophysiological and functional features

    Directory of Open Access Journals (Sweden)

    T.V. Shepelenko

    2018-02-01

    Full Text Available Purpose : to develop structure of training process creation in a year cycle of qualified athletes’ preparation in aerobics (woman. Material : qualified athletes in aerobics participated in a research (n=46, age 20-22 years, height is 168±2, 4 cm, body weight is 62±4, 2 kg. Athletes were divided into experimental group (n=24 and control group (n=22. It was determined the level of special preparation: performance of standard combinations of basic aerobic steps. Results . The general principles of training programs preparation are developed. Programs include basic and variable components. The basic component of programs represents the standardized structure of means and methods selection of athletes’ preparation. The variable component of programs contained special means and methods differ on character and volume. One of the main parts of a variable component is the psychophysical training. It is based on performance of special sets of exercises in combination with mental figurative representations of motor nature. Conclusions . It is appropriate to carry out planning of training process in a year cycle of preparation considering specific features of factorial structure of athletes’ preparation.

  11. Relación entre la fuerza máxima en squat y acciones de salto, sprint y golpeo de balón. (Relationship among maximal strength in squat exercise, jump, sprint and kicking ball performance.

    Directory of Open Access Journals (Sweden)

    Alfredo Arija Blázquez

    2008-01-01

    Full Text Available ResumenEl objetivo del presente estudio fue analizar las posibles relaciones entre la fuerza máxima en squat y accionesexplosivas de salto, sprint y golpeo de balón. Para ello, se contó con una muestra formada por estudiantes de Ciencias del Deporte (N= 16; 19,6 ± 1,7 años de sexo masculino (con escasa experiencia en el entrenamiento de fuerza, que llevaron a cabo un test de 1RM en squat (calculándose el peso levantado, la fuerza media total y la fuerza dinámica máxima, tests de salto vertical (SJ, CMJ y CMJa, un test de sprint de 20 m (con mediciones de tiempo cada 5 m, y un test de golpeo con el pie donde se calculaba la velocidad del balón. Se encontraron coeficientes de correlación moderados (entre 0,52 y 0,67 y significativos de las medidas de fuerza máxima y las alturas de salto, mientras que los coeficientes obtenidos entre los tiempos de sprint y dichas medidas de fuerza máxima se situaron entre -0,06 y -0,32, no siendo ninguno de ellos significativo; al igual que tampoco fueron significativos los coeficientes de correlación de las medidas de fuerza máxima y la velocidad de tiro, se situaron entre 0,25 y 0,34. Por tanto, la relación entre la fuerza máxima en squat y la altura de salto en sujetos con escasa experiencia en el entrenamiento de fuerza resultó moderada, mientras que no parece existir relación con el tiempo de sprint y la velocidad de tiro.AbstractThe purpose of the present study was to analyze the possible relationships between maximal strength insquat exercise and jump, sprint and kicking ball actions. Sixteen males sport science students (19,6 ± 1,7years, with little experience in strength training, performed a 1RM in squat exercise (from which liftedweight, the total average- and maximal-dynamic strength was assessed, vertical jump (SJ, CMJ and CMJa, a 20 m sprint test (with time measurement every 5 m, and a kicking ball test where the velocity of the ball was calculated. Moderate (0,52 - 0,67 and

  12. Recovery of voluntary and evoked muscle performance following intermittent-sprint exercise in the heat.

    Science.gov (United States)

    Duffield, Rob; King, Monique; Skein, Melissa

    2009-06-01

    This study investigated the effects of hot conditions on the acute recovery of voluntary and evoked muscle performance and physiological responses following intermittent exercise. Seven youth male and six female team-sport athletes performed two sessions separated by 7 d, involving a 30-min exercise protocol and 60-min passive recovery in either 22 degrees C or 33 degrees C and 40% relative humidity. The exercise protocol involved a 20-s maximal sprint every 5 min, separated by constant-intensity exercise at 100 W on a cycle ergometer. Maximal voluntary contraction (MVC) and a resting evoked twitch (Pf) of the right knee extensors were assessed before and immediately following exercise and again 15, 30, and 60 min postexercise, and capillary blood was obtained at the same time points to measure lactate, pH, and HCO3. During and following exercise, core temperature, heart rate and rating of perceived exertion (RPE) were also measured. No differences (P=0.73 to 0.95) in peak power during repeated sprints were present between conditions. Postexercise MVC was reduced (Pheat (83+/-10 vs 74+/-11% recovered). Both heart rate and core temperature were significantly higher (Precovery in the heat. Capillary blood values did not differ between conditions at any time point, whereas sessional RPE was higher 60 min postexercise in the heat. The current data suggests that passive recovery in warm temperatures not only delays cardiovascular and thermal recovery, but may also slow the recovery of MVC and RPE.

  13. Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions.

    Science.gov (United States)

    Castle, Paul C; Macdonald, Adam L; Philp, Andrew; Webborn, Anthony; Watt, Peter W; Maxwell, Neil S

    2006-04-01

    We used three techniques of precooling to test the hypothesis that heat strain would be alleviated, muscle temperature (Tmu) would be reduced, and as a result there would be delayed decrements in peak power output (PPO) during exercise in hot, humid conditions. Twelve male team-sport players completed four cycling intermittent sprint protocols (CISP). Each CISP consisted of twenty 2-min periods, each including 10 s of passive rest, 5 s of maximal sprint against a resistance of 7.5% body mass, and 105 s of active recovery. The CISP, preceded by 20 min of no cooling (Control), precooling via an ice vest (Vest), cold water immersion (Water), and ice packs covering the upper legs (Packs), was performed in hot, humid conditions (mean +/- SE; 33.7 +/- 0.3 degrees C, 51.6 +/- 2.2% relative humidity) in a randomized order. The rate of heat strain increase during the CISP was faster in Control than Water and Packs (P body or whole body cooling.

  14. Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients

    Directory of Open Access Journals (Sweden)

    Wang K

    2017-09-01

    Full Text Available Kai Wang,1,* Guang-qiao Zeng,2,* Rui Li,1,* Yu-wen Luo,1 Mei Wang,1 Yu-he Hu,1 Wen-hui Xu,1 Lu-qian Zhou,2 Rong-chang Chen,2 Xin Chen1 1Department of Respiratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China; 2Department of Respiratory Medicine, The State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China *These authors contributed equally to this work Background: Cycle ergometer training (CET has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment.Materials and methods: Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group, 27 received 8 weeks of CET alone (CET group, and 26 only received 8 weeks of free walking (control group. Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program.Results: Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05 after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPImax [maximal inspiratory pressure] 5.20±0.89 cmH2O vs 1.32±0.91 cmH2O

  15. Jump Squat is More Related to Sprinting and Jumping Abilities than Olympic Push Press.

    Science.gov (United States)

    Loturco, I; Kobal, R; Maldonado, T; Piazzi, A F; Bottino, A; Kitamura, K; Abad, C C C; Pereira, L A; Nakamura, F Y

    2017-07-01

    The aim of this study was to test the relationships between jump squat (JS) and Olympic push press (OPP) power outputs and performance in sprint, squat jump (SJ), countermovement jump (CMJ) and change of direction (COD) speed tests in elite soccer players. 27 athletes performed a maximum power load test to determine their bar mean propulsive power (MPP) and bar mean propulsive velocity (MPV) in the JS and OPP exercises. Magnitude-based inference was used to compare the exercises. The MPV was almost certainly higher in the OPP than in the JS. The MPP relative to body mass (MPP REL) was possibly higher in the OPP. Only the JS MPP REL presented very large correlations with linear speed ( r> 0.7, for speed in 5, 10, 20 and 30 m) and vertical jumping abilities ( r> 0.8, for SJ and CMJ), and moderate correlation with COD speed ( r= 0.45). Although significant (except for COD), the associations between OPP outcomes and field-based measurements (speed, SJ and CMJ) were all moderate, ranging from 0.40 to 0.48. In a group composed of elite soccer players, the JS exercise is more associated with jumping and sprinting abilities than the OPP. Longitudinal studies are needed to confirm if these strong relationships imply superior training effects in favor of the JS exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  16. CHANGES IN MOTOR SKILLS OF CHILDREN WHO TRAIN SPORTS SWIMMING AT THE INITIAL STAGE OF SCHOOL EDUCATION (IN ANNUAL TRAINING CYCLE

    Directory of Open Access Journals (Sweden)

    Paul Eider

    2015-12-01

    Full Text Available Introduction: This is an empirical article aiming at defining the changes of motor fitness in children practicing swimming at early stage of training in year-long training cycle. Proper selection of candidates to practice certain sports is a very complex process. One needs to select from the very large population of children, girls and boys, characterized by certain features, including somatic and motor features, which developed in a longstanding process of training, will lead them to become champions. The purpose of the research: The purpose of the research was to define the changes of motor fitness in girls’ practicing swimming at early stage of training in year-long training cycle. Material and Methods: The subjects to the research were 85 girls aged 7 (1st year of primary school, including 36 girls in swimming group and 49 girls in control group. 36 of them belonged to swimmers’ group- all girls were members of the Municipal Swimming Club in Szczecin. Control group consisted of 49 girls, who attended the same elementary schools. The examinations were carried out twice in the 2009-2010 academic year. The most reliable and accurate indirect test- EUROFIT Test Battery-was used. Results : The research revealed changes in both groups (Sw, C in terms of all eight tests. Examination II proved statistically significant improvement of results in both groups (Sw, C in comparison to Examination I. The dynamics of changes in general balance, flexibility, static force, functional force, running agility, was bigger in the girls who practiced swimming. As the speed of movement of upper limb, explosive force and thorax force are concerned; the differences of results in both examinations were similar in both groups (swimming group and control group. Progressive changes in motor fitness of the examined groups are a positive phenomenon in the development of child’s young organism. Conclusions: Swimming training significantly affected the dynamics of

  17. Exercise and exercise training-induced increase in autophagy markers in human skeletal muscle

    DEFF Research Database (Denmark)

    Brandt, Nina; Gunnarsson, Thomas Gunnar Petursson; Bangsbo, Jens

    2018-01-01

    Moderately trained male subjects (mean age 25 years; range 19-33 years) completed an 8-week exercise training intervention consisting of continuous moderate cycling at 157 ± 20 W for 60 min (MOD; n = 6) or continuous moderate cycling (157 ± 20 W) interspersed by 30-sec sprints (473 ± 79 W) every 10...... muscle AMPKThr172 and ULKSer317 phosphorylation was elevated immediately after exercise, whereas mTORSer2448 and ULKSer757 phosphorylation was unchanged. Two hours after exercise LC3I, LC3II and BNIP3 protein content was overall higher than before exercise with no change in p62 protein. In MOD, Beclin1...... protein content was higher immediately and 2 h after exercise than before exercise, while there were no differences within SPRINT. Oxphos complex I, LC3I, BNIP3 and Parkin protein content was higher after the training intervention than before in both groups, while there was no difference in LC3II and p62...

  18. Effect of intensified training on muscle ion kinetics, fatigue development and repeated short term performance in endurance trained cyclists

    DEFF Research Database (Denmark)

    Gunnarsson, Thomas Gunnar Petursson; Christensen, Peter Møller; Thomassen, Martin

    2013-01-01

    The effects of intensified training in combination with a reduced training volume on muscle ion kinetics, transporters and work capacity were examined. Eight well-trained cyclists replaced their regular training with speed-endurance training (12x30-s sprints) 2-3 times per wk and aerobic high...

  19. Development of repeated sprint ability in talented youth basketball players

    NARCIS (Netherlands)

    te Wierike, Simon; Lemmink, Koen; de Jong, M.C.; Tromp, E.J.; Vuijk, P.J.; Malina, R.M.; Elferink-Gemser, Marije; Visscher, Chris

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  20. Supervisory Presentation for Research, Information, Integration and Testing (SPRINT)

    Science.gov (United States)

    2015-03-29

    in Microsoft Visual Studio and several third party developer libraries (See Figure 4). All distributed laboratory sites have similar hardware...Testing (SPRINT). 15. SUBJECT TERMS Supervisory Control, Multi-Modal Interfaces, Scalable Interfaces, Advanced Visualization , Augmented Symbology 16...23 Figure 9. Fusion Visual Framework Components

  1. Development of repeated sprint ability in talented youth basketball players.

    NARCIS (Netherlands)

    Koen A.P.M. Lemmink; P.J. Vuijk; S.C. te Wierike; C. Visscher; M.T. Elferink-Gemser; M.C. de Jong; R.M. Malina; E.J. Tromp

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  2. Kinematic analysis of competitive sprinting | Ansari | African Journal ...

    African Journals Online (AJOL)

    The results of the study showed that the kinematic variables i.e. knee angle, hip angle, ankle angle, shoulder rotation and extension had a significant influence on sprinting style. The results indicated that the kinematic variables of running style, knee angle at landing, hip flexion, ankle angle at landing, ankle angle at take-off, ...

  3. Validity And Reliability Of The Stages Cycling Power Meter.

    Science.gov (United States)

    Granier, Cyril; Hausswirth, Christophe; Dorel, Sylvain; Yann, Le Meur

    2017-09-06

    This study aimed to determine the validity and the reliability of the Stages power meter crank system (Boulder, United States) during several laboratory cycling tasks. Eleven trained participants completed laboratory cycling trials on an indoor cycle fitted with SRM Professional and Stages systems. The trials consisted of an incremental test at 100W, 200W, 300W, 400W and four 7s sprints. The level of pedaling asymmetry was determined for each cycling intensity during a similar protocol completed on a Lode Excalibur Sport ergometer. The reliability of Stages and SRM power meters was compared by repeating the incremental test during a test-retest protocol on a Cyclus 2 ergometer. Over power ranges of 100-1250W the Stages system produced trivial to small differences compared to the SRM (standardized typical error values of 0.06, 0.24 and 0.08 for the incremental, sprint and combined trials, respectively). A large correlation was reported between the difference in power output (PO) between the two systems and the level of pedaling asymmetry (r=0.58, p system according to the level of pedaling asymmetry provided only marginal improvements in PO measures. The reliability of the Stages power meter at the sub-maximal intensities was similar to the SRM Professional model (coefficient of variation: 2.1 and 1.3% for Stages and SRM, respectively). The Stages system is a suitable device for PO measurements, except when a typical error of measurement power ranges of 100-1250W is expected.

  4. Sprint-based exercise and cognitive function in adolescents

    Directory of Open Access Journals (Sweden)

    Simon B. Cooper

    2016-12-01

    Full Text Available Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y completed an exercise (E and resting (R trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking. A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST and Corsi blocks tests were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027 and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038, while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289 or substitutions made during the DSST (p = 0.689. The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition.

  5. A controlled clinical trial investigating the effects of cycle ergometry training on exercise tolerance, balance and quality of life in patients with Parkinson's disease.

    LENUS (Irish Health Repository)

    Lauhoff, Paula

    2013-03-01

    To establish the effect of a 6-week programme of cycle ergometry training on exercise tolerance, balance, activities of daily living (ADL) and quality of life in individuals with Parkinson\\'s disease (PD).

  6. Effect of 8 days of a hypergravity condition on the sprinting speed and lower-body power of elite rugby players.

    Science.gov (United States)

    Barr, Matthew J; Gabbett, Tim J; Newton, Robert U; Sheppard, Jeremy M

    2015-03-01

    -Sprinting speed and lower-body power are considered to be key physical abilities for rugby players. A method of improving the lower-body power of athletes is simulated hypergravity. This method involves wearing a weighted vest at all times during the day for an extended period of time. There are no studies that have examined the effect of hypergravity on speed or the benefit for rugby players. An experimental group (n = 8) and a control group (n = 7) of national team rugby players took part in the study, which consisted of rugby, conditioning, speed, and strength sessions. The experimental group wore a weighted vest equating to 12% of their body mass for 8 days. All players were tested for speed and lower-body power before, 2 days after, and 9 days after the intervention. Speed testing involved the athletes completing 40-m sprints with timing lights and high-speed video cameras assessing acceleration and maximal velocity sprinting kinematics. Lower-body power was assessed using weighted countermovement jumps (CMJs). No group differences were found for sprinting speed at any point. The experimental group displayed a large decrease in acceleration ground contact time (-0.01 ± 0.005 s, d = 1.07) and a moderate increase in 15-kg CMJ velocity (0.07 ± 0.11 m·s, d = 0.71). Individual responses showed that players in the experimental group had both negative and positive speed and power responses to the training intervention. Simulated hypergravity for 8 days is likely ineffective at improving sprinting speed while undergoing standard rugby training.

  7. Muscular coordination and strength training. Implications for injury rehabilitation.

    Science.gov (United States)

    Rutherford, O M

    1988-03-01

    Strength training is commonly used in the rehabilitation of muscles atrophied as a result of injury and/or disuse. Studies on the effects of conventional leg extension training in healthy subjects have shown the changes to be very task-specific to the training manoeuvre itself. After conventional leg extension training for the quadriceps muscle the major improvement was in weightlifting ability with only small increases in isometric strength. The maximum dynamic force and power output during sprint cycling showed no improvement. These results suggest that the major benefit of this type of training is learning to coordinate the different muscle groups involved in the training movement rather than intrinsic increases in strength of the muscle group being trained. Other studies have shown changes in strength to be specific to the length and speed at which the muscle has been trained. The implication for rehabilitation is that strength training for isolated muscle groups may not be the most effective way of increasing functional ability. As the major changes are task-specific it may be better to incorporate the training into task-related practice. This would have the advantage of strengthening the muscle groups affected whilst increasing performance in those activities which are required in daily life.

  8. High-intensity high-volume swimming induces more robust signaling through PGC-1α and AMPK activation than sprint interval swimming in m. triceps brachii

    DEFF Research Database (Denmark)

    Casuso, Rafael A; Plaza-Díaz, Julio; Ruiz-Ojeda, Francisco J

    2017-01-01

    We aimed to test whether high-intensity high-volume training (HIHVT) swimming would induce more robust signaling than sprint interval training (SIT) swimming within the m. triceps brachii due to lower metabolic and oxidation. Nine well-trained swimmers performed the two training procedures...... on separate randomized days. Muscle biopsies from m. triceps brachii and blood samples were collected at three different time points: a) before the intervention (pre), b) immediately after the swimming procedures (post) and c) after 3 h of rest (3 h). Hydroperoxides, creatine kinase (CK), and lactate...

  9. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions : reliability of a repeated sprint test

    NARCIS (Netherlands)

    Reininga, Inge H. F.; Lemmink, Koen A. P. M.; Diercks, Ron L.; Buizer, Arina T.; Stevens, Martin

    2010-01-01

    Background: Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint

  10. Comparison of sprinting vs non-sprinting to wean nasal continuous positive airway pressure off in very preterm infants.

    Science.gov (United States)

    Eze, N; Murphy, D; Dhar, V; Rehan, V K

    2018-02-01

    Though nasal continuous positive airway pressure (NCPAP) is commonly used for non-invasive neonatal respiratory support, the optimal method of weaning NCPAP is not established. In this prospective, two-center randomized control trial we hypothesize that gradually increasing spontaneous breathing time off NCPAP increases successful weaning from NCPAP in infants born 0.05). It took 1.3 (1 to 1.75) (median (IQR)) attempts and 7 (7 to 7) days to wean NCPAP off in the sprinting group vs 1.3 (1 to 1.75) attempts and 7 (7 to 10) days in the non-sprinting group (P>0.05). Additionally, no differences in the secondary outcomes of bronchopulmonary dysplasia, severe retinopathy of prematurity (⩾stage 3), periventricular leukomalacia and length of stay were noted between the two groups. Weaning NCPAP via sprinting or non-sprinting protocol is comparable, not only for successful weaning but also for the occurrence of common neonatal morbidities that impact the long-term outcome in premature infants (ClinicalTrials.gov number, NCT02819050).

  11. The role of a short post-lunch nap in improving cognitive, motor, and sprint performance in participants with partial sleep deprivation.

    Science.gov (United States)

    Waterhouse, J; Atkinson, G; Edwards, B; Reilly, T

    2007-12-01

    The aim of this study was to determine the effects of a post-lunch nap on subjective alertness and performance following partial sleep loss. Ten healthy males (mean age 23.3 years, s = 3.4) either napped or sat quietly from 13:00 to 13:30 h after a night of shortened sleep (sleep 23:00-03:00 h only). Thirty minutes after the afternoon nap or control (no-nap) condition, alertness, short-term memory, intra-aural temperature, heart rate, choice reaction time, grip strength, and times for 2-m and 20-m sprints were recorded. The afternoon nap lowered heart rate and intra-aural temperature. Alertness, sleepiness, short-term memory, and accuracy at the 8-choice reaction time test were improved by napping (P 0.05). Sprint times were improved. Mean time for the 2-m sprints fell from 1.060 s (s(x) = 0.018) to 1.019 s (s(x) = 0.019) (P = 0.031 paired t-test); mean time for the 20-m sprints fell from 3.971 s (s(x) = 0.054) to 3.878 s (s(x) = 0.047) (P = 0.013). These results indicate that a post-lunch nap improves alertness and aspects of mental and physical performance following partial sleep loss, and have implications for athletes with restricted sleep during training or before competition.

  12. International inventory of training facilities in nuclear power and its fuel cycle 1978

    International Nuclear Information System (INIS)

    1979-01-01

    The revised inventory is arranged according to the following subject areas: nuclear power plant (NPP) engineering, nuclear safety, quality assurance, NPP operation and maintenance, NPP instrumentation and control, nuclear fuel management, nuclear materials control. Training in each subject area is classified into five groups depending on the type of organization offering the training courses. Each course is briefly described by its name or purpose, institution and location, duration, frequency, language, and content

  13. Training induced decrease in oxygen cost of cycling is accompanied by down-regulation of SERCA expression in human vastus lateralis muscle.

    Science.gov (United States)

    Majerczak, J; Karasinski, J; Zoladz, J A

    2008-09-01

    We have examined the effect of 5 week cycling endurance training program on the sarco(endo)plasmic reticulum Ca2+ ATPase isoforms (SERCA1 and 2) and myosin heavy chain (MyHC) in the vastus lateralis muscle as well as on the oxygen uptake to power output ratio (VO2/PO) during incremental cycling. Fifteen untrained men performed an incremental cycling exercise until exhaustion before and after moderate intensity training. Muscle biopsies were taken from vastus lateralis before and after training program. Training resulted in higher (P = 0.048) maximal oxygen uptake (VO(2max)) as well as in higher power output reached at VO(2max) (P = 0.0001). Moreover, lower (P = 0.02) VO2/PO ratio determined during incremental moderate intensity cycling (i.e. 30-120 W) as well as lower (P = 0.003) VO2/PO ratio reached at VO(2max) were observed after the training. A significant down regulation of SERCA2 protein (P = 0.03) and tendency (P = 0.055) to lower SERCA1 content accompanied by lower (P<10(-4)) plasma thyroid hormone concentration, with no changes (P = 0.67) in MyHC composition in vastus lateralis muscle were found after training. We have concluded that the increase in mechanical efficiency of cycling occurring during first weeks of endurance training is not related to changes in MyHC composition but it may be due to down-regulation of SERCA pumps.

  14. Research into the Impact of Bikeability Training on Children's Ability to Perceive and Appropriately Respond to Hazards When Cycling on the Road

    Science.gov (United States)

    Hodgson, Claire; Worth, Jack

    2015-01-01

    Bikeability (2014) is described as "cycling proficiency for the 21st century". The training is practical, skill-based, outcome-led and designed to "boost the confidence of the trainee and to minimise risk". There are three levels of training and children typically start Bikeability lessons once they have learned to ride a bike.…

  15. Metabolic Responses and Pacing Strategies during Successive Sprint Skiing Time Trials

    DEFF Research Database (Denmark)

    Andersson, Erik; Holmberg, Hans-Christer; Ørtenblad, Niels

    2016-01-01

    PURPOSE: To examine the metabolic responses and pacing strategies during the performance of successive sprint time trials (STTs) in cross-country skiing. METHODS: Ten well-trained male cross-country skiers performed four self-paced 1300-m STTs on a treadmill, each separated by 45 min of recovery...... to estimate the anaerobic energy supply. RESULTS: The individual trial-to-trial variability in STT performance time was 1.3%, where variations in O2 deficit and V˙O2 explained 69% (P 0.05) of the variation in performance. The first and last STTs were equally fast (228 ± 10 s), and ~ 1...... on the first than second course half. In addition, metabolic rates were substantially higher (~_30%) for uphill than for flat skiing, indicating that pacing was regulated to the terrain. CONCLUSIONS: The fastest STTs were characterized primarily by a greater anaerobic energy production, which also explained 69...

  16. Biomechanical comparison of the double-push technique and the conventional skate skiing technique in cross-country sprint skiing.

    Science.gov (United States)

    Stöggl, Thomas; Müller, Erich; Lindinger, Stefan

    2008-09-01

    The aims of the study were to: (1) adapt the "double-push" technique from inline skating to cross-country skiing; (2) compare this new skiing technique with the conventional skate skiing cross-country technique; and (3) test the hypothesis that the double-push technique improves skiing speed in a short sprint. 13 elite skiers performed maximum-speed sprints over 100 m using the double-push skate skiing technique and using the conventional "V2" skate skiing technique. Pole and plantar forces, knee angle, cycle characteristics, and electromyography of nine lower body muscles were analysed. We found that the double-push technique could be successfully transferred to cross-country skiing, and that this new technique is faster than the conventional skate skiing technique. The double-push technique was 2.9 +/- 2.2% faster (P push technique had a longer cycle length and a lower cycle rate, and it was characterized by higher muscle activity, higher knee extension amplitudes and velocities, and higher peak foot forces, especially in the first phase of the push-off. Also, the foot was more loaded laterally in the double-push technique than in the conventional skate skiing technique.

  17. Simulations and Measurements for a concept of powering CALICE-AHCAL at a train-cycled accelerator

    International Nuclear Information System (INIS)

    Göttlicher, P

    2013-01-01

    Improving calorimetry by usage of the particle-flow algorithm requires to record the details of the shower development. Therefore a high granularity analogue readout hadron calorimeter (AHCAL) with small sensors and with electronics handling the enormous amount of channels, ≈ 40 000/m 3 , is required. Homogeneity is maintained by avoiding cooling tubes in the active volume and only cooling at the service end. For this concept low power consumption per channel, 40 μW, is essential. Future linear e+e − − collider designs, ILC or CLIC, foresee duty cycles for the bunch delivery. At ILC bunch trains of 1 ms duration are followed by long breaks of 200 ms. Power cycling the front end electronics with the train structure can reduce power consumption by a factor 100. However for a full scale CALICE-AHCAL switched currents reach magnitudes of kilo-amperes. This paper describes the design chain from front end PCB's through to external power supplies. By simulations a concept is developed, in which effects of electromagnetic interferences are kept small and localized. The goal is to keep current loops small, to limit the switched current to the region near the switched consumer and to allow only small frequency currents to spread out further into the system. By that analogue performance can be kept high and parasitic couplings to the surrounding metal structures and other sub-detectors will be minimized. Measurements with existing prototypes support the validity of the simulations.

  18. Effects of music tempo on performance, psychological, and physiological variables during 20 km cycling in well-trained cyclists.

    Science.gov (United States)

    2013-10-01

    Few studies have investigated the effects of music on trained athletes during high intensity endurance tasks. Therefore, this study investigated the effects of different music tempi on performance, psychological, and physiological responses of well-trained cyclists to time trial cycling. 10 male road cyclists (M age = 35 yr., SD = 7), with a minimum of three years racing experience, performed four 20-km time trials on a Computrainer Pro 3D indoor cycle trainer over a period of four weeks. The time-trials were spaced one week apart. The music conditions for each trial were randomised between fast-tempo (140 bpm), medium-tempo (120 bpm), slow-tempo (100 bpm), and no music. Performance (completion time, power output, average speed and cadence), physiological (heart rate, oxygen consumption, breathing frequency and respiratory exchange ratio), psychophysical (RPE), and psychological (mood states) data were collected for each trial. Results indicated no significant changes in performance, physiological, or psychophysical variables. Total mood disturbance and tension increased significantly in the fast-tempo trial when compared with medium and no-music conditions.

  19. Is there a 'pig cycle' in the labour supply of doctors? How training and immigration policies respond to physician shortages.

    Science.gov (United States)

    Chojnicki, Xavier; Moullan, Yasser

    2018-03-01

    Many OECD countries are faced with the considerable challenge of a physician shortage. This paper investigates the strategies that OECD governments adopt and determines whether these policies effectively address these medical shortages. Due to the amount of time medical training requires, it takes longer for an expansion in medical school capacity to have an effect than the recruitment of foreign-trained physicians. Using data obtained from the OECD (2014) and Bhargava et al. (2011), we constructed a unique country-level panel dataset that includes annual data for 17 OECD countries on physician shortages, the number of medical school graduates and immigration and emigration rates from 1991 to 2004. By calculating panel fixed-effect estimates, we find that after a period of medical shortages, OECD governments produce more medical graduates in the long run but in the short term, they primarily recruit from abroad; however, at the same time, certain practising physicians choose to emigrate. Simulation results show the limits of recruiting only abroad in the long term but also highlight its appropriateness for the short term when there is a recurrent cycle of shortages/surpluses in the labour supply of physicians (pig cycle theory). Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Repeated Sprint Ability in Young Basketball Players (Part 2): The Chronic Effects of Multidirection and of One Change of Direction Are Comparable in Terms of Physiological and Performance Responses

    OpenAIRE

    Attene, Giuseppe; Nikolaidis, Pantelis T.; Bragazzi, Nicola L.; Dello Iacono, Antonio; Pizzolato, Fabio; Zagatto, Alessandro M.; Dal Pupo, Juliano; Oggianu, Marcello; Migliaccio, Gian M.; Mannucci Pacini, Elena; Padulo, Johnny

    2016-01-01

    The aim of this study was to examine the effects of a 5-week training program, consisting of repeated 30-m sprints, on two repeated sprint ability (RSA) test formats: one with one change of direction (RSA) and the other with multiple changes of direction (RSM). Thirty-six young male and female basketball players (age 16.1 ± 0.9 years), divided into two experimental groups, were tested for RSA, RSM, squat jump, counter-movement jump, and the Yo-Yo Intermittent Recovery-Level-1 (Yo-Yo IR1) test...

  1. Single-leg lateral, horizontal, and vertical jump assessment: reliability, interrelationships, and ability to predict sprint and change-of-direction performance.

    Science.gov (United States)

    Meylan, Cesar; McMaster, Travis; Cronin, John; Mohammad, Nur Ikhwan; Rogers, Cailyn; Deklerk, Melissa

    2009-07-01

    The purposes of this study were to determine the reliability of unilateral vertical, horizontal, and lateral countermovement jump assessments, the interrelationship between these tests, and their usefulness as predictors of sprint (10 m) and change-of-direction (COD) performance for 80 men and women physical education students. Jump performance was assessed on a contact mat and sprint, and COD performances were assessed using timing lights. With regard to the reliability statistics, the largest coefficient of variation (CV) was observed for the vertical jump (CV = 6.7-7.2%) of both genders, whereas the sprint and COD assessments had smallest variability (CV = 0.8 to 2.8%). All intraclass correlation coefficients (ICC) were greater than 0.85, except for the men's COD assessment with the alternate leg. The shared variance between the single-leg vertical, horizontal, and lateral jumps for men and women was less than 50%, indicating that the jumps are relatively independent of one another and represent different leg strength/power qualities. The ability of the jumps to predict sprint and COD performance was limited (R2 < 43%). It would seem that the ability to change direction with 1 leg is relatively independent of a COD with the other leg, especially in the women (R < 30%) of this study. However, if 1 jump assessment were selected to predict sprint and COD performance in a test battery, the single-leg horizontal countermovement jump would seem the logical choice, given the results of this study. Many of the findings in this study have interesting diagnostic and training implications for the strength and conditioning coach.

  2. Short-Term Intensified Cycle Training Alters Acute and Chronic Responses of PGC1α and Cytochrome C Oxidase IV to Exercise in Human Skeletal Muscle

    Science.gov (United States)

    Stepto, Nigel K.; Benziane, Boubacar; Wadley, Glenn D.; Chibalin, Alexander V.; Canny, Benedict J.; Eynon, Nir; McConell, Glenn K.

    2012-01-01

    Reduced activation of exercise responsive signalling pathways have been reported in response to acute exercise after training; however little is known about the adaptive responses of the mitochondria. Accordingly, we investigated changes in mitochondrial gene expression and protein abundance in response to the same acute exercise before and after 10-d of intensive cycle training. Nine untrained, healthy participants (mean±SD; VO2peak 44.1±17.6 ml/kg/min) performed a 60 min bout of cycling exercise at 164±18 W (72% of pre-training VO2peak). Muscle biopsies were obtained from the vastus lateralis muscle at rest, immediately and 3 h after exercise. The participants then underwent 10-d of cycle training which included four high-intensity interval training sessions (6×5 min; 90–100% VO2peak) and six prolonged moderate-intensity sessions (45–90 min; 75% VO2peak). Participants repeated the pre-training exercise trial at the same absolute work load (64% of pre-training VO2peak). Muscle PGC1-α mRNA expression was attenuated as it increased by 11- and 4- fold (Pexercise pre- and post-training, respectively. PGC1-α protein expression increased 1.5 fold (Pexercise pre-training with no further increases after the post-training exercise bout. RIP140 protein abundance was responsive to acute exercise only (Pexercise pre- and post-training. These findings demonstrate that short-term intensified training promotes increased mitochondrial gene expression and protein abundance. Furthermore, acute indicators of exercise-induced mitochondrial adaptation appear to be blunted in response to exercise at the same absolute intensity following short-term training. PMID:23285255

  3. Data Sprints: A Collaborative Format in Digital Controversy Mapping

    DEFF Research Database (Denmark)

    Munk, Anders Kristian; Tommaso, Venturini; Meunier, Axel

    2017-01-01

    driven by a desire to provide navigational aids to actors faced with the challenge of making sense of complicated techno-scientific problems. Natively digital media technologies have thus been re-appropriated by STS researchers specifically for the purpose of mapping controversies in a way that would...... experiences with various forms of public engagement and participation. Through a concrete reappropriation of a collaborative format that is indeed native to the digital domain - namely the hackathon - we will show how digital methods can make a difference in participatory STS research. The data sprint, as we...... in amsterdam. Through a mix of digital methods ranging from web cartography and text mining to scientometrics and social media analysis we took on questions related to climate adaptation funding, vulnerability assessment, project management, and dynamics of the international negotiations. The sprints hardwired...

  4. SPRINT RA 230: Methodology for knowledge based developments

    International Nuclear Information System (INIS)

    Wallsgrove, R.; Munro, F.

    1991-01-01

    SPRINT RA 230: A Methodology for Knowledge Based Developments, funded by the European Commission, was set up to investigate the use of KBS in the engineering industry. Its aim was to find out low KBS were currently used and what people's conceptions of them was, to disseminate current knowledge and to recommend further research into this area. A survey (by post and face to face interviews) was carried out under SPRINT RA 230 to investigate requirements for more intelligent software. In the survey we looked both at how people think about Knowledge Based Systems (KBS), what they find useful and what is not useful, and what current expertise problems or limitations of conventional software might suggest KBS solutions. (orig./DG)

  5. Physiological, Perceptual, and Affective Responses to Six High-Intensity Interval Training Protocols.

    Science.gov (United States)

    Follador, Lucio; Alves, Ragami C; Ferreira, Sandro Dos S; Buzzachera, Cosme F; Andrade, Vinicius F Dos S; Garcia, Erick D S de A; Osiecki, Raul; Barbosa, Sara C; de Oliveira, Letícia M; da Silva, Sergio G

    2018-04-01

    This study examined the extent to which different high-intensity interval training (HIIT) and sprint interval training (SIT) protocols could influence psychophysiological responses in moderately active young men. Fourteen participants completed, in a randomized order, three cycling protocols (SIT: 4 × 30-second all-out sprints; Tabata: 7 × 20 seconds at 170% ⋮O 2max ; and HIIT: 10 × 60 seconds at 90% HR max ) and three running HIIT protocols (4 × 4 minutes at 90%-95% HR max , 5 × at v⋮O 2max , and 4 × 1,000 meters at a rating of perceived exertion (RPE) of 8, from the OMNI-Walk/Run scale). Oxygen uptake (⋮O 2 ), heart rate, and RPE were recorded during each interval. Affective responses were assessed before and after each trial. The Tabata protocol elicited the highest ⋮O 2 and RPE responses, and the least pleasant session-affect among the cycling trials. The v⋮O 2max elicited the highest ⋮O 2 and RPE responses and the lowest mean session-affect among the running trials. Findings highlight the limited application of SIT and some HIIT protocols to individuals with low fitness levels.

  6. Exploiting parallel R in the cloud with SPRINT.

    Science.gov (United States)

    Piotrowski, M; McGilvary, G A; Sloan, T M; Mewissen, M; Lloyd, A D; Forster, T; Mitchell, L; Ghazal, P; Hill, J

    2013-01-01

    Advances in DNA Microarray devices and next-generation massively parallel DNA sequencing platforms have led to an exponential growth in data availability but the arising opportunities require adequate computing resources. High Performance Computing (HPC) in the Cloud offers an affordable way of meeting this need. Bioconductor, a popular tool for high-throughput genomic data analysis, is distributed as add-on modules for the R statistical programming language but R has no native capabilities for exploiting multi-processor architectures. SPRINT is an R package that enables easy access to HPC for genomics researchers. This paper investigates: setting up and running SPRINT-enabled genomic analyses on Amazon's Elastic Compute Cloud (EC2), the advantages of submitting applications to EC2 from different parts of the world and, if resource underutilization can improve application performance. The SPRINT parallel implementations of correlation, permutation testing, partitioning around medoids and the multi-purpose papply have been benchmarked on data sets of various size on Amazon EC2. Jobs have been submitted from both the UK and Thailand to investigate monetary differences. It is possible to obtain good, scalable performance but the level of improvement is dependent upon the nature of the algorithm. Resource underutilization can further improve the time to result. End-user's location impacts on costs due to factors such as local taxation. Although not designed to satisfy HPC requirements, Amazon EC2 and cloud computing in general provides an interesting alternative and provides new possibilities for smaller organisations with limited funds.

  7. EL ENTRENAMIENTO DEL SPRINT CON MÉTODOS RESISTIDOS

    Directory of Open Access Journals (Sweden)

    Pedro E. Alcaraz Ramón

    2010-01-01

    Full Text Available Para la mejora del rendimiento en el sprint se utilizan distintos métodos de entrenamiento, entre los más populares se encuentran los métodos resistidos. Un método resistido, para el sprint, se caracteriza por utilizar sprints con una sobrecarga o resistencia añadida. Dependiendo de las características del dispositivo, tanto la magnitud como la dirección de la resistencia va a ser diferente. Así, existen distintos tipos de métodos resistidos, estos son: arrastres de trineos o ruedas, lastres de chalecos o cinturones, arrastres de paracaídas, carreras cuesta arriba, e incluso carreras sobre la arena de la playa. El principal objetivo al usar métodos resistidos es mejorar la fuerza específica de los deportistas sin producir una modificación significativa de la técnica del deportista. En el presente trabajo se revisan las características y efectos de los métodos resistidos tanto de forma aguda, como sus efectos a corto, medio y largo plazo.

  8. The Reliability and Validity of Fatigue Measures During Multiple-Sprint Work: An Issue Revisited

    OpenAIRE

    Glaister, Mark; Howatson, Glyn; Pattison, John R.; McInnes, Gill

    2008-01-01

    The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 × 30-m sprints repeated every 35 seconds; pro...

  9. Eccentric exercise: mechanisms and effects when used as training regime or training adjunct.

    Science.gov (United States)

    Vogt, Michael; Hoppeler, Hans H

    2014-06-01

    The aim of the current review is to discuss applications and mechanism of eccentric exercise in training regimes of competitive sports. Eccentric muscle work is important in most sports. Eccentric muscle contractions enhance the performance during the concentric phase of stretch-shortening cycles, which is important in disciplines like sprinting, jumping, throwing, and running. Muscles activated during lengthening movements can also function as shock absorbers, to decelerate during landing tasks or to precisely deal with high external loading in sports like alpine skiing. The few studies available on trained subjects reveal that eccentric training can further enhance maximal muscle strength and power. It can further optimize muscle length for maximal tension development at a greater degree of extension, and has potential to improve muscle coordination during eccentric tasks. In skeletal muscles, these functional adaptations are based on increases in muscle mass, fascicle length, number of sarcomeres, and cross-sectional area of type II fibers. Identified modalities for eccentric loading in athletic populations involve classical isotonic exercises, accentuated jumping exercises, eccentric overloading exercises, and eccentric cycle ergometry. We conclude that eccentric exercise offers a promising training modality to enhance performance and to prevent injuries in athletes. However, further research is necessary to better understand how the neuromuscular system adapts to eccentric loading in athletes. Copyright © 2014 the American Physiological Society.

  10. FAMILIARISATION AND RELIABILITY OF SPRINT TEST INDICES DURING LABORATORY AND FIELD ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Andrew Galbraith

    2009-12-01

    Full Text Available The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT and indoor laboratory trials (ILT using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001. The coefficient of variation (CV for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N, mean force (147.2 ± 24.7N, peak power (1376.8 ± 451.9W and mean power (514.8 ± 164.4W, and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%, 7.9% (6.4-10.2%, 10.1% (8.2-13.1% and 6.2% (5.1-8.0% for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores

  11. An integrated gait rehabilitation training based on Functional Electrical Stimulation cycling and overground robotic exoskeleton in complete spinal cord injury patients: Preliminary results.

    Science.gov (United States)

    Mazzoleni, S; Battini, E; Rustici, A; Stampacchia, G

    2017-07-01

    The aim of this study is to investigate the effects of an integrated gait rehabilitation training based on Functional Electrical Stimulation (FES)-cycling and overground robotic exoskeleton in a group of seven complete spinal cord injury patients on spasticity and patient-robot interaction. They underwent a robot-assisted rehabilitation training based on two phases: n=20 sessions of FES-cycling followed by n= 20 sessions of robot-assisted gait training based on an overground robotic exoskeleton. The following clinical outcome measures were used: Modified Ashworth Scale (MAS), Numerical Rating Scale (NRS) on spasticity, Penn Spasm Frequency Scale (PSFS), Spinal Cord Independence Measure Scale (SCIM), NRS on pain and International Spinal Cord Injury Pain Data Set (ISCI). Clinical outcome measures were assessed before (T0) after (T1) the FES-cycling training and after (T2) the powered overground gait training. The ability to walk when using exoskeleton was assessed by means of 10 Meter Walk Test (10MWT), 6 Minute Walk Test (6MWT), Timed Up and Go test (TUG), standing time, walking time and number of steps. Statistically significant changes were found on the MAS score, NRS-spasticity, 6MWT, TUG, standing time and number of steps. The preliminary results of this study show that an integrated gait rehabilitation training based on FES-cycling and overground robotic exoskeleton in complete SCI patients can provide a significant reduction of spasticity and improvements in terms of patient-robot interaction.

  12. Training Rowing with Virtual Environments

    Directory of Open Access Journals (Sweden)

    Gopher Daniel

    2011-12-01

    Full Text Available This paper presents the results of the design, implementation and evaluation of a platform for rowing training in Virtual Reality called SPRINT. The paper discusses how various aspects of the rowing skill can be analyzed and trained over a single common methodology and system platform. The result is a vision for new directions in the domain of sport training with Virtual Reality.

  13. Recovery benefits of using a heat and moisture exchange mask during sprint exercise in cold temperatures.

    Science.gov (United States)

    Seifert, John G; Frost, Jeremy; St Cyr, John A

    2017-01-01

    Breathing cold air can lead to bronchoconstriction and peripheral vasoconstriction, both of which could impact muscular performance by affecting metabolic demands during exercise. Successful solutions dealing with these physiological changes during exercise in the cold has been lacking; therefore, we investigated the influence of a heat and moisture exchange mask during exercise in the cold. There were three trial arms within this study: wearing the heat and moisture exchange mask during the rest periods in the cold, no-mask application during the rest periods in the cold, and a trial at room temperature (22°C). Eight subjects cycled in four 35 kJ sprint sessions with each session separated by 20 min rest period. Workload was 4% of body mass. Mean sprint times were faster with heat and moisture exchange mask and room temperature trial than cold, no-mask trial (133.8 ± 8.6, 134.9 ± 8.8, and 138.0 ± 8.4 s (p = 0.001)). Systolic blood pressure and mean arterial pressure were greater during the cold trial with no mask (15% and 13%, respectively), and heart rate was 10 bpm less during the third rest or recovery period during cold, no mask compared to the heat and moisture exchange mask and room temperature trials. Subjects demonstrated significant decreases in vital capacity and peak expiratory flow rate during the cold with no mask applied during the rest periods. These negative responses to cold exposure were alleviated by the use of a heat and moisture exchange mask worn during the rest intervals by minimizing cold-induced temperature stress on the respiratory system with subsequent maintenance of cardiovascular function.

  14. Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.

    Science.gov (United States)

    Sandbakk, Øyvind; Holmberg, Hans-Christer; Leirdal, Stig; Ettema, Gertjan

    2010-06-01

    The present study investigated metabolic rate (MR) and gross efficiency (GE) at moderate and high work rates, and the relationships to gross kinematics and physical characteristics in elite cross-country skiers. Eight world class (WC) and eight national level (NL) male sprint cross-country skiers performed three 5-min stages using the skating G3 technique, whilst roller skiing on a treadmill. GE was calculated by dividing work rate by MR. Work rate was calculated as the sum of power against gravity and frictional rolling forces. MR was calculated using gas exchange and blood lactate values. Gross kinematics, i.e. cycle length (CL) and cycle rate (CR) were measured by video analysis. Furthermore, the skiers were tested for time to exhaustion (TTE), peak oxygen uptake (VO(2peak)), and maximal speed (V(max)) on the treadmill, and maximal strength in the laboratory. Individual performance level in sprint skating was determined by FIS points. WC skiers did not differ in aerobic MR, but showed lower anaerobic MR and higher GE than NL skiers at a given speed (all P higher V(max) and TTE (all P better technique and to technique-specific power.

  15. Pacing and sprint performance in speed skating during a competitive season.

    Science.gov (United States)

    Muehlbauer, Thomas; Schindler, Christian; Panzer, Stefan

    2010-06-01

    This study assessed the effect of time spent in several race sectors (S) on finishing time and determined the variance in distribution of skating time and in total race time for official 1000-m sprint races conducted during a competitive season. Total race and sector times for the first 200 m (S1) and the following two 400-m laps (S2 and S3) of 34 female and 31 male elite speed skaters performed during a series of World Cup Meetings were analyzed. Overall, skaters started fast, reached their peak in S2, and slowed down in S3, irrespective of race category considered (eg, rank of athlete, number of race, altitude of rink, starting lane). Regression analyses revealed that spending a shorter fraction of time in the last (women in S3: B = 239.1; P < .0001; men in S3: B = 201.5; P < .0001) but not in the first (women in S1: B = -313.1; P < .0001; men in S1: B = -345.6; P < .0001) race sector is associated with a short total race time. Upper- compared with lower-ranked skaters varied less in competition-to-competition sector and total race times (women: 0.02 to 0.33 vs 0.02 to 0.51; men: 0.01 to 0.15 vs 0.02 to 0.57). This study confirmed that skaters adopted a fast start pacing strategy during official 1000-m sprint races. However, analyses indicate that shortening time in the closing but not in the starting sector is beneficial for finishing fast. In addition, findings suggest that lower-ranked skaters should concentrate training on lowering their competition-to-competition variability in sector times.

  16. Energy intake over 2 days is unaffected by acute sprint interval exercise despite increased appetite and energy expenditure.

    Science.gov (United States)

    Beaulieu, Kristine; Olver, T Dylan; Abbott, Kolten C; Lemon, Peter W R

    2015-01-01

    A cumulative effect of reduced energy intake, increased oxygen consumption, and/or increased lipid oxidation could explain the fat loss associated with sprint interval exercise training (SIT). This study assessed the effects of acute sprint interval exercise (SIE) on energy intake, subjective appetite, appetite-related peptides, oxygen consumption, and respiratory exchange ratio over 2 days. Eight men (25 ± 3 years, 79.6 ± 9.7 kg, body fat 13% ± 6%; mean ± SD) completed 2 experimental treatments: SIE and recovery (SIEx) and nonexercise control. Each 34-h treatment consisted of 2 consecutive 10-h test days. Between 0800-1800 h, participants remained in the laboratory for 8 breath-by-breath gas collections, 3 buffet-type meals, 14 appetite ratings, and 4 blood samples for appetite-related peptides. Treatment comparisons were made using 2-way repeated measures ANOVA or t tests. An immediate, albeit short-lived (SIEx (P SIEx (P = 0.04), elicited by the 1491-kJ (22%) greater energy expenditure over the first 24 h (P = 0.01). Despite its effects on oxygen consumption, appetite, and PYY, acute SIE did not affect energy intake. Consequently, if these dietary responses to SIE are sustained with regular SIT, augmentations in oxygen consumption and/or a substrate shift toward increased fat use postexercise are most likely responsible for the observed body fat loss with this type of exercise training.

  17. Acute and chronic effects of sprint interval exercise on postprandial lipemia in women at-risk for the metabolic syndrome.

    Science.gov (United States)

    Freese, Eric C; Gist, Nicholas H; Acitelli, Rachelle M; McConnell, Whitni J; Beck, Catherine D; Hausman, Dorothy B; Murrow, Jonathan R; Cureton, Kirk J; Evans, Ellen M

    2015-04-01

    Individuals diagnosed with the metabolic syndrome (MetS) exhibit elevated postprandial lipemia (PPL). The aims of this investigation were to determine 1) if an acute bout of sprint interval training (SIT) attenuates PPL; and 2) if the attenuation of PPL following 6 wk of SIT is magnified compared with a single session of SIT prior to training in women at-risk for MetS (n = 45; 30-65 yr). Women were randomized to SIT (n = 22) or a nonexercise control (n = 23; CON) for 6 wk. Postprandial responses to a high-fat meal challenge (HFMC) were assessed in the CON group before (B-HFMC) and after (Post-HFMC) without prior exercise and in the SIT group at baseline (B-HFMC) without prior exercise, after an acute bout of SIT (four 30-s all-out sprints with 4-min recovery) prior to (Pre-HFMC), and after the 6-wk intervention (Post-HFMC). Responses to the HFMC were assessed by collecting venous blood samples in the fasted state and at 0, 30, 60, 120, and 180 min postprandial. Compared with baseline, an acute bout of SIT before (Pre-HFMC) and after the 6-wk intervention (Post-HFMC) significantly attenuated fasted TG (P exercise to reduce fasted and postprandial TG concentrations in women at-risk for MetS. Six weeks of SIT does not magnify the attenuation of PPL in response to a single session of SIT. Copyright © 2015 the American Physiological Society.

  18. Improvement of the training process of qualified female athletes engaged in bodybuilding in the general preparatory stage of the preparatory period, taking into account the biological cycle

    Directory of Open Access Journals (Sweden)

    Viacheslav Mulyk

    2017-06-01

    Full Text Available Purpose: substantiation of the methodology of the training process of qualified female athletes engaged in bodybuilding in the general preparatory stage of the preparatory period, taking into account the biological cycle. Material & Methods: in the study participated 18 qualified female athletes engaged in bodybuilding, included in the Kharkov region team of bodybuilding. Results: comparative characteristic of the most frequently used methodology of the training process in bodybuilding are shows. An optimal methodology for qualified female athletes engaged in bodybuilding has been developed and justified, depending on the initial form of the athlete at the beginning of the general preparatory stage of the training. The dependence of the change in the body weight of female athletes from the training process is shows. Conclusion: on the basis of the study, the author suggests an optimal training methodology depending on the mesocycle of training in the preparatory period in the general preparatory stage.

  19. Evidence for a causal role of low energy availability in the induction of menstrual cycle disturbances during strenuous exercise training.

    Science.gov (United States)

    Williams, N I; Helmreich, D L; Parfitt, D B; Caston-Balderrama, A; Cameron, J L

    2001-11-01

    Cross-sectional and short-term prospective studies in humans support the concept that low energy availability, and not other factors associated with exercise, causes the development of exercise-induced reproductive dysfunction. To rigorously test this hypothesis, we performed a longitudinal study, examining the role of low energy availability on both the development and the reversal of exercise-induced amenorrhea, using a monkey model (Macaca fascicularis). Eight adult female monkeys developed amenorrhea (defined as absence of menses for at least 100 d, with low and unchanging concentrations of LH, FSH, E2, and P4) after gradually increasing their daily exercise to 12.3 +/- 0.9 km/d of running over a 7- to 24-month period. Food intake remained constant during exercise training. To test whether amenorrhea is caused by low energy availability, four of the eight amenorrheic monkeys were provided with supplemental calories (138-181% of calorie intake during amenorrhea) while they maintained their daily training. All four monkeys exhibited increased reproductive hormone levels and reestablished ovulatory cycles, with recovery times for circulating gonadotropin levels ranging from 12-57 d from the initiation of supplemental feeding. The rapidity of recovery within the reproductive axis in a given monkey was directly related to the amount of energy that was consumed during the period of supplemental feeding (r = -0.97; P amenorrhea (P exercise-induced amenorrhea.

  20. Effects of cluster vs. traditional plyometric training sets on maximal-intensity exercise performance

    Directory of Open Access Journals (Sweden)

    Abbas Asadi

    2016-01-01

    Conclusions: Although both plyometric training methods improved lower body maximal-intensity exercise performance, the traditional sets methods resulted in greater adaptations in sprint performance, while the cluster sets method resulted in greater jump and agility adaptations.

  1. An audit cycle of consent form completion: A useful tool to improve junior doctor training.

    Science.gov (United States)

    Leng, Catherine; Sharma, Kavita

    2016-01-01

    Consent for surgical procedures is an essential part of the patient's pathway. Junior doctors are often expected to do this, especially in the emergency setting. As a result, the aim of our audit was to assess our practice in consenting and institute changes within our department to maintain best medical practice. An audit of consent form completion was conducted in March 2013. Standards were taken from Good Surgical Practice (2008) and General Medical Council guidelines. Inclusion of consent teaching at a formal consultant delivered orientation programme was then instituted. A re-audit was completed to reassess compliance. Thirty-seven consent forms were analysed. The re-audit demonstrated an improvement in documentation of benefits (91-100%) and additional procedures (0-7.5%). Additional areas for improvement such as offering a copy of the consent form to the patient and confirmation of consent if a delay occurred between consenting and the procedure were identified. The re-audit demonstrated an improvement in the consent process. It also identified new areas of emphasis that were addressed in formal teaching sessions. The audit cycle can be a useful tool in monitoring, assessing and improving clinical practice to ensure the provision of best patient care.

  2. The public health nutrition intervention management bi-cycle: a model for training and practice improvement.

    Science.gov (United States)

    Hughes, Roger; Margetts, Barrie

    2012-11-01

    The present paper describes a model for public health nutrition practice designed to facilitate practice improvement and provide a step-wise approach to assist with workforce development. The bi-cycle model for public health nutrition practice has been developed based on existing cyclical models for intervention management but modified to integrate discrete capacity-building practices. Education and practice settings. This model will have applications for educators and practitioners. Modifications to existing models have been informed by the authors' observations and experiences as practitioners and educators, and reflect a conceptual framework with applications in workforce development and practice improvement. From a workforce development and educational perspective, the model is designed to reflect adult learning principles, exposing students to experiential, problem-solving and practical learning experiences that reflect the realities of work as a public health nutritionist. In doing so, it assists the development of competency beyond knowing to knowing how, showing how and doing. This progression of learning from knowledge to performance is critical to effective competency development for effective practice. Public health nutrition practice is dynamic and varied, and models need to be adaptable and applicable to practice context to have utility. The paper serves to stimulate debate in the public health nutrition community, to encourage critical feedback about the validity, applicability and utility of this model in different practice contexts.

  3. Effect of fatigue on force production and force application technique during repeated sprints.

    Science.gov (United States)

    Morin, Jean-Benoit; Samozino, Pierre; Edouard, Pascal; Tomazin, Katja

    2011-10-13

    We investigated the changes in the technical ability of force application/orientation against the ground vs. the physical capability of total force production after a multiple-set repeated sprints series. Twelve male physical education students familiar with sprint running performed four sets of five 6-s sprints (24s of passive rest between sprints, 3min between sets). Sprints were performed from a standing start on an instrumented treadmill, allowing the computation of vertical (F(V)), net horizontal (F(H)) and total (F(Tot)) ground reaction forces for each step. Furthermore, the ratio of forces was calculated as RF=F(H)F(Tot)(-1), and the index of force application technique (D(RF)) representing the decrement in RF with increase in speed was computed as the slope of the linear RF-speed relationship. Changes between pre- (first two sprints) and post-fatigue (last two sprints) were tested using paired t-tests. Performance decreased significantly (e.g. top speed decreased by 15.7±5.4%; Pmultiple-set repeated sprint series, both the total force production capability and the technical ability to apply force effectively against the ground are altered, the latter to a larger extent than the former. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Muscle Damage and Metabolic Responses to Repeated-Sprint Running With and Without Deceleration.

    Science.gov (United States)

    Minahan, Clare L; Poke, Daniel P; Morrison, Jaime; Bellinger, Phillip M

    2018-04-04

    Minahan, CL, Poke, DP, Morrison, J, and Bellinger, PM. Muscle damage and metabolic responses to repeated-sprint running with and without deceleration. J Strength Cond Res XX(X): 000-000, 2017-This study aimed to determine whether repeated-sprint running with deceleration aggravates markers of muscle damage or delays the recovery of performance compared with repeated-sprint running without deceleration. Fourteen male team-sport athletes performed 2 randomly ordered testing sessions on a nonmotorized treadmill with one session requiring participants to decelerate (TMd) within 4 seconds before stopping or immediately step to the side of the treadmill belt at the completion of each sprint (TMa). Peak and mean velocities, speed decrement, blood lactate concentrations, and oxygen uptake were monitored during the repeated-sprint running protocols. Countermovement vertical jump (CMJ) performance, perceived muscle soreness, sit-and-reach flexibility, plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) concentrations were quantified immediately before and after and 45 minutes, 24 and 48 hours after repeated-sprint running protocols. Although muscle damage was indicated by increases in CK, LDH, and Mb (p ≤ 0.05) in both groups, there was no significant effect of condition (TMa vs. TMd) on any of the measured performance or physiological variables (p > 0.05). The present study indicated that the removal of deceleration from repeated-sprint running on a nonmotorized treadmill has no effect on metabolism or performance during or after repeated-sprint running or markers of muscle damage.

  5. Reduction in plasma leucine after sprint exercise is greater in males than in females

    DEFF Research Database (Denmark)

    Esbjörnsson, M; Rooyackers, O; Norman, B

    2012-01-01

    There is a pronounced gender difference in the accumulation of plasma ammonia after sprint exercise. Ammonia is a key intermediate in amino acid metabolism, which implies that gender-related differences in plasma and muscle amino acid concentrations after sprint exercise exist. To study this, three...

  6. The Effects of Psoas Major and Lumbar Lordosis on Hip Flexion and Sprint Performance

    Science.gov (United States)

    Copaver, Karine; Hertogh, Claude; Hue, Olivier

    2012-01-01

    In this study, we analyzed the correlations between hip flexion power, sprint performance, lumbar lordosis (LL) and the cross-sectional area (CSA) of the psoas muscle (PM). Ten young adults performed two sprint tests and isokinetic tests to determine hip flexion power. Magnetic resonance imaging was used to determine LL and PM CSA. There were…

  7. Continuing Education In Radiation Protection In The Nuclear Fuel Cycle: The Case Of Nuclear Industries Of Brazil Education And Training In The Uranium Production Cycle

    International Nuclear Information System (INIS)

    Pereira, Wagner; Kelecom, Alphonse

    2014-01-01

    Conclusion: • Small changes in how to conduct the training have been proposed and are being incorporated. • The assembly of groups of employees resulted in low production of the facility, caused by lack of staff in production lines. • From this observation the training program was rescheduled. Now new trainings are made in individual form. • Organization of classes now occurs only for initial training. • This training occurs when new formations of classes are requested which only occurs when of new employees are admitted. • In these cases the classes are small, no more than 5 employees.

  8. An Analysis of Collaborative Problem-Solving Mechanisms in Sponsored Projects: Applying the 5-Day Sprint Model

    Science.gov (United States)

    Raubenolt, Amy

    2016-01-01

    In May 2016, the office of Finance and Sponsored Projects at The Research Institute at Nationwide Children's Hospital conducted a 5-day design sprint session to re-evaluate and redesign a flawed final reporting process within the department. The department sprint was modeled after the design sprint sessions that occur routinely in software…

  9. Neck-cooling improves repeated sprint performance in the heat

    Directory of Open Access Journals (Sweden)

    Caroline eSunderland

    2015-11-01

    Full Text Available The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 x 6 s before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0  0.2 ºC; 53 ± 2% relative humidity. Participants wore a neck-cooling collar in one of the trials (CC. Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively. The improved power output was particularly pronounced (d = 0.51 – 0.88 after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P 0.05. There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE. Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 minutes onwards (interaction trial x time P=0.04. RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial x time P = 0.01. Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement.

  10. Dynamic factors and electromyographic activity in a sprint start

    Directory of Open Access Journals (Sweden)

    M Čoh

    2009-07-01

    Full Text Available The aim of the study was to establish the major dynamic parameters as well as the EMG activation of muscles in a sprint start as the first derivative of sprint velocity. The subject of the analysis was block velocity, the production of force in the front and rear starting blocks, the block acceleration in the first two steps and the electromyographic activity (EMG of the following muscles: the erector spinae muscle, gluteus maximus muscle, rectus femoris muscle, vastus medialis muscle, vastus lateralis muscle, biceps femoris muscle and gastrocnemius–medialis muscle. One international-class female sprinter participated in the experiment. She performed eight starts in constant laboratory conditions. The 3-D kinematic analysis was made using a system of nine Smart-e 600 cameras operating at a frame rate of 60 Hz. Dynamic parameters were established by means of two separate force platforms to which the starting blocks were fixed. A 16-channel electromyograph was used to analyse electromyographic activity (EMG. It was established that the block velocity depended on the absolute force produced in the front and rear starting blocks and that it was 2.84±0.21 m.s-1. The maximal force on the rear and front blocks was 628±34 N and 1023±30 N, respectively. In view of the total impulse (210±11 Ns the force production/time ratio in the rear and front blocks was 34%:66%. The erector spinae muscle, vastus lateralis muscle and gastrocnemius–medialis muscle generate the efficiency of the start. The block acceleration in the first two steps primarily depends on the activation of the gluteus maximus muscle, rectus femoris muscle, biceps femoris muscle and gastrocnemius–medialis muscle. A sprint start is a complex motor stereotype requiring a high degree of integration of the processes of central movement regulation and an optimal level of biomotor abilities.

  11. The force, power and energy of the 100 meter sprint

    OpenAIRE

    Helene, O.; Yamashita, M. T.

    2009-01-01

    At the 2008 Summer Olympics in Beijing, Usain Bolt broke the world record for the 100 m sprint. Just one year later, at the 2009 World Championships in Athletics in Berlin he broke it again. A few months after Beijing, Eriksen [Am. J. Phys. 77, 224-228 (2009)] studied Bolt's performance and predicted that Bolt could have run about one-tenth of a second faster, which was confirmed in Berlin. In this paper we extend the analysis of Eriksen to model Bolt's velocity time dependence for the Beijin...

  12. Task-Specific and Functional Effects of Speed-Focused Elliptical or Motor-Assisted Cycle Training in Children With Bilateral Cerebral Palsy: Randomized Clinical Trial.

    Science.gov (United States)

    Damiano, Diane L; Stanley, Christopher J; Ohlrich, Laurie; Alter, Katharine E

    2017-08-01

    Locomotor training using treadmills or robotic devices is commonly utilized to improve gait in cerebral palsy (CP); however, effects are inconsistent and fail to exceed those of equally intense alternatives. Possible limitations of existing devices include fixed nonvariable rhythm and too much limb or body weight assistance. To quantify and compare effectiveness of a motor-assisted cycle and a novel alternative, an elliptical, in CP to improve interlimb reciprocal coordination through intensive speed-focused leg training. A total of 27 children with bilateral CP, 5 to 17 years old, were randomized to 12 weeks of 20 minutes, 5 days per week home-based training (elliptical = 14; cycle = 13) at a minimum of 40 revolutions per minute, with resistance added when speed target was achieved. Primary outcomes were self-selected and fastest voluntary cadence on the devices and gait speed. Secondary outcomes included knee muscle strength, and selective control and functional mobility measures. Cadence on trained but not nontrained devices increased, demonstrating task specificity of training and increased exercise capability. Mean gait speed did not increase in either group, nor did parent-reported functional mobility. Knee extensor strength increased in both. An interaction between group and time was seen in selective control with scores slightly increasing for the elliptical and decreasing for the cycle, possibly related to tighter limb coupling with cycling. Task-specific effects were similarly positive across groups, but no transfer was seen to gait or function. Training dose was low (≤20 hours) compared with intensive upper-limb training recommendations and may be insufficient to produce appreciable clinical change.

  13. Dynamic Contractility and Efficiency Impairments in Stretch-Shortening Cycle Are Stretch-Load-Dependent After Training-Induced Muscle Damage

    NARCIS (Netherlands)

    Vaczi, Mark; Racz, Levente; Hortobagyi, Tibor; Tihanyi, Jozsef

    Vaczi, M, Racz, L, Hortobagyi, T, and Tihanyi, J. Dynamic contractility and efficiency impairments in stretch-shortening cycle are stretch-load-dependent after training-induced muscle damage. J Strength Cond Res 27(8): 2171-2179, 2013To determine the acute task and stretch-load dependency of

  14. High intensity interval and moderate continuous cycle training in a physical education programme improves health-related fitness in young females

    Directory of Open Access Journals (Sweden)

    K Mazurek

    2016-04-01

    Full Text Available The aim of the study was to investigate the effects of eight weeks of regular physical education classes supplemented with high intensity interval cycle exercise (HIIE or continuous cycle exercises of moderate intensity (CME. Forty-eight collegiate females exercising in two regular physical education classes per week were randomly assigned to two programmes (HIIE; n=24 or CME; n=24 of additional (one session of 63 minutes per week physical activity for 8 weeks. Participants performed HIIE comprising 2 series of 6x10 s sprinting with maximal pedalling cadence and active recovery pedalling with intensity 65%–75% HRmax or performed CME corresponding to 65%-75% HRmax. Before and after the 8-week programmes, anthropometric data and aero- and anaerobic capacity were measured. Two-way ANOVA revealed a significant time main effect for VO2max (p<0.001, similar improvements being found in both groups (+12% in HIIE and +11% in CME, despite body mass not changing significantly (p=0.59; +0.4% in HIIE and -0.1% in CME. A significant main time effect was found for relative fat mass (FM and fat-free mass (FFM (p<0.001 and p<0.001, respectively. A group x time interaction effect was found for relative FM and FFM (p=0.018 and p=0.018; a greater reduction in FM and greater increase in FFM were noted in the CME than the HIIE group. Improvements in anaerobic power were observed in both groups (p<0.001, but it was greater in the HIIE group (interaction effect, p=0.022. Weight loss is not mandatory for exercise-induced effects on improving aerobic and anaerobic capacity in collegiate females. Eight weeks of regular physical education classes supplemented with CME sessions are more effective in improving body composition than physical education classes supplemented with HIIE sessions. In contrast to earlier, smaller trials, similar improvements in aerobic capacity were observed following physical activity with additional HIIE or CME sessions.

  15. Effect of a typical in-season week on strength jump and sprint performances in national-level female basketball players.

    Science.gov (United States)

    Delextrat, A; Trochym, E; Calleja-González, J

    2012-04-01

    The aim of this study was to investigate the effect of a typical in-season week including four practice sessions and one competitive game on strength, jump and sprint performances in national-level female basketball players. Nine female basketball players (24.3±4.1 years old, 173.0±7.9 cm, 65.1±10.9 kg, 21.1±3.8% body fat) participated in ten testing sessions, before and immediately after practices and game (five pre- and five post-tests). Each session involved isokinetic peak torque measurements of the quadriceps and hamstrings of the dominant leg at 60º.s-1, countermovement jump (CMJ) and 20-m sprint. Fluid loss and subjective training load were measured during each practice session, while the frequencies of the main movements performed during the game were recorded. A two-way ANOVA was used to asses the effect of each practice/game and the effect of the day of the week on performances, and the relationship between performance variations and variables recorded during practices/game were analyzed by a Pearson correlation coefficient. Individual sessions induced significant decreases in lower limb strength (from 4.6 to 10.9%, Pjump ability, and monitor the recovery of their players' strength, sprint and jump capacities following specific sessions.

  16. Proximal Neuromuscular Control Protects Against Hamstring Injuries in Male Soccer Players: A Prospective Study With Electromyography Time-Series Analysis During Maximal Sprinting.

    Science.gov (United States)

    Schuermans, Joke; Danneels, Lieven; Van Tiggelen, Damien; Palmans, Tanneke; Witvrouw, Erik

    2017-05-01

    With their unremittingly high incidence rate and detrimental functional repercussions, hamstring injuries remain a substantial problem in male soccer. Proximal neuromuscular control ("core stability") is considered to be of key importance in primary and secondary hamstring injury prevention, although scientific evidence and insights on the exact nature of the core-hamstring association are nonexistent at present. The muscle activation pattern throughout the running cycle would not differ between participants based on injury occurrence during follow-up. Case-control study; Level of evidence, 3. Sixty amateur soccer players participated in a multimuscle surface electromyography (sEMG) assessment during maximal acceleration to full-speed sprinting. Subsequently, hamstring injury occurrence was registered during a 1.5-season follow-up period. Hamstring, gluteal, and trunk muscle activity time series during the airborne and stance phases of acceleration were evaluated and statistically explored for a possible causal association with injury occurrence and absence from sport during follow-up. Players who did not experience a hamstring injury during follow-up had significantly higher amounts of gluteal muscle activity during the front swing phase ( P = .027) and higher amounts of trunk muscle activity during the backswing phase of sprinting ( P = .042). In particular, the risk of sustaining a hamstring injury during follow-up lowered by 20% and 6%, with a 10% increment in normalized muscle activity of the gluteus maximus during the front swing and the trunk muscles during the backswing, respectively ( P hamstring injury occurrence in male soccer players. Higher amounts of gluteal and trunk muscle activity during the airborne phases of sprinting were associated with a lower risk of hamstring injuries during follow-up. Hence, the present results provide a basis for improved, evidence-based rehabilitation and prevention, particularly focusing on increasing neuromuscular

  17. Modelling of optimal training load patterns during the 11 weeks preceding major competition in elite swimmers.

    Science.gov (United States)

    Hellard, Philippe; Scordia, Charlotte; Avalos, Marta; Mujika, Inigo; Pyne, David B

    2017-10-01

    Periodization of swim training in the final training phases prior to competition and its effect on performance have been poorly described. We modeled the relationships between the final 11 weeks of training and competition performance in 138 elite sprint, middle-distance, and long-distance swimmers over 20 competitive seasons. Total training load (TTL), strength training (ST), and low- to medium-intensity and high-intensity training variables were monitored. Training loads were scaled as a percentage of the maximal volume measured at each intensity level. Four training periods (meso-cycles) were defined: the taper (weeks 1 to 2 before competition), short-term (weeks 3 to 5), medium-term (weeks 6 to 8), and long-term (weeks 9 to 11). Mixed-effects models were used to analyze the association between training loads in each training meso-cycle and end-of-season major competition performance. For sprinters, a 10% increase between ∼20% and 70% of the TTL in medium- and long-term meso-cycles was associated with 0.07 s and 0.20 s faster performance in the 50 m and 100 m events, respectively (p training yielded faster competition performance (e.g., a 10% increase in TTL was associated with improvements of 0.1-1.0 s in 200 m events and 0.3-1.6 s in 400 m freestyle, p < 0.01). For sprinters, a 60%-70% maximal ST load 6-8 weeks before competition induced the largest positive effects on performance (p < 0.01). An increase in TTL during the medium- and long-term preparation (6-11 weeks to competition) was associated with improved performance. Periodization plans should be adapted to the specialty of swimmers.

  18. The reliability and validity of fatigue measures during multiple-sprint work: an issue revisited.

    Science.gov (United States)

    Glaister, Mark; Howatson, Glyn; Pattison, John R; McInnes, Gill

    2008-09-01

    The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 x 30-m sprints repeated every 35 seconds; protocol 2 consisted of 12 x 30-m sprints repeated every 65 seconds. All testing was performed in an indoor sports facility, and sprint times were recorded using twin-beam photocells. All but one of the formulae showed good construct validity, as evidenced by similar within-protocol fatigue scores. However, the assumptions on which many of the formulae were based, combined with poor or inconsistent test-retest reliability (coefficient of variation range: 0.8-145.7%; intraclass correlation coefficient range: 0.09-0.75), suggested many problems regarding logical validity. In line with previous research, the results support the percentage decrement calculation as the most valid and reliable method of quantifying fatigue in tests of multiple-sprint performance.

  19. Effects of Plyometric Training on Physical Fitness in Team Sport Athletes: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Slimani Maamer

    2016-12-01

    Full Text Available Plyometric training (PT is a very popular form of physical conditioning of healthy individuals that has been extensively studied over the last decades. In this article, we critically review the available literature related to PT and its effects on physical fitness in team sport athletes. We also considered studies that combined PT with other popular training modalities (e.g. strength/sprint training. Generally, short-term PT (i.e. 2-3 sessions a week for 4-16 weeks improves jump height, sprint and agility performances in team sport players. Literature shows that short PT (<8 weeks has the potential to enhance a wide range of athletic performance (i.e. jumping, sprinting and agility in children and young adult amateur players. Nevertheless, 6 to 7 weeks training appears to be too short to improve physical performance in elite male players. Available evidence suggests that short-term PT on non-rigid surfaces (i.e. aquatic, grass or sand-based PT could elicit similar increases in jumping, sprinting and agility performances as traditional PT. Furthermore, the combination of various plyometric exercises and the bilateral and unilateral jumps could improve these performances more than the use of single plyometric drills or traditional PT. Thus, the present review shows a greater effect of PT alone on jump and sprint (30 m sprint performance only performances than the combination of PT with sprint/strength training. Although many issues related to PT remain to be resolved, the results presented in this review allow recommending the use of well-designed and sport-specific PT as a safe and effective training modality for improving jumping and sprint performance as well as agility in team sport athletes.

  20. Effects of Plyometric Training on Physical Fitness in Team Sport Athletes: A Systematic Review.

    Science.gov (United States)

    Slimani, Maamer; Chamari, Karim; Miarka, Bianca; Del Vecchio, Fabricio B; Chéour, Foued

    2016-12-01

    Plyometric training (PT) is a very popular form of physical conditioning of healthy individuals that has been extensively studied over the last decades. In this article, we critically review the available literature related to PT and its effects on physical fitness in team sport athletes. We also considered studies that combined PT with other popular training modalities (e.g. strength/sprint training). Generally, short-term PT (i.e. 2-3 sessions a week for 4-16 weeks) improves jump height, sprint and agility performances in team sport players. Literature shows that short PT (plyometric exercises and the bilateral and unilateral jumps could improve these performances more than the use of single plyometric drills or traditional PT. Thus, the present review shows a greater effect of PT alone on jump and sprint (30 m sprint performance only) performances than the combination of PT with sprint/strength training. Although many issues related to PT remain to be resolved, the results presented in this review allow recommending the use of well-designed and sport-specific PT as a safe and effective training modality for improving jumping and sprint performance as well as agility in team sport athletes.

  1. Sprinting performance on the Woodway Curve 3.0 is related to muscle architecture.

    Science.gov (United States)

    Mangine, Gerald T; Fukuda, David H; Townsend, Jeremy R; Wells, Adam J; Gonzalez, Adam M; Jajtner, Adam R; Bohner, Jonathan D; LaMonica, Michael; Hoffman, Jay R; Fragala, Maren S; Stout, Jeffrey R

    2015-01-01

    To determine if unilateral measures of muscle architecture in the rectus femoris (RF) and vastus lateralis (VL) were related to (and predictive of) sprinting speed and unilateral (and bilateral) force (FRC) and power (POW) during a 30 s maximal sprint on the Woodway Curve 3.0 non-motorized treadmill. Twenty-eight healthy, physically active men (n = 14) and women (n = 14) (age = 22.9 ± 2.4 years; body mass = 77.1 ± 16.2 kg; height = 171.6 ± 11.2 cm; body-fa t = 19.4 ± 8.1%) completed one familiarization and one 30-s maximal sprint on the TM to obtain maximal sprinting speed, POW and FRC. Muscle thickness (MT), cross-sectional area (CSA) and echo intensity (ECHO) of the RF and VL in the dominant (DOM; determined by unilateral sprinting power) and non-dominant (ND) legs were measured via ultrasound. Pearson correlations indicated several significant (p architecture. Stepwise regression indicated that POW(DOM) was predictive of ipsilateral RF (MT and CSA) and VL (CSA and ECHO), while POW(ND) was predictive of ipsilateral RF (MT and CSA) and VL (CSA); sprinting power/force asymmetry was not predictive of architecture asymmetry. Sprinting time was best predicted by peak power and peak force, though muscle quality (ECHO) and the bilateral percent difference in VL (CSA) were strong architectural predictors. Muscle architecture is related to (and predictive of) TM sprinting performance, while unilateral POW is predictive of ipsilateral architecture. However, the extent to which architecture and other factors (i.e. neuromuscular control and sprinting technique) affect TM performance remains unknown.

  2. Anthropometric factors related to sprint and agility performance in young male soccer players

    Directory of Open Access Journals (Sweden)

    Mathisen G

    2015-11-01

    Full Text Available Gunnar Mathisen, Svein Arne Pettersen School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway Objective: To investigate the relationship between anthropometrics and sprint and agility performance and describe the development of sprint (acceleration and agility performance in 10- to 16-year-old male soccer players. Methods: One hundred and thirty-two participants were divided into three age groups, 10–12 years (mean 10.8±0.50, 13–14 years (mean 13.9±0.50, and 15–16 years (mean 15.5±0.24, with assessment of 20 m sprint with 10 m split time and agility performance related to body height and body mass within groups. Results: In the 10- to 12-year-olds, there were no significant correlations between height, weight, and the performance variables, except for body mass, which was correlated to 10–20 m sprint (r=0.30. In the 13- to 14-year-olds, body height was significantly correlated with 10 m sprint (r=0.50 and 20 m sprint (r=0.52, as well as 10–20 m sprint (r=0.50 and agility performance (r=0.28. In the 15- to 16-year-old group, body height was correlated to 20 m (r=0.38 and 10–20 m (r=0.45 sprint. Body mass was significantly correlated to 10 m spring (r=0.35 in the 13- to 14-year-olds, as well as 20 m (r=0.33 and 10–20 m (r=0.35 sprint in the 15- to 16-year-olds. Conclusion: Height and body mass were significantly correlated with sprint performance in 13- to 16-year-old male soccer players. However, the 10- to 12-year-olds showed no significant relationship between sprint performance and anthropometrics, except for a small correlation in 10–20 m sprint. This may be attributed to maturation, with large differences in body height and body mass due to different patterns in the growth spurt. The agility performance related to anthropometrics was insignificant apart from a moderate correlation in the 13- to 14-year-olds. Keywords: youth soccer, running speed, development, football, puberty, skills 

  3. Continuous AFM observation of martensitic transformation and its reversion in training cycles of Fe-Mn-Si based shape memory alloys

    International Nuclear Information System (INIS)

    Liu, D.Z.; Kikuchi, T.; Kajiwara, S.; Shinya, N.

    2000-01-01

    The effect of thermomechanical treatment (so-called ''training'') cycles on stress-induced martensitic transformation and its reversion has been studied by atomic force microscopy (AFM) to make clear the origin of improvement of shape memory effect (SME) due to training in Fe-Mn-Si based shape memory alloys (SMAs). It was found that training cycles make martensite plates tend to grow on the primary shear system, i.e., on the most favorable shear system for the fcc to hcp martensitic transformation. In addition, training cycles lead to a more uniform distribution of thin martensite plates in a grain. Martensitic plates with the above characteristics are easier to be reverted back to parent phase when heated, and then nearly perfect SME is obtained. AFM observation shows that the key factor to realize perfect SME in Fe-Mn-Si based SMAs is to produce the uniform distribution of thin martensite plates on the primary shear system when deformed by external stress. (orig.)

  4. Psychological and Physiological Biomarkers of Neuromuscular Fatigue after Two Bouts of Sprint Interval Exercise

    Directory of Open Access Journals (Sweden)

    Albertas Skurvydas

    2017-12-01

    Full Text Available The main aim of our study was to determinate whether a repeated bout (RB (vs. first bout [FB] of sprint interval cycling exercise (SIE is sufficient to mitigate SIE-induced psychological and physiological biomarker kinetics within 48 h after the exercise. Ten physically active men (age, 22.6 ± 5.2 years; VO2max, 44.3 ± 5.7 ml/kg/min performed the FB of SIE (12 repeats of 5 s each on one day and the RB 2 weeks later. The following parameters were measured: motor performance (voluntary, electrically induced and isokinetic skeletal muscle contraction torque, and central activation ratio [CAR]; stress markers [brain-derived neurotrophic factor (BDNF, cortisol, norepinephrine, and epinephrine]; inflammatory markers (IL-6, IL-10, and TNF-α; metabolic markers (glucose and lactate; muscle and rectal temperature; cycling power output; and psychological perceptions. The average cycling power output and neuromuscular fatigue after exercise did not differ between the FB and RB. There were significant decreases in cortisol and BDNF concentration at 12 h (P < 0.05 and 24 h (P < 0.001 after the FB, respectively. The decrease in cortisol concentration observed 12 h after exercise was significantly greater after the RB (P < 0.05 than after the FB. The immune-metabolic response to the RB (vs. FB SIE was suppressed and accompanied by lower psychological exertion. Most of the changes in psychological and physiological biomarkers in the FB and RB were closely related to the response kinetics of changes in BDNF concentration.

  5. PECULIARITIES OF ORGANIZATION OF POST-SPEAKED ASSOCIATION OF ALUMNI STUDY TRAINING PROGRAMS IN THE CONTEXT OF LIFE CYCLE SUPPORT OF THE TEACHER PROFESSION

    Directory of Open Access Journals (Sweden)

    E. Y. Ilaltdinova

    2017-01-01

    Full Text Available The article reveals the peculiarities of the organization of graduate support of graduates of the targeted training program in the context of supporting the life cycle of the teacher's profession. Important stages of the life cycle of the pedagogical profession are described. The model of the teacher's special training and contract employment is offered, the mechanisms of its implementation in the context of the trajectory of the entrance, promotion and exit after the completion of the targeted training program are defined. The mechanism of graduate support of graduates as one of the elements of the model of targeted training of teachers is presented, its priority goals and tasks are described, as well as the fundamental principles that determine the logic of the graduate's graduate support process. The tools of the mechanism of postgraduate accompaniment are developed, among which the defining role is played by the electronic interactive multifunctional online support service. The article describes the results obtained during the approbation of the developed mechanism for graduate support of graduates of the targeted training program and their impact on the solution of the problem of updating the teaching staff.

  6. The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate.

    Science.gov (United States)

    Peart, Daniel J; Kirk, Richard J; Hillman, Angela R; Madden, Leigh A; Siegler, Jason C; Vince, Rebecca V

    2013-01-01

    The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (NaHCO(3)) (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO(3) is unlikely to be due to a decreased oxidative stress.

  7. Butterfly Sprint Swimming Technique, Analysis of Somatic and Spatial-Temporal Coordination Variables

    Directory of Open Access Journals (Sweden)

    Strzała Marek

    2017-12-01

    Full Text Available The aim of this study was to investigate somatic properties and force production of leg extensor muscles measured in the countermovement jump test (CMJ, as well as to analyse kinematic variables of sprint surface butterfly swimming. Thirty-four male competitive swimmers were recruited with an average age of 19.3 ± 1.83 years. Their average body height (BH was 183.7 ± 5.93 cm, body fat content 10.8 ± 2.64% and body mass (BM 78.3 ± 5.0 kg. Length measurements of particular body segments were taken and a counter movement jump (CMJ as well as an all-out 50 m butterfly speed test were completed. The underwater movements of the swimmers’ bodies were recorded with a digital camera providing side-shots. We registered a significant relationship between body mass (r = 0.46, lean body mass (r = 0.48 and sprint surface butterfly swimming (VSBF. The anaerobic power measured in the CMJ test, total body length (TBL as well as upper and lower extremity length indices did not influence swimming speed significantly. The temporal entry-kick index (the time ratio between the first kick and arm entry significantly influenced VSBF (r = -0.45. Similarly, medium power of the coefficient was indicated between a stroke rate kinematics (SR, b duration of the first leg kick (LP1, c air phase duration of arm recovery (Fly-arm, and VSBF (r = 0.40; r = 0.40 and r = 0.41, respectively. The entry-kick temporal index showed that, in the butterfly cycle, an appropriately early executed initial kick when compared to arm entry was associated with a longer arm propulsion phase, which in turn was associated with minimizing resistive gliding phases and enabled relatively longer and less resistive air arm recovery (higher value of the fly-arm index. The higher value of SR kinematic was another important element of the best butterfly results in this study.

  8. Inter-limb coordination, strength, jump, and sprint performances following a youth men's basketball game.

    Science.gov (United States)

    Cortis, Cristina; Tessitore, Antonio; Lupo, Corrado; Pesce, Caterina; Fossile, Eugenio; Figura, Francesco; Capranica, Laura

    2011-01-01

    This study aimed to verify whether basketball players are able to maintain strength (handgrip), jump (countermovement jump [CMJ]), sprint (10 m and 10 m bouncing the ball [10 mBB]), and interlimb coordination (i.e., synchronized hand and foot flexions and extensions at 80, 120, and 180 bpm) performances at the end of their game. Ten young (age 15.7 ± 0.2 years) male basketball players volunteered for this study. During the friendly game, heart rate (HR), rate of perceived exertion (RPE), and rate of muscle pain (RMP) were assessed to evaluate the exercise intensity. Overall, players spent 80% of the time playing at intensities higher than 85% HRmax. Main effects (p jump (pre = 35.2 ± 5.2 cm, post = 35.7 ± 5.2 cm), handgrip (pre = 437 ± 73 N, post = 427 ± 55 N), and coordinative performances at lower frequencies of executions (80 bpm: pre = 59.7 ± 1.3 seconds, post = 60.0 ± 0.0 seconds; 120 bpm: pre = 54.7 ± 12.3 seconds, post = 57.3 ± 6.7 seconds). These findings indicate that the heavy load of the game exerts beneficial effects on the efficiency of executive and attentive control functions involved in complex motor behaviors. Coaches should structure training sessions that couple intense physical exercises with complex coordination tasks to improve the attentional capabilities of the players.

  9. Rock-dwelling lizards exhibit less sensitivity of sprint speed to increases in substrate rugosity.

    Science.gov (United States)

    Collins, Clint E; Self, Jessica D; Anderson, Roger A; McBrayer, Lance D

    2013-06-01

    Effectively moving across variable substrates is important to all terrestrial animals. The effects of substrates on lizard performance have ecological ramifications including the partitioning of habitat according to sprinting ability on different surfaces. This phenomenon is known as sprint sensitivity, or the decrease in sprint speed due to change in substrate. However, sprint sensitivity has been characterized only in arboreal Anolis lizards. Our study measured sensitivity to substrate rugosity among six lizard species that occupy rocky, sandy, and/or arboreal habitats. Lizards that use rocky habitats are less sensitive to changes in substrate rugosity, followed by arboreal lizards, and then by lizards that use sandy habitats. We infer from comparative phylogenetic analysis that forelimb, chest, and tail dimensions are important external morphological features related to sensitivity to changes in substrate rugosity. Copyright © 2013 Elsevier GmbH. All rights reserved.

  10. Kinematic characteristics of a sprinting technique and morphofunctional structures of its providing

    Directory of Open Access Journals (Sweden)

    V. A. Druz

    2017-02-01

    2Kazimierz Wielki University in Bydgoszcz     Abstract Introduction The overall performance of a coach and the efficiency of performances of sportsmen are defined completely by the depth of understanding of regularities which are the cornerstone of the mechanisms, which provide the performance of competitive exercises. The most comprehensive investigations of these questions in track and field athletics are devoted to studying of sprint that significantly promoted the improvement of the process of a coach (Yefremenko, 2013 -2015; Shesterova, Yanhao, 2014-2016. However, the uniform generalization in the received scientific results isn't reached. It considerably reduces the overall performance of a coach. The optimization of the training process and the efficiency of performance of a sportsman are defined by the depth of knowledge of the interdependent relations of kinematic and dynamic characteristics of the performed physical actions and their connections with the morphofunctional educations, which provide their implementation. At the same time the final result depends on the motive endowments of a sportsman, the level of preparedness and the current functional state. The purpose of the research. To present the uniform system of the interdependent relations of the biomechanical and physiological regularities which provide the fastest movement of the general center of body weight GCBW of a sportsman when passing by him the established distance of run and to establish the structure of creation of an optimum algorithm of the training process taking into account individual physical development of a sportsman on the basis of provisions of the theory of training. The achievement of the purpose defined the need of the solution of the following tasks: 1. To carry out the analysis of literature and to systematize scientific achievements on the considered problem. 2. To select the fundamental laws of mechanics which define kinematic and dynamic characteristics of movement

  11. THE INFLUENCE OF EXPERIMENTAL MODEL OF SPRINT ON DEVELOPMENT OF MOTOR AND FUNCTIONAL ABILITIES OF YOUNG FOOTBALLERS

    Directory of Open Access Journals (Sweden)

    Niko Raičković

    2008-08-01

    Full Text Available At the sample of 34 examinees, Elementary school students at the age of 14 and 15, involved in the training process in football clubs in Podgorica,was applied the experimental model for improving of sprint.The goal was to determine influence of experimental model on development of motor and functional abilities of examinees. Instruments for measuring of motor abilities were consisted of Segmental Speed dimensions,Explosive and Repetitive Strength dimensions,and of variables:Absolute Value of Maximal Consumption of Oxygen (FAV MCO, Maximal Aerobic Power (FMARP, Vital Capacity (FVI CA and Puls in Stationary Position (FPUSP, for measuring of functional abilities. Canonical Discriminative Analisis was used for testing differences between inicial and final measuring of examinees at the end of experimental period. The results of examination point at statistically significant increase in Explosive and Repetitive Strength, at Absolute Values of Maximal Oxygen Consumption and Maximal Anaerobic Power.

  12. Comparison of step-by-step kinematics of resisted, assisted and unloaded 20-m sprint runs.

    Science.gov (United States)

    van den Tillaar, Roland; Gamble, Paul

    2018-03-26

    This investigation examined step-by-step kinematics of sprint running acceleration. Using a randomised counterbalanced approach, 37 female team handball players (age 17.8 ± 1.6 years, body mass 69.6 ± 9.1 kg, height 1.74 ± 0.06 m) performed resisted, assisted and unloaded 20-m sprints within a single session. 20-m sprint times and step velocity, as well as step length, step frequency, contact and flight times of each step were evaluated for each condition with a laser gun and an infrared mat. Almost all measured parameters were altered for each step under the resisted and assisted sprint conditions (η 2  ≥ 0.28). The exception was step frequency, which did not differ between assisted and normal sprints. Contact time, flight time and step frequency at almost each step were different between 'fast' vs. 'slow' sub-groups (η 2  ≥ 0.22). Nevertheless overall both groups responded similarly to the respective sprint conditions. No significant differences in step length were observed between groups for the respective condition. It is possible that continued exposure to assisted sprinting might allow the female team-sports players studied to adapt their coordination to the 'over-speed' condition and increase step frequency. It is notable that step-by-step kinematics in these sprints were easy to obtain using relatively inexpensive equipment with possibilities of direct feedback.

  13. Effect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance.

    Science.gov (United States)

    Ducker, Kagan J; Dawson, Brian; Wallman, Karen E

    2013-12-01

    This study aimed to investigate if combining beta alanine (BA) and sodium bicarbonate (NaHCO3) supplementation could lead to enhanced repeated-sprint performance in team-sport athletes, beyond what is possible with either supplement alone. Participants (n = 24) completed duplicate trials of a repeated-sprint test (3 sets; 6 × 20 m departing every 25 seconds, 4 minutes active recovery between sets) and were then allocated into 4 groups as follows: BA only (n = 6; 28 days BA, acute sodium chloride placebo); NaHCO3 only (n = 6; 28 days glucose placebo, acute NaHCO3); BA/NaHCO3 (n = 6; 28 days BA, acute NaHCO3); placebo only (n = 6; 28 days glucose placebo, acute sodium chloride placebo), then completed duplicate trials postsupplementation. Sodium bicarbonate alone resulted in moderate effect size (d = 0.40-0.71) and "likely" and "very likely" benefit for overall total sprint times (TST) and for each individual set and for first sprint (sets 2 and 3) and best sprint time (sets 2 and 3). Combining BA and NaHCO3 resulted in "possible" to "likely" benefits for overall TST and for sets 2 and 3. First sprint (set 3) and best sprint time (sets 2 and 3) also showed "likely" benefit after this trial. The BA and placebo groups showed no differences in performance after supplementation. In conclusion, these results indicate that supplementation with acute NaHCO3 improved repeated-sprint performance more than either a combination of NaHCO3 and BA or BA alone.

  14. The Characteristics of Static Plantar Loading in the First-Division College Sprint Athletes

    OpenAIRE

    Tong-Hsien Chow

    2016-01-01

    Background: Plantar pressure measurement is an effective method for assessing plantar loading and can be applied to evaluating movement performance of the foot. The purpose of this study is to explore the sprint athletes' plantar loading characteristics and pain profiles in static standing. Methods: Experiments were undertaken on 80 first-division college sprint athletes and 85 healthy non-sprinters. 'JC Mat', the optical plantar pressure measurement was applied to examining the differences b...

  15. The effect of hamstring flexibility on peak hamstring muscle strain in sprinting

    OpenAIRE

    Xianglin Wan; Feng Qu; William E. Garrett; Hui Liu; Bing Yu

    2017-01-01

    Background: The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting, until now, remained unknown, which limited our understanding of risk factors of hamstring muscle strain injury (hamstring injury). As a continuation of our previous study, this study was aimed to examine the relationship between hamstring flexibility and peak hamstring muscle strains in sprinting. Methods: Ten male and 10 female college students participated in this study. Hamstring flexibili...

  16. Effects of sodium phosphate and caffeine ingestion on repeated-sprint ability in male athletes.

    Science.gov (United States)

    Kopec, Benjamin J; Dawson, Brian T; Buck, Christopher; Wallman, Karen E

    2016-03-01

    To assess the effects of sodium phosphate (SP) and caffeine supplementation on repeated-sprint performance. Randomized, double-blind, Latin-square design. Eleven team-sport males participated in four trials: (1) SP (50mgkg(-1) of free fat-mass daily for six days) and caffeine (6mgkg(-1) ingested 1h before exercise); SP+C, (2) SP and placebo (for caffeine), (3) caffeine and placebo (for SP) and (4) placebo (for SP and caffeine). After loading, participants performed a simulated team-game circuit (STGC) consisting of 2×30min halves, with 6×20-m repeated-sprint sets performed at the start, half-time and end of the STGC. There were no interaction effects between trials for first-sprint (FS), best-sprint (BS) or total-sprint (TS) times (p>0.05). However, SP resulted in the fastest times for all sprints, as supported by moderate to large effect sizes (ES; d=0.51-0.83) and 'likely' to 'very likely' chances of benefit, compared with placebo. Compared with caffeine, SP resulted in 'possible' to 'likely' chances of benefit for FS, BS and TS for numerous sets and a 'possible' chance of benefit compared with SP+C for BS (set 2). Compared with placebo, SP+C resulted in moderate ES (d=0.50-0.62) and 'possible' to 'likely' benefit for numerous sprints, while caffeine resulted in a moderate ES (d=0.63; FS: set 3) and 'likely' chances of benefit for a number of sets. While not significant, ES and qualitative analysis results suggest that SP supplementation may improve repeated-sprint performance when compared with placebo. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  17. Analysis of the functional state of students in the process of healthy training exercises in different phases of the ovarian-menstrual cycle

    Directory of Open Access Journals (Sweden)

    N.V. Petrenko

    2017-11-01

    Full Text Available Aim: to substantiate the application of a rational program of health-training sessions in the educational process of physical education of students in different phases of the ovarian-menstrual cycle. Material: in study participated students (n=127, who did not have deviations in health (the main medical group. According to the results of the tests were determined: heart rate; blood pressure; vital capacity of the lungs. To determine physical performance was used Harvard step-test. Physical exercises from the main means of health fitness were used differentially and dosed. Results: It was established that the consideration in the phases of the ovarian-menstrual cycle of indicators of the functional state, changes in well-being and working capacity give an opportunity: planning loads in the training process; adjustment of volume and intensity of loads. We recommend to schedule the load of our program as follows: in the menstrual phase - the development of flexibility (moderate load; in the postmenstrual phase - development of coordination, overall endurance; in ovulatory - speed development; in postovulatory - development of special endurance; in premenstrual - the development of strength, flexibility. In the postmenstrual and postovulatory phase, a high level of physical working capacity, functional state of the cardiopulmonary system has been registered. It also has a positive effect on body weight correction in the women students. Conclusions: When developing programs of health training sessions with women students it is necessary to take into account the phases of the ovarian-menstrual cycle.

  18. Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players

    DEFF Research Database (Denmark)

    Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter

    2018-01-01

    The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9±1.2 years, height 1.72±0.12 cm......, body mass 62.2±5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long...... study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials....

  19. Intermittent-sprint performance and muscle glycogen after 30 h of sleep deprivation.

    Science.gov (United States)

    Skein, Melissa; Duffield, Rob; Edge, Johann; Short, Michael J; Mündel, Toby

    2011-07-01

    The aim of this study was to determine the effects of 30 h of sleep deprivation on consecutive-day intermittent-sprint performance and muscle glycogen content. Ten male, team-sport athletes performed a single-day "baseline" session and two consecutive-day experimental trials separated either by a normal night's sleep (CONT1 and CONT2) or no sleep (SDEP1 and SDEP2). Each session included a 30-min graded exercise run and 50-min intermittent-sprint exercise protocol, including a 15-m maximal sprint every minute and self-paced exercise bouts of varying intensities. Muscle biopsies were extracted before and after exercise during the baseline session and before exercise on day 2 during experimental trials. Voluntary force and activation of the right quadriceps, nude mass, HR, core temperature, capillary blood lactate and glucose, RPE, and a modified POMS were recorded before, after, and during the exercise protocols. Mean sprint times were slower on SDEP2 (2.78±0.17 s) compared with SDEP1 (2.70±0.16 s) and CONT2 (2.74±0.15 s, PSleep loss did not affect RPE but negatively affected POMS ratings (PSleep loss and associated reductions in muscle glycogen and perceptual stress reduced sprint performance and slowed pacing strategies during intermittent-sprint exercise for male team-sport athletes.

  20. Nutrition and hydration status improve with exercise training using stationary cycling during hemodialysis (HD) in patients with end-stage renal disease (ESRD).

    Science.gov (United States)

    Załuska, Alicja; Załuska, Wojciech T; Bednarek-Skublewska, Anna; Ksiazek, Andrzej

    2002-01-01

    Patients with end-stage renal disease (ESRD) undergoing hemodialysis and peritoneal dialysis are functionally limited as a consequence of their physical, emotional, and social problems. Exercise intolerance is a major problem in chronic renal failure. Stationary cycle training during hemodialysis is recommended as safe, effective, and practical in ESRD patients treated on hemodialysis. The aim of the present study was to evaluate the effect of cycling exercises in 10 HD patients during 6-month period (including each of dialysis sessions) on nutrition, dialysis adequacy, and fluid parameters as measured by biochemical, and bioimpedance parameters. A significant increase in serum albumin concentration, Kt/V, and nPCR, and decrease in serum CRP have been observed after 6 months of regular stationary cycling during hemodialysis. Relative changes (pre-post HD) in extracellular water compartment and ECW/TBW ratio have significantly increased after 6 months of observation period.

  1. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    Science.gov (United States)

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  2. Is Home-Based, High-Intensity Interval Training Cycling Feasible and Safe for Patients With Knee Osteoarthritis?: Study Protocol for a Randomized Pilot Study.

    Science.gov (United States)

    Keogh, Justin W L; Grigg, Josephine; Vertullo, Christopher J

    2017-03-01

    Osteoarthritis (OA) is a degenerative joint disease affecting the knee joint of many middle-aged and older adults. As OA symptoms typically involve knee pain and stiffness, individuals with knee OA are often insufficiently physically active, have low levels of physical function, and are at increased risk of other comorbidities and reduced quality of life. While moderate-intensity continuous training (MICT) cycling is often recommended, little is known about the feasibility, safety, and benefits of high-intensity interval training (HIIT) cycling for this population, even though the feasibility, safety, and benefits of HIIT have been demonstrated in other chronic disease groups. The primary objective of this pilot study was to examine the feasibility and safety of home-based HIIT and MICT cycling in middle-aged and older adults with knee OA. A secondary objective was to gain some insight into the relative efficacy of HIIT and MICT for improving health status (pain, stiffness, and disability), muscle function, and body composition in this population. This study protocol is being published separately to allow a detailed description of the research methods, explain the rationale for choosing the methodological details, and to stimulate consideration of the best means to simulate a research protocol that is relevant to a real-life treatment environment. Randomized pilot study protocol. This trial sought to recruit 40 middle-aged and older adults with knee OA. Participants were randomly allocated to either continuous (MICT) or HIIT home-based cycle training programs, with both programs requiring the performance of 4 cycling sessions (approximately 25 minutes per session) each week. Participants were measured at baseline and postintervention (8 weeks). Feasibility and safety were assessed by adherence rate, dropout rate, and number of adverse events. The relative efficacy of the cycling programs was investigated by 2 knee OA health status questionnaires (Western Ontario

  3. Percentile Values for Running Sprint Field Tests in Children Ages 6-17 Years: Influence of Weight Status

    Science.gov (United States)

    Castro-Pinero, Jose; Gonzalez-Montesinos, Jose Luis; Keating, Xiaofen D.; Mora, Jesus; Sjostrom, Michael; Ruiz, Jonatan R.

    2010-01-01

    The aim of this study was to provide percentile values for six different sprint tests in 2,708 Spanish children (1,234 girls) ages 6-17.9 years. We also examined the influence of weight status on sprint performance across age groups, with a focus on underweight and obese groups. We used the 20-m, 30-m, and 50-m running sprint standing start and…

  4. Four weeks of normobaric "live high-train low" do not alter muscular or systemic capacity for maintaining pH and K+ homeostasis during intense exercise

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai B; Siebenmann, C; Jacobs, R A

    2012-01-01

    was double-blind and placebo controlled. Mean power during 30-s all-out cycling was similar before and immediately after LHTL (650 ± 31 vs. 628 ± 32 W; n = 10) and placebo exposure (658 ± 22 vs. 660 ± 23 W; n = 6). Supporting the performance data, arterial plasma pH, lactate, and K(+) during submaximal......It was investigated if athletes subjected to 4 wk of living in normobaric hypoxia (3,000 m; 16 h/day) while training at 800-1,300 m ["live high-train low" (LHTL)] increase muscular and systemic capacity for maintaining pH and K(+) homeostasis as well as intense exercise performance. The design...... before and after 4 wk of placebo-controlled normobaric LHTL. In accordance, 30-s all-out sprint ability was similar before and after LHTL....

  5. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

    Science.gov (United States)

    Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

    2015-01-01

    Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

  6. Sprint acceleration mechanics: the major role of hamstrings in horizontal force production

    Directory of Open Access Journals (Sweden)

    Jean-Benoit eMORIN

    2015-12-01

    Full Text Available Recent literature supports the importance of horizontal ground reaction force (GRF production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG activity of the vastus lateralis, rectus femoris, biceps femoris and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024 between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.

  7. The Association of Sprint Performance with Anthropometric Parameters in Youth Soccer Players

    Directory of Open Access Journals (Sweden)

    Arjan Hyka

    2017-02-01

    Full Text Available Several studies have investigated the association between strength and speed, showing that stronger athletes perform better during sprint performances (Baker & Nance, 1999. Moreover, the aim of this study was to evaluate the correlation between sprint performance and anthropometric parameters. Subjects were 32 youth soccer players. The age of participants was 15.1±0.3 years. Speed time (50 m sprint was evaluated during sprint test, and anthropometric parameters were measured (weight, height, percent body fat. Correlation analysis (Pearson test was performed to evaluate the correlation between speed and anthropometrics. Results showed correlation between body weight and speed (r=-0.041 Sig=0.834; BMI values and speed (r=0.231; Sig=0.236, body height and speed (r=-0.384; Sig=0.044; percent body fat and speed (r=0.440; Sig=0.019.In conclusion, the results of this study show no significance association between body weight and BMI with sprint performance and significance correlation between body height (negative correlation and percent body fat (positive correlation with speed.

  8. [Specific features of the functional state of the cardiorespiratory system in athletes differing in the types of muscular activity during the preparatory period of the training cycle].

    Science.gov (United States)

    Ivanova, N B

    2011-01-01

    The present study of the functional state of the cadiorespiratory system included athletes engaged in cyclic team sports. The state of the cardiorespiratory system was estimated from the measurement of central hemodynamics and cardiac rhythm variability, results of electrocardiography, spirography, and pneumotachography performed during the preparatory period for the training cycle. It was shown that the cardiovascular and respiratory systems as well as vegetative regulation of the cardiac rhythm of the athletes under examination underwent differently directed structural modification depending on the specific patterns of muscular activity.

  9. Listening to music during sprint interval exercise: The impact on exercise attitudes and intentions.

    Science.gov (United States)

    Stork, Matthew J; Martin Ginis, Kathleen A

    2017-10-01

    This study investigated the impact of listening to music during exercise on perceived enjoyment, attitudes and intentions towards sprint interval training (SIT). Twenty men (24.8 ± 4.5 years) and women (20.1 ± 2.6 years) unfamiliar with SIT exercise completed two acute sessions of SIT, one with and one without music. Perceived enjoyment, attitudes and intentions towards SIT were measured post-exercise for each condition. Attitudes and intentions to engage in SIT were also measured at baseline and follow-up. Post-exercise attitudes mediated the effects of enjoyment on intentions in the music condition (95% confidence interval [CI]: [0.01, 0.07], κ 2  = 0.36) and in the no music condition (95% CI: [0.01, 0.08], κ 2  = 0.37). Attitudes towards SIT were significantly more positive following the music than no music condition (P = 0.004), while intentions towards SIT were not (P = 0.29). Further, attitudes and intentions towards SIT did not change from baseline to follow-up (Ps > 0.05). These findings revealed that participants had relatively positive attitudes and intentions towards SIT, which did not become more negative despite experiencing intense SIT protocols. This study highlights the importance of acute affective responses to SIT exercise for influencing one's attitudes and intentions towards participating in SIT exercise. Such factors could ultimately play a key role in determining whether an individual engages in SIT exercise in the long term.

  10. Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity?

    NARCIS (Netherlands)

    van der Scheer, Jan W.; de Groot, Sonja; Vegter, Riemer J. K.; Veeger, DirkJan (H. E. J. ); van der Woude, Lucas H. V.

    OBJECTIVE: To evaluate whether outcomes based on stopwatch time and power output (PO) over a 15m-overground wheelchair sprint test can be used to assess wheelchair-specific anaerobic work capacity, by studying their relationship with outcomes on a Wingate-based 30s-wheelchair ergometer sprint

  11. Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity?

    NARCIS (Netherlands)

    van der Scheer, J.W.; De Groot, S.; Vegter, R.J.K.; Veeger, H.E.J.; van der Woude, L.H.V.

    2014-01-01

    Objective: To evaluate whether outcomes based on stopwatch time and power output (PO) over a 15. m-overground wheelchair sprint test can be used to assess wheelchair-specific anaerobic work capacity, by studying their relationship with outcomes on a Wingate-based 30. s-wheelchair ergometer sprint

  12. Protein intake during training sessions has no effect on performance and recovery during a strenuous training camp for elite cyclists.

    Science.gov (United States)

    Hansen, Mette; Bangsbo, Jens; Jensen, Jørgen; Krause-Jensen, Matilde; Bibby, Bo Martin; Sollie, Ove; Hall, Ulrika Andersson; Madsen, Klavs

    2016-01-01

    Training camps for top-class endurance athletes place high physiological demands on the body. Focus on optimizing recovery between training sessions is necessary to minimize the risk of injuries and improve adaptations to the training stimuli. Carbohydrate supplementation during sessions is generally accepted as being beneficial to aid performance and recovery, whereas the effect of protein supplementation and timing is less well understood. We studied the effects of protein ingestion during training sessions on performance and recovery of elite cyclists during a strenuous training camp. In a randomized, double-blinded study, 18 elite cyclists consumed either a whey protein hydrolysate-carbohydrate beverage (PRO-CHO, 14 g protein/h and 69 g CHO/h) or an isocaloric carbohydrate beverage (CHO, 84 g/h) during each training session for six days (25-29 h cycling in total). Diet and training were standardized and supervised. The diet was energy balanced and contained 1.7 g protein/kg/day. A 10-s peak power test and a 5-min all-out performance test were conducted before and after the first training session and repeated at day 6 of the camp. Blood and saliva samples were collected in the morning after overnight fasting during the week and analyzed for biochemical markers of muscle damage, stress, and immune function. In both groups, 5-min all-out performance was reduced after the first training session and at day 6 compared to before the first training session, with no difference between groups. Peak power in the sprint test did not change significantly between tests or between groups. In addition, changes in markers for muscle damage, stress, and immune function were not significantly influenced by treatment. Intake of protein combined with carbohydrate during cycling at a training camp for top cyclists did not result in marked performance benefits compared to intake of carbohydrates when a recovery drink containing adequate protein and carbohydrate was ingested

  13. The influence of ego depletion on sprint start performance in athletes without track and field experience.

    Science.gov (United States)

    Englert, Chris; Persaud, Brittany N; Oudejans, Raôul R D; Bertrams, Alex

    2015-01-01

    We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting signal requires self-control. In line with our assumption, we found a significant interaction as there was only a significant increase in the number of false starts from T1 to T2 for the depletion group while this was not the case for the non-depletion group. We conclude that ego depletion has a detrimental influence on the sprint start in athletes without track and field experience.

  14. Book Sprint: A new model for rapid book authoring and content development

    International Nuclear Information System (INIS)

    Zennaro, M.; Canessa, E.; Fonda, C.; Belcher, M.; Flickenger, R.

    2007-01-01

    We discuss our experiences and successes with the new 'Book Sprint' methodology for use in rapid authoring and content development for technical books and documentation, using a distributed team and appropriate on-line collaborative technologies. A sprint begins by assembling a group of domain experts for a short period of time-intensive content creation. The outline, scope, and approximate length of the book are established, and key contributors are identified. This is followed by remote and distributed work over a period of a few months, focussing on the bulk of the book. The Sprint Book methodology has already been used in the 'Wireless Networking in the Developing World' and 'Bandwidth Optimization and Management' books. Both of these are freely available under a Creative Commons License. (author)

  15. Lower limb joint kinetics and ankle joint stiffness in the sprint start push-off.

    Science.gov (United States)

    Charalambous, Laura; Irwin, Gareth; Bezodis, Ian N; Kerwin, David

    2012-01-01

    Sprint push-off technique is fundamental to sprint performance and joint stiffness has been identified as a performance-related variable during dynamic movements. However, joint stiffness for the push-off and its relationship with performance (times and velocities) has not been reported. The aim of this study was to quantify and explain lower limb net joint moments and mechanical powers, and ankle stiffness during the first stance phase of the push-off. One elite sprinter performed 10 maximal sprint starts. An automatic motion analysis system (CODA, 200 Hz) with synchronized force plates (Kistler, 1000 Hz) collected kinematic profiles at the hip, knee, and ankle and ground reaction forces, providing input for inverse dynamics analyses. The lower-limb joints predominately extended and revealed a proximal-to-distal sequential pattern of maximal extensor angular velocity and positive power production. Pearson correlations revealed relationships (P push-off in different ways, depending on the phase of stance considered.

  16. Sprint Start Kinetics of Amputee and Non-Amputee Sprinters

    Science.gov (United States)

    Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

    2016-01-01

    The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58–14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70–12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (−33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (−17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs. PMID:27846241

  17. Sprint Start Kinetics of Amputee and Non-Amputee Sprinters.

    Directory of Open Access Journals (Sweden)

    Steffen Willwacher

    Full Text Available The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs of amputee sprinters (ASs and non-amputee sprinters (NASs. SPs of 154 male and female NASs (100-m personal records [PRs], 9.58-14.00 s and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70-12.70 s with running specific prostheses (RSPs were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power. Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (-33.8%; d = 2.11, p < 0.001, while a non-significant performance reduction was observed when absolute 100-m PRs were used (-17.7%; d = 0.79, p = 0.09. These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs.

  18. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

    Science.gov (United States)

    van der Zwaard, Stephan; van der Laarse, Willem J; Weide, Guido; Bloemers, Frank W; Hofmijster, Mathijs J; Levels, Koen; Noordhof, Dionne A; de Koning, Jos J; de Ruiter, Cornelis J; Jaspers, Richard T

    2018-04-01

    Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15-km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass 2/3 to eliminate the influence of body size. Performance determinants were obtained from whole-body oxygen consumption, blood sampling, knee-extensor maximal force, muscle oxygenation, whole-muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast-type fibers and muscle volume ( R 2 = 0.65; P body.

  19. Kinetic Sprint Asymmetries on a non-motorised Treadmill in Rugby Union Athletes.

    Science.gov (United States)

    Brown, Scott R; Cross, Matt R; Girard, Olivier; Brocherie, Franck; Samozino, Pierre; Morin, Jean-Benoît

    2017-11-01

    The purpose of this study was to present a potential link between sprint kinetic (vertical [F V ] and horizontal force [F H ]) asymmetries and athletic performance during acceleration and maximal velocity (v max ) sprinting. Thirty un-injured male rugby athletes performed 8-s sprints on a non-motorised treadmill. Kinetic data were divided into 'strong' and 'weak' legs based on individually averaged peak values observed during sprinting and were analysed to evaluate asymmetry. Large differences were found between the strong and weak legs in F H during acceleration (4.3 vs. 3.5 N·kg -1 ) and v max (3.7 vs. 2.8 N·kg -1 ) sprinting (both ES=1.2), but not in F V (21.8 vs. 20.8 N·kg -1 , ES=- 0.6 for acceleration; 23.9 vs. 22.8 N·kg -1 , ES=- 0.5 for v max , respectively). Group mean asymmetry was lower in F V compared to F H during acceleration (1.6 vs. 6.8%) and v max (1.6 vs. 8.2%). The range of asymmetry was much lower in F V (0.03-4.3%) compared to F H (0.2-28%). In un-injured rugby athletes, the magnitude and range of asymmetry scores in F H , occurring during acceleration and v max phases, where much greater than those found in F V . These findings highlight the potential for some un-injured athletes to possess kinetic asymmetries known as crucial components for acceleration performance in sprinting. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Mechanical, hormonal, and hypertrophic adaptations to 10 weeks of eccentric and stretch-shortening cycle exercise training in old males

    NARCIS (Netherlands)

    Vaczi, Mark; Nagy, Szilvia A.; Koszegi, Tamas; Ambrus, Mira; Bogner, Peter; Perlaki, Gabor; Orsi, Gergely; Toth, Katalin; Hortobagyi, Tibor

    2014-01-01

    The growth promoting effects of eccentric (ECC) contractions are well documented but it is unknown if the rate of stretch per se plays a role in such muscular responses in healthy aging human skeletal muscle. We tested the hypothesis that exercise training of the quadriceps muscle with low rate ECC

  1. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  2. Muscle and Blood Metabolites during a Soccer Game: Implications for Sprint Performance

    DEFF Research Database (Denmark)

    Krustrup, Peter; Mohr, Magni; Steensberg, Adam

    2006-01-01

    Abstract: Purpose: To examine muscle and blood metabolites during soccer match play and relate it to possible changes in sprint performance. Methods: Thirty-one Danish fourth division players took part in three friendly games. Blood samples were collected frequently during the game, and muscle......, muscle pH, or total glycogen content. Conclusion: Sprint performance is reduced both temporarily during a game and at the end of a soccer game. The latter finding may be explained by low glycogen levels in individual muscle fibers. Blood lactate is a poor indicator of muscle lactate during soccer match...

  3. Human power output during repeated sprint cycle exercise: the influence of thermal stress

    NARCIS (Netherlands)

    Ball, D.; Burrows, C.; Sargeant, A.J.

    1999-01-01

    Thermal stress is known to impair endurance capacity during moderate prolonged exercise. However, there is relatively little available information concerning the effects of thermal stress on the performance of high-intensity short-duration exercise. The present experiment examined human power output

  4. A passive heat maintenance strategy implemented during a simulated half-time improves lower body power output and repeated sprint ability in professional Rugby Union players.

    Directory of Open Access Journals (Sweden)

    Mark Russell

    Full Text Available Reduced physical performance has been observed following the half-time period in team sports players, likely due to a decrease in muscle temperature during this period. We examined the effects of a passive heat maintenance strategy employed between successive exercise bouts on core temperature (Tcore and subsequent exercise performance. Eighteen professional Rugby Union players completed this randomised and counter-balanced study. After a standardised warm-up (WU and 15 min of rest, players completed a repeated sprint test (RSSA 1 and countermovement jumps (CMJ. Thereafter, in normal training attire (Control or a survival jacket (Passive, players rested for a further 15 min (simulating a typical half-time before performing a second RSSA (RSSA 2 and CMJ's. Measurements of Tcore were taken at baseline, post-WU, pre-RSSA 1, post-RSSA 1 and pre-RSSA 2. Peak power output (PPO and repeated sprint ability was assessed before and after the simulated half-time. Similar Tcore responses were observed between conditions at baseline (Control: 37.06±0.05°C; Passive: 37.03±0.05°C and for all other Tcore measurements taken before half-time. After the simulated half-time, the decline in Tcore was lower (-0.74±0.08% vs. -1.54±0.06%, p<0.001 and PPO was higher (5610±105 W vs. 5440±105 W, p<0.001 in the Passive versus Control condition. The decline in PPO over half-time was related to the decline in Tcore (r = 0.632, p = 0.005. In RSSA 2, best, mean and total sprint times were 1.39±0.17% (p<0.001, 0.55±0.06% (p<0.001 and 0.55±0.06% (p<0.001 faster for Passive versus Control. Passive heat maintenance reduced declines in Tcore that were observed during a simulated half-time period and improved subsequent PPO and repeated sprint ability in professional Rugby Union players.

  5. Does hydrotherapy help or hinder adaptation to training in competitive cyclists?

    Science.gov (United States)

    Halson, Shona L; Bartram, Jason; West, Nicholas; Stephens, Jessica; Argus, Christos K; Driller, Matthew W; Sargent, Charli; Lastella, Michele; Hopkins, Will G; Martin, David T

    2014-08-01

    Cold water immersion (CWI) may be beneficial for acute recovery from exercise, but it may impair long-term performance by attenuating the stimuli responsible for adaptation to training. We compared effects of CWI and passive rest on cycling performance during a simulated cycling grand tour. Thirty-four male endurance-trained competitive cyclists were randomized to CWI for four times per week for 15 min at 15°C or control (passive recovery) groups for 7 d of baseline training, 21 d of intensified training, and an 11-d taper. Criteria for completion of training and testing were satisfied by 10 cyclists in the CWI group (maximal aerobic power, 5.13 ± 0.21 W·kg; mean ± SD) and 11 in the control group (5.01 ± 0.41 W·kg). Each week, cyclists completed a high-intensity interval cycling test and two 4-min bouts separated by 30 min. CWI was performed four times per week for 15 min at 15°C. Between baseline and taper, cyclists in the CWI group had an unclear change in overall 4-min power relative to control (2.7% ± 5.7%), although mean power in the second effort relative to the first was likely higher for the CWI group relative to control (3.0% ± 3.8%). The change in 1-s maximum mean sprint power in the CWI group was likely beneficial compared with control (4.4% ± 4.2%). Differences between groups for the 10-min time trial were unclear (-0.4% ± 4.3%). Although some effects of CWI on performance were unclear, data from this study do not support recent speculation that CWI is detrimental to performance after increased training load in competitive cyclists.

  6. Validation of the short posttraumatic stress disorder rating interview (SPRINT-E in a sample of people affected by F-27 Chilean earthquake and tsunami

    Directory of Open Access Journals (Sweden)

    Marcelo C. Leiva-Bianchi

    2013-05-01

    Full Text Available On February 27, 2010 (F-27 there was an earthquake and a tsunami m Chile that has caused a great impact on the mental health of the population of this country, specifically in the increase of cases of posttraumatic stress disorder (PTSD. In view of count better instruments to measure PTSD was applied for the first time since it was created, the SPRINTE scale in a population other than the U.S., specifically in 291 people who experienced the F-27. The analysis of reliability (α=. 916, concurrent validity (all items significantly correlated with the scale used as a criterion DTS and construct validity (CMIN=2.237, RMSEA=.092, NFI=.901, CFI=.942 and PNFI=.704 for two-factor model indicate that SPRINT-E is a valid and reliable scale to measure PTSD in this population. Finally, some reflections about new factor structure discovered in this analysis, which is consistent with the meaning of items and with theoretical models such as covert stimuli. It also reflects on the usefulness of a brief scale, proven valid and very good psychometric characteristics in a Spanish-speaking population prone to natural disasters such as Chilean F-27, Japan (March 11, 2011 or Spain (May 11, 2011.

  7. Comparison of Sprint Reaction and Visual Reaction Times of Athletes in Different Branches

    Science.gov (United States)

    Akyüz, Murat; Uzaldi, Basar Basri; Akyüz, Öznur; Dogru, Yeliz

    2017-01-01

    The aims of this study are to analyse sprint reaction and visual reaction times of female athletes of different branches competing in Professional leagues and to show the differences between them. 42 voluntary female athletes from various branches of Professional leagues of Istanbul (volleyball, basketball, handball) were included in the…

  8. Comparison of muscle strength, sprint power and aerobic capacity in adults with and without cerebral palsy

    NARCIS (Netherlands)

    de Groot, Sonja; Dallmeijer, Annet J.; Bessems, Paul J. C.; Lamberts, Marcel L.; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

    Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and

  9. The Effect of Gender on Sprint Performance of 10-13 Aged Middle School Students

    Directory of Open Access Journals (Sweden)

    Serhat Turan

    2016-04-01

    Full Text Available The aim of the study was to investigate the effect of gender on the 30 m sprint performance of middle school students (10-13 ages. The study included 25 male and 25 female total 50 middle school students. The mean age of female students was found as 12,36 ± 0,48 (year, the mean body weight as 42,03 ± 3,63 (kg, and the mean height as 151,11 ±5,61 (cm, and the mean age of male students was found as 12,28 ± 0,45 (year, the mean height as 152,28 ± 5,04 (cm, and the mean body weight as 43,35 ± 1,88 (kg. The mean sprint performance of female students was calculated as 6,33 ± 0,53 seconds, and the mean sprint performance of the male students was 6,17 ± 0,47 seconds. As a result the effect of gender on sprint performance was found to be insignificant between the groups (p>0,05.

  10. Comparison of muscle strength, sprint power and aerobic capacity in adults with and without cerebral palsy

    NARCIS (Netherlands)

    de Groot, S.; Dallmeijer, A.J.; Bessems, P.J.C.; Lamberts, M.L.; van der Woude, L.H.V.; Janssen, T.W.J.

    2012-01-01

    Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and

  11. A Modified T-Test for Football Referees to Test Agility, Quickness and Sprint Performances

    Science.gov (United States)

    Muniroglu, S.; Subak, E.

    2018-01-01

    The football referees perform many actions as jogging, running, sprinting, side steps and backward steps during a football match. Further, the football referees change match activities every 5-6 seconds. Many tests are being conducted to determine the physical levels and competences of football referees like 50 m running, 200 m running, 12 minutes…

  12. Isometric strength, sprint power, and aerobic power in individuals with a spinal cord injury

    NARCIS (Netherlands)

    Janssen, T W; van Oers, C A; Hollander, A P; Veeger, DirkJan (H. E. J.); van der Woude, L H

    This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging

  13. The effect of a sport development programme on sprinting and long ...

    African Journals Online (AJOL)

    The talented children in both groups then underwent a specific test battery designed for sprinting and long jump. Maturity was determined by means of a maturity questionnaire. The development programme contributed statistically significant to the improvement in flexibility, muscle endurance, 0-40 meter speed and ...

  14. Sprinting on a running track: a rare cause of a Lisfranc dislocation.

    LENUS (Irish Health Repository)

    Khan, F

    2012-02-03

    We present a case report of a young man who sustained a serious foot injury while sprinting in a straight line. We discuss the management of these injuries and emphasise the importance of a high index of suspicion amongst orthopaedic, casualty and radiology trainees.

  15. Effects of the Nordic Hamstring exercise on sprint capacity in male football players

    DEFF Research Database (Denmark)

    Ishøi, Lasse; Hölmich, Per; Aagaard, Per

    2018-01-01

    This assessor-blinded, randomized controlled superiority trial investigated the efficacy of the 10-week Nordic Hamstring exercise (NHE) protocol on sprint performance in football players. Thirty-five amateur male players (age: 17-26 years) were randomized to a do-as-usual control group (CG; n = 1...

  16. Specific physical trainability in elite young soccer players: efficiency over 6 weeks’ in-season training

    Science.gov (United States)

    Rouissi, M; Haddad, M; Chtara, H; Chaalali, A; Owen, A; Chamari, K

    2017-01-01

    The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS]) on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6%) participated in a short-term (6-week) randomized parallel fully controlled training study (pre-to-post measurements): PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions). The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between). Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time), agility (20 m zigzag), and repeated sprint ability (RSA) (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns). Significant main effects for time (i.e. training application) and group (training type) were detected. Improvements in horizontal jumping were higher (pperformances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively) compared with PLYO (2.0%) and CON training (0.8%). No significant differences were reported in the RSAdec between groups. Elite young male soccer players’ physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training. PMID:28566807

  17. Specific physical trainability in elite young soccer players: efficiency over 6 weeks' in-season training.

    Science.gov (United States)

    Chtara, M; Rouissi, M; Haddad, M; Chtara, H; Chaalali, A; Owen, A; Chamari, K

    2017-06-01

    The aim of the present study was to compare the effects of 3 training protocols (plyometric [PLYO], agility [AG], or repeated shuttle sprints [RS]) on physical performance in the same population of young soccer players. Forty-two youth-level male players (13.6±0.3-years; 1.65±0.07 m; 54.1±6.5 kg; body fat: 12.8±2.6%) participated in a short-term (6-week) randomized parallel fully controlled training study (pre-to-post measurements): PLYO group, n=10; AG group, n=10; RS group, n=12; and control group [CON] n=10. PLYO training = 9 lower limb exercises (2-3 sets of 8-12 repetitions). The AG group performed planned AG drills and direction changes. RS training consisted of 2-4 sets of 5-6x 20 to 30 m shuttle sprints (20 seconds recovery in between). Progressive overload principles were incorporated into the programme by increasing the number of foot contacts and varying the complexity of the exercises. Pre/post-training tests were: bilateral standing horizontal jump, and unilateral horizontal jumps, sprint (30 m with 10 m lap time), agility (20 m zigzag), and repeated sprint ability (RSA) (i.e. 6x30 m shuttle sprints: 2x15 m with 180° turns). Significant main effects for time (i.e. training application) and group (training type) were detected. Improvements in horizontal jumping were higher (pperformances. Significantly greater increases in 20 m zigzag performance were observed following AG and RS training (4.0 and 3.8%, respectively) compared with PLYO (2.0%) and CON training (0.8%). No significant differences were reported in the RSA dec between groups. Elite young male soccer players' physical performances can be significantly and specifically improved either using PLYO or AG or RSA training over short-term in-season training.

  18. JUMP KINETIC DETERMINANTS OF SPRINT ACCELERATION PERFORMANCE FROM STARTING BLOCKS IN MALE SPRINTERS

    Directory of Open Access Journals (Sweden)

    Peter S. Maulder

    2006-06-01

    Full Text Available The purpose of this research was to identify the jump kinetic determinants of sprint acceleration performance from a block start. Ten male (mean ± SD: age 20 ± 3 years; height 1.82 ± 0.06 m; weight 76.7 ± 7.9 kg; 100 m personal best: 10.87 + 0.36 s {10.37 - 11.42} track sprinters at a national and regional competitive level performed 10 m sprints from a block start. Anthropometric dimensions along with squat jump (SJ, countermovement jump (CMJ, continuous straight legged jump (SLJ, single leg hop for distance, and single leg triple hop for distance measures of power were also tested. Stepwise multiple regression analysis identified CMJ average power (W/kg as a predictor of 10 m sprint performance from a block start (r = 0.79, r2 = 0.63, p<0.01, SEE = 0.04 (s, %SEE = 2.0. Pearson correlation analysis revealed CMJ force and power (r = -0.70 to -0.79; p = 0.011 - 0.035 and SJ power (r = -0.72 to -0.73; p = 0.026 - 0.028 generating capabilities to be strongly related to sprint performance. Further linear regression analysis predicted an increase in CMJ average and peak take-off power of 1 W/kg (3% & 1.5% respectively to both result in a decrease of 0.01 s (0.5% in 10 m sprint performance. Further, an increase in SJ average and peak take-off power of 1 W/kg (3.5% & 1.5% respectively was predicted to result in a 0.01 s (0.5% reduction in 10 m sprint time. The results of this study seem to suggest that the ability to generate power both elastically during a CMJ and concentrically during a SJ to be good indicators of predicting sprint performance over 10 m from a block start

  19. Sprint profile of professional female soccer players during competitive matches: Female Athletes in Motion (FAiM) study.

    Science.gov (United States)

    Vescovi, Jason D

    2012-01-01

    The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18 km · h⁻¹ was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9 km· h⁻¹; Zone 2: 21.0-22.9 km · h⁻¹; Zone 3: 23.0-24.9 km · h⁻¹ and Zone 4: >25 km · h⁻¹. Outcomes included: duration (s), distance (m), maximum speed (km · h⁻¹), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3 ± 1.5 s, 15.1 ± 9.4 m, 21.8 ± 2.3 km· h⁻¹, and 2.5 ± 2.5 min, respectively. Mean sprint distances were 657 ± 157, 447 ± 185, and 545 ± 217 m for forwards, midfielders and defenders, respectively (P ≤ 0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P ≤ 0.003) and maximum speed (P professional female soccer players covered 5.3 ± 2.0% of total distance ≥18 km · h⁻¹ with positional differences and percent decrements distinct from other previously identified elite players. These data should guide the development of high intensity and sprint thresholds for elite-standard female soccer players.

  20. Short-term adaptations following Complex Training in team-sports: A meta-analysis.

    Science.gov (United States)

    Freitas, Tomás T; Martinez-Rodriguez, Alejandro; Calleja-González, Julio; Alcaraz, Pedro E

    2017-01-01

    The purpose of this meta-analysis was to study the short-term adaptations on sprint and vertical jump (VJ) performance following Complex Training (CT) in team-sports. CT is a resistance training method aimed at developing both strength and power, which has a direct effect on sprint and VJ. It consists on alternating heavy resistance training exercises with plyometric/power ones, set for set, on the same workout. A search of electronic databases up to July 2016 (PubMed-MEDLINE, SPORTDiscus, Web of Knowledge) was conducted. Inclusion criteria: 1) at least one CT intervention group; 2) training protocols ≥4-wks; 3) sample of team-sport players; 4) sprint or VJ as an outcome variable. Effect sizes (ES) of each intervention were calculated and subgroup analyses were performed. A total of 9 studies (13 CT groups) met the inclusion criteria. Medium effect sizes (ES) (ES = 0.73) were obtained for pre-post improvements in sprint, and small (ES = 0.41) in VJ, following CT. Experimental-groups presented better post-intervention sprint (ES = 1.01) and VJ (ES = 0.63) performance than control-groups. large ESs were exhibited in younger athletes (training programs >12 total sessions (ES = 0.74). Large ESs in programs with >12 total sessions (ES = 0.81). Medium ESs obtained for under-Division I individuals (ES = 0.56); protocols with intracomplex rest intervals ≥2 min (ES = 0.55); conditioning activities with intensities ≤85% 1RM (ES = 0.64); basketball/volleyball players (ES = 0.55). Small ESs were found for younger athletes (ES = 0.42); interventions ≥6 weeks (ES = 0.45). CT interventions have positive medium effects on sprint performance and small effects on VJ in team-sport athletes. This training method is a suitable option to include in the season planning.

  1. Three Days of Intermittent Fasting: Repeated-Sprint Performance Decreased by Vertical-Stiffness Impairment.

    Science.gov (United States)

    Cherif, Anissa; Meeusen, Romain; Farooq, Abdulaziz; Ryu, Joong; Fenneni, Mohamed Amine; Nikolovski, Zoran; Elshafie, Sittana; Chamari, Karim; Roelands, Bart

    2017-03-01

    To examine the effects of 3 d of intermittent fasting (3d-IF: abstaining from eating/drinking from dawn to sunset) on physical performance and metabolic responses to repeated sprints (RSs). Twenty-one active males performed an RS test (2 sets: 5 × 5-s maximal sprints with 25 s of recovery between and 3 min of recovery between sets on an instrumented treadmill) in 2 conditions: counterbalanced fed/control session (CS) and fasting session (FS). Biomechanical and biochemical markers were assessed preexercise and postexercise. Significant main effects of IF were observed for sprints: maximal speed (P = .016), mean speed (P = .015), maximal power (P = .035), mean power (P = .049), vertical stiffness (P = .032), and vertical center-of-mass displacement (P = .047). Sprint speed and vertical stiffness decreased during the 1st (P = .003 and P = .005) and 2nd sprints (P = .046 and P = .048) of set 2, respectively. Postexercise insulin decreased in CS (P = .023) but not in FS (P = .230). Free-fatty-acid levels were higher in FS than in CS at preexercise (P < .001) and at postexercise (P = .009). High-density lipoprotein cholesterol (HDL-C) was higher at postexercise in FS (1.32 ± 0.22 mmol/L) than in CS (1.26 ± 0.21 mmol/L, P = .039). The triglyceride (TG) concentration was decreased in FS (P < .05) compared with CS. 3d-IF impaired speed and power through a decrease in vertical stiffness during the initial runs of the 2nd set of RS. The findings of the current study confirmed the benefits of 3d-IF: improved HDL-C and TG profiles while maintaining total cholesterol and low-density lipoprotein cholesterol levels. Moreover, improving muscle power might be a key factor to retain a higher vertical stiffness and to partly counteract the negative effects of intermittent fasting.

  2. Physical fitness training reference manual for security force personnel at fuel cycle facilities possessing formula quantities of special nuclear materials

    International Nuclear Information System (INIS)

    Arzino, P.A.; Caplan, C.S.; Goold, R.E.

    1991-09-01

    The recommendations contained throughout this NUREG are being provided to the Nuclear Regulatory Commission (NRC) as a reference manual which can be used by licensee management as they develop a program plan for the safe participation of guards, Tactical Response Team members (TRTs), and all other armed response personnel in physical fitness training and in physical performance standards testing. The information provided in this NUREG will help licensees to determine if guards, TRTs, and other armed response personnel can effectively perform their normal and emergency duties without undue hazard to themselves, to fellow employees, to the plant site, and to the general public. The recommendations in this NUREG are similar in part to those contained within the Department of Energy (DOE) Medical and Fitness Implementation Guide which was published in March 1991. The guidelines contained in this NUREG are not requirements, and compliance is not required. 25 refs

  3. Physical fitness training reference manual for security force personnel at fuel cycle facilities possessing formula quantities of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Arzino, P.A.; Caplan, C.S.; Goold, R.E. (California State Univ., Hayward, CA (United States). Foundation)

    1991-09-01

    The recommendations contained throughout this NUREG are being provided to the Nuclear Regulatory Commission (NRC) as a reference manual which can be used by licensee management as they develop a program plan for the safe participation of guards, Tactical Response Team members (TRTs), and all other armed response personnel in physical fitness training and in physical performance standards testing. The information provided in this NUREG will help licensees to determine if guards, TRTs, and other armed response personnel can effectively perform their normal and emergency duties without undue hazard to themselves, to fellow employees, to the plant site, and to the general public. The recommendations in this NUREG are similar in part to those contained within the Department of Energy (DOE) Medical and Fitness Implementation Guide which was published in March 1991. The guidelines contained in this NUREG are not requirements, and compliance is not required. 25 refs.

  4. High-intensity interval training has positive effects on performance in ice hockey players.

    Science.gov (United States)

    Naimo, M A; de Souza, E O; Wilson, J M; Carpenter, A L; Gilchrist, P; Lowery, R P; Averbuch, B; White, T M; Joy, J

    2015-01-01

    In spite of the well-known benefits that have been shown, few studies have looked at the practical applications of high-intensity interval training (HIIT) on athletic performance. This study investigated the effects of a HIIT program compared to traditional continuous endurance exercise training. 24 hockey players were randomly assigned to either a continuous or high-intensity interval group during a 4-week training program. The interval group (IG) was involved in a periodized HIIT program. The continuous group (CG) performed moderate intensity cycling for 45-60 min at an intensity that was 65% of their calculated heart rate reserve. Body composition, muscle thickness, anaerobic power, and on-ice measures were assessed pre- and post-training. Muscle thickness was significantly greater in IG (p=0.01) when compared to CG. The IG had greater values for both ∆ peak power (p<0.003) and ∆ mean power (p<0.02). Additionally, IG demonstrated a faster ∆ sprint (p<0.02) and a trend (p=0.08) for faster ∆ endurance test time to completion for IG. These results indicate that hockey players may utilize short-term HIIT to elicit positive effects in muscle thickness, power and on-ice performance. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Making Olympic lizards: the effects of specialised exercise training on performance.

    Science.gov (United States)

    Husak, Jerry F; Keith, Allison R; Wittry, Beth N

    2015-03-01

    Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically. © 2015. Published by The Company of Biologists Ltd.

  6. Postexercise hypotension in an endurance-trained population of men and women following high-intensity interval and steady-state cycling.

    Science.gov (United States)

    Rossow, Lindy; Yan, Huimin; Fahs, Christopher A; Ranadive, Sushant M; Agiovlasitis, Stamatis; Wilund, Kenneth R; Baynard, Tracy; Fernhall, Bo

    2010-04-01

    The acute effect of high-intensity interval exercise (HI) on blood pressure (BP) is unknown although this type of exercise has similar or greater cardiovascular benefits compared to steady-state aerobic exercise (SS). This study examined postexercise hypotension (PEH) and potential mechanisms of this response in endurance-trained subjects following acute SS and HI. Sex differences were also evaluated. A total of 25 endurance-trained men (n = 15) and women (n = 10) performed a bout of HI and a bout of SS cycling in randomized order on separate days. Before exercise, 30 min postexercise, and 60 min postexercise, we measured brachial and aortic BP. Cardiac output (CO), stroke volume (SV), end diastolic volume (EDV), end systolic volume (ESV), and left ventricular wall-velocities were measured using ultrasonography with tissue Doppler capabilities. Ejection fraction and fractional shortening (FS), total peripheral resistance (TPR), and calf vascular resistance were calculated from the above variables and measures of leg blood flow. BP, ejection fraction, and FS decreased by a similar magnitude following both bouts but changes in CO, heart rate (HR), TPR, and calf vascular resistance were greater in magnitude following HI than following SS. Men and women responded similarly to HI. Although men and women exhibited a similar PEH following SS, they showed differential changes in SV, EDV, and TPR. HI acutely reduces BP similarly to SS. The mechanistic response to HI appears to differ from that of SS, and endurance-trained men and women may exhibit differential mechanisms for PEH following SS but not HI.

  7. Sprint running: how changes in step frequency affect running mechanics and leg spring behaviour at maximal speed.

    Science.gov (United States)

    Monte, Andrea; Muollo, Valentina; Nardello, Francesca; Zamparo, Paola

    2017-02-01

    The purpose of this study was to investigate the changes in selected biomechanical variables in 80-m maximal sprint runs while imposing changes in step frequency (SF) and to investigate if these adaptations differ based on gender and training level. A total of 40 athletes (10 elite men and 10 women, 10 intermediate men and 10 women) participated in this study; they were requested to perform 5 trials at maximal running speed (RS): at the self-selected frequency (SF s ) and at SF ±15% and ±30%SF s . Contact time (CT) and flight time (FT) as well as step length (SL) decreased with increasing SF, while k vert increased with it. At SF s , k leg was the lowest (a 20% decrease at ±30%SF s ), while RS was the largest (a 12% decrease at ±30%SF s ). Only small changes (1.5%) in maximal vertical force (F max ) were observed as a function of SF, but maximum leg spring compression (ΔL) was largest at SF s and decreased by about 25% at ±30%SF s . Significant differences in F max , Δy, k leg and k vert were observed as a function of skill and gender (P < 0.001). Our results indicate that RS is optimised at SF s and that, while k vert follows the changes in SF, k leg is lowest at SF s .

  8. Ball-Sport Endurance and Sprint Test (BEAST90): validity and reliability of a 90-minute soccer performance test.

    Science.gov (United States)

    Williams, Jeremy D; Abt, Grant; Kilding, Andrew E

    2010-12-01

    The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ball-sport Endurance and Sprint Test (BEAST90). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the BEAST90, separated by 7 days. The total 90-minute distance, mean percent peak heart rate (HRpeak), and estimated percent peak oxygen uptake of the BEAST90 were 8,097 ± 458 m, 85 ± 5% and 82 ± 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The BEAST90 protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and HRpeak values, as well as having an aerobic load similar to that observed during a soccer match. Reproducibility of key physical measures during the BEAST90 were mostly high, suggesting good reliability. The BEAST90 could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance.

  9. Control of propulsion and body lift during the first two stances of sprint running: a simulation study.

    Science.gov (United States)

    Debaere, Sofie; Delecluse, Christophe; Aerenhouts, Dirk; Hagman, Friso; Jonkers, Ilse

    2015-01-01

    The aim of this study was to relate the contribution of lower limb joint moments and individual muscle forces to the body centre of mass (COM) vertical and horizontal acceleration during the initial two steps of sprint running. Start performance of seven well-trained sprinters was recorded using an optoelectronic motion analysis system and two force plates. Participant-specific torque-driven and muscle-driven simulations were conducted in OpenSim to quantify, respectively, the contributions of the individual joints and muscles to body propulsion and lift. The ankle is the major contributor to both actions during the first two stances, with an even larger contribution in the second compared to the first stance. Biarticular gastrocnemius is the main muscle contributor to propulsion in the second stance. The contribution of the hip and knee depends highly on the position of the athlete: During the first stance, where the athlete runs in a forward bending position, the knee contributes primarily to body lift and the hip contributes to propulsion and body lift. In conclusion, a small increase in ankle power generation seems to affect the body COM acceleration, whereas increases in hip and knee power generation tend to affect acceleration less.

  10. Aerobic power and lean mass are indicators of competitive sprint performance among elite female cross-country skiers

    Directory of Open Access Journals (Sweden)

    Carlsson T

    2016-11-01

    Full Text Available Tomas Carlsson, Michail Tonkonogi, Magnus Carlsson School of Education, Health and Social Studies, Dalarna University, Falun, SwedenAbstract: The purpose of this study was to establish the optimal allometric models to predict International Ski Federation’s ski-ranking points for sprint competitions (FISsprint among elite female cross-country skiers based on maximal oxygen uptake (V̇O2max and lean mass (LM. Ten elite female cross-country skiers (age: 24.5±2.8 years [mean ± SD] completed a treadmill roller-skiing test to determine V̇O2max (ie, aerobic power using the diagonal stride technique, whereas LM (ie, a surrogate indicator of anaerobic capacity was determined by dual-emission X-ray anthropometry. The subjects’ FISsprint were used as competitive performance measures. Power function modeling was used to predict the skiers’ FISsprint based on V̇O2max, LM, and body mass. The subjects’ test and performance data were as follows: V̇O2max, 4.0±0.3 L min-1; LM, 48.9±4.4 kg; body mass, 64.0±5.2 kg; and FISsprint, 116.4±59.6 points. The following power function models were established for the prediction of FISsprint: 3.91×105 ∙ VO -6.00 2max and 6.95×1010 ∙ LM-5.25; these models explained 66% (P=0.0043 and 52% (P=0.019, respectively, of the variance in the FISsprint. Body mass failed to contribute to both models; hence, the models are based on V̇O2max and LM expressed absolutely. The results demonstrate that the physiological variables that reflect aerobic power and anaerobic capacity are important indicators of competitive sprint performance among elite female skiers. To accurately indicate performance capability among elite female skiers, the presented power function models should be used. Skiers whose V̇O2max differs by 1% will differ in their FISsprint by 5.8%, whereas the corresponding 1% difference in LM is related to an FISsprint difference of 5.1%, where both differences are in favor of the skier with

  11. Transfer of strength and power training to sports performance.

    Science.gov (United States)

    Young, Warren B

    2006-06-01

    The purposes of this review are to identify the factors that contribute to the transference of strength and power training to sports performance and to provide resistance-training guidelines. Using sprinting performance as an example, exercises involving bilateral contractions of the leg muscles resulting in vertical movement, such as squats and jump squats, have minimal transfer to performance. However, plyometric training, including unilateral exercises and horizontal movement of the whole body, elicits significant increases in sprint acceleration performance, thus highlighting the importance of movement pattern and contraction velocity specificity. Relatively large gains in power output in nonspecific movements (intramuscular coordination) can be accompanied by small changes in sprint performance. Research on neural adaptations to resistance training indicates that intermuscular coordination is an important component in achieving transfer to sports skills. Although the specificity of resistance training is important, general strength training is potentially useful for the purposes of increasing body mass, decreasing the risk of soft-tissue injuries, and developing core stability. Hypertrophy and general power exercises can enhance sports performance, but optimal transfer from training also requires a specific exercise program.

  12. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an ‘hypoxic to normoxic recovery’ approach

    Directory of Open Access Journals (Sweden)

    Olivier eGIRARD

    2015-09-01

    Full Text Available To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, thirteen active males performed eight 5-s sprints (recovery = 25 s on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%, moderate (MH; FiO2 = 16.8% or severe normobaric hypoxia (SH; FiO2 = 13.3% followed, 6 min later, by four 5-s sprints (recovery = 25 s in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (-8.2% compared to SL (-5.3% and MH (-7.2%; P<0.05], changes in contact time, step frequency and root mean square activity (surface electromyography of the quadriceps (rectus femoris muscle in SH exceeded those in SL and MH (P<0.05. During first sprint of the subsequent normoxic set, the distance covered (99.6%, 96.4% and 98.3% of sprint 1 in SL, MH and SH, respectively, the main kinetic (mean, horizontal and resultant forces and kinematic (contact time and step frequency variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1 to 8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure, sprint mechanical performance and neural alterations were largerly influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level, with a

  13. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an “hypoxic to normoxic recovery” approach

    Science.gov (United States)

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P.

    2015-01-01

    To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, 13 active males performed eight 5-s sprints (recovery = 25 s) on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%), moderate (MH; FiO2 = 16.8%) or severe normobaric hypoxia (SH; FiO2 = 13.3%) followed, 6 min later, by four 5-s sprints (recovery = 25 s) in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (−8.2%) compared to SL (−5.3%) and MH (−7.2%); P < 0.05], changes in contact time, step frequency and root mean square activity (surface electromyography) of the quadriceps (Rectus femoris muscle) in SH exceeded those in SL and MH (P < 0.05). During first sprint of the subsequent normoxic set, the distance covered (99.6, 96.4, and 98.3% of sprint 1 in SL, MH, and SH, respectively), the main kinetic (mean vertical, horizontal, and resultant forces) and kinematic (contact time and step frequency) variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1–8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure), sprint mechanical performance and neural alterations were largely influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level

  14. Effects of plyometric training and creatine supplementation on maximal-intensity exercise and endurance in female soccer players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; González-Jurado, José Antonio; Martínez, Cristian; Nakamura, Fábio Yuzo; Peñailillo, Luis; Meylan, Cesar M P; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; Moran, Jason; Alonso-Martínez, Alicia M; Izquierdo, Mikel

    2016-08-01

    To investigate the effects of a six-week plyometric training and creatine supplementation intervention on maximal-intensity and endurance performance in female soccer players during in-season training. Randomized, double-blind, placebo-controlled trial. Young (age 22.9±2.5y) female players with similar training load and competitive background were assigned to a plyometric training group receiving placebo (PLACEBO, n=10), a plyometric training group receiving creatine supplementation (CREATINE, n=10) or a control group receiving placebo without following a plyometric program (CONTROL, n=10). Athletes were evaluated for jumping, maximal and repeated sprinting, endurance and change-of-direction speed performance before and after six weeks of training. After intervention the CONTROL group did not change, whereas both plyometric training groups improved jumps (ES=0.25-0.49), sprint (ES=0.35-0.41), repeated sprinting (ES=0.48-0.55), endurance (ES=0.32-0.34) and change-of-direction speed performance (ES=0.46-0.55). However, the CREATINE group improved more in the jumps and repeated sprinting performance tests than the CONTROL and the PLACEBO groups. Adaptations to plyometric training may be enhanced with creatine supplementation. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  15. Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise.

    Science.gov (United States)

    Linthorne, Nicholas P; Cooper, James E

    2013-06-01

    This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (micro = 0.21-0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient offriction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected.

  16. EFFECT OF MUSCLE ENERGY TECHNIQUE ON FLEXIBILITY OF HAMSTRING AND CALF MUSCLES AND SPRINTING PERFORMANCE IN SPRINTERS

    Directory of Open Access Journals (Sweden)

    M. Prasad Naik

    2015-10-01

    Full Text Available Background: Muscle energy technique is used for restoring normal tone in hypertonic muscles, strengthening weak muscles, preparing muscle for subsequent stretching, one of the main uses of this method is to normalize joint range which may help in increase flexibility and performance in sprinters. The aim of the study is to evaluate the effect of muscle energy technique on flexibility of hamstrings and calf muscles and sprinting performance in sprinters. The objective of the study is to determine the muscle energy technique on hamstrings and calf muscle flexibility and sprinting performance in sprinters by using goniometer and timing of sprinting performance. Method: The study design is an experimental study in which 30 male sprinters were recruited in this study. The study sample included all male healthy sprinters, aged between 15 -30 years. All subjects received warm up, muscle energy technique and cool down exercises daily for a period of 6weeks.The outcome measures are 90°-90°popliteal angle for assessing hamstring flexibility and ROM of ankle joint for calf muscles by universal goniometer and sprinting performance time by using stopwatch. Results: Independent t-test and paired t- test are used to analyse the data. A significant difference was found between pre and post values of hamstring and calf muscle flexibility and sprinting performance after the analysis in this study. Conclusion: This study shows that there was a significant effect of MET on hamstring and calf muscle flexibility and sprinting performance.

  17. On the performance of Usain Bolt in the 100 m sprint

    Science.gov (United States)

    Hernández Gómez, J. J.; Marquina, V.; Gómez, R. W.

    2013-09-01

    Many university texts on mechanics consider the effect of air drag force, using the slowing down of a parachute as an example. Very few discuss what happens when the drag force is proportional to both u and u2. In this paper we deal with a real problem to illustrate the effect of both terms on the speed of a runner: a theoretical model of the world-record 100 m sprint of Usain Bolt during the 2009 World Championships in Berlin is developed, assuming a drag force proportional to u and to u2. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Association of Athletics Federations, which recorded Bolt's position with a laser velocity guard device. It is worth noting that our model works only for short sprints.

  18. Sprint: The first flight demonstration of the external work system robots

    Science.gov (United States)

    Price, Charles R.; Grimm, Keith

    1995-01-01

    The External Works Systems (EWS) 'X Program' is a new NASA initiative that will, in the next ten years, develop a new generation of space robots for active and participative support of zero g external operations. The robotic development will center on three areas: the assistant robot, the associate robot, and the surrogate robot that will support external vehicular activities (EVA) prior to and after, during, and instead of space-suited human external activities respectively. The EWS robotics program will be a combination of technology developments and flight demonstrations for operational proof of concept. The first EWS flight will be a flying camera called 'Sprint' that will seek to demonstrate operationally flexible, remote viewing capability for EVA operations, inspections, and contingencies for the space shuttle and space station. This paper describes the need for Sprint and its characteristics.

  19. High-intensity sprint training inhibits mitochondrial respiration through aconitase inactivation

    DEFF Research Database (Denmark)

    Larsen, Filip J; Schiffer, Tomas A; Ørtenblad, Niels

    2016-01-01

    . In contrast, the triceps failed to increase mitochondrial density, and citrate did not accumulate. Instead, mitochondrial H2O2 emission was decreased to 40% of the pretraining levels, together with a 6-fold increase in protein abundance of catalase. In this study, a novel mitochondrial stress response...

  20. High-dose inhaled terbutaline increases muscle strength and enhances maximal sprint performance in trained men

    DEFF Research Database (Denmark)

    Hostrup, Morten; Kalsen, Anders; Bangsbo, Jens

    2014-01-01

    ) participated in a double-blinded randomized crossover study. After administration of inhaled terbutaline (30 × 0.5 mg) or placebo, subjects' maximal voluntary isometric contraction (MVC) of m.quadriceps was measured. After MVC, subjects performed a 30-s Wingate test. Sixty minutes following the Wingate test......, subjects exercised for 10 min at 80 % of [Formula: see text] and completed a 100-kcal time trial. Aerobic contribution was determined during the Wingate test by indirect calorimetry. Furthermore, plasma terbutaline, lactate, glucose, and K(+) were measured. RESULTS: Inhalation of 15 mg terbutaline resulted...... = 0.019) and 3.3 ± 1.0 % (P = 0.009) higher for terbutaline than placebo. Net accumulation of plasma lactate was higher (P = 0.003) for terbutaline than placebo during the Wingate test, whereas [Formula: see text] above baseline was unchanged by terbutaline (P = 0.882). Time-trial performance...

  1. The Relationship between Repeated Sprint Performance and Velocity Values during Loaded-Squat Jump Exercise

    Science.gov (United States)

    Can, Ibrahim; Sadik, Seda; Bayrakdaroglu, Serdar

    2018-01-01

    The purpose of this study is to investigate the relationship between repeated sprint performance and velocity values during loaded-squat jump exercise. In accordance with this purpose, 23 kickboxing athletes (age: 21,1 ± 2,10 years; height: 178,7 ± 5,01 cm; weight: 70,8 ± 7,85 kg) participated voluntarily in this study. Participants were performed…

  2. Adaptations in athletic performance after ballistic power versus strength training.

    Science.gov (United States)

    Cormie, Prue; McGuigan, Michael R; Newton, Robert U

    2010-08-01

    To determine whether the magnitude of improvement in athletic performance and the mechanisms driving these adaptations differ in relatively weak individuals exposed to either ballistic power training or heavy strength training. Relatively weak men (n = 24) who could perform the back squat with proficient technique were randomized into three groups: strength training (n = 8; ST), power training (n = 8; PT), or control (n = 8). Training involved three sessions per week for 10 wk in which subjects performed back squats with 75%-90% of one-repetition maximum (1RM; ST) or maximal-effort jump squats with 0%-30% 1RM (PT). Jump and sprint performances were assessed as well as measures of the force-velocity relationship, jumping mechanics, muscle architecture, and neural drive. Both experimental groups showed significant (P training with no significant between-group differences evident in either jump (peak power: ST = 17.7% +/- 9.3%, PT = 17.6% +/- 4.5%) or sprint performance (40-m sprint: ST = 2.2% +/- 1.9%, PT = 3.6% +/- 2.3%). ST also displayed a significant increase in maximal strength that was significantly greater than the PT group (squat 1RM: ST = 31.2% +/- 11.3%, PT = 4.5% +/- 7.1%). The mechanisms driving these improvements included significant (P force-velocity relationship, jump mechanics, muscle architecture, and neural activation that showed a degree of specificity to the different training stimuli. Improvements in athletic performance were similar in relatively weak individuals exposed to either ballistic power training or heavy strength training for 10 wk. These performance improvements were mediated through neuromuscular adaptations specific to the training stimulus. The ability of strength training to render similar short-term improvements in athletic performance as ballistic power training, coupled with the potential long-term benefits of improved maximal strength, makes strength training a more effective training modality for relatively weak individuals.

  3. Mechanical Properties of Sprinting in Elite Rugby Union and Rugby League.

    Science.gov (United States)

    Cross, Matt R; Brughelli, Matt; Brown, Scott R; Samozino, Pierre; Gill, Nicholas D; Cronin, John B; Morin, Jean-Benoît

    2015-09-01

    To compare mechanical properties of overground sprint running in elite rugby union and rugby league athletes. Thirty elite rugby code (15 rugby union and 15 rugby league) athletes participated in this cross-sectional analysis. Radar was used to measure maximal overground sprint performance over 20 or 30 m (forwards and backs, respectively). In addition to time at 2, 5, 10, 20, and 30 m, velocity-time signals were analyzed to derive external horizontal force-velocity relationships with a recently validated method. From this relationship, the maximal theoretical velocity, external relative and absolute horizontal force, horizontal power, and optimal horizontal force for peak power production were determined. While differences in maximal velocity were unclear between codes, rugby union backs produced moderately faster split times, with the most substantial differences occurring at 2 and 5 m (ES 0.95 and 0.86, respectively). In addition, rugby union backs produced moderately larger relative horizontal force, optimal force, and peak power capabilities than rugby league backs (ES 0.73-0.77). Rugby union forwards had a higher absolute force (ES 0.77) despite having ~12% more body weight than rugby league forwards. In this elite sample, rugby union athletes typically displayed greater short-distance sprint performance, which may be linked to an ability to generate high levels of horizontal force and power. The acceleration characteristics presented in this study could be a result of the individual movement and positional demands of each code.

  4. Reliability and Usefulness of Linear Sprint Testing in Adolescent Rugby Union and League Players.

    Science.gov (United States)

    Darrall-Jones, Joshua D; Jones, Ben; Roe, Gregory; Till, Kevin

    2016-05-01

    The purpose of this study was to evaluate (a) whether there were differences in sprint times at 5, 10, 20, 30, and 40 m between rugby union and rugby league players, (b) determine the reliability and usefulness of linear sprint testing in adolescent rugby players. Data were collected on 28 rugby union and league academy players over 2 testing sessions, with 3-day rest between sessions. Rugby league players were faster at 5 m than rugby union players, with further difference unclear. Sprint time at 10, 20, 30, and 40 m was all reliable (coefficient of variation [CV] = 3.1, 1.8, 2.0, and 1.3%) but greater than the smallest worthwhile change (SWC [0.2 × between-subject SD]), rating the test as marginal for usefulness. Although the test was incapable of detecting the SWC, we recommend that practitioners and researchers use Hopkins' proposed method; whereby plotting the change score of the individual at each split (±typical error [TE] expressed as a CV) against the SWC and visually inspecting whether the TE crosses into the SWC are capable of identifying whether a change is both real (greater than the noise of the test, i.e., >TE) and of practical significance (>SWC). Researchers and practitioners can use the TE and SWC from this study to assess changes in performance of adolescent rugby players when using single beam timing gates.

  5. Características y efectos de los métodos resistidos en el sprint

    Directory of Open Access Journals (Sweden)

    Pedro E. Alcaraz

    2009-01-01

    Full Text Available Para la mejora del rendimiento en el sprint se utilizan distintos métodos de entrenamiento, entre los más populares se encuentran los métodos resistidos. Un método resistido para el sprint se caracteriza por utilizar sprints con una sobrecarga o resistencia añadida. Dependiendo de las características del dispositivo, tanto la magnitud como la dirección de la resistencia va a ser diferente. Así, existen distintos tipos de métodos resistidos, estos son: arrastres de trineos o ruedas, lastres de chalecos o cinturones, arrastres de paracaídas, carreras cuesta arriba, e incluso carreras sobre la arena de la playa. El principal objetivo al usar métodos resistidos es mejorar la fuerza específica de los deportistas sin producir una modificación significativa de la técnica del deportista. En el presente trabajo se revisan las características y efectos de los métodos resistidos tanto de forma aguda, como sus efectos a corto, medio y largo plazo.

  6. Friction-loaded cycle ergometers: Past, present and future

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    Henry Vandewalle

    2015-12-01

    Full Text Available The first friction-cycle ergometers of the end of the nineteenth century and the beginning of the 20th century are presented before the description of more recent ergometers such as Fleisch ergometer (1954, ErgomécaTM (1985, sinus-balance ergometer, and weight-basket loaded ergometer. The limits of each ergometer are debated. The interest of friction-loaded ergometers was renewed with the proposal of different protocols enabling the assessment of maximal power during short all-out sprints on a cycle ergometer. These protocols are succinctly presented: corrected peak power protocol, force-speed test during repeated all-out sprints against different loads, torque–velocity relationship during a single all-out sprint. The different calibration procedures (static, dynamic, and physiological calibrations of friction-loaded ergometers are described before the presentation of their results in the literature. Some improvements for the future friction-loaded ergometers are presented at the end of the paper.

  7. Effects of Two Different Training Periodization Models on Physical and Physiological Aspects of Elite Female Team Handball Players.

    Science.gov (United States)

    Manchado, Carmen; Cortell-Tormo, Juan M; Tortosa-Martínez, Juan

    2018-01-01

    Manchado, C, Cortell-Tormo, JM, and Tortosa-Martínez, J. Effects of two different training periodization models on physical and physiological aspects of elite female team handball players. J Strength Cond Res 32(1): 280-287, 2018-The aim of this study was to compare training-induced changes in selected physiological and physical team handball performance factors after 2 training periodization models: traditional periodization (TP) vs. block periodization (BP). Eleven female team handball players who played over 2 consecutive seasons for a Spanish first league team were assessed twice per season during a training cycle. On each occasion, participants completed anthropometric, maximal strength, and lower-body power assessments. In addition, incremental tests to determine maximum oxygen uptake (V[Combining Dot Above]O2max), sprint- and sport-specific throwing velocity tests were performed. Block periodization group experienced significantly greater improvements than TP on squat jump (5.97%; p handball performance factors in high level female handball players.

  8. Explosive strength training improves speed and agility in wheelchair basketball athletes

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    Tarik Ozmen

    2014-04-01

    Full Text Available INTRODUCTION: Wheelchair basketball is a paralympic sport characterized by intermittent high-intensity activities that require explosive strength and speed. OBJECTIVE: To investigate the effect of explosive strength training on speed and agility performance in wheelchair basketball players. METHODS: Ten male wheelchair basketball players (Mage=31±4 yrs were divided into two groups [i.e. explosive strength training (ES; control (CN] based on International Wheelchair Basketball Federation (IWBF classification scores. The ES group underwent 6-weeks of training, twice weekly, at 50% 1RM, 10-12 repetitions and 3-4 sets in addition to routine training. Effects of training were measured by the 20 m sprint test and Illinois agility test. RESULTS: The ES group, showed significantly higher increases in speed and agility performance (p ≤ .05. CONCLUSION: A short-duration (i.e. 6-week explosive strength training programme in wheelchair basketball athletes results in significant improvements in sprint and agility performance.

  9. Enhanced Strength and Sprint Levels, and Changes in Blood Parameters during a Complete Athletics Season in 800 m High-Level Athletes

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    Beatriz Bachero-Mena

    2017-08-01

    Full Text Available The purpose of this study was to analyze changes in sprint, strength, hematological, and hormonal parameters in high-level 800 m athletes during a complete athletics season. Thirteen male athletes of national and international level in 800 m (personal best ranging from 1:43 to 1:58 min:ss participated in this study. A total of 5 tests were conducted during a complete athletics season. Athletes performed sprint tests (20 and 200 m, countermovement jump (CMJ, jump squat (JS, and full squat (SQ tests. Blood samples (red and white blood profile and hormones were collected in test 1 (T1, test 3 (T3, and test 5 (T5. A general increase in the performance of the strength and sprint parameters analyzed (CMJ, JS, SQ, 20 m, and 200 m during the season was observed, with a significant time effect in CMJ (P < 0.01, SQ (P < 0.01, and 200 m (P < 0.05. This improvement was accompanied by a significant enhancement of the 800 m performance from T3 to T5 (P < 0.01. Significant changes in some hematological variables: hematocrit (Hct (P < 0.01, mean corpuscular volume (MCV (P < 0.001, mean corpuscular hemoglobin content (MCHC (P < 0.001, white blood cells count (WBC (P < 0.05, neutrophils (P < 0.05, monocytes (P < 0.05, and mean platelet volume (MPV (P < 0.05 were observed throughout the season. The hormonal response and creatin kinase (CK did not show significant variations during the season, except for insulin-like growth factor I (IGF-1 (P < 0.05. In conclusion, our results suggest the importance of strength levels in middle-distance athletes. On the other hand, variations in some hematological parameters and a depression of the immune system occurred during the season. Therefore, monitoring of the mechanical, hematological and hormonal response in athletes may help coaches and athletes to optimize the regulation of training contents and may be useful to diagnose states of overreaching or overtraining in athletes throughout the season.

  10. Elevations in core and muscle temperature impairs repeated sprint performance

    DEFF Research Database (Denmark)

    Drust, B.; Rasmussen, P.; Mohr, Magni

    2005-01-01

    on a cycle ergometer in normal (approximately 20 degrees C, control) and hot (40 degrees C, hyperthermia) environments. RESULTS: Completion of the intermittent protocol in the heat elevated core and muscle temperatures (39.5 +/- 0.2 degrees C; 40.2 +/- 0.4 degrees C), heart rate (178 +/- 11 beats min(-1...... metabolic fatigue agents and we, therefore, suggest that it may relate to the influence of high core temperature on the function of the central nervous system.......)), rating of perceived exertion (RPE) (18 +/- 1) and noradrenaline (38.9 +/- 13.2 micromol l(-1)) (all P

  11. Recruitment strategies and challenges in a large intervention trial: Systolic Blood Pressure Intervention Trial (SPRINT)

    Science.gov (United States)

    Ramsey, Thomas M; Snyder, Joni K; Lovato, Laura C; Roumie, Christianne L; Glasser, Steven P; Cosgrove, Nora M; Olney, Christine M; Tang, Rocky H; Johnson, Karen C; Still, Carolyn H; Gren, Lisa H; Childs, Jeffery C; Crago, Osa L; Summerson, John H; Walsh, Sandy M; Perdue, Letitia H; Bankowski, Denise M; Goff, David C

    2016-01-01

    Background The Systolic Blood Pressure Intervention Trial (SPRINT) is a multicenter, randomized clinical trial of 9,361 participants with hypertension who are ≥ 50 years old. The trial is designed to evaluate the effect of intensive systolic blood pressure control (systolic blood pressure goal recruitment strategies and lessons learned during recruitment of the SPRINT cohort and five targeted participant subgroups: pre-existing cardiovascular disease, pre-existing chronic kidney disease, age ≥ 75 years, women, and minorities. Methods In collaboration with the National Institutes of Health Project Office and SPRINT Coordinating Center, five Clinical Center Networks oversaw clinical site selection, recruitment, and trial activities. Recruitment began November 8, 2010 and ended March 15, 2013 (about 28 months). Various recruitment strategies were used, including mass mailing, brochures, referrals from healthcare providers or friends, posters, newspaper ads, radio ads, and electronic medical record searches. Results Recruitment was scheduled to last 24 months to enroll a target of 9,250 participants; in just over 28 months, the trial enrolled 9,361 participants. The trial screened 14,692 volunteers, with 33% of initial screens originating from the use of mass mailing lists. Screening results show that participants also responded to recruitment efforts through referral by SPRINT staff, healthcare providers, or friends (45%); brochures or posters placed in clinic waiting areas (15%); and television, radio, newspaper, internet ads, or toll-free numbers (8%). The overall recruitment yield (number randomized /number screened) was 64% (9,361 randomized /14,692 screened), 77% for those with cardiovascular disease, 79% for those with chronic kidney disease, 70% for those age ≥ 75 years, 55% for women, and 61% for minorities. As recruitment was observed to lag behind expectations, additional clinics were included and inclusion criteria were broadened, keeping event rates

  12. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants

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    David Morales-Alamo

    2018-03-01

    Full Text Available Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH activation and reactive nitrogen and oxygen species (RNOS in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (PIO2 = 75 mmHg or room air (PIO2 = 143 mmHg. Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO2. Immediately after the sprints, Ser293- and Ser300-PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively. However, 30 min into recovery Ser293-PDH-E1α phosphorylation reached pre-exercise values while Ser300-PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser293-PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser293 and Ser300-PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo (r = 0.74, P < 0.001; n = 18, but not after antioxidants ingestion (r = 0.35, P = 0.15. In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser293 re-phosphorylates at a faster rate than Ser300-PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms.

  13. REPEATED SPRINT ABILITY IN PROFESSIONAL SOCCER vs. PROFESSIONAL FUTSAL PLAYERS [Capacidad de realizar esprints repetidos en jugadores profesionales de fútbol vs. Fútbol sala

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    V. Cuadrado-Peñafiel

    2014-10-01

    Full Text Available Purpose: To investigate the changes through repeated explosive effort sequences (20+20-m sprint with change of direction, jumping, metabolic response (lactate, as well as the relationship between these variables and fitness qualities (strength and endurance in professional futsal and soccer players. Methods: Male players (n =30, Twelve futsal and twenty soccer players completed three testing sessions. In the first session was measured VO2max on a motorized treadmill. In the second session was measured counter movement jump (CMJ and full squat RM in Smith Machine. Finally, in the third session six repeated-explosive effort sequences (RES was performed. Results: Similar values of lower limbs strength, CMJ height, LAC after RSA test and VO2max (95,12 vs. 94,73; 34,5 vs. 35,9; 13,65 vs. 14,33; 62,78 vs. 62,95 soccer vs. futsal respectively and significant differences when are analysed the loss of performance in velocity (total and between three first and three last and vertical jump height (2,67 vs. 4,4**; 1,28 vs. 2,1*; 2,88 vs. 6,1**; 9,71 vs. 14,3* soccer vs. futsal respectively. Conclusions: Professional futsal and soccer obtain significant differences in speed and vertical jump height (CMJ loss despite having similar values in squat, oxygen consumption, lactate after RSA test and CMJ height. Issue that could be attributed to the characteristics of the sport. This suggests that the volume should be increased oriented ability to perform repeated