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Sample records for repeated sprint ability

  1. Repeated-sprint ability and aerobic fitness.

    Science.gov (United States)

    Thébault, Nicolas; Léger, Luc A; Passelergue, Philippe

    2011-10-01

    The purpose of this study was to reinvestigate the relationship between aerobic fitness and fatigue indices of repeated-sprint ability (RSA), with special attention to methodological normalization. Soldiers were divided into low (n = 10) and high (n = 9) fitness groups according to a preset maximal aerobic speed (MAS) of 17 km·h(-1) (∼60 ml O2·kg(-1)·min) measured with the University of Montreal Track Test (UMTT). Subjects' assessment included the RSA test (3 sets of 5 40-m sprints with 1-minute rest between sprints and 1.5 minutes between sets), a 40-m sprint (criterion test used in the computation of fatigue indices for the RSA test), strength and power measurement of the lower limbs, and the 20-m shuttle run test (20-m SRT) and the UMTT, which are measures of maximal aerobic power. The highest correlation with the RSA fatigue indices was obtained with the 20-m SRT (r = 0.90, p = 0.0001, n = 19), a test with 180° direction changes and accelerations and decelerations. The lower correlation (r = 0.66, p repeated sprints and achieved better recovery between series. A MAS of at least 17 km·h(-1) favors constant and high speed level during repeated sprints. From a practical point of view, a high aerobic fitness is a precious asset in counteracting fatigue in sports with numerous sprint repetitions.

  2. Improving repeated sprint ability in young elite soccer players: repeated shuttle sprints vs. explosive strength training.

    Science.gov (United States)

    Buchheit, Martin; Mendez-Villanueva, Alberto; Delhomel, Gregory; Brughelli, Matt; Ahmaidi, Said

    2010-10-01

    To compare the effects of explosive strength (ExpS) vs. repeated shuttle sprint (RS) training on repeated sprint ability (RSA) in young elite soccer players, 15 elite male adolescents (14.5 ± 0.5 years) performed, in addition to their soccer training program, RS (n = 7) or ExpS (n = 8) training once a week for a total of 10 weeks. RS training consisted of 2-3 sets of 5-6 × 15- to 20-m repeated shuttle sprints interspersed with 14 seconds of passive or 23 seconds of active recovery (≈2 m·s⁻¹); ExpS training consisted of 4-6 series of 4-6 exercises (e.g., maximal unilateral countermovement jumps (CMJs), calf and squat plyometric jumps, and short sprints). Before and after training, performance was assessed by 10 and 30 m (10 and 30 m) sprint times, best (RSAbest) and mean (RSAmean) times on a repeated shuttle sprint ability test, a CMJ, and a hopping (Hop) test. After training, except for 10 m (p = 0.22), all performances were significantly improved in both groups (all p's repeated shuttle sprint test were only observed after RS training, whereas CMJ height was only increased after ExpS. Because RS and ExpS were equally efficient at enhancing maximal sprinting speed, RS training-induced improvements in RSA were likely more related to progresses in the ability to change direction.

  3. 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

  4. 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

    2014-01-01

    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 i

  5. 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

    2014-01-01

    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 i

  6. Repeated-sprint and effort ability in rugby league players.

    Science.gov (United States)

    Johnston, Rich D; Gabbett, Tim J

    2011-10-01

    The aim of this study was to (a) investigate the influence of tackling on repeated-sprint performance; (b) determine whether repeated-sprint ability (RSA) and repeated-effort ability (REA) are 2 distinct qualities; and (c) assess the test-retest reliability of repeated-sprint and repeated-effort tests in rugby league. Twelve rugby league players performed a repeated-sprint (12 × 20-m sprints performed on a 20-second cycle) and a repeated-effort (12 × 20-m sprints with intermittent tackling, performed on a 20-second cycle) test 7 days apart. The test-retest reliability of these tests was also established. Heart rate and rating of perceived exertion were recorded throughout the tests. There was a significantly greater (p ≤ 0.05) and large effect size (ES) differences for total sprint time (ES = 1.19), average heart rate (ES = 1.64), peak heart rate (ES = 1.35), and perceived exertion (ES = 3.39) for the repeated-effort test compared with the repeated-sprint test. A large difference (ES = 1.02, p = 0.06) was detected for percentage decrement between the 2 tests. No significant relationship was found between the repeated-sprint and repeated-effort tests for any of the dependent variables. Both tests proved reliable, with total sprint time being the most reliable method of assessing performance. This study demonstrates that the addition of tackling significantly increases the physiological response to repeated-sprint exercise and reduces repeated-sprint performance in rugby league players. Furthermore, RSA and REA appear to be 2 distinct qualities that can be reliably assessed with total time being the most reliable measure of performance.

  7. Aerobic Capacity is Related to Repeated Sprint Ability with Sprint Distances Less Than 40 Meters.

    Science.gov (United States)

    Sanders, Gabriel J; Turner, Zachary; Boos, Brian; Peacock, Corey A; Peveler, Willard; Lipping, Alar

    2017-01-01

    Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ -0.69, P sprint times and average sprint time. More aerobically fit Division I soccer athletes were faster at all time points during the RSA test. Aerobic fitness is associated with faster sprint times during a more anaerobic RSA test when sprint distances are less than 40 meters.

  8. Evolution of Determinant Factors of Repeated Sprint Ability.

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    Pareja-Blanco, Fernando; Suarez-Arrones, Luis; Rodríguez-Rosell, David; López-Segovia, Manuel; Jiménez-Reyes, Pedro; Bachero-Mena, Beatriz; González-Badillo, Juan José

    2016-12-01

    The aim of this study was to investigate the changes in the relationships between repeated sprint ability (RSA) and anthropometric measures as well as fitness qualities in soccer players. Twenty-one professional soccer players performed several anthropometric and physical tests including countermovement vertical jumps (CMJs), a straight-line 30 m sprint (T30), an RSA test (6 x 20 + 20 m with 20 s recovery), a progressive isoinertial loading test in a full squat, a Yo-Yo Intermittent Recovery Test Level-1 (YYIRT-1) and a 20 m shuttle run test (20mSRT). The mean (RSAmean), the fastest (RSAbest), each single sprint time, and the percentage in a sprint decrease (%Dec) in the RSA test were calculated. RSAbest correlated significantly with RSAmean (r = .82) and with all single sprints (p sprints performed increased. No significant relationship was observed between the %Dec and RSA performance. CMJs and the T30 also showed a correlation with RSA performance, whereas lower limb strength did not show any relationship with RSA performance. RSAmean showed significant (p repeated sprints increased. The 20mSRT showed minimal relationships with RSA performance. In conclusion, maximal sprint capacity seems to be relevant for the RSA performance, mainly in the first sprints. However, high intermittent endurance capacity and low adiposity might help enhance the RSA performance when increasing the number of repeated sprints.

  9. Evolution of Determinant Factors of Repeated Sprint Ability

    Directory of Open Access Journals (Sweden)

    Pareja-Blanco Fernando

    2016-12-01

    Full Text Available The aim of this study was to investigate the changes in the relationships between repeated sprint ability (RSA and anthropometric measures as well as fitness qualities in soccer players. Twenty-one professional soccer players performed several anthropometric and physical tests including countermovement vertical jumps (CMJs, a straight-line 30 m sprint (T30, an RSA test (6 x 20 + 20 m with 20 s recovery, a progressive isoinertial loading test in a full squat, a Yo-Yo Intermittent Recovery Test Level-1 (YYIRT-1 and a 20 m shuttle run test (20mSRT. The mean (RSAmean, the fastest (RSAbest, each single sprint time, and the percentage in a sprint decrease (%Dec in the RSA test were calculated. RSAbest correlated significantly with RSAmean (r = .82 and with all single sprints (p < 0.05, showing a downward trend as the number of sprints performed increased. No significant relationship was observed between the %Dec and RSA performance. CMJs and the T30 also showed a correlation with RSA performance, whereas lower limb strength did not show any relationship with RSA performance. RSAmean showed significant (p < 0.05 relationships with body mass (r = .44, adiposity (r = .59 and the YYIRT-1 (r = -.62, increasing as the number of repeated sprints increased. The 20mSRT showed minimal relationships with RSA performance. In conclusion, maximal sprint capacity seems to be relevant for the RSA performance, mainly in the first sprints. However, high intermittent endurance capacity and low adiposity might help enhance the RSA performance when increasing the number of repeated sprints.

  10. Time of day effects on repeated sprint ability.

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    Zarrouk, N; Chtourou, H; Rebai, H; Hammouda, O; Souissi, N; Dogui, M; Hug, F

    2012-12-01

    The present study aimed at investigating the effects of time-of-day on muscle power and associated electromyographic (EMG) activity level of 4 thigh muscles during a repeated pedalling sprint exercise. After a familiarization session, 12 male subjects were asked to perform the repeated sprint ability test during 2 experimental sessions (randomized order), which were set up either at 06:00 or 18:00 h. For each sprint, peak power output, percentage of peak power decrement and total work were calculated. EMG activity of vastus lateralis, rectus femoris, vastus medialis and biceps femoris muscles was recorded throughout the test and analyzed for each sprint. Total work and percentage of peak power decrement were higher in the evening than in the morning (psprints (psprint 1 and psprint 2 and 3). There was no time-of-day effect for EMG activity level. The neuromuscular efficiency decreased significantly over the repeated sprint ability test at the 2 times of testing (prepeated sprint ability test, EMG activity of major thigh muscles was not time-of-day dependent. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Intermittent endurance and repeated sprint ability in soccer players.

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    Chaouachi, Anis; Manzi, Vincenzo; Wong, Del P; Chaalali, Anis; Laurencelle, Louis; Chamari, Karim; Castagna, Carlo

    2010-10-01

    The ability to perform high-intensity intermittent exercise (i.e., Yo-Yo Intermittent Recovery Test [Yo-Yo IR1]) and to repeat sprints with relatively short recovery times (i.e., 20- to 30-seconds, relatively short time interval [repeated sprint ability (RSA)]) has been shown to be relevant fitness variables in soccer. However, though they potentially share common features, it is not known whether these 2 abilities are associated. The aim of this study was to examine the relationships between Yo-Yo IR1 and RSA performances in elite soccer players. Twenty-three soccer players (age 19 ± 1 years, height 181 ± 5.7 cm, body mass 73.2 ± 4.1 kg, %body fat 11 ± 2.4) performed the Yo-Yo IR1 and a test for RSA (7 × 30 m with 25-second recovery). Results were 2,289 ± 409 m, 31.21 ± 1.13 seconds, and 4 ± 2.1% for Yo-Yo IR1, total sprint time, and sprint decrement, respectively. Yo-Yo IR1 showed a significant and moderate relationship with sprint decrement (r² = -0.44, p = 0.04). Splitting the sample into Best and Worst Yo-Yo IR1 performers according to median score (2,320 m), the Best group showed lower RSA total time (30.69 ± 0.99 vs. 31.79 ± 1.06, p Sprint-time deterioration over 30 m occurred earlier (from the second sprint on) in the Yo-YoWorst compared with in the Yo-YoBest group (from the fourth sprint on, p sprint bouts.

  12. Aerobic Capacity is Related to Repeated Sprint Ability with Sprint Distances Less Than 40 Meters

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    SANDERS, GABRIEL J.; TURNER, ZACHARY; BOOS, BRIAN; PEACOCK, COREY A.; PEVELER, WILLARD; LIPPING, ALAR

    2017-01-01

    Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ −0.69, P distances are less than 40 meters.

  13. Repeated-sprint ability - part II: recommendations for training.

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    Bishop, David; Girard, Olivier; Mendez-Villanueva, Alberto

    2011-09-01

    Short-duration sprints, interspersed with brief recoveries, are common during most team sports. The ability to produce the best possible average sprint performance over a series of sprints (≤10 seconds), separated by short (≤60 seconds) recovery periods has been termed repeated-sprint ability (RSA). RSA is therefore an important fitness requirement of team-sport athletes, and it is important to better understand training strategies that can improve this fitness component. Surprisingly, however, there has been little research about the best training methods to improve RSA. In the absence of strong scientific evidence, two principal training theories have emerged. One is based on the concept of training specificity and maintains that the best way to train RSA is to perform repeated sprints. The second proposes that training interventions that target the main factors limiting RSA may be a more effective approach. The aim of this review (Part II) is to critically analyse training strategies to improve both RSA and the underlying factors responsible for fatigue during repeated sprints (see Part I of the preceding companion article). This review has highlighted that there is not one type of training that can be recommended to best improve RSA and all of the factors believed to be responsible for performance decrements during repeated-sprint tasks. This is not surprising, as RSA is a complex fitness component that depends on both metabolic (e.g. oxidative capacity, phosphocreatine recovery and H+ buffering) and neural factors (e.g. muscle activation and recruitment strategies) among others. While different training strategies can be used in order to improve each of these potential limiting factors, and in turn RSA, two key recommendations emerge from this review; it is important to include (i) some training to improve single-sprint performance (e.g. 'traditional' sprint training and strength/power training); and (ii) some high-intensity (80-90% maximal oxygen

  14. Repeated-sprint ability - part I: factors contributing to fatigue.

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    Girard, Olivier; Mendez-Villanueva, Alberto; Bishop, David

    2011-08-01

    Short-duration sprints (ability to recover and to reproduce performance in subsequent sprints is probably an important fitness requirement of athletes engaged in these disciplines, and has been termed repeated-sprint ability (RSA). This review (Part I) examines how fatigue manifests during repeated-sprint exercise (RSE), and discusses the potential underpinning muscular and neural mechanisms. A subsequent companion review to this article will explain a better understanding of the training interventions that could eventually improve RSA. Using laboratory and field-based protocols, performance analyses have consistently shown that fatigue during RSE typically manifests as a decline in maximal/mean sprint speed (i.e. running) or a decrease in peak power or total work (i.e. cycling) over sprint repetitions. A consistent result among these studies is that performance decrements (i.e. fatigue) during successive bouts are inversely correlated to initial sprint performance. To date, there is no doubt that the details of the task (e.g. changes in the nature of the work/recovery bouts) alter the time course/magnitude of fatigue development during RSE (i.e. task dependency) and potentially the contribution of the underlying mechanisms. At the muscle level, limitations in energy supply, which include energy available from phosphocreatine hydrolysis, anaerobic glycolysis and oxidative metabolism, and the intramuscular accumulation of metabolic by-products, such as hydrogen ions, emerge as key factors responsible for fatigue. Although not as extensively studied, the use of surface electromyography techniques has revealed that failure to fully activate the contracting musculature and/or changes in inter-muscle recruitment strategies (i.e. neural factors) are also associated with fatigue outcomes. Pending confirmatory research, other factors such as stiffness regulation, hypoglycaemia, muscle damage and hostile environments (e.g. heat, hypoxia) are also likely to compromise

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

    NARCIS (Netherlands)

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

    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 administe

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

    NARCIS (Netherlands)

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

    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

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

    NARCIS (Netherlands)

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

    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 administe

  18. 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.

  19. Muscle power and repeated sprint ability in soccer players

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    Saray Giovana dos Santos

    2010-06-01

    Full Text Available Muscle power is one of the most important physical qualities of soccer playerperformance and needs to be maintained during a match. Thus, the aim of this study was toinvestigate the levels of muscle power in soccer players before and after performing repeatedsprints (RS, and the association between power and RS performance. Twenty soccer playersfrom the under-20 category aged 18-20 years participated in this study. The study consisted ofthe execution of vertical jumps, execution of RS, new execution of vertical jumps, and collectionof blood samples. The continuous jump (CJ test was performed on a piezoelectric force platformfor the measurement of muscle power and the RAST test was used to evaluate RS ability. Nosignificant difference in the levels of muscle power was observed after RS (p=0.57. Significantdifferences were observed in the first to fifth sprint times (p<0.01, but not between the fifth andsixth sprint (p=0.06. CJ height before RS was correlated with first sprint time (r=-0.62, p<0.01,best sprint time (r=-0.60, p<0.01, and average sprint time (r= -0.54, p<0.01. In conclusion,the soccer players studied showed no significant reduction in muscle power after RS. A decreasein performance was observed from the first to the fifth sprint, but not between the fifth and sixthsprint. The muscle power of soccer players was a determinant factor to perform one maximumsprint, as well as successive sprints.

  20. Repeated-sprint ability and team selection in Australian football league players.

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    Le Rossignol, Peter; Gabbett, Tim J; Comerford, Dan; Stanton, Warren R

    2014-01-01

    To investigate the relationship between selected physical capacities and repeated-sprint performance of Australian Football League (AFL) players and to determine which physical capacities contributed to being selected for the first competition game. Sum of skinfolds, 40-m sprint (with 10-, 20-, 30-, and 40-m splits), repeated-sprint ability (6 × 30-m sprints), and 3-km-run time were measured during the preseason in 20 AFL players. The physical qualities of players selected to play the first match of the season and those not selected were compared. Pearson correlation coefficients were used to determine the relationship among variables, and a regression analysis identified variables significantly related to repeated-sprint performance. In the regression analysis, maximum velocity was the best predictor of repeated-sprint time, with 3-km-run time also contributing significantly to the predictive model. Sum of skinfolds was significantly correlated with 10-m (r = .61, P sprint times. A 2.6% ± 2.1% difference in repeated-sprint time (P repeated-sprint performance in AFL players than short 10- to 20-m intervals from standing starts. Further research is warranted to establish the relative importance of endurance training for improving repeated-sprint performance in AFL football.

  1. Reliability of specific on-ice repeated-sprint ability test for ice-hockey players

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    Karel Hůlka

    2014-06-01

    Full Text Available Background: Repeated sprint ability tests are today widely used to evaluate the performance capability in team sports. Objective: The aim of this study was to determine the reliability of a specific ice hockey test, which indicates the agility and repeated-sprint ability of the players. Methods: Twenty four highly trained junior ice hockey players (age = 17.68 ± 1.52 years; BMI = 23.8 ± 1.92 kg . m-2 participated in the study. Each participant was assessed for specific on-ice repeated-sprint ability test 12 × 54 m with 30 s rest. Intraclass correlation coefficient (association between two repeated measurements and coefficient of variation were calculated to assess the reliability of the test. Results: All intraclass correlation coefficients were .78 for sprint decrement and .98 for total time and the best time, the coefficient of variation was 1.52% for best sprint time, 1.31% for total time and 19.3% for sprint decrement variable. Conclusions: The results suggest the high reliability of the ice hockey agility test expressed by the best sprint time and repeated-sprint ability by the total time and less reliability of sprint decrement.

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

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    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 repeated sprint 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.

  3. The development of a test of repeated-sprint ability for elite women's soccer players.

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    Gabbett, Tim J

    2010-05-01

    The purpose of this study was to develop a game-specific test of repeated-sprint ability for elite women's soccer players. Nineteen elite women's soccer players (mean +/- SD; age, 18.1 +/- 2.9 y) participated in this study. After familiarization, players completed a repeated-sprint test consisting of 6 x 20-m maximal effort sprints, on a 15-second cycle. At the completion of each sprint, players performed a 10-m deceleration and a 10-m active jog recovery. Ten elite female soccer players performed the test on 2 occasions, 1 week apart, to determine the reliability of the test. In addition, the validity of the repeated-sprint test to discriminate among players of different playing ability was evaluated by testing national (n = 11) and state (n = 8) women's soccer players. Heart rate and blood lactate concentration were recorded to determine the physiological responses to the test. The total sprint time proved to be highly reproducible (intraclass correlation coefficient = 0.91; typical error of measurement = 1.5%). However, the percentage decrement was less reliable (intraclass correlation coefficient = 0.14, typical error of measurement = 19.5%). The repeated-sprint test was valid in discriminating between national- and state-level players, with national players having significantly lower (p repeated-sprint times than state players (20.9 +/- 0.5 s vs. 23.3 +/- 0.4 s). The mean (+/-SD) heart rate and blood lactate concentration were 182 +/- 6 beats/min and 9.3 +/- 2.0 mmol/L, respectively. The results of this study demonstrate that the developed repeated-sprint test discriminates players of higher and lesser skill levels and offers a reliable method of assessing repeated-sprint ability in elite women's soccer players when results are expressed as the total sprint time.

  4. Relationship between Repeated Sprint Ability and Aerobic Capacity in Professional Soccer Players

    Directory of Open Access Journals (Sweden)

    Rhys M. Jones

    2013-01-01

    Full Text Available Aim. The aim of the present study was to investigate the relationship between maximal aerobic capacity ( and repeated sprint ability (RSA in a group of professional soccer players. Methods. Forty-one professional soccer players (age  yrs, height  cm, weight  kg were required to perform tests to assess RSA and on two separate days with at least 48 hr rest between testing sessions. Each player performed a treadmill test to determine their and a test for RSA involving the players completing  m sprints (turn after 20 m with 20 s active recovery between each sprint. Results. There was a significant negative correlation between body mass normalised and mean sprint time ( (; and total sprint time ( (, . Conclusion. Results of the current study indicate that is one important factor aiding soccer players in the recovery from repeated sprint type activities.

  5. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability

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    Goods, Paul S.R.; Dawson, Brian; Landers, Grant J.; Gore, Christopher J.; Peeling, Peter

    2015-01-01

    To assess the impact of ‘top-up’ normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, ‘top-up’ training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this ‘top-up’ training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the ‘top-up’ training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points ‘Top-up’ repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players. The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.

  6. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability.

    Science.gov (United States)

    Goods, Paul S R; Dawson, Brian; Landers, Grant J; Gore, Christopher J; Peeling, Peter

    2015-09-01

    To assess the impact of 'top-up' normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, 'top-up' training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this 'top-up' training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the 'top-up' training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points'Top-up' repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players.The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.'Top-up' cycling repeat-sprint training

  7. Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players.

    Science.gov (United States)

    Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter; Fenarnandes-da-Silva, Juliano; Póvoas, Susana C A; Bernardini, Andrea; D'Ottavio, Stefano

    2017-07-28

    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-term reliability ICCs and TEMs for total sprint time and best sprint performance were nearly perfect and satisfactory, respectively. Usefulness (as smallest worthwhile change and TEM ratio) resulted acceptable (i.e =1) and good (i.e >1) for total sprint time and best sprint performance, respectively. The present 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.

  8. Age-related differences in repeated-sprint ability in highly trained youth football players.

    Science.gov (United States)

    Mujika, Inigo; Spencer, Matt; Santisteban, Juanma; Goiriena, Juan Jose; Bishop, David

    2009-12-01

    In this study, we investigated the age-related differences in repeated-sprint ability and blood lactate responses in 134 youth football players. Players from the development programme of a professional club were grouped according to their respective under-age team (U-11 to U-18). Following familiarization, the participants performed a repeated-sprint ability test [6 x 30-m sprints 30 s apart, with active recovery (2.0-2.2 m . s(-1)) between sprints]. The test variables were total time, percent sprint decrement, and post-test peak lactate concentration. Total time improved from the U-11 to U-15 age groups (range 33.15 +/- 1.84 vs. 27.25 +/- 0.82 s), whereas no further significant improvements were evident from U-15 to U-18. No significant differences in percent sprint decrement were reported among groups (range 4.0 +/- 1.0% to 5.5 +/- 2.1%). Post-test peak lactate increased from one age group to the next (range 7.3 +/- 1.8 to 12.6 +/- 1.6 mmol . l(-1)), but remained constant when adjusted for age-related difference in body mass. Peak lactate concentration was moderately correlated with sprint time (r = 0.70, P > 0.001). Our results suggest that performance in repeated-sprint ability improves during maturation of highly trained youth football players, although a plateau occurs from 15 years of age. In contrast to expectations based on previous suggestions, percent sprint decrement during repeated sprints did not deteriorate with age.

  9. The relationship between repeated sprint ability and the aerobic and anaerobic energy systems.

    Science.gov (United States)

    Wadley, G; Le Rossignol, P

    1998-06-01

    A large number of team games require participants to repeatedly produce maximal or near maximal sprints of short duration with brief recovery periods. The purpose of the present study was to determine the relationship between a repeated sprint ability (RSA) test that is specific to the energy demands of Australian Rules football (ARF), and the aerobic and anaerobic energy systems. Seventeen ARF players participated in the study. Each participant was assessed for VO2 max, accumulated oxygen deficit (AOD), best 20 m sprint time and RSA. The RSA test involved 12x20 m sprints departing every 20 s. When including the work performed during the time taken to decelerate, the test involved a work to rest ratio of approximately 1:3. Total sprinting time and the percentage decrement of repeated sprinting times were the two derived measures of RSA. The results indicate that the best 20 m sprint time was the only factor to correlate significantly with total sprinting time (r = 0.829, P RSA test. This was interpreted to signify that the phosphagen system was the major energy contributor for this test.

  10. Effects of Sprint Training With and Without Weighted Vest on Speed and Repeated Sprint Ability in Male Soccer Players.

    Science.gov (United States)

    Rey, Ezequiel; Padrón-Cabo, Alexis; Fernández-Penedo, Diego

    2016-11-16

    The purpose of this study was to assess the effect resisted sprint training using weighted vests (WV) compared with unresisted sprint training (US) on physical fitness (countermovement jump, 10 m sprint, 30 m sprint and repeated sprint ability (RSA)) in amateur male soccer players. 19 soccer players (age: 23.7±4.5 years; height: 178.3±5.8 cm; body mass: 72.9±5.2 kg) were randomly assigned to a WV (n= 10) or a US (n= 9) group. The intervention program had to be carried out 2 times a week over 6 weeks. The only difference between the two interventions was that the WV group performed all the sprints with an additional weight of 18.9% ± 2.1% of body mass. Within-group analysis showed significant improvements (psprint performance from pretest to post-test in WB (+9.42% and +6.04%) and CTU (+10.87% and +5.10%). Players in both WV and US also showed significant enhancements in RSA average time, fastest time, and total time from pretest to posttest. Percentage changes in 30 m sprint performance, for both groups combined, had a very large correlation with percentage changes in average time of RSA. In the between-groups analysis, there were no differences between the sprint training groups (WV vs US) in any variable. In conclusion, the findings of this study indicate that both sprint training methods used seem to be effective to improve soccer related performance measures, and could be beneficial to players and coaches in field settings.

  11. Avaliação da capacidade de realizar sprints repetidos no futebol Repeated sprint ability evaluation in soccer

    Directory of Open Access Journals (Sweden)

    Henrique Bortolotti

    2010-12-01

    Full Text Available A maioria dos esportes coletivos (ex.: futebol, basquete, handebol tem como característica a intermitência, flutuando entre breves períodos de esforços máximos ou próximos ao máximo seguidos de períodos e formas de recuperação. Alguns autores têm proposto diversos testes que tem por finalidade mensurar a capacidade desses atletas em realizar esforços repetidos máximos (RSA, a qual estaria diretamente relacionada aos momentos decisivos durante partida. Dessa forma, o presente estudo teve como objetivo descrever os diferentes protocolos de testes para avaliar a RSA em jogadores de futebol, com base em artigos originais e algumas revisões levantadas na base de dados Medline. Diante dos achados, sugerimos a utilização de quatro protocolos, dois envolvendo sprints lineares (AZIZ et al., 2008; REILLY, 2001 e dois utilizando sprints com mudanças de direção (BANGSBO, 2008; IMPELLIZZERI et al., 2008 para avaliação da RSA em jogadores de futebol, gerando importantes parâmetros de desempenho, que permitem ainda a elaboração de programas de treinamento para a melhora dessa capacidade. Recomendamos ainda, a utilização do tempo médio e/ou total como uma medida geral da capacidade de realizar sprints repetidos e as parciais de tempo de cada sprint para identificar possíveis pontos fortes e fraco de cada atleta.The most of team sports (soccer, basketball, handball is characterized by intermittency, fluctuating between brief periods of maximum effort or near the maximum followed by periods and forms of recovery. Some authors have proposed several tests to measure the ability of these athletes to perform repeated sprints (repeated sprint ability - RSA, which would be directly related to the decisive moments during match. Then, this study aimed to describe the different test protocols to assess RSA in soccer players, based on original articles and reviews selected in some databases (Medline. Therefore, we suggest four protocols, two

  12. The effect of an official match on repeated sprint ability in junior basketball players.

    Science.gov (United States)

    Caprino, Davide; Clarke, Neil David; Delextrat, Anne

    2012-01-01

    The aim of this study was to investigate the effect of an official basketball match on repeated sprint ability indices in male junior players. Ten (16 ± 1 years old; 183.6 ± 7.0 cm; 76.6 ± 8.0 kg) starting players for their teams performed three repeated sprint ability tests, before, at half-time and immediately after an official match. Each repeated sprint ability test consisted of 10 shuttle-run sprints of 30 m (15 + 15 m) separated by 30 seconds of passive recovery. The matches were video-taped to determine the frequency of eight types of movement patterns, and blood lactate concentration was measured before and immediately after each repeated sprint ability test. Differences in total time, ideal time and percentage decrement between tests was assessed by a one-way analysis of variance (ANOVA) with repeated measures, while a two-way ANOVA with repeated measures was used to identify differences in blood lactate concentration. The main results indicated a significant decrease in total movement frequency (-9.9%), high-intensity activity frequency (-13.3%), run frequency (-13.0%) and sprint frequency (-23.3%) in the second compared to the first half, and significantly worse total time and ideal time at the end of the match, compared to the start and half-time (differences ranging from -2.1% to -2.9%, P < 0.05). The practical implications of these findings suggest that regional basketball players should participate in conditioning sessions that focus on the improvement of repeated sprint ability.

  13. Improving acceleration and repeated sprint ability in well-trained adolescent handball players: speed versus sprint interval training.

    Science.gov (United States)

    Buchheit, Martin; Mendez-Villanueva, Alberto; Quod, Marc; Quesnel, Thomas; Ahmaidi, Said

    2010-06-01

    The aim of the current study was to compare the effects of speed/agility (S/A) training with sprint interval training (SIT) on acceleration and repeated sprint ability (RSA) in well-trained male handball players. In addition to their normal training program, players performed either S/A (n = 7) or SIT (n = 7) training for 4 wk. Speed/agility sessions consisted of 3 to 4 series of 4 to 6 exercises (eg, agility drills, standing start and very short sprints, all of Sprint interval training consisted of 3 to 5 repetitions of 30-s all-out shuttle sprints over 40 m, interspersed with 2 min of passive recovery. Pre- and posttests included a countermovement jump (CMJ), 10-m sprint (10m), RSA test and a graded intermittent aerobic test (30-15 Intermittent Fitness Test, V(IFT)). S/A training produced a very likely greater improvement in 10-m sprint (+4.6%, 90% CL 1.2 to 7.8), best (+2.7%, 90% CL 0.1 to 5.2) and mean (+2.2%, 90% CL -0.2 to 4.5) RSA times than SIT (all effect sizes [ES] greater than 0.79). In contrast, SIT resulted in an almost certain greater improvement in V(IFT) compared with S/A (+5.2%, 90% CL 3.5 to 6.9, with ES = -0.83). In well-trained handball players, 4 wk of SIT is likely to have a moderate impact on intermittent endurance capacity only, whereas S/A training is likely to improve acceleration and repeated sprint performance.

  14. Specific Measurement of Tethered Running Kinetics and its Relationship to Repeated Sprint Ability.

    Science.gov (United States)

    Sousa, Filipe; Dos Reis, Ivan; Ribeiro, Luiz; Martins, Luiz; Gobatto, Claudio

    2015-12-22

    Repeated sprint ability has been widely studied by researchers, however, analysis of the relationship between most kinetic variables and the effect of fatigue is still an ongoing process. To search for the best biomechanical parameter to evaluate repeated sprint ability, several kinetic variables were measured in a tethered field running test and compared regarding their sensitivity to fatigue and correlation with time trials in a free running condition. Nine male sprint runners (best average times: 100 m = 10.45 ± 0.07 s; 200 m = 21.36 ± 0.17 s; 400 m = 47.35 ± 1.09 s) completed two test sessions on a synthetic track. Each session consisted of six 35 m sprints interspersed by 10 s rest under tethered field running or free running conditions. Force, power, work, an impulse and a rate of force development were all directly measured using the sensors of a new tethered running apparatus, and a one-way ANOVA with Scheffé post-hoc test used to verify differences between sprints (p sprints. These three variables presented low to moderate correlations with free running performance (r between 0.01 and -0.35). Maximum and mean power presented the strongest correlations with free running performance (r = -0.71 and -0.76, respectively; p sprint ability than the other studied variables.

  15. 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 (P<0.05) were observed. Strong inverse correlation was found between CMJ and RSAtot (r=-0.74, P<0.01). No significant correlation was found between VO2max and RSA outcomes neither between CMJ and RSAFI. CMJ is a predictor of RSA in elite basketball 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.

  16. Fitness determinants of repeated-sprint ability in highly trained youth football players.

    Science.gov (United States)

    Spencer, Matt; Pyne, David; Santisteban, Juanma; Mujika, Iñigo

    2011-12-01

    Variations in rates of growth and development in young football players can influence relationships among various fitness qualities. To investigate the relationships between repeated-sprint ability and other fundamental fitness qualities of acceleration, agility, explosive leg power, and aerobic conditioning through the age groups of U11 to U18 in highly trained junior football players. Male players (n = 119) across the age groups completed a fitness assessment battery over two testing sessions. The first session consisted of countermovement jumps without and with arm swing, 15-m sprint run, 15-m agility run, and the 20-m Shuttle Run (U11 to U15) or the Yo-Yo Intermittent Recovery Test, Level 1 (U16 to U18). The players were tested for repeated-sprint ability in the second testing session using a protocol of 6 × 30-m sprints on 30 s with an active recovery. The correlations of repeated-sprint ability with the assorted fitness tests varied considerably between the age groups, especially for agility (r = .02 to .92) and explosive leg power (r = .04 to .84). Correlations of repeated sprint ability with acceleration (r = .48 to .93) and aerobic conditioning (r = .28 to .68) were less variable with age. Repeated-sprint ability associates differently with other fundamental fitness tests throughout the teenage years in highly trained football players, although stabilization of these relationships occurs by the age of 18 y. Coaches in junior football should prescribe physical training accounting for variations in short-term disruptions or impairment of physical performance during this developmental period.

  17. Are "classical" tests of repeated-sprint ability in football externally valid? A new approach to determine in-game sprinting behaviour in elite football players.

    Science.gov (United States)

    Schimpchen, Jan; Skorski, Sabrina; Nopp, Stephan; Meyer, Tim

    2016-01-01

    The aim of this study was to investigate the occurrence of repeated sprinting bouts in elite football. Furthermore, the construct validity of current tests assessing repeated-sprint ability (RSA) was analysed using information of sprinting sequences as they actually occurred during match-play. Sprinting behaviour in official competition was analysed for 19 games of the German national team between August 2012 and June 2014. A sprinting threshold was individually calculated based on the peak velocity reached during in-game sprinting. Players performed 17.2 ± 3.9 sprints per game and during the entire 19 games a total of 35 bouts of repeated sprinting (a minimum of three consecutive sprints with a recovery duration repeated sprinting per player every 463 min. No general decrement in maximal sprinting speed was observed during bouts with up to five consecutive sprints. Results of the present study question the importance of RSA as it is classically defined. They indicate that shorter accelerations are more important in game-specific situations which do not reach speeds necessary to qualify them as sprints. The construct validity of classic tests of RSA in football is not supported by these observations.

  18. Specific Measurement of Tethered Running Kinetics and its Relationship to Repeated Sprint Ability

    Directory of Open Access Journals (Sweden)

    Sousa Filipe

    2015-12-01

    Full Text Available Repeated sprint ability has been widely studied by researchers, however, analysis of the relationship between most kinetic variables and the effect of fatigue is still an ongoing process. To search for the best biomechanical parameter to evaluate repeated sprint ability, several kinetic variables were measured in a tethered field running test and compared regarding their sensitivity to fatigue and correlation with time trials in a free running condition. Nine male sprint runners (best average times: 100 m = 10.45 ± 0.07 s; 200 m = 21.36 ± 0.17 s; 400 m = 47.35 ± 1.09 s completed two test sessions on a synthetic track. Each session consisted of six 35 m sprints interspersed by 10 s rest under tethered field running or free running conditions. Force, power, work, an impulse and a rate of force development were all directly measured using the sensors of a new tethered running apparatus, and a one-way ANOVA with Scheffé post-hoc test used to verify differences between sprints (p < 0.05. Pearson product-moment correlation measured the relationship between mechanical variables and free running performance. A total impulse, the rate of force development and maximum force did not show significant differences for most sprints. These three variables presented low to moderate correlations with free running performance (r between 0.01 and -0.35. Maximum and mean power presented the strongest correlations with free running performance (r = -0.71 and -0.76, respectively; p < 0.001, followed by mean force (r = -0.61; p < 0.001 and total work (r = -0.50; p < 0.001. It was concluded that under a severe work-to-rest ratio condition, power variables were better suited to evaluating repeated sprint ability than the other studied variables.

  19. Effects of sodium phosphate and beetroot juice supplementation on repeated-sprint ability in females.

    Science.gov (United States)

    Buck, Christopher L; Henry, Timothy; Guelfi, Kym; Dawson, Brian; McNaughton, Lars R; Wallman, Karen

    2015-10-01

    Sodium phosphate (SP) and beetroot juice (BJ) supplementation was assessed on repeated-sprint ability (RSA). Thirteen female team-sport participants completed four trials: (1) SP and BJ (SP + BJ), (2) SP and placebo (for BJ), (3) BJ and placebo (for SP) and (4) placebo (for SP + BJ), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (STGC) consisting of four 15 min quarters, with a 6 × 20-m repeated-sprint set performed at the start, half-time and end. Total sprint times were between 0.95-1.30 and 0.83-1.12 s faster for each RSA set and 3.25 and 3.12 s faster overall (~5% improvement) after SP compared with placebo and BJ, respectively (p = 0.02 for sets 1, 2 and overall; Cohen's effect size: d = -0.51 to -0.90 for all sets and overall). Additionally, total sprint times were 0.48 s faster after SP + BJ compared with placebo (set 2; p = 0.05, ~2% improvement). Furthermore, best sprints were 0.13-0.23 and 0.15-0.20 s faster (~6% improvement; p sprint times were faster after SP compared with placebo and BJ.

  20. Relationship between repeated sprint ability and aerobic capacity in professional soccer players.

    Science.gov (United States)

    Jones, Rhys M; Cook, Christian C; Kilduff, Liam P; Milanović, Zoran; James, Nic; Sporiš, Goran; Fiorentini, Bruno; Fiorentini, Fredi; Turner, Anthony; Vučković, Goran

    2013-01-01

    The aim of the present study was to investigate the relationship between maximal aerobic capacity (VO(2max)) and repeated sprint ability (RSA) in a group of professional soccer players. Forty-one professional soccer players (age 23 ± 4 yrs, height 180.0 ± 5.3 cm, weight 79.6 ± 5.3 kg) were required to perform tests to assess RSA and VO(2max) on two separate days with at least 48 hr rest between testing sessions. Each player performed a treadmill test to determine their VO(2max) and a test for RSA involving the players completing 6 × 40 m sprints (turn after 20 m) with 20 s active recovery between each sprint. There was a significant negative correlation between body mass normalised VO(2max) and mean sprint time (RSAmean) (r = -0.655; P sprint time (RSAtotal) (r = -0.591, P repeated sprint type activities.

  1. Relationship between Repeated Sprint Ability and Aerobic Capacity in Professional Soccer Players

    Science.gov (United States)

    Jones, Rhys M.; Cook, Christian C.; Kilduff, Liam P.; Milanović, Zoran; James, Nic; Sporiš, Goran; Fiorentini, Bruno; Fiorentini, Fredi; Turner, Anthony; Vučković, Goran

    2013-01-01

    Aim. The aim of the present study was to investigate the relationship between maximal aerobic capacity (VO2 max) and repeated sprint ability (RSA) in a group of professional soccer players. Methods. Forty-one professional soccer players (age 23 ± 4 yrs, height 180.0 ± 5.3 cm, weight 79.6 ± 5.3 kg) were required to perform tests to assess RSA and VO2 max on two separate days with at least 48 hr rest between testing sessions. Each player performed a treadmill test to determine their VO2 max and a test for RSA involving the players completing 6 × 40 m sprints (turn after 20 m) with 20 s active recovery between each sprint. Results. There was a significant negative correlation between body mass normalised VO2 max and mean sprint time (RSAmean) (r = −0.655; P < 0.01) and total sprint time (RSAtotal) (r = −0.591, P < 0.01). Conclusion. Results of the current study indicate that VO2 max is one important factor aiding soccer players in the recovery from repeated sprint type activities. PMID:24198732

  2. Effects of sodium phosphate and caffeine loading on repeated-sprint ability.

    Science.gov (United States)

    Buck, Christopher; Guelfi, Kym; Dawson, Brian; McNaughton, Lars; Wallman, Karen

    2015-01-01

    The effects of sodium phosphate and caffeine supplementation were assessed on repeated-sprint ability. Using a randomised, double-blind, Latin-square design, 12 female, team-sport players participated in four trials: (1) sodium phosphate and caffeine, (2) sodium phosphate and placebo (for caffeine), (3) caffeine and placebo (for sodium phosphate) and (4) placebo (for sodium phosphate and caffeine), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (4 × 15 min quarters) with 6 × 20-m repeated-sprints performed once before (Set 1), at half-time (Set 2), and after end (Set 3). Total sprint times were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 1: P = 0.003; Set 2: d = -0.51; Set 3: P sprint times were faster after sodium phosphate supplementation compared with placebo (Set 1: d = -0.52; Set 3: d = -0.58). Best sprint results were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 3: P = 0.007, d = -0.90) and caffeine (Set 3: P = 0.024, d = -0.73). Best sprint times were also faster after sodium phosphate supplementation compared with placebo (d = -0.54 to -0.61 for all sets). Sodium phosphate and combined sodium phosphate and caffeine loading improved repeated-sprint ability.

  3. Reliability, usefulness, and validity of a repeated sprint and jump ability test.

    Science.gov (United States)

    Buchheit, Martin; Spencer, Matt; Ahmaidi, Said

    2010-03-01

    Two studies involving 122 handball players were conducted to assess the reliability, usefulness, and validity of a repeated shuttle-sprint and jump ability (RSSJA) test. The test consisted of 6x(2x12.5-m) sprints departing on 25 s, with a countermovement jump performed during recovery between sprints. For the reliability and usefulness study, 14 well-trained male handball players performed the RSSJA test 7 d apart. Reliability of the test variables was assessed by the typical error of measurement, expressed as a coefficient of variation (CV). The minimal changes likely to be "real" in sprint time and jump power were also calculated. For the validity study, players of seven teams (national to international levels, women and men) performed the RSSJA test. CV values for best and mean sprint time were 1.0% (90% CL, 0.7 to 1.6) and 1.0% (90% CL, 0.7 to 1.4). CV values for best and mean jump peak power were 1.7% (90% CL, 1.2 to 2.7) and 1.5% (90% CL, 1.1 to 2.5). The percent sprint and jump decrements were less reliable, with CVs of 22.3% (90% CL, 15.7 to 38.3) and 34.8% (90% CL, 24.2 to 61.8). Minimal changes likely to be "real" for mean sprint time and jumping peak power were -2.6% and 4.8%. Qualitative analysis revealed that the majority of between-team differences were rated as "almost certain" (ie, 100% probability that the true differences were meaningful) for mean sprint and jump performances. The RSSJA test is reliable and valid to assess repeated explosive effort sequences in team sports such as handball. Test results are likely to be representative of gender and competition level; thus the test could be used to discriminate across playing standards and monitor fitness levels.

  4. Relationship among Repeated Sprint Ability, Chronological Age and Puberty in young soccer players.

    Science.gov (United States)

    Perroni, Fabrizio; Pintus, Antonio; Frandino, Mattia; Guidetti, Laura; Baldari, Carlo

    2016-01-20

    The aim of this study was to analyzed the relationship of Repeated Sprinting Ability (RSA) with chronological age and puberty in 100 young soccer players (Age: 13 ± 3 yr - 160 ± 33 month-; High: 159 ± 16 cm, Weight: 49.7 ± 14.1 kg; BMI 19.2 ± 2.5 kg/m) grouped on "Pulcini" (9 - 10 yrs), "Esordienti" (11 - 12 yrs), "Giovanissimi" (13 - 14 yrs), "Allievi" (15 - 16 yrs) and "Juniores" (> 17 yrs) categories. Anthropometric (Weight, Height, BMI), RSA (7x30 m sprint with 25s active rest: Total Time -TT, the lowest sprinting time (LST) and the fatigue index percentage -%IF), and Development (Self-Administered Rating Scale for pubertal development - PDS; Puberty) parameters were measured. ANOVA among categories was applied to asses differences (pinjury and overtraining during the different phases of growth and maturation.

  5. Repeated sprint ability in soccer players: associations with physiological and neuromuscular factors.

    Science.gov (United States)

    Baldi, Marcelo; DA Silva, Juliano F; Buzzachera, Cosme F; Castagna, Carlo; Guglielmo, Luiz G

    2017-01-01

    The aim of this study was to examine the relationship between repeated sprint ability (RSA, 6×40 m [20+20 m] with 20-s recovery) and neuromuscular and aerobic fitness variables in male collegiate soccer players. Twenty-six players (age 22.5±3.6 years) were tested on separate days for countermovement jump (CMJ), squat jump (SJ), and standing long jump (LJ), and for maximal oxygen consumption (V̇O2max), velocity at onset of blood lactate accumulation (vOBLA), maximal aerobic speed (vV̇O2max), and peak blood lactate concentration (peak [La]). They were also tested for best and mean times on a repeated shuttle sprint ability test. RSA best time (r=-0.73 and r=-0.54) and RSA mean sprint time (r=-0.69 and r=-0.62) were significantly (Psprint time and sprint decrement with vOBLA (r=-0.44) and peak [La] (r=0.47), respectively. This study showed that RSA performance had a large to very large association with the individual level of jump performance and to a smaller extent to aerobic fitness variables in male collegiate soccer players. Given this finding, lower limbs' explosive-strength performance should be regarded as a relevant factor for male soccer.

  6. Sympathetic enhancement in futsal players but not in football players after repeated sprint ability test

    OpenAIRE

    Chen, Yung-Sheng; Liao, Chih-Jung; Lu, Wan-An; Kuo, Cheng-Deng

    2015-01-01

    Background Heart rate variability (HRV) can disclose the specific adaptation of sympathovagal modulation to exercise. This study investigated the change in HRV measures after anaerobic and aerobic intermittent exercises in university football and futsal players. Method 36 male university students with physically active lifestyle (n=14), football (n=12), and futsal (n=10) participated in this study. The participants completed the repeated sprint ability (RSA) test and Yo-Yo (YY) intermittent r...

  7. The relationship between short- and long-distance swimming performance and repeated sprint ability.

    Science.gov (United States)

    Meckel, Yoav; Bishop, David J; Rabinovich, Moran; Kaufman, Leonid; Nemet, Dan; Eliakim, Alon

    2012-12-01

    The purpose of this study was to determine indices of repeated sprint ability (RSA) during a repeated sprint swimming test (RST), to compare these with previous similar running and cycling RST, and to correlate these indices with the best short (100 m, as an index of anaerobic performance) and long (2,000 m, as an index of aerobic performance) distance swimming times in 20 elite, national team level, male swimmers. Indices of RSA included the ideal sprint time (IS), the total sprint time (TS), and the performance decrement (PD) recorded during an 8 × 15-m swimming RST. The PD during the present swimming RST (4.7 ± 2.3%) was similar to that in previous running or cycling RSTs. However, the physiological responses after the swimming RST (heart rate 168 ± 7 b·min(-1) and blood lactate concentration 5.5 ± 2.0 mmol·L(-1)) were lower than typical responses after running or cycling RSTs. There was no significant relationship between any of the RST performance indices and either the 100-m or 2,000-m swimming results. Multiple regression analysis indicated that the 3 RST indices (IS, TS, and PD), contributed 36% of the variance of the 2,000-m, but not the 100-m, swimming time. A strong correlation was found between the 100- and 2,000-m swim times (r = 0.74, p 100- and 2,000-m swim times is unique for swimming.

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

    Directory of Open Access Journals (Sweden)

    Sultan

    2016-04-01

    Full Text Available 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 trained and untrained group, respectively. The groups were tested using Yo-Yo intermittent recovery test level 1 (YIRT1 and maximum oxygen uptake (VO2max was calculated using a formula from distance covered in YIRT1. Groups performed a repeated sprint ability (RSA, 6x6 s of Wingate test protocol + 30 s of rest test after 48 h. Blood lactate level and heart rate of groups were recorded at rest, immediately, 5, 15, and 30 min after RSA test. The absolute peak power and relative mean power in repeated sprints and the VO2max values were significantly higher in trained group than in untrained group (p<0.05. The absolute values of mean power was also significantly higher in trained group compared to that of the untrained group, except for the first sprint (p<0.05. On the other hand, it was observed that blood lactate level at 30 min and heart rate at 15 and 30 min of the recovery after testing was significantly lower in trained group than those of untrained group (p<0.05. The performance and metabolic results showed that VO2max level would be effective both in maintaining repeated sprint ability performance and for the acceleration of the recovery period.

  9. Laboratory Determinants of Repeated-Sprint and Sport-Specific-Technique Ability in World-Class Ice Sledge Hockey Players.

    Science.gov (United States)

    Baumgart, Julia Kathrin; Sandbakk, Øyvind

    2016-03-01

    To investigate on-ice repeated-sprint and sports-specific-technique abilities and the relationships to aerobic and anaerobic off-ice capacities in world-class ice sledge hockey players. Twelve Norwegian national team players performed 8 repeated maximal 30-m sprints and a sports-specific-technique test while upper-body poling on ice, followed by 4 maximal upper-body strength tests and 8-s peak power and 3-min peak aerobic-capacity (VO2peak) tests while ergometer poling. The fastest 30-m sprint time was 6.5 ± 0.4 s, the fastest initial 10-m split-time 2.9 ± 0.2 s, and the corresponding power output 212 ± 37 W. Average 30-m time during the 8 repeated sprints was 6.7 ± 0.4 s, and the sprint-time decrement was 4.3% ± 1.8%. Time to execute the sport-specific-technique test was 25.6 ± 2.7 s. Averaged 1-repetition-maximum strength of the 4 exercises correlated with the fastest 30-m sprint time (r = -.77), the fastest initial 10-m split time (r = -.72), the corresponding power output (r = .67), and the average 30-m sprint time (r = -.84) (all P sprint test correlated with the highest initial 10-m power (r = .83, P sprint time (r = -.68, P sprint-time decrement. All off-ice variables except VO2peak correlated with technique-test time (r = -.58 to .73, all P ability to sprint fast and rapid execution of a technically complex test, whereas mode-specific endurance capacity is particularly important for maintenance of sprint ability in ice sledge hockey.

  10. Altering Work to Rest Ratios Differentially Influences Fatigue Indices During Repeated Sprint Ability Testing.

    Science.gov (United States)

    La Monica, Michael B; Fukuda, David H; Beyer, Kyle S; Hoffman, Mattan W; Miramonti, Amelia A; Riffe, Josh J; Baker, Kayla M; Fragala, Maren S; Hoffman, Jay R; Stout, Jeffrey R

    2016-02-01

    This study examined the influence of recovery time on fatigue indices, performance (total work [TW], peak power [PP], and mean power [MP]), and oxygen consumption during repeated sprint ability (RSA) on a cycle ergometer. Eight recreationally-trained men performed 3 RSA protocols consisting of 10 × 6 s sprints with 12 s, 18 s, and 24 s rest intervals between each sprint. Fatigue indices were determined as percent decrement (%Dec) and rate of decline using either a log transform method or standard slope approach for TW, PP, and MP during respective RSA protocols. The maximal VO2 value in response to given sprint intervals and the minimal VO2 value in response to given rest periods (VO2 work and VO2 rest, respectively) were recorded. A repeated measures analysis of variance was used to analyze all variables. Average VO2 work was not different among rest interval trials. Average VO2 rest with 12 s rest was greater than 18 s and 24 s (2.16 ± 0.17 L · min(-1), 1.91 ± 0.18 L · min(-1), 1.72 ± 0.15 L · min(-1), respectively), while 18 s was greater than 24 s. Average TW and MP were greater with 24 s rest than 12 s (4,604.44 ± 915.98 J vs. 4,305.46 ± 727.17 J, respectively), with no differences between RSA protocols for PP. No differences in %Dec were observed. Both methods of calculating rates of decline per sprint for PP and TW were greater during 12 s than 18 s or 24 s. Since changes were only noted between the 12 s and 24 s protocols, a 6 s differential in rest intervals may not be enough to elicit alterations in TW, PP, MP, or %Dec in RSA performance. Rate of decline may be a more sensitive measure of fatigue than %Dec.

  11. Aerobic and anaerobic determinants of repeated sprint ability in team sports athletes.

    Science.gov (United States)

    Gharbi, Z; Dardouri, W; Haj-Sassi, R; Chamari, K; Souissi, N

    2015-09-01

    The aim of this study was to examine in team sports athletes the relationship between repeated sprint ability (RSA) indices and both aerobic and anaerobic fitness components. Sixteen team-sport players were included (age, 23.4 ± 2.3 years; weight, 71.2 ± 8.3 kg; height, 178 ± 7 cm; body mass index, 22.4 ± 2 kg · m(-2); estimated VO2max, 54.16 ± 3.5 mL · kg(-1) · min(-1)). Subjects were licensed in various team sports: soccer (n = 8), basketball (n = 5), and handball (n = 3). They performed 4 tests: the 20 m multi-stage shuttle run test (MSRT), the 30-s Wingate test (WingT), the Maximal Anaerobic Shuttle Running Test (MASRT), and the RSA test (10 repetitions of 30 m shuttle sprints (15 + 15 m with 180° change of direction) with 30 s passive recovery in between). Pearson's product moment of correlation among the different physical tests was performed. No significant correlations were found between any RSA test indices and WingT. However, negative correlations were found between MASRT and RSA total sprint time (TT) and fatigue index (FI) (r = -0.53, p sprint time (PT) and total sprint time (TT) was found. Nevertheless, VO2max was significantly correlated with the RSA FI (r = -0.57, p ability to resist fatigue during RSA exercise. Our results highlighted the usefulness of MASRT, in contrast to WingT, as a specific anaerobic testing procedure to identify the anaerobic energy system contribution during RSA.

  12. Aerobic and anaerobic determinants of repeated sprint ability in team sports athletes

    Directory of Open Access Journals (Sweden)

    Z Gharbi

    2015-09-01

    Full Text Available The aim of this study was to examine in team sports athletes the relationship between repeated sprint ability (RSA indices and both aerobic and anaerobic fitness components. Sixteen team-sport players were included (age, 23.4 ± 2.3 years; weight, 71.2 ± 8.3 kg; height, 178 ± 7 cm; body mass index, 22.4 ± 2 kg · m -2 ; estimated VO 2 max, 54.16 ± 3.5 mL · kg-1 · min-1. Subjects were licensed in various team sports: soccer (n = 8, basketball (n = 5, and handball (n = 3. They performed 4 tests: the 20 m multi-stage shuttle run test (MSRT, the 30-s Wingate test (WingT, the Maximal Anaerobic Shuttle Running Test (MASRT, and the RSA test (10 repetitions of 30 m shuttle sprints (15 + 15 m with 180° change of direction with 30 s passive recovery in between. Pearson’s product moment of correlation among the different physical tests was performed. No significant correlations were found between any RSA test indices and WingT. However, negative correlations were found between MASRT and RSA total sprint time (TT and fatigue index (FI (r = -0.53, p < 0.05 and r = -0.65, p < 0.01, respectively. No significant relationship between VO 2 max and RSA peak sprint time (PT and total sprint time (TT was found. Nevertheless, VO 2 max was significantly correlated with the RSA FI (r = -0.57, p < 0.05. In conclusion, aerobic fitness is an important factor influencing the ability to resist fatigue during RSA exercise. Our results highlighted the usefulness of MASRT, in contrast to WingT, as a specific anaerobic testing procedure to identify the anaerobic energy system contribution during RSA.

  13. Repeated sprint ability in young soccer players at different game stages.

    Science.gov (United States)

    Meckel, Yoav; Einy, Avner; Gottlieb, Roni; Eliakim, Alon

    2014-09-01

    The purpose of this study was to determine the repeated sprint ability (RSA) of young (16.9 ± 0.5 years) soccer players at different game stages. Players performed repeated sprint test (RST) (12 × 20 m) after warm-up before a game, at half-time, and after a full soccer game, each on a different day, in a random order. The ideal (fastest) sprint time (IS) and total (accumulative) sprint time (TS) were significantly slower at the end of the game compared with those after the warm-up before the game (p < 0.01 for each). Differences between IS and TS after the warm-up before the game and at half-time, and between half-time and end of the game, were not statistically significant. There was no significant difference in the performance decrement during the RST after warm-up before the game, at half-time, or the end of the game. Significant negative correlation was found between predicted V[Combining Dot Above]O2 and the difference between TS after the warm-up before the game and the end of the game (r = -0.52), but not between predicted V[Combining Dot Above]O2 and the difference in any of the RST performance indices between warm-up before the game and half-time, or between half-time and the end of the game. The findings indicate a significant RSA reduction only at the end but not at the half-time of a soccer game. The results also suggest that the contribution of the aerobic system to soccer intensity maintenance is crucial, mainly during the final stages of the game.

  14. Effect of between-set recovery durations on repeated sprint ability in young soccer players.

    Science.gov (United States)

    Selmi, M A; Haj, Sassi R; Haj, Yahmed M; Moalla, W; Elloumi, M

    2016-06-01

    The purposes of this study were to examine the effect of between-set recovery duration on physiological responses (heart rate and blood lactate), rating of perceived exertion (RPE) and performance indices of repeated sprint sets (RSS) and to investigate their relationship with aerobic power. Twenty-four young male soccer players (age: 17.4 ± 0.32 years) performed three randomized RSS protocols consisting of 2 sets of 5x20 m with 15 s recovery between sprints and 1 min (RSS1), 2 min (RSS2) and 4 min (RSS4) between sets, and a multi-stage aerobic track test to estimate VO2max. Results showed that in contrast to RSS2 and RSS4, RSS1 leads to a large decline in performance expressed as the sum of sprint times (34.0±1.0 s, 34.0±1.1s and 34.6±1.1s, respectively) and a significant increase of both mean heart rate (124.0±9.7 bpm, 112.5±6.7 bpm and 137.3±12.4, respectively) and RPE (3.2±1.5, 3.4±1.2 and 6.3±1.4, respectively) with no change in blood lactate and peak HR between the three rest conditions. No significant correlations were obtained between estimated VO2max and any of the indices of the three RSS protocols. In conclusion, 1 min of recovery between sets is sufficient to ensure a significant decrease in performance in the second set, while 2 min and 4 min of recovery were long enough to provide maintenance of high intensity work in the second set. These findings would be useful for coaches and sport scientists when attempting to assess repeated sprint abilities, allowing coaches to accurately define the intended training goals in young soccer players.

  15. Effect of between-set recovery durations on repeated sprint ability in young soccer players

    Directory of Open Access Journals (Sweden)

    MA Selmi

    2016-04-01

    Full Text Available The purposes of this study were to examine the effect of between-set recovery duration on physiological responses (heart rate and blood lactate, rating of perceived exertion (RPE and performance indices of repeated sprint sets (RSS and to investigate their relationship with aerobic power. Twenty-four young male soccer players (age: 17.4 ± 0.32 years performed three randomized RSS protocols consisting of 2 sets of 5x20 m with 15 s recovery between sprints and 1 min (RSS1, 2 min (RSS2 and 4 min (RSS4 between sets, and a multi-stage aerobic track test to estimate VO2max. Results showed that in contrast to RSS2 and RSS4, RSS1 leads to a large decline in performance expressed as the sum of sprint times (34.0±1.0 s, 34.0±1.1s and 34.6±1.1s, respectively and a significant increase of both mean heart rate (124.0±9.7 bpm, 112.5±6.7 bpm and 137.3±12.4, respectively and RPE (3.2±1.5, 3.4±1.2 and 6.3±1.4, respectively with no change in blood lactate and peak HR between the three rest conditions. No significant correlations were obtained between estimated VO2max and any of the indices of the three RSS protocols. In conclusion, 1 min of recovery between sets is sufficient to ensure a significant decrease in performance in the second set, while 2 min and 4 min of recovery were long enough to provide maintenance of high intensity work in the second set. These findings would be useful for coaches and sport scientists when attempting to assess repeated sprint abilities, allowing coaches to accurately define the intended training goals in young soccer players.

  16. Postactivation potentiation on repeated-sprint ability in elite handball players.

    Science.gov (United States)

    Okuno, Nilo M; Tricoli, Valmor; Silva, Salomão B C; Bertuzzi, Rômulo; Moreira, Alexandre; Kiss, Maria A P D M

    2013-03-01

    The aim of this study was to analyze the changes on repeated-sprint ability (RSA) performance after heavy load exercise in elite handball players. Twelve subjects were submitted to the following experimental sessions: (a) 1-repetition maximum (1RM) test on the half squat exercise, (b) RSA test (control condition), and (c) RSA with a conditioning activity on the same exercise as 1RM test (experimental condition). The conditioning activity comprised 1 set of 5 × 50% 1RM, 1 set of 3 × 70% 1RM, and 5 sets of 1 × 90% 1RM. A significant improvement in the best sprint time (RSAbest) and mean sprint time (RSAmean) was observed with the conditioning activity (RSAbest = 5.74 ± 0.16 seconds; RSAmean = 5.99 ± 0.19 seconds) when compared with the situation without the conditioning activity (RSAbest = 5.82 ± 0.15 seconds; RSAmean = 6.06 ± 0.18 seconds; p < 0.01) with a moderate (Cohen's d = -0.54) and small effect (Cohen's d = -0.41) to RSAbest and RSAmean, respectively. Therefore, the findings of this study demonstrated that prior heavy load exercise can be used to improve the RSA performance, however, with a small to moderate magnitude of change.

  17. Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 1).

    Science.gov (United States)

    Padulo, Johnny; Laffaye, Guillaume; Haddad, Monoem; Chaouachi, Anis; Attene, Giuseppe; Migliaccio, Gian Mario; Chamari, Karim; Pizzolato, Fabio

    2015-01-01

    The present study aimed to compare the changes of direction on repeated sprint ability (RSA) vs. intensive repeated sprint ability (IRSA) protocols in basketball. Eighteen young male basketball players performed on RSA [10 × 30-m (15 + 15-m, one change of direction)] and IRSA [10 × 30-m (10 + 10 + 10-m, two changes of direction)]. A correlation matrix between RSA, IRSA, "squat jump (SJ)-countermovement jump (CMJ)", footstep analysis and total distance in Yo-Yo intermittent recovery level 1 was performed. The best time, worst time, total time and the number of footsteps were significantly smaller in the RSA test compared to IRSA test (P  0.80, P  0.478, P  0.515, P  0.489, P basketball game's actions (~2 s). Besides, IRSA could be an appropriate choice for assessing both RSA and changes of direction capacities in basketball players.

  18. The Effects of Novel Ingestion of Sodium Bicarbonate on Repeated Sprint Ability.

    Science.gov (United States)

    Miller, Peter; Robinson, Amy L; Sparks, S Andy; Bridge, Craig A; Bentley, David J; McNaughton, Lars R

    2016-02-01

    This work examined the influence of an acute dose of sodium bicarbonate (NaHCO3) on buffering capacity and performance during a repeated sprint ability (RSA) protocol. Eleven (mean ± SD: age 24.6 ± 6.1 years; mass 74.9 ± 5.7 kg; height 177.2 ± 6.7 cm) participated in the study, undertaking 4 test sessions. On the first visit to the laboratory, each participant ingested 300 mg · kg(-1) of NaHCO3 (in 450 ml of flavored water) and blood samples were obtained at regular intervals to determine the individual times peak pH and HCO3. In subsequent visits, participants ingested 300 mg · kg(-1) of NaHCO3, 270 mg · kg(-1) body mass (BM) of NaCI, or no drink followed by a RSA cycling protocol (10 × 6 seconds sprints with 60 seconds recovery), which commenced at each individuals predetermined ingestion peak pH response time. Blood samples were obtained before exercise and after the first, fifth, and 10th sprint to determine the blood pH, HCO3, and lactate (La) responses. Total work completed during the repeated sprint protocol was higher (p ≤ 0.05) in the NaHCO3 condition (69.8 ± 11.7 kJ) compared with both the control (59.6 ± 12.2 kJ) and placebo (63.0 ± 8.3 kJ) conditions. Peak power output was similar (p > 0.05) between the 3 conditions. Relative to the control and placebo conditions, NaHCO3 ingestion induced higher (p ≤ 0.05) blood pH and HCO3 concentrations before exercise and during the bouts, and higher lactate concentrations (p ≤ 0.05) after the final sprint. Results suggest that NaHCO3 improves the total amount of work completed during RSA through enhanced buffering capacity.

  19. Repeated sprint ability is not enhanced by caffeine, arginine, and branched-chain amino acids in moderately trained soccer players.

    Science.gov (United States)

    Ermolao, Andrea; Zanotto, Tobia; Carraro, Nicolò; Fornasier, Tommaso; Zaccaria, Marco; Neunhaeuserer, Daniel; Bergamin, Marco

    2017-02-01

    The aim was to investigate the effect of a dietary supplementation on the repeated sprint ability (RSA) performance in recreationally trained team sports athletes. Twelve young men underwent a RSA exercise protocol in five trials, in which participants ingested carbohydrates (CHO) plus caffeine (Caf), CHO plus arginine (Arg), CHO plus branched-chain amino acids (BCAA), CHO plus Caf, Arg, and BCAA (ALL), and CHO only. Heart rate, oxygen saturation, hematic lactate, ratings of perceived exertion, average sprint time, total time, best sprint time, peak power, and average power were taken. Data revealed no significant effects neither on physiological nor performance parameters with any of the supplements.

  20. Repeated sprint ability is not enhanced by caffeine, arginine, and branched-chain amino acids in moderately trained soccer players

    Science.gov (United States)

    Ermolao, Andrea; Zanotto, Tobia; Carraro, Nicolò; Fornasier, Tommaso; Zaccaria, Marco; Neunhaeuserer, Daniel; Bergamin, Marco

    2017-01-01

    The aim was to investigate the effect of a dietary supplementation on the repeated sprint ability (RSA) performance in recreationally trained team sports athletes. Twelve young men underwent a RSA exercise protocol in five trials, in which participants ingested carbohydrates (CHO) plus caffeine (Caf), CHO plus arginine (Arg), CHO plus branched-chain amino acids (BCAA), CHO plus Caf, Arg, and BCAA (ALL), and CHO only. Heart rate, oxygen saturation, hematic lactate, ratings of perceived exertion, average sprint time, total time, best sprint time, peak power, and average power were taken. Data revealed no significant effects neither on physiological nor performance parameters with any of the supplements. PMID:28349034

  1. Evaluation of critical rest interval determined from repeated sprint ability testing.

    Science.gov (United States)

    LA Monica, Michael B; Fukuda, David H; Beyer, Kyle S; Hoffman, Mattan W; Miramonti, Amelia A; Fragala, Maren S; Stout, Jeffrey R; Hoffman, Jay R

    2016-10-01

    To test if the critical power (CP) concept can be utilized to determine the critical rest interval (CRI) using repeated sprint ability (RSA) testing with varying work-to-rest ratios. Twelve recreationally trained men (mean±SD; age 24.1±3.6 years) completed a graded exercise test and three RSA protocols with 6-second maximal sprints and varying rest intervals (12-36 s) on a cycle ergometer to determine CRI. Intermittent critical power (ICP) was calculated through the linear total work (TW) and time-to-exhaustion (TTE) relationship, whereas CRI was estimated using average work per sprint and ICP. Validation trials above and below CRI were conducted to evaluate physiological response. Repeated measures analysis of variance were used to analyze variables from RSA trials and changes in blood lactate, oxygen uptake (V̇O2), heart rate (HR), peak power, and TW throughout the validation trials. Blood lactate, average V̇O2, V̇O2peak, and heart rate were significantly greater below CRI (8.94±4.89 mmol/L, 2.05±0.36 L/min, 2.84±0.48 L/min, and 151.14±18.46 bpm, respectively) when compared to above CRI (6.56±3.45 mmol/L, 1.78±0.26 L/min, 2.61±0.43 L/min, and 138.14±17.51 bpm). Significant interactions were found between above and below CRI for minimal V̇O2 response and maximal HR response, which were consistent with the heavy and severe exercise intensity domains. The use of the work-time relationship determined from RSA testing with varying rest intervals can be used to determine CRI and may distinguish between physiological responses related to exercise intensity domains.

  2. Is there a diurnal variation in repeated sprint ability on a non-motorised treadmill?

    Science.gov (United States)

    Pullinger, Samuel A; Brocklehurst, Emma L; Iveson, Reece P; Burniston, Jatin G; Doran, Dominic A; Waterhouse, James M; Edwards, Ben J

    2014-04-01

    In active males, muscle force production and short-term (variation is attributed to motivational, peripheral and central factors, and possibly the higher core and muscle temperatures observed in the evening. However, little is known regarding whether diurnal variation on a treadmill also exists in team-sport specific tests of repeated sprint ability (RSA), as would be relevant to football, for example. A controlled laboratory protocol using a non-motorised treadmill has been used to investigate whether daily variation in RSA is present in highly motivated athletes. Twenty active males (mean ± SD: age, 21.0 ± 2.2 yrs; maximal oxygen uptake ([Formula: see text] max), 60.8 ± 4.8 ml kg min(-1); body mass, 77.02 ± 10.5 kg and height, 1.79 ± 0.07 m) volunteered and completed two sessions counterbalanced in order of administration (separated by >48 h): a morning (M, 07:30 h) and evening (E, 17:30 h) session. Both sessions included a 5-min active warm-up on a motorised treadmill at 10 km h(-1) followed by three task-specific warm-up sprints at 50%, 70% and 80%, respectively, on a non-motorised treadmill. During each trial, 10 × 3 s repeated sprints with 30 s recoveries were performed on the non-motorised treadmill. Rectal (Trec) and muscle temperature measurements (Tm) were taken after subjects had reclined for 30 min at the start of the protocol, and again after the active warm-up. Values of heart rate, thermal comfort (TC), rating of perceived exertion (RPE) and effort were measured throughout. Blood samples were taken at rest, after the sprints and 5-min post sprints. Data were analysed using a GLM with repeated measures. Trec and Tm values were higher at rest in the evening than the morning (0.46 °C and 0.57 °C, respectively, p p > 0.05). All subjects reported maximal values for "effort" for each sprint. There were significant positive correlations between Trec and Tm, Trec and RPE, TC and all measures of RSA performance. However, there was no correlation

  3. Is repeated-sprint ability of soccer players predictable from field-based or laboratory physiological tests?

    Science.gov (United States)

    Psotta, R; Bunc, V; Hendl, J; Tenney, D; Heller, J

    2011-03-01

    The aim of this study was to investigate multiple regression models with prediction equations that would enable a valid estimate of running repeated-sprint ability (RSA) in soccer players from the variables measured in field and laboratory physiological tests. Adolescent soccer players (N=33) performed five field performance tests and two laboratory tests for assessment of muscle strength of legs, sprint ability, anaerobic power and capacity, aerobic power and capacity, and running economy. These tests served as potential predictors of RSA. RSA was assessed by a intermittent anaerobic running test (IAnRT) consisted of ten 20 m sprints. Multiple regression analysis revealed that the mean speed in the 20 m sprint test and the 2 km endurance running test accounted for 89% of total variation in the mean running speed in the IAnRT (VIAnRT) as the indicator of capacity for multiple sprint work (R2=0.89, SEM=0.09 m.s-1). Using the variables from the laboratory tests, the best prediction of the VIAnRT was obtained from the running speed at the ventilatory threshold level (VVT) and anaerobic power (Pmax.kg-1) (R2=0.49, SEM=0.21 m.s-1). Performance in the multiple-sprint exercise as an indicator of RSA can be estimated by the regression equation with two predictors - mean speed in the 20 m sprint and 2 km running test with an error of 4%.

  4. The effect of slope on repeated sprint ability in young soccer players.

    Science.gov (United States)

    Padulo, J; Ardigò, L P; Attene, G; Cava, C; Wong, D P; Chamari, K; Migliaccio, G M

    2016-01-01

    This study aimed to describe a gradient repeated sprint ability (RSA) test in comparison with a standard level one by investigating performance, metabolic demand and muscular jumping performance as a proxy for running mechanics. Eighteen athletes performed two level RSA tests (40 m × 6) - for reliability evaluation - and one ±5% gradient RSA test, second leg downhill (RSAgrad). Rating of perceived exertion (RPE), blood lactate concentration (BLa) concentration, vertical jump heights were assessed as well. Level test measures resulted highly reliable (Intra-class correlation coefficient (ICC) ≥0.96). RSAgrad worsened only first sprints' performance (-2%) but not overall test performance (~45 s). RSAgrad resulted to be less deteriorating in terms of fatigue index (FI) (-36%), BLa (-23%), RPE (-11%), jumping performance (RSAgrad post-/pre-squat jump, countermovement jump heights (CMJh): -3%, -6%, respectively). RSAgrad could be used to diversify common training protocol without stressing excessively athletes' current metabolic-anaerobic capacity. Such physical conditioning procedures could improve acceleration/braking capability.

  5. 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.

  6. Effects of Three Different Resistance Training Frequencies on Jump, Sprint, and Repeated Sprint Ability Performance in Professional Futsal Players.

    Science.gov (United States)

    Paz-Franco, Adrián; Rey, Ezequiel; Barcala-Furelos, Roberto

    2017-02-21

    The aim of this study was to examine the effect of 3 different resistance training frequencies (one strength training session per week (1W), two strength training sessions per week (2W) or one strength training session every second week (0.5W)) on jump, sprint and repeated sprint performance (RSA) in professional futsal players. Thirty-five futsal players were randomized into 1 of 3 groups, the 1W group (n= 12), 2W group (n= 12), or the 0.5W group (n= 11). The players performed the same resistance training during 6 weeks and only training frequency differed between the groups. Within-group analysis showed significant improvements in jump (p≤0.001, Effect Size (ES)= 0.13-0.35), sprint (p≤0.001, ES= 0.48-0.71), and RSA (p≤0.01, ES= 0.22-0.63) from pretest to posttest in 1W and 2W. However, no significant (p>0.05) pre-post changes were observed for the 0.5W in any variable. In the between-groups analysis, significant better results were found in jump (p≤0.01), sprint (p≤0.01), and RSA performance (p≤0.01) in the 1W group and 2W group in comparison with 0.5W group. Also, jump (p≤0.05) and 5 m sprint (p≤0.05) performances was significantly better in the 2W group in comparison with 1W group. In conclusion, the current study showed that 6 weeks of RT one or two times per week in addition to typical futsal training, produced significant improvements in jump, sprint and RSA performance. Additionally, RT one every second week may be sufficient to maintain physical fitness in professional futsal players. This information may be useful for coaches when planning training contents during congested fixture schedules or in periods where the emphasis need to be put on other qualities and spend as little time as possible on maintaining or increasing physical performance.

  7. Modelling Developmental Changes in Repeated-Sprint Ability by Chronological and Skeletal Ages in Young Soccer Players

    NARCIS (Netherlands)

    Valente-dos-Santos, J.; Coelho-e-Silva, M. J.; Martins, R. A.; Figueiredo, A. J.; Cyrino, E. S.; Sherar, L. B.; Vaeyens, R.; Huijgen, B. C. H.; Elferink-Gemser, M. T.; Malina, R. M.

    2012-01-01

    This study investigated the influence of chronological (CA) and skeletal ages (SA), anthropometry, aerobic endurance and lower limb explosive strength on developmental changes in repeated-sprint ability (RSA) in soccer players aged 11-17 years. Participants were annually followed over 5 years, resul

  8. Modelling Developmental Changes in Repeated-Sprint Ability by Chronological and Skeletal Ages in Young Soccer Players

    NARCIS (Netherlands)

    Valente-dos-Santos, J.; Coelho-e-Silva, M. J.; Martins, R. A.; Figueiredo, A. J.; Cyrino, E. S.; Sherar, L. B.; Vaeyens, R.; Huijgen, B. C. H.; Elferink-Gemser, M. T.; Malina, R. M.

    2012-01-01

    This study investigated the influence of chronological (CA) and skeletal ages (SA), anthropometry, aerobic endurance and lower limb explosive strength on developmental changes in repeated-sprint ability (RSA) in soccer players aged 11-17 years. Participants were annually followed over 5 years, resul

  9. Modelling Developmental Changes in Repeated-Sprint Ability by Chronological and Skeletal Ages in Young Soccer Players

    NARCIS (Netherlands)

    Valente-dos-Santos, J.; Coelho-e-Silva, M. J.; Martins, R. A.; Figueiredo, A. J.; Cyrino, E. S.; Sherar, L. B.; Vaeyens, R.; Huijgen, B. C. H.; Elferink-Gemser, M. T.; Malina, R. M.

    2012-01-01

    This study investigated the influence of chronological (CA) and skeletal ages (SA), anthropometry, aerobic endurance and lower limb explosive strength on developmental changes in repeated-sprint ability (RSA) in soccer players aged 11-17 years. Participants were annually followed over 5 years,

  10. Repeated sprint ability in elite water polo players and swimmers and its relationship to aerobic and anaerobic performance.

    Science.gov (United States)

    Meckel, Yoav; Bishop, David; Rabinovich, Moran; Kaufman, Leonid; Nemet, Dan; Eliakim, Alon

    2013-01-01

    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. Key PointsElite water polo players demonstrated lower repeated sprint ability (RSA), aerobic and anaerobic capabilities compared to elite swimmers.A 25-m swim trial correlated significantly with ideal sprint time and total sprint time, emphasizing the important contribution of anaerobic metabolism for these exercise types in both water polo players and swimmers.800-m swim results did not correlate with RSA or 25-m

  11. Effects of Four Weeks of β-Alanine Supplementation on Repeated Sprint Ability in Water Polo Players.

    Science.gov (United States)

    Brisola, Gabriel Motta Pinheiro; Artioli, Guilherme Giannini; Papoti, Marcelo; Zagatto, Alessandro Moura

    2016-01-01

    The purpose of this study was to investigate the effect of four weeks of β-alanine supplementation on repeated sprint ability in water polo players. Twenty-two male water polo players participated in the study, divided randomly into two homogeneous groups (placebo and β-alanine groups). The study design was double-blind, parallel and placebo controlled. Before and after the supplementation period (28 days), the athletes performed two specific repeated sprint ability tests interspaced by a 30-minute swimming test. Participants received 4.8g∙day-1 of the supplement (dextrose or β-alanine) on the first 10 days and 6.4g∙day-1 on the final 18 days. There was no significant group-time interaction for any variable. The qualitative inference for substantial changes demonstrated a likely beneficial effect in the β-alanine group (β-alanine vs placebo) for mean time (6.6±0.4s vs 6.7±0.4s; 81% likely beneficial), worst time (6.9±0.5s vs 7.1±0.5s; 78% likely beneficial) and total time (39.3±2.5s vs 40.4±2.5s; 81% likely beneficial) in the first repeated sprint ability set and for worst time (7.2±0.6s vs 7.5±0.6s; 57% possible beneficial) in the second repeated sprint ability set. Further, was found substantial change for total time for both repeated sprint ability tests (80.8±5.7s vs 83.4±5.6s; 52% possible beneficial). To conclude, four weeks of β-alanine supplementation had a likely beneficial effect in the first set of repeated sprint ability tests and a possible beneficial effect for worst time in the second set performed in a specific protocol in water polo players.

  12. Effects of Four Weeks of β-Alanine Supplementation on Repeated Sprint Ability in Water Polo Players

    Science.gov (United States)

    Brisola, Gabriel Motta Pinheiro; Artioli, Guilherme Giannini; Papoti, Marcelo; Zagatto, Alessandro Moura

    2016-01-01

    The purpose of this study was to investigate the effect of four weeks of β-alanine supplementation on repeated sprint ability in water polo players. Twenty-two male water polo players participated in the study, divided randomly into two homogeneous groups (placebo and β-alanine groups). The study design was double-blind, parallel and placebo controlled. Before and after the supplementation period (28 days), the athletes performed two specific repeated sprint ability tests interspaced by a 30-minute swimming test. Participants received 4.8g∙day-1 of the supplement (dextrose or β-alanine) on the first 10 days and 6.4g∙day-1 on the final 18 days. There was no significant group-time interaction for any variable. The qualitative inference for substantial changes demonstrated a likely beneficial effect in the β-alanine group (β-alanine vs placebo) for mean time (6.6±0.4s vs 6.7±0.4s; 81% likely beneficial), worst time (6.9±0.5s vs 7.1±0.5s; 78% likely beneficial) and total time (39.3±2.5s vs 40.4±2.5s; 81% likely beneficial) in the first repeated sprint ability set and for worst time (7.2±0.6s vs 7.5±0.6s; 57% possible beneficial) in the second repeated sprint ability set. Further, was found substantial change for total time for both repeated sprint ability tests (80.8±5.7s vs 83.4±5.6s; 52% possible beneficial). To conclude, four weeks of β-alanine supplementation had a likely beneficial effect in the first set of repeated sprint ability tests and a possible beneficial effect for worst time in the second set performed in a specific protocol in water polo players. PMID:27930743

  13. Relationships between repeated sprint ability, mechanical parameters, and blood metabolites in professional soccer players.

    Science.gov (United States)

    Morcillo, Jose A; Jiménez-Reyes, Pedro; Cuadrado-Peñafiel, Victor; Lozano, Emilio; Ortega-Becerra, Manuel; Párraga, Juan

    2015-06-01

    This study analyzed the acute metabolic and mechanical responses to a specific repeated sprint ability (RSA) test. Eighteen male professional soccer players from a team of the First Division of Spanish National League participated. A 12 × 30-m RSA test with 30-second recovery together with countermovement jump test (CMJ) pre a post RSA test was performed. Mechanical responses (i.e., height performance in CMJ and speed loss) and metabolic responses (i.e., blood lactate and ammonia concentrations) were measured before and after exercise. A related sample t-test was used to analyze CMJ height pre-post changes as well as to compare pre- and post-exercise lactate and ammonia levels. Countermovement jump height loss pre-post session (8%) was significant, and fatigue, measured as CMJ height loss, was strongly correlated to lactate (r = 0.97; p < 0.001) and ammonia (r = 0.92; p < 0.001) for all players. The relationships between the variables studied were determined by calculating the Pearson correlation coefficients. The metabolic stress developed during the effort can be estimated by controlling CMJ because of the high correlation between CMJ and blood lactate and ammonia concentrations. The high correlations found between mechanical (speed and CMJ height losses) and metabolic (lactate and ammonia) measures of fatigue highlight the utility and validity of using CMJ to monitor training load and quantify objectively neuromuscular fatigue during RSA.

  14. Evaluation of the running-based anaerobic sprint test as a measure of repeated sprint ability in collegiate-level soccer players.

    Science.gov (United States)

    Keir, Daniel A; Thériault, Francis; Serresse, Olivier

    2013-06-01

    Repeated sprint ability (RSA) refers to an individual's ability to perform maximal sprints of short duration in succession with little recovery between sprints. The running-based anaerobic sprint test (RAST) has been adapted from the Wingate anaerobic test (WAnT) protocol as a tool to assess RSA and anaerobic power. The purpose of this study was to evaluate the relationship between performance variables and physiological responses obtained during the RAST and the WAnT using 8 collegiate-level soccer players. Participants performed a single trial of both the WAnT and the RAST. Breath-by-breath gas exchange was monitored throughout each trial, and blood lactate (BL) measures were recorded postexercise. The oxygen uptake (VO2) profile suggested that the RAST required greater contributions from aerobic metabolism although there was no difference in VO2peak (p < 0.05). Peak BL values were also similar between the RAST and the WAnT (p < 0.05). Neither peak physiological values nor performance variables (peak and mean power) were significantly correlated between protocols. The weak association in physiological responses indicates that different combinations of metabolic contributions exist between protocols, suggesting that individual performances on each test are not related in collegiate soccer players. Further studies on these relationships with players of other competitive levels and team sport athletes are warranted.

  15. 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.

  16. Relationship between measures of aerobic fitness, speed and repeated sprint ability in full and part time youth soccer players.

    Science.gov (United States)

    Gibson, N; Currie, J; Johnston, R; Hill, J

    2013-02-01

    The aim of the study was to investigate the relationship between repeated sprint ability (RSA) involving changes in direction, short linear sprinting and aerobic capacity in young elite soccer players. A secondary aim was to assess any differences in performance of these assessments between players of different age groups. Thirty-two male adolescent soccer players belonging to the same elite club academy were assessed for RSA comprising 6 x 40m efforts interspersed by 25s recovery, linear sprinting speed over 15m, and aerobic capacity via the YYIE2 assessment. There was a significant correlation between performance in the YYIE2 and RSA total time, RSA fastest sprint and RSA percentage decrement (r = -0.71, -0.53, and -0.52 respectively. Psprint (Psprinting. Assessments of RSA over 40m and incorporating changes of direction appear to be significantly correlated with YYIE2 performance in young elite level soccer players. In addition older players performed significantly better in the YYIE2 assessment and RSA protocol but not in short linear sprinting. These results have implications for the design of assessment protocols for young elite soccer players of different ages.

  17. Effect of ischemic preconditioning on repeated sprint ability in team sport athletes.

    Science.gov (United States)

    Gibson, Neil; Mahony, Ben; Tracey, Claire; Fawkner, Samantha; Murray, Andrew

    2015-01-01

    This study investigated whether ischemic preconditioning (IPC) in a trained population affected repeated sprint performance. A secondary aim was to assess responses according to gender. Sixteen (nine females and seven males) well trained team sport athletes took part in a randomised crossover study design. Participants underwent an IPC and placebo treatment involving three periods of 5 min occlusion applied unilaterally (3 × 5 min occlusion to each leg) at either 220 mmHg or 50 mmHg. Each period of occlusion was followed by 5 min reperfusion. Following treatment 5 × 6 s maximal effort sprints were undertaken on a cycle ergometer against 7.5% body mass, each interspersed by 24 s recovery. Measured parameters included peak power, total power, percentage decrement, post-exercise blood lactate and ratings of perceived exertion. Nor within subject main effect for IPC was observed, neither was there an interaction effect with gender. Effect sizes were trivial (ES repeated sprint performance. A lower blood lactate response in female participants following IPC may suggest improved blood flow through vasodilation.

  18. Sympathetic enhancement in futsal players but not in football players after repeated sprint ability test.

    Science.gov (United States)

    Chen, Yung-Sheng; Liao, Chih-Jung; Lu, Wan-An; Kuo, Cheng-Deng

    2015-01-01

    Heart rate variability (HRV) can disclose the specific adaptation of sympathovagal modulation to exercise. This study investigated the change in HRV measures after anaerobic and aerobic intermittent exercises in university football and futsal players. 36 male university students with physically active lifestyle (n=14), football (n=12), and futsal (n=10) participated in this study. The participants completed the repeated sprint ability (RSA) test and Yo-Yo (YY) intermittent recovery test level 1 in randomised order. ECG signals of the participants were recorded in supine position 15 min before and 30 min after exercises. Before exercise, and 5 and 30 min after exercise, the blood pressures were also taken. In the RSA protocol, the percentage changes in normalised high-frequency power (nHFP) were significantly decreased, while the percentage changes in the very low/high frequency power ratio (VLHR) and low/high frequency power ratio (LHR) were significantly increased in futsal players after exercise, as compared with the controls. No significant changes in all HRV indices were found in the YY protocol, except the respiratory frequency. After exercise, the percent decrease in vagal modulation in futsal players was significantly reduced, while the percentage increase in sympathetic modulation in futsal players was significantly enhanced in the RSA test, but not in the YY test, as compared with the control group. The increase in sympathetic activity and the decrease in vagal activity in the futsal players were greater than the corresponding increase and decrease in the football players in the RSA test.

  19. Repeated sprint ability and stride kinematics are altered following an official match in national-level basketball players.

    Science.gov (United States)

    Delextrat, A; Baliqi, F; Clarke, N

    2013-04-01

    The aim of the study was to investigate the effects of playing an official national-level basketball match on repeated sprint ability (RSA) and stride kinematics. Nine male starting basketball players (22.8±2.2 years old, 191.3±5.8 cm, 88±10.3 kg, 12.3±4.6% body fat) volunteered to take part. Six repetitions of maximal 4-s sprints were performed on a non-motorised treadmill, separated by 21-s of passive recovery, before and immediately after playing an official match. Fluid loss, playing time, and the frequencies of the main match activities were recorded. The peak, mean, and performance decrement for average and maximal speed, acceleration, power, vertical and horizontal forces, and stride parameters were calculated over the six sprints. Differences between pre- and post-match were assessed by student t-tests. Significant differences between pre- and post-tests were observed in mean speed (-3.3%), peak and mean horizontal forces (-4.3% and -17.4%), peak and mean vertical forces (-3.4% and -3.7%), contact time (+7.3%), stride duration (+4.6%) and stride frequency (-4.0%), (Psprint, jump and shuffle frequencies (Prepeated sprint ability depends on the specific activities performed, and that replacing fluid loss through sweating during a match is crucial.

  20. The optimal exercise to rest ratios in repeated sprint ability training in youth soccer players.

    Science.gov (United States)

    Ruscello, Bruno; Partipilo, Filippo; Pantanella, Laura; Esposito, Mario; D'Ottavio, Stefano

    2016-12-01

    The aim of this study was to investigate the applicability of three different exercise to rest ratios in RSA training in youth soccer players, applying those ones already adopted in adult players, when performing three different sprinting modes (straight, shuttle and sprinting with changing of direction). Eighteen young trained male soccer players (Height: 1.66±0.07 m; weight: 58.22±7.64 kg; BMI 19.37±3.42 kg·m-2; age:14 years) participated to the study. In order to compare the different values of the time recorded, a Fatigue Index (FI) was used. Recovery times among trials in the sets were administered according to the 1:5, 1:3; 1:2 exercise to rest ratio, respectively. Significant differences among trials within each set (Repeated Measures Anova; Psprinting modalities when applying the investigated exercise to rest ratios (Factorial Anova; between; P>0.05). The results of this study confirm that the exercise to rest ratios considered in this study might be suitable to design effective testing protocols and training sessions aimed at the development of the RSA in youth soccer players, keeping the performances in the speed domain (FI%< ≈7-8%) but inducing the fatigue processes sought with this kind of training method.

  1. Oxygen uptake during repeated-sprint exercise.

    Science.gov (United States)

    McGawley, Kerry; Bishop, David J

    2015-03-01

    Repeated-sprint ability appears to be influenced by oxidative metabolism, with reductions in fatigue and improved sprint times related to markers of aerobic fitness. The aim of the current study was to measure the oxygen uptake (VO₂) during the first and last sprints during two, 5 × 6-s repeated-sprint bouts. Cross-sectional study. Eight female soccer players performed two, consecutive, 5 × 6-s maximal sprint bouts (B1 and B2) on five separate occasions, in order to identify the minimum time (trec) required to recover total work done (Wtot) in B1. On a sixth occasion, expired air was collected during the first and last sprint of B1 and B2, which were separated by trec. The trec was 10.9 ± 1.1 min. The VO₂ during the first sprint was significantly less than the last sprint in each bout (psprint (measured in kJ) was significantly related to VO₂max in both B1 (r=0.81, p=0.015) and B2 (r=0.93, p=0.001). In addition, the VO₂ attained in the final sprint was not significantly different from VO₂max in B1 (p=0.284) or B2 (p=0.448). The current study shows that the VO₂ increases from the first to the last of 5 × 6-s sprints and that VO₂max may be a limiting factor to performance in latter sprints. Increasing V˙O₂max in team-sport athletes may enable increased aerobic energy delivery, and consequently work done, during a bout of repeated sprints. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. 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.

  3. Not quite so fast: effect of training at 90% sprint speed on maximal and repeated-sprint ability in soccer players.

    Science.gov (United States)

    Haugen, Thomas; Tonnessen, Espen; Leirstein, Svein; Hem, Erlend; Seiler, Stephen

    2014-12-01

    Abstract The aim of the present study was to investigate the effect of training at an intensity eliciting 90% of maximal sprinting speed on maximal and repeated-sprint performance in soccer. It was hypothesised that sprint training at 90% of maximal velocity would improve soccer-related sprinting. Twenty-two junior club-level male and female soccer players (age 17 ± 1 year, body mass 64 ± 8 kg, body height 174 ± 8 cm) completed an intervention study where the training group (TG) replaced one of their weekly soccer training sessions with a repeated-sprint training session performed at 90% of maximal sprint speed, while the control group (CG) completed regular soccer training according to their teams' original training plans. Countermovement jump, 12 × 20-m repeated-sprint, VO2max and the Yo-Yo Intermittent Recovery Level 1 test were performed prior to and after a 9-week intervention period. No significant between-group differences were observed for any of the performance indices and effect magnitudes were trivial or small. Before rejecting the hypothesis, we recommend that future studies should perform intervention programmes with either stronger stimulus or at other times during the season where total training load is reduced.

  4. Influence of the number of trials and the exercise to rest ratio in repeated sprint ability, with changes of direction and orientation.

    Science.gov (United States)

    Ruscello, Bruno; Tozzo, Nazzareno; Briotti, Gianluca; Padua, Elvira; Ponzetti, Francesco; D'Ottavio, Stefano

    2013-07-01

    The purpose of this investigation was to determine if there were different trends in physical fatigue observed in 3 different sets, of 7 trials each, in repeated sprint training, performed in 3 different modes: straight sprinting over 30 m, shuttle sprinting over 15 + 15 m, and sprinting over 30 m with changes of direction. Recovery time among trials in the sets was administered according to the 1:5 exercise to rest ratio. The sets were performed on 3 different days, with at least 48 hours between each set. The study involved 17 trained male soccer players (height, 177.33 ± 6.21 cm; body mass, 71.63 ± 9.58 kg; body mass index, 23 ± 2.39 kg·m; age, 21.94 ± 3.58 years). To compare the different values of the time recorded, an index of fatigue was used. Significant differences among trials within each set (repeated measures analysis of variance; p repeated sprint ability in nonlinear and multidirectional sprints (shuttle and change of direction), which might imply a different number of trials within the set or different exercise to rest ratios from the ones usually adopted for straight sprinting, to induce similar trends of fatigue. As practical applications, the estimated numbers of necessary trials in the different sets and the possible exercise to rest ratios, resulting from mathematical modeling, are provided for each investigated sprinting mode.

  5. Acute effects of two different initial heart rates on testing the Repeated Sprint Ability in young soccer players.

    Science.gov (United States)

    Ruscello, B; Briotti, G; Tozzo, N; Partipilo, F; Taraborelli, M; Zeppetella, A; Padulo, J; D'Ottavio, S

    2015-10-01

    The aim of this paper was to investigate the acute effects of two different initial heart rates intensities when testing the repeated sprint ability (RSA) performances in young soccer players. Since there are many kinds of pre-match warm-ups, we chose to take as an absolute indicator of internal load the heart rate reached at the end of two different warm-up protocols (60 vs. 90% HRmax) and to compare the respective RSA performances. The RSA tests were performed on fifteen male soccer players (age: 17.9±1.5 years) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different HR% (60 & 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed, while the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic demand. Significant differences among trials within each sets (P4 mmol/L(-1)).

  6. Repeated sprint ability in young basketball players: multi-direction vs. one-change of direction (Part 1

    Directory of Open Access Journals (Sweden)

    Johnny ePadulo

    2016-04-01

    Full Text Available The aim of the present study was to examine the reliability of a novel multi-direction repeated sprint ability test (RSM; 10×(6×5-m compared with a repeated sprint ability test (RSA with one change of direction (10×(2×15-m, and the relationship of the RSM and RSA with Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1 and jump performances [squat jump (SJ and counter-movement-jump (CMJ]. Thirty-six (male, n=14, female n=22 young basketball players (age 16.0±0.9 yrs performed the RSM, RSA, Yo-Yo IR1, SJ and CMJ, and were re-tested only for RSM and RSA after one week. The absolute error of reliability (standard error of the measurement was lower than 0.212-s and 0.617-s for the time variables of the RSA and RSM test, respectively. Performance in the RSA and RSM test significantly correlated with CMJ and SJ. The best time, worst time and total time of the RSA and RSM test were negatively correlated with Yo-Yo IR1 distance. Based on these findings, consistent with previously published studies, it was concluded that the novel RSM test was valid and reliable.

  7. 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 sprint times and higher peak speeds. Over sprints, the tests did not differ from each other in terms of V[Combining Dot Above]O2 (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.

  8. Repeated sprint training in normobaric hypoxia.

    Science.gov (United States)

    Galvin, Harvey M; Cooke, Karl; Sumners, David P; Mileva, Katya N; Bowtell, Joanna L

    2013-12-01

    Repeated sprint ability (RSA) is a critical success factor for intermittent sport performance. Repeated sprint training has been shown to improve RSA, we hypothesised that hypoxia would augment these training adaptations. Thirty male well-trained academy rugby union and rugby league players (18.4 ± 1.5 years, 1.83 ± 0.07 m, 88.1 ± 8.9 kg) participated in this single-blind repeated sprint training study. Participants completed 12 sessions of repeated sprint training (10 × 6 s, 30 s recovery) over 4 weeks in either hypoxia (13% FiO₂) or normoxia (21% FiO₂). Pretraining and post-training, participants completed sports specific endurance and sprint field tests and a 10 × 6 s RSA test on a non-motorised treadmill while measuring speed, heart rate, capillary blood lactate, muscle and cerebral deoxygenation and respiratory measures. Yo-Yo Intermittent Recovery Level 1 test performance improved after RS training in both groups, but gains were significantly greater in the hypoxic (33 ± 12%) than the normoxic group (14 ± 10%, prepeated aerobic high intensity workout than an equivalent normoxic training. Performance gains are evident in the short term (4 weeks), a period similar to a preseason training block.

  9. Relationships between anthropometric measures and athletic performance, with special reference to repeated-sprint ability, in the Qatar national soccer team.

    Science.gov (United States)

    Brocherie, Franck; Girard, Olivier; Forchino, Fabricio; Al Haddad, Hani; Dos Santos, Gilvan A; Millet, Grégoire P

    2014-01-01

    The aim of this study was to determine potential relationships between anthropometric parameters and athletic performance with special consideration to repeated-sprint ability (RSA). Sixteen players of the senior male Qatar national soccer team performed a series of anthropometric and physical tests including countermovement jumps without (CMJ) and with free arms (CMJwA), straight-line 20 m sprint, RSA (6 × 35 m with 10 s recovery) and incremental field test. Significant (P sprinting times and r = 0.54 for maximal sprinting speed) with the exception of the sprint decrement score (Sdec). The sum of six skinfolds and adipose mass index were largely correlated with Sdec (r = 0.68, P 0.05, respectively) or any standard athletic tests. Multiple regression analyses indicated that muscular cross-sectional area for mid-thigh, adipose index, straight-line 20 m time, maximal sprinting speed and CMJwA are the strongest predictors of Sdec (r(2) = 0.89) and TT (r(2) = 0.95) during our RSA test. In the Qatar national soccer team, players' power-related qualities and RSA are associated with a high muscular profile and a low adiposity. This supports the relevance of explosive power for the soccer players and the larger importance of neuromuscular qualities determining the RSA.

  10. Effetti dell'allenamento intermittente breve ad alta intensità e delle ripetute aerobiche sul Test Repeated Sprint Ability in giovani calciatori d'elite

    OpenAIRE

    Ibba, Gianfranco

    2016-01-01

    The purpose of this study is to evaluate the effects of two different training methods: the repeated aerobic bouts and the short intermittent high intensity workout on the ability to carry out repeated sprint bouts RSA in a group of young soccer players and also to determine the impact of training on aerobic and neuromuscular performances. Twenty-Four (24) male soccer players have been assessed and trained, all of them partecipating regularly in the 2013-2014 season at the Nati...

  11. Repeated Sprint Ability in Young Basketball Players: Multi-direction vs. One-Change of Direction (Part 1).

    Science.gov (United States)

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

    2016-01-01

    The aim of the present study was to examine the reliability of a novel multi-direction repeated sprint ability (RSA) test [RSM; 10 × (6 × 5-m)] compared with a RSA with one change of direction [10 × (2 × 15-m)], and the relationship of the RSM and RSA with Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) and jump performances [squat jump (SJ) and counter-movement-jump (CMJ)]. Thirty-six (male, n = 14, female n = 22) young basketball players (age 16.0 ± 0.9 yrs) performed the RSM, RSA, Yo-Yo IR1, SJ, and CMJ, and were re-tested only for RSM and RSA after 1 week. The absolute error of reliability (standard error of the measurement) was lower than 0.212 and 0.617-s for the time variables of the RSA and RSM test, respectively. Performance in the RSA and RSM test significantly correlated with CMJ and SJ. The best time, worst time, and total time of the RSA and RSM test were negatively correlated with Yo-Yo IR1 distance. Based on these findings, consistent with previously published studies, it was concluded that the novel RSM test was valid and reliable.

  12. Comparison between traditional strength training and complex contrast training on repeated sprint ability and muscle architecture in elite soccer players.

    Science.gov (United States)

    Spineti, Juliano; Figueiredo, Tiago; Bastos DE Oliveira, Viviane; Assis, Marcio; Fernandes DE Oliveira, Liliam; Miranda, Humberto; Machado DE Ribeiro Reis, Victor M; Simão, Roberto

    2016-11-01

    The purpose of this study was to compare traditional strength training (TST) and complex contrast training (CCT) on the repeated-shuttle-sprint ability (RSSA), the countermovement squat jump (CMJ) height, the one repetition maximum (1RM) at squat on the Smith machine, and on muscle architecture in young, male elite soccer players. Twenty-two soccer players (mean age 18.4±0.4 years; mean weight 70.2±9.1 kg; mean height 179.9±7.5 cm) who belonged to the under-20 age group were randomly assigned into two groups: CCT (N.=10) or TST (N.=12). During the study period, the soccer players trained with CCT through power exercises performed before high-velocity exercises and TST based on a set-repetition format through daily, undulatory periodization. After statistical analysis (Pability (large effect size). However, the TST promoted significant changes in 1RM (large effect size) and a significant increase in the muscle thickness of the vastus intermedius (moderate effect size). The CCT protocol could be used to improve the RSSA parameters, CMJ and 1RM, and the TST developed dynamic strength and muscle growth. Coaches can choose either CCT or TST protocols according to the needs of their soccer players.

  13. The validity and reliability of a global positioning satellite system device to assess speed and repeated sprint ability (RSA) in athletes.

    Science.gov (United States)

    Barbero-Alvarez, José C; Coutts, Aaron; Granda, Juan; Barbero-Alvarez, Verónica; Castagna, Carlo

    2010-03-01

    There is a limited understanding of the validity and reliability of commercially available global positioning satellite (GPS) devices for assessing repeated sprint performance in athletes. The aims of this study were to assess the convergent validity and the test-retest reliability of a GPS device for measuring repeated sprint ability test (RSAT) variables. Two groups participated in this study, a group of 21 physical education students (age: 20.2+/-2.3 years, stature: 1.75+/-0.42 m, body mass: 68.0+/-6.8kg) and a second group 14 elite junior soccer players (age: 14.5+/-1.2 years, stature: 1.60+/-0.09 m, body mass: 57.7+/-3.8kg) volunteered to participate in this study. Convergent validity was assessed as the correlation between sprint performance (15 and 30-m) using both timing lights and a portable GPS device during a RSAT (7 x 30-m sprints with 30-s of active recovery). The 7 x 30-m RSAT test-retest reliability using GPS device was assessed in elite junior soccer players repeating the test 1 week apart and expressing reliability as a coefficient of variation. Results showed a strong correlation between peak speed measures with the GPS device and RSAT performance measured with timing lights for the 15-m (r(2)=0.87, pspeed (1.7%) and peak speed (1.2%) during the 7 x 30-m RSAT, but high variation for the percentage decrement score (36.2%). These results provide evidence to support the use of the GPS device as an alternative measure to assess repeated sprint performance but suggest a percentage decrement score is not a reliable measure of RSAT performance.

  14. Effects of a small-sided game-based training programme on repeated sprint and change of direction abilities in recreationally-trained football players.

    Science.gov (United States)

    Bujalance-Moreno, Pascual; García-Pinillos, Felipe; Latorre-Román, Pedro Á

    2017-02-21

    To examine the effects of 6-week periodized small-sided game (SSG) training intervention on change of direction [COD], sprint and repeated sprint ability [RSA] in recreational male football players. Twenty-three young football players (age: 20.86 years) were randomized in a control group (n = 11) and an experimental group (n = 12). The SSG programme was included in the experimental group's training sessions. The players completed two variations of a SSG (i.e. 2 vs. 2 and 4 vs. 4 players) during intervention. To examine the changes in physical performance after the 6-week periodized SSG training intervention, all players were tested 6 weeks apart (i.e. pre-test and post-test) in sprint, COD ability test, and RSA shuttle test. A 2x2 ANOVA showed that 6-week SSG training intervention induced significant improvements (P0.7) in COD ability test, and variables related to both sprint test and RSA in the experimental group, whereas the control group remained unchanged (P≥0.05, ESsprint in recreationally trained football players.

  15. Comparison of shuttle and straight repeated-sprint ability tests and their relationship to anthropometrics and explosive muscular performance of lower limb in elite handball players.

    Science.gov (United States)

    Hermassi, Souhail; Schwesig, René; Wollny, Rainer; Fieseler, Georg; van den Tillaar, Roland; Fernandez-Fernandez, Jaime; Shephard, Roy J; Chelly, Mohamed S

    2017-06-21

    This study assessed inter-relationships between shuttle and straight repeated-sprint ability tests and the relationship of each measure to anthropometric and explosive lower limb performance data in elite handball players. Twenty-two elite male handball players (18.9 ± 0.2 years; body mass: 83.3 ± 1.1 kg, height: 1.79 ± 2.30 m, body fat: 12.8 ± 0.2%) completed tests that included a lower limb force-velocity test of peak power (Wpeak), jumping ability (squat and counter-movement jumps; SJ, CMJ), 1 repetition maximum (1-RM) half back squat, average sprint velocity over 5 m (V-5 m), peak velocity between 25-30 m (Vmax), and Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), and anthropometric determinations of cross-sectional areas and muscle volumes for leg and thigh muscles. Data were compared with performance on 2 repeated sprint tests; the straight test [6 × 30 m (RSA30)] and the intermittent test [6 x (2 x 15 m) shuttle sprints (RSA15)]. V-5 m; 1-RM; and thigh and leg muscle cross-sectional areas and volumes showed relevant relationships to the shuttle RSA test (r2≥0.5). The Yo-Yo IR1 explained the largest percentage of variance in RSA15 total time (60%), and V-5 m also explained 56% of the variance in RSA15 total time. RSA15% fatigue was only related to 1-RM (explained variance: 58%), and the RSA30 test showed no useful correlations with any of the investigated predictors. Multiple-regression analyses using all physical tests explained 91% of the variance in RSA15 total time (prepeated sprints over distances of 15 m or less. RSA15 is related to muscular power, maximal strength, speed and endurance performance; however, the straight repeated sprint ability test is not, and thus does not seem relevant for the testing of handball players.

  16. THE RELATIONSHIP BETWEEN AEROBIC POWER AND REPEATED SPRINT ABILITY IN YOUNG SOCCER PLAYERS WITH DIFFERENT LEVELS OF VO2 MAX

    Directory of Open Access Journals (Sweden)

    Rostam Alizadeh

    2010-06-01

    Full Text Available In some team sports such as soccer which is interval, athletes need to prepare themselves immediatelyfor the next activity. Therefore it is very important to have enough information on characteristics of recovery phase and quick recovery to the first situation and to have the minimum speed reduction. The purpose of this study was to determine the relationship between aerobic power and repeated sprint ability (RSA or decrementindex in young soccer players in three different levels of Vo2max. Methods: For this reason 41 volunteers were divided in to three groups with different levels of Vo2max ml.kg-1.min-1 low 37.22 ± 2.3 (n= 18, age 17.1 ± 0.9 year, height 170.6 ± 0.76 cm, weight 67.1 ± 5.05 kg medium 46.46± 1.97 ml.kg-1.min-1 (n= 13, age 17.6± 0.76year, height 173.8 ± 4.84 cm, weight 65.9 ± 4.92 kg and high 55.63 ± 1.52 ml.kg-1.min-1 (n=10, age 17.4 ±0.69 year, height 177 ± 3.23 cm, weight 71.4 ± 3.94 kg. To determine Vo2max a graded exercise test until volitional exhaustion on treadmill was used, and also RAST was used to measure RSA. The lactate accumulation was measured before and after RSA protocol. Pearson's correlation was used to determine the correlation between the aerobic power and RSA. The results indicated that there are significant relationship between Vo2max anddecremental index in low Vo2max group (r= 0.86, p= 0.001, no significant relationship medium Vo2max group (r= 0.14, p= 0.63 and negative significant relationship in high Vo2max group (r= - 0.64, p= 0.04. There are no significant relationship between Lactate accumulation and decremental index in medium (r= 0.005, p= 0.98 and high Vo2max groups (r=0.27, p= 0.45. Discussion: It is possible that the recovery of inter muscular resources relates to aerobic ability, but there are other factors effective in RSA rather than Vo2max and Lactate accumulation. The current study showed a normal curved relationship between Vo2max and RSA.

  17. Repeated sprint ability but not neuromuscular fatigue is dependent on short versus long duration recovery time between sprints in healthy males.

    Science.gov (United States)

    Monks, Michael R; Compton, Chris T; Yetman, Joseph D; Power, Kevin E; Button, Duane C

    2017-06-01

    During maximal intensity leg cycling sprints, previous research has shown that central and peripheral fatigue development occurs with various (sprints. The aim of the current study was to compare the development of neuromuscular fatigue during maximal intensity lower-body sprints interspersed with short and longer duration recovery periods. Crossover study. Ten participants completed 10, 10s sprints interspersed with either 30 or 180s of recovery. Peak power outputs were measured for each sprint. Maximal force, voluntary activation (VA) and evoked contractile properties of the knee extensors were measured at pre-sprint 1, post-sprint 5 and post-sprint 10. Perceived pain was also measured immediately following each sprint. Peak power output was significantly lower by 16.1±4.2% (psprint 10 with 30 compared to 180s of recovery. Irrespective of recovery time, maximal force, VA and potentiated twitch force decreased by 26.7±7.2% (psprint 1 to post-sprint 10. MVC and PT decreased by 17±4% (psprint 1 to post-sprint 5. Although decreases in peak power and increases in perceived pain were greater when sprints were interspersed with 30 compared to 180s of recovery, the development of neuromuscular fatigue of the knee extensors was similar. The results illustrate that peripheral fatigue developed early whereas central fatigue developed later in the sprint protocol, however the effect of recovery time on neuromuscular fatigue could be task specific. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. 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.

    Science.gov (United States)

    Russell, Mark; West, Daniel J; Briggs, Marc A; Bracken, Richard M; Cook, Christian J; Giroud, Thibault; Gill, Nicholas; Kilduff, Liam P

    2015-01-01

    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%, psprint times were 1.39±0.17% (prepeated sprint ability in professional Rugby Union players.

  19. 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 S; Chamari, Karim; Shephard, Roy J; Chelly, Mohamed S

    2016-11-16

    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 min 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. Demonstrated 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. 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 (2=0.811) and CMJ (2=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.

  20. Caffeine Ingestion Improves Repeated Freestyle Sprints in Elite Male Swimmers

    Directory of Open Access Journals (Sweden)

    Paul S.R. Goods, Grant Landers, Sacha Fulton

    2017-03-01

    Full Text Available The purpose of this investigation was to determine the efficacy of a moderate dose of caffeine to improve repeat-sprint performance in elite freestyle sprinters. Nine highly trained male swimmers performed 6 x 75 m freestyle sprints on two occasions 1-h after consuming either 3 mg·kg-1 caffeine (CAF, or placebo, in a cross-over manner. Capillary blood samples for the analysis of blood lactate concentration and pH were collected after the 1st, 3rd, and 5th sprint, while heart rate and perceived exertion (RPE were collected after every sprint. There was a moderate effect for improved mean sprint time in the CAF condition (0.52 s; 1.3%; d = 0.50. When assessed individually, there was a large effect for improved performance in sprints 3 (1.00 s; 2.5%; d = 1.02 and 4 (0.84 s; 2.1%; d = 0.84 in CAF compared to placebo, with worthwhile performance improvement found for each of the first 5 sprints. There was a significant treatment effect for higher blood lactate concentration for CAF (p = 0.029, and a significant treatment*time effect for reduced pH in the CAF condition (p = 0.004. Mean heart rate (167 ± 9 bpm vs 169 ± 7 bpm and RPE (17 ± 1 vs 17 ± 1 were not different between placebo and CAF trials, respectively. This investigation is the first to demonstrate enhanced repeat-sprint ability in swimmers following acute caffeine ingestion. It appears likely that the combination of a moderate dose of caffeine (3-6 mg·kg-1 with trained athletes is most likely to enhance repeat-sprint ability in various athletic populations; however, the exact mechanism(s for an improved repeat-sprint ability following acute caffeine ingestion remain unknown.

  1. Sport-Specific Repeated Sprint Training Improves Punching Ability And Upper-Body Aerobic Power In Experienced Amateur Boxers.

    Science.gov (United States)

    Kamandulis, Sigitas; Bruzas, Vidas; Mockus, Pranas; Stasiulis, Alvydas; Snieckus, Audrius; Venckunas, Tomas

    2017-08-09

    High-intensity interval training improves endurance and performance, but it is unclear whether sprint-type upper-body interval training is similarly effective. This study explored the effects of 4-week sport-specific sprint interval training on punch characteristics and endurance capacity in boxers. Experienced male amateur boxers (n = 18) participated in this 4-week training study, and were divided into an experimental group (EG) and a control group (CG) (n = 9 per group). Both groups completed standard low-intensity training. The EG also completed 3 rounds (14 sets of 3 s all-out punching with 10 s rest) of a simulated fight using a punching bag with 1 min rest between rounds 3 times per week, while the CG performed the same 3 rounds of a simulated fight at low intensity. Three rounds of 14 sets of 3 s all-out punching of a bag ergometer with 10 s rest were performed to measure punching abilities. Peak oxygen consumption and peak power were measured during progressive arm cranking before and after training. In response to training peak oxygen consumption and peak power in arm cranking test increased in EG; also, punching force increased and maintenance of punching frequency and punch force improved during the simulated fight, which resulted in greater cumulative force throughout the 3 rounds. There were no changes in the CG. The study shows that 1 month of all-out punching training (3 sessions per week with ∼2 min of all-out punching per session) improved both upper-body aerobic power and punching abilities in experienced amateur boxers.

  2. 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 (βmin 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. βmin 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 O2 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

  3. Hypoxic Repeat Sprint Training Improves Rugby Player's Repeated Sprint but Not Endurance Performance.

    Science.gov (United States)

    Hamlin, Michael J; Olsen, Peter D; Marshall, Helen C; Lizamore, Catherine A; Elliot, Catherine A

    2017-01-01

    hypoxia for six sessions increases repeat sprint ability but not YYIR1 performance in well-trained rugby players.

  4. Hypoxic Repeat Sprint Training Improves Rugby Player's Repeated Sprint but Not Endurance Performance

    Science.gov (United States)

    Hamlin, Michael J.; Olsen, Peter D.; Marshall, Helen C.; Lizamore, Catherine A.; Elliot, Catherine A.

    2017-01-01

    group. Repeat-sprint training in hypoxia for six sessions increases repeat sprint ability but not YYIR1 performance in well-trained rugby players. PMID:28223938

  5. Can a Repeated Sprint Ability Test Help Clear a Previously Injured Soccer Player for Fully Functional Return to Activity? A Pilot Study.

    Science.gov (United States)

    Padulo, Johnny; Attene, Giuseppe; Ardigò, Luca P; Bragazzi, Nicola L; Maffulli, Nicola; Zagatto, Alessandro M; Dello Iacono, Antonio

    2017-07-01

    To investigate the effects of fatigue induced by a repeated sprint ability (RSA) test on the neuromuscular responses of soccer players with a recent history of lower limb injuries (CH) and a matched control group in good fitness condition (GH). This was a case-control study. Nine CH and 9 GH. Allocation to CH or GH. Each player was assessed for blood lactate concentration and jumping performance [squat jump (SJ) and countermovement jump (CMJ)] before/after RSA. Post-RSA rate of perceived exertion (RPE) was obtained. Receiver operating characteristic analysis was performed to calculate RSA sensitivity and specificity in distinguishing between CH and GH. Intraclass correlation coefficient was used to assess reliability. No baseline differences were found for any variable. ΔSJ before/after RSA was -14 ± 2% and -5 ± 2% in CH and GH, respectively (P Repeated sprint ability is a simple, low-cost field test potentially able to assist in clinical decision making for return to sport.

  6. 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.

  7. Caffeine Ingestion Improves Repeated Freestyle Sprints in Elite Male Swimmers

    Science.gov (United States)

    Goods, Paul S.R.; Landers, Grant; Fulton, Sacha

    2017-01-01

    The purpose of this investigation was to determine the efficacy of a moderate dose of caffeine to improve repeat-sprint performance in elite freestyle sprinters. Nine highly trained male swimmers performed 6 x 75 m freestyle sprints on two occasions 1-h after consuming either 3 mg·kg-1 caffeine (CAF), or placebo, in a cross-over manner. Capillary blood samples for the analysis of blood lactate concentration and pH were collected after the 1st, 3rd, and 5th sprint, while heart rate and perceived exertion (RPE) were collected after every sprint. There was a moderate effect for improved mean sprint time in the CAF condition (0.52 s; 1.3%; d = 0.50). When assessed individually, there was a large effect for improved performance in sprints 3 (1.00 s; 2.5%; d = 1.02) and 4 (0.84 s; 2.1%; d = 0.84) in CAF compared to placebo, with worthwhile performance improvement found for each of the first 5 sprints. There was a significant treatment effect for higher blood lactate concentration for CAF (p = 0.029), and a significant treatment*time effect for reduced pH in the CAF condition (p = 0.004). Mean heart rate (167 ± 9 bpm vs 169 ± 7 bpm) and RPE (17 ± 1 vs 17 ± 1) were not different between placebo and CAF trials, respectively. This investigation is the first to demonstrate enhanced repeat-sprint ability in swimmers following acute caffeine ingestion. It appears likely that the combination of a moderate dose of caffeine (3-6 mg·kg-1) with trained athletes is most likely to enhance repeat-sprint ability in various athletic populations; however, the exact mechanism(s) for an improved repeat-sprint ability following acute caffeine ingestion remain unknown. Key points A moderate dose of caffeine (3 mg·kg-1) ingested 1 h before a repeat-sprint freestyle set significantly improves mean sprint time in elite swimmers. The combination of at least a moderate dose of caffeine (>3 mg·kg-1) with trained athletes appears the most likely to result in ergogenic benefit to anaerobic

  8. Six weeks of β-alanine supplementation did not enhance repeated-sprint ability or technical performances in young elite basketball players.

    Science.gov (United States)

    Milioni, Fabio; Redkva, Paulo E; Barbieri, Fabio A; Zagatto, Alessandro M

    2017-06-01

    Supplementation with β-alanine plays an important role as a precursor of carnosine, the most effective intramuscular buffer, and has been seen as a potential ergogenic aid, especially for high-intensity modalities such as basketball. Thus, the aim of the present study was to investigate the effects of 6 weeks of β-alanine supplementation on repeated sprint ability (RSA) and technical performances in young elite Brazilian basketball players. In total, 27 young basketball players (17±1 years) were randomized into a β-alanine group (Gβ - 6.4 g day(-1) of β-alanine) and a placebo group (GP - 6.4 g day(-1) of dextrose). Before and after the supplementation period the athletes performed a RSA test composed of ten 30 m sprints with two 180° changes of direction interspaced by 30 s of recovery. During the recovery period (i.e., after the sprints) the athletes performed a countermovement jump (CMJ) and a set of three free throws. After 48 h they performed a Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Both groups increased the distance covered in the Yo-Yo IR1 after the supplementation period ( p = 0.001). On the other hand, both groups presented impairment in RSA time-performance (total time, best time, and mean time, p ≤ 0.04), while no significant changes were observed for technical task performances (i.e., CMJ and free throws) ( p ≥ 0.07). No between-group interactions were observed for any variable measured ( p ≥ 0.31). Thus, 6 weeks of β-alanine supplementation did not improve RSA or technical performances in young elite basketball players.

  9. REPEATED SPRINT ABILITY IN PROFESSIONAL SOCCER vs. PROFESSIONAL FUTSAL PLAYERS [Capacidad de realizar esprints repetidos en jugadores profesionales de fútbol vs. Fútbol sala

    Directory of Open Access Journals (Sweden)

    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 sprint actions over other type of training aimed at improving aerobic capacity especially at professional level.

  10. REPEATED SPRINT ABILITY IN PROFESSIONAL SOCCER vs. PROFESSIONAL FUTSAL PLAYERS [Capacidad de realizar esprints repetidos en jugadores profesionales de fútbol vs. Fútbol sala

    Directory of Open Access Journals (Sweden)

    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 sprint actions over other type of training aimed at improving aerobic capacity especially at professional level.

  11. 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...

  12. 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 repeated 30-m sprints, either with one change of direction or multidirectional, induce similar physiological and performance responses in young basketball players, but have a different psycho-physiological impact.

  13. Beta-Alanine Supplementation Improves Throwing Velocities in Repeated Sprint Ability and 200-m Swimming Performance in Young Water Polo Players.

    Science.gov (United States)

    Claus, Gabriel Machado; Redkva, Paulo Eduardo; Brisola, Gabriel Mota Pinheiro; Malta, Elvis Sousa; de Araujo Bonetti de Poli, Rodrigo; Miyagi, Willian Eiji; Zagatto, Alessandro Moura

    2017-05-01

    The purpose of this study was to investigate the effects of beta-alanine supplementation on specific tests for water polo. Fifteen young water polo players (16 ± 2 years) underwent a 200-m swimming performance, repeated-sprint ability test (RSA) with free throw (shooting), and 30-s maximal tethered eggbeater kicks. Participants were randomly allocated into two groups (placebo × beta-alanine) and supplemented with 6.4g∙day(-1)of beta-alanine or a placebo for six weeks. The mean and total RSA times, the magnitude based inference analysis showed a likely beneficial effect for beta-alanine supplementation (both). The ball velocity measured in the throwing performance after each sprint in the RSA presented a very like beneficial inference in the beta-alanine group for mean (96.4%) and percentage decrement of ball velocity (92.5%, likely beneficial). Furthermore, the percentage change for mean ball velocity was different between groups (beta-alanine=+2.5% and placebo=-3.5%; p = .034). In the 30-s maximal tethered eggbeater kicks the placebo group presented decreased peak force, mean force, and fatigue index, while the beta-alanine group maintained performance in mean force (44.1%, possibly beneficial), only presenting decreases in peak force. The 200-m swimming performance showed a possibly beneficial effect (68.7%). Six weeks of beta-alanine supplementation was effective for improving ball velocity shooting in the RSA, maintaining performance in the 30-s test, and providing possibly beneficial effects in the 200-m swimming performance.

  14. Acute Responses to 10×15 m Repeated Sprint Ability Exercise in Adolescent Athletes: the Role of Change of Direction and Sport Specialization.

    Science.gov (United States)

    Nikolaidis, Pantelis Theodoros; Meletakos, Panagiotis; Tasiopoulos, Ioannis; Kostoulas, Ioannis; Ganavias, Panagiotis

    2016-06-01

    The repeated sprint ability (RSA) has been studied with protocols using distances longer than 20 m per sprint, whereas basketball players cover on average less than 20-meter distance per sprint during match. The aim of the present study was to examine the physiological impact of 10 × 15 m RSA test in straight-line (RSASL) or with change of direction (RSACOD), i.e. 10 × (7.5 + 7.5 m)) in young national level basketball players. Young basketball players (n = 11, age 17.1 (1.0) years, body mass 76 (6) kg, height 184 (4) cm, body mass index 22.6 (1.8) kgm(-2), sport experience 6.9 (2.7) years, mean (standard deviation)) and a control group consisting of high-school athletes (n = 7, 16.1 (0.7) years, 67 (6) kg, 177 (6) cm, 21.5 (1.0) kgm(-2), 7.7 (1.6) years, respectively) performed RSASL and RSACOD on a counter-balanced order. Sprints started every 30 seconds (active recovery) and there was 30 minutes break between RSA protocols; time variables were total time (TT), best time (BT) and fatigue index (FI). Countermovement jump (CMJ) was tested before and after each RSA protocol. Heart rate (HR) was continuously monitored during testing procedures. Compared with RSASL, TT and BT were worst in RSACOD (38.13 vs. 27.52 s and 3.67 vs. 2.66 s, P repeated measures ANOVA showed main effect of RSA on CMJ (pre-test vs. post-test, increase + 1.8 cm, P = 0.020, η(2) = 0.28); there was neither main effect of RSA protocols (RSASL vs. RSACOD +0.7 cm, P = 0.251, η(2) = 0.08) nor an interaction between pre-post measurements and RSA protocols (P = 0.578, η(2) = 0.02). Compared with RSASL, RSACOD induced higher mean and peak HR responses (175 vs 172 bpm, P < 0.001, and 185 vs 182 bpm, P = 0.002, respectively). No statistical difference was observed between basketball players and control group neither for TT (27.98 vs. 26.80 seconds, + 4.4%, P = 0.149) and BT (2.71 vs. 2.59 seconds, + 4.5%, P = 0.157) in RSASL nor for TT (38.55 vs. 37.47 seconds, + 2.9%, P = 0.169) and BT (3.70 vs. 3

  15. 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.

  16. Low volume short duration high-intensity interval training and repeated sprint ability in Gaelic football players

    OpenAIRE

    Kelly, David

    2014-01-01

    Gaelic Football is the most popular sport in Ireland and is characterized by irregular changes of pace and high-intensity efforts interspersed with periods of light to moderate intensity activity. Speed, power and aerobic capacity are essential fitness components for optimal performance during match play. A high level of aerobic conditioning is required to generate and maintain power output during repeated high intensity activities. Study 1: Anthropometric, physiological, metabolic and en...

  17. Effect of training in hypoxia on repeated sprint performance in female athletes.

    Science.gov (United States)

    Kasai, Nobukazu; Mizuno, Sahiro; Ishimoto, Sayuri; Sakamoto, Etsuko; Maruta, Misato; Goto, Kazushige

    2015-01-01

    This study determined the effect of repeated sprint training in hypoxia (RSH) in female athletes. Thirty-two college female athletes performed repeated cycling sprints of two sets of 10 × 7-s sprints with a 30-s rest between sprints twice per week for 4 weeks under either normoxic conditions (RSN group; FiO2, 20.9%; n = 16) or hypoxic conditions (RSH group; FiO2, 14.5%; n = 16). The repeated sprint ability (10 × 7-s sprints) and maximal oxygen uptake ([Formula: see text]) were determined before and after the training period. After training, when compared to pre-values, the mean power output was higher in all sprints during the repeated sprint test in the RSH group but only for the second half of the sprints in the RSN group (P ≤ 0.05). The percentage increases in peak and mean power output between before and after the training period were significantly greater in the RSH group than in the RSN group (peak power output, 5.0 ± 0.7% vs. 1.5 ± 0.9%, respectively; mean power output, 9.7 ± 0.9% vs. 6.0 ± 0.8%, respectively; P repeated sprint test compared with RSN.

  18. Relationship between aerobic fitness and repeated sprint ability in soccer: protocol effect. DOI: 10.5007/1980-0037.2011v13n2p111

    Directory of Open Access Journals (Sweden)

    Leandro Teixeira Floriano

    2011-03-01

    Full Text Available The aim of this study was to evaluate the association between physiological variables related to physical fitness determined by continuous straight running on a treadmill (peak velocity on treadmill: PVTRE, maximum oxygen uptake: VO2max, minimum velocity needed to reach VO2max: vVO2max, and velocity at the anaerobic threshold: vAT and intermittent running with directional changes (peak velocity: PV and repeated sprint ability (RSA in soccer players. Twenty-nine athletes (17.9 ± 1.0 years, 178.7 ± 5.2 cm, 73.6 ± 6.7 kg, and 11.1 ± 1.3% body fat performed the following tests on different days: 1 incremental protocol on a treadmill to determine PVTRE, VO2max, vVO2max, and vAT; 2 incremental intermittent running test to determine PV, and 3 Bangsbo test to evaluate RSA and to determine the mean time (MT, fastest time (FT, and fatigue index (FI. Pearson’s correlation coefficient was used and a level of significance of 5% was adopted. PV obtained in the intermittent running test showed a higher correlation with MT and FT of the RSA test (r = -0.70, p 0.05 and PVTRE (r = -0.42, p 0.05 determined by straight running on a treadmill. In conclusion, the relationship between physical fitness and RSA depends on the type of protocol (continuous line running vs. intermittent with directional changes and the aerobic index used (capacity vs. power.

  19. Neuro-mechanical and metabolic adjustments to the repeated anaerobic sprint test in professional football players.

    Science.gov (United States)

    Brocherie, Franck; Millet, Gregoire P; Girard, Olivier

    2015-05-01

    This study aimed to determine the neuro-mechanical and metabolic adjustments in the lower limbs induced by the running anaerobic sprint test (the so-called RAST). Eight professional football players performed 6 × 35 m sprints interspersed with 10 s of active recovery on artificial turf with their football shoes. Sprinting mechanics (plantar pressure insoles), root mean square activity of the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) muscles (surface electromyography, EMG) and VL muscle oxygenation (near-infrared spectroscopy) were monitored continuously. Sprint time, contact time and total stride duration increased from the first to the last repetition (+17.4, +20.0 and +16.6 %; all P 0.05), decreased over sprint repetitions and were correlated with the increase in running time (r = -0.82 and -0.90; both P sprint repetitions, players with a better repeated-sprint performance (lower cumulated times) also displayed faster muscle de- (during sprints) and re-oxygenation (during recovery) rates (r = -0.74 and -0.84; P repeated anaerobic sprint test leads to substantial alterations in stride mechanics and leg-spring behaviour. Our results also strengthen the link between repeated-sprint ability and the change in neuromuscular activation as well as in muscle de- and re-oxygenation rates.

  20. Sex differences in acute translational repressor 4E-BP1 activity and sprint performance in response to repeated-sprint exercise in team sport athletes.

    Science.gov (United States)

    Dent, Jessica R; Edge, Johann A; Hawke, Emma; McMahon, Christopher; Mündel, Toby

    2015-11-01

    The physiological requirements underlying soccer-specific exercise are incomplete and sex-based comparisons are sparse. The aim of this study was to determine the effects of a repeated-sprint protocol on the translational repressor 4E-BP1 and sprint performance in male and female soccer players. Cross-over design involving eight female and seven male university soccer players. Participants performed four bouts of 6 × 30-m maximal sprints spread equally over 40 min. Heart rate, sprint time and sprint decrement were measured for each sprint and during the course of each bout. Venous blood samples and muscle biopsies from the vastus lateralis were taken at rest, at 15 min and 2h post-exercise. While males maintained a faster mean sprint time for each bout (P sprint performance for each bout (P sprint performance in males, with no sex differences for heart rate or lactate. Muscle analyses revealed sex differences in resting total (P repeated sprints. We show that females have a larger sprint decrement indicating that males have a superior ability to recover sprint performance. Sex differences in resting 4E-BP1 Thr37/46 suggest diversity in the training-induced phenotype of the muscle of males and females competing in equivalent levels of team-sport competition. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Fatigue in repeated-sprint exercise is related to muscle power factors and reduced neuromuscular activity.

    Science.gov (United States)

    Mendez-Villanueva, Alberto; Hamer, Peter; Bishop, David

    2008-07-01

    The purpose of this study was (1) to determine the relationship between each individual's anaerobic power reserve (APR) [i.e., the difference between the maximum anaerobic (Pana) and aerobic power (Paer)] and fatigability during repeated-sprint exercise and (2) to examine the acute effects of repeated sprints on neuromuscular activity, as evidenced by changes in the surface electromyogram (EMG) signals. Eight healthy males carried out tests to determine Pana (defined as the highest power output attained during a 6-s cycling sprint), Paer (defined as the highest power output achieved during a progressive, discontinuous cycling test to failure) and a repeated cycling sprint test (10 x 6-s max sprints with 30 s rest). Peak power output (PPO) and mean power output (MPO) were calculated for each maximal 6-s cycling bout. Root mean square (RMS) was utilized to quantify EMG activity from the vastus lateralis (VL) muscle of the right leg. Over the ten sprints, PPO and MPO decreased by 24.6 and 28.3% from the maximal value (i.e., sprint 1), respectively. Fatigue index during repeated sprints was significantly correlated with APR (R = 0.87; P < 0.05). RMS values decreased over the ten sprints by 14.6% (+/-6.3%). There was a strong linear relationship (R2 = 0.97; P < 0.05) between the changes in MPO and EMG RMS from the vastus lateralis muscle during the ten sprints. The individual advantage in fatigue-resistance when performing a repeated sprint task was related with a lower anaerobic power reserve. Additionally, a suboptimal net motor unit activity might also impair the ability to repeatedly generate maximum power outputs.

  2. Effects of Hypohydration on Repeated 40-yd Sprint Performance.

    Science.gov (United States)

    Gann, Joshua J; Green, James M; OʼNeal, Eric K; Renfroe, Lee G; Andre, Thomas L

    2016-04-01

    This study examined the effects of hypohydration on repeated 40-yd sprint performance. Anaerobically fit current and former Division II male athletes (n = 12) completed 2 bouts of 10 × 40-yd sprints followed by an agility test, dehydrated (∼3% body weight [DT]), or hydrated trial (HT). Statistical analysis of group means indicated that hypohydration had little effect on sprint times for either the first (DT= 5.38 ± 0.37; HT = 5.35 ± 0.34) or second (DT = 5.47 ± 0.39; HT = 5.42 ± 0.39) bout of 10 sprints with only sprint number 2, 5, and 6 of bout 2 reaching statistical significance. However, when individual sprint performance was considered, a greater effect was seen. In all, 83% (10 of 12) of subjects experienced a meaningful change (≥0.1 seconds) (positive or negative) in mean sprint time (DT vs. HT) for one or more bout of 10 sprints. Ratings of perceived exertion was significantly higher (∼1 unit on a 10 point scale) for DT in all sprints during bout 1 and the first 2 sprints of bout 2. These results indicate that the effect of hypohydration on repeated sprint performance varies among individuals. Some improved performance with hypohydration, while others experienced detrimental effects. Hypohydration also resulted in a particularly notable negative impact on perceptual measures of exertion even when performance was similar.

  3. Repeated double-poling sprint training in hypoxia by competitive cross-country skiers.

    Science.gov (United States)

    Faiss, Raphael; Willis, Sarah; Born, Dennis-Peter; Sperlich, Billy; Vesin, Jean-Marc; Holmberg, Hans-Christer; Millet, Grégoire P

    2015-04-01

    Repeated-sprint training in hypoxia (RSH) was recently shown to improve repeated-sprint ability (RSA) in cycling. This phenomenon is likely to reflect fiber type-dependent, compensatory vasodilation, and therefore, our hypothesis was that RSH is even more beneficial for activities involving upper body muscles, such as double poling during cross-country skiing. In a double-blinded fashion, 17 competitive cross-country skiers performed six sessions of repeated sprints (each consisting of four sets of five 10-s sprints, with 20-s intervals of recovery) either in normoxia (RSN, 300 m; FiO2, 20.9%; n = 8) or normobaric hypoxia (RSH, 3000 m; FiO2, 13.8 %; n = 9). Before (pre) and after (post) training, performance was evaluated with an RSA test (10-s all-out sprints-20-s recovery, until peak power output declined by 30%) and a simulated team sprint (team sprint, 3 × 3-min all-out with 3-min rest) on a double-poling ergometer. Triceps brachii oxygenation was measured by near-infrared spectroscopy. From pretraining to posttraining, peak power output in the RSA was increased (P sprints performed was enhanced in RSH (10.9 ± 5.2 vs 17.1 ± 6.8, P sprints throughout RSA rose more in RSH (P sprints improved by 11% ± 9% in RSH and 15% ± 7% in RSN. Our findings reveal greater improvement in the performance of repeated double-poling sprints, together with larger variations in the perfusion of upper body muscles in RSH compared with those in RSN.

  4. 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.

  5. 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.

  6. Significant Molecular and Systemic Adaptations after Repeated Sprint Training in Hypoxia

    Science.gov (United States)

    Faiss, Raphael; Léger, Bertrand; Vesin, Jean-Marc; Fournier, Pierre-Etienne; Eggel, Yan; Dériaz, Olivier; Millet, Grégoire P.

    2013-01-01

    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 O2 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 (psprints to exhaustion was increased in RSH (9.4±4.8 vs. 13.0±6.2 sprints, psprints throughout RSA test increased to a greater extent (prepeated sprint performance in RSH than in RSN with significant molecular adaptations and larger blood perfusion variations in active muscles. PMID:23437154

  7. The effect of 40-m repeated sprint training on maximum sprinting speed, repeated sprint speed endurance, vertical jump, and aerobic capacity in young elite male soccer players.

    Science.gov (United States)

    Tønnessen, Espen; Shalfawi, Shaher A I; Haugen, Thomas; Enoksen, Eystein

    2011-09-01

    The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study. All participants were tested on 40-m running speed, 10 × 40-m repeated sprint speed, 20-m acceleration speed, 20-m top speed, countermovement jump (CMJ), and aerobic endurance (beep test). Participants were divided into training group (TG) (n = 10) and control group (CG) (n = 10). The study was conducted in the precompetition phase of the training program for the participants and ended 13 weeks before the start of the season; the duration of the precompetition period was 26 weeks. The TG followed a Periodized repeated sprint training program once a week. The training program consisted of running 40 m with different intensities and duration from week to week. Within-group results indicate that TG had a statistically marked improvement in their performance from pre to posttest in 40-m maximum sprint (-0.06 seconds), 10 × 40-m repeated sprint speed (-0.12 seconds), 20- to 40-m top speed (-0.05 seconds), and CMJ (2.7 cm). The CG showed only a statistically notable improvement from pre to posttest in 10 × 40-m repeated sprint speed (-0.06 seconds). Between-group differences showed a statistically marked improvement for the TG over the CG in 10 × 40-m repeated sprint speed (-0.07 seconds) and 20- to 40-m top speed (-0.05 seconds), but the effect of the improvement was moderate. The results further indicate that a weekly training with repeated sprint gave a moderate but not statistically marked improvement in 40-m sprinting, CMJ, and beep test. The results of this study indicate that the repeated sprint program had a positive effect on several of the parameters tested

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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%; psprint performance, whereas 5-30 lowered the 20-m sprint time (2.7±1.6%; psprint performance. The distance covered during the Yo-Yo Intermittent Recovery Test Level 2 increased following 5-15 (11.4±5.0%; prepeated-sprint ability test were possibly greater following 5-30 (3.6±0.9%; prepeated-sprint ability test as well as in blood lactate concentration during submaximal exercise (17-18%). No changes occurred in the control group. In soccer 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.

  10. The effect of a short practical warm-up protocol on repeated sprint performance.

    Science.gov (United States)

    Taylor, Jonathan M; Weston, Matthew; Portas, Matthew D

    2013-07-01

    The aim of our study was to investigate the effect of a short, practical, 2-phase warm-up on repeated sprint performance when compared with more traditional warm-up protocols that contain stretching activities. Eleven subelite male soccer players completed a warm-up protocol that commenced with 5 minutes jogging at approximately 65% of maximal heart rate, followed by no stretching, static stretching, or dynamic stretching and finishing with a task-specific high-intensity activity. Using a crossover design, the 3 warm-up protocols were performed in a counterbalanced order with at least 48 hours between sessions. Repeated sprint performance was measured using a repeated sprint test that consisted of 6 × 40-m maximal sprints interspersed with a 20-second recovery. There were trivial differences in mean sprint time (0.2%) and posttest blood lactate (3.1%) between the 2-phase warm-up and the 3-phase warm-up that included dynamic stretching, whereas the short warm-up had a possibly detrimental effect on fastest sprint time (0.7%). Fastest (-1.1%) and mean (-1.2%) sprint times were quicker and posttest blood lactates were higher (13.2%) after the 2-phase warm-up when compared with the 3-phase warm-up that included static stretching. Although it is not harmful to complete a traditional 3-phase warm-up that includes dynamic stretching, it appears practical for athletes preparing for activities dependent on repeated sprint ability to complete a 2-phase warm-up consisting of a cardiovascular and specific high-intensity activity.

  11. Elevations in core and muscle temperature impairs repeated sprint performance

    DEFF Research Database (Denmark)

    Drust, B.; Rasmussen, P.; Mohr, Magni

    2005-01-01

    following the hyperthermic sprints compared to control. CONCLUSION: Although an elevated muscle temperature is expected to promote sprint performance, power output during the repeated sprints was reduced by hyperthermia. The impaired performance does not seem to relate to the accumulation of recognized...... 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......)), rating of perceived exertion (RPE) (18 +/- 1) and noradrenaline (38.9 +/- 13.2 micromol l(-1)) (all P power output were similar across the environmental conditions. However, mean power over the last four sprints declined to a larger extent...

  12. Performance and physiological responses to repeated-sprint exercise: a novel multiple-set approach.

    Science.gov (United States)

    Serpiello, Fabio R; McKenna, Michael J; Stepto, Nigel K; Bishop, David J; Aughey, Robert J

    2011-04-01

    We investigated the acute and chronic responses to multiple sets of repeated-sprint exercise (RSE), focusing on changes in acceleration, intermittent running capacity and physiological responses. Ten healthy young adults (7 males, 3 females) performed an incremental test, a Yo-Yo intermittent recovery test level1 (Yo-Yo IR1), and one session of RSE. RSE comprised three sets of 5 × 4-s maximal sprints on a non-motorised treadmill, with 20 s of passive recovery between repetitions and 4.5 min of passive recovery between sets. After ten repeated-sprint training sessions, participants repeated all tests. During RSE, performance was determined by measuring acceleration, mean and peak power/velocity. Recovery heart rate (HR), HR variability, and finger-tip capillary lactate concentration ([Lac(-)]) were measured. Performance progressively decreased across the three sets of RSE, with the indices of repeated-sprint ability being impaired to a different extent before and after training. Training induced a significant increase (p RSE. There were strong correlations between Yo-Yo IR1 performance and indices of RSE performance, especially acceleration post-training (r = 0.88, p = 0.004). Repeated-sprint training, comprising only 10 min of exercise overall, effectively improved performance during multiple-set RSE. This exercise model better reflects team-sport activities than single-set RSE. The rapid training-induced improvement in acceleration, quantified here for the first time, has wide applications for professional and recreational sport activities.

  13. 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.

  14. Repeated-sprint performance, locomotor profile and muscle oxygen uptake recovery: effect of training background.

    Science.gov (United States)

    Ufland, P; Ahmaidi, S; Buchheit, M

    2013-10-01

    The aim of the present study was to examine the respective importance of locomotor profile and muscle oxygen uptake (mV(˙)O₂) recovery on repeated-sprint ability (RSA) and overall repeated-sprint performance. 11 sprint- (STR) and 10 middle-distance-trained (MDTR) athletes (20.8±4.0 yr) performed an incremental test and a 40-to-50-m sprint to estimate their maximal aerobic (MAS) and sprinting (MSS) speeds. They also performed 6×30-m sprints, departing every 30 s, where mean (RS(mean)) sprint time was calculated. Muscle oxygenation (Near-infrared spectroscopy, NIRS, [Hb(diff)]) was measured for ~ 4 min post test. The mean response time of [Hb(diff)]-mV(˙)O₂ recovery (monoexponential curve fitting, MRT[Hb(diff)]-mV(˙)O₂) was calculated. Compared with MDTR, STR presented faster MSS (+11.4±6.7%, with 99% chances to observe a substantially greater value) and RS(mean) (-3.7±5.4%, 78%), but slower MAS (-15.8±8.0%, 100%) and MRT[Hb(diff)]-mV(˙)O₂ (+46.2±31.7%, 96%). RS(mean) was largely correlated with MSS [r=-0.83 (90%CL, -0.92;-0.67)], but neither with MAS [r=-0.12 (-0.47;0.25)] nor MRT[Hb(diff)]-mV(˙)O₂ [r=-0.27(-0.58;0.11)]. RS(mean) adjusted for MSS (which indirectly reflects RSA) was largely correlated with both MAS [r=0.51(0.18;0.74)] and MRT[Hb(diff)]-mV(˙)O₂ [r=0.53(0.20;0.75)]. While a fast mV(˙)O₂ recovery is associated with an improved RSA, MSS remains of primary importance for overall repeated-sprint performance (i.e., RS(mean)).

  15. Research Advancement of Metabolic Mechanisms about Repeated Sprint Ability for Team Ball Games Players%集体球类项目运动员反复冲刺能力的能量代谢机制的研究现状

    Institute of Scientific and Technical Information of China (English)

    刘小平; 程丽平

    2012-01-01

    对于集体球类项目(篮球、足球、橄榄球、手球等)来讲,运动员为了有效地完成比赛的技战术要求,取得竞争优势,必须在场上进行反复的高强度冲刺活动,所以反复冲刺的能力(Repeated-sprint ability:RSA)对运动员的竞技表现是至关重要的。本文旨在通过对国内外集体球类项目运动员反复冲刺能力的研究成果进行梳理分析,总结归纳出反复冲刺能力的能量代谢基础、测试方法及影响因素,以期能对我国竞技水平普遍不高的集体球类运动项目的科学化训练提供理论指导。%For the team ball games(basketball,football,rugby,etc.),the athlete must run high intensity sprint repeatedly in the field or court to effectively complete the game's technical and tactical requirements and get competitive advantage,therefore,repeated sprint ability(repeated-sprint ability: RSA) of the athletes is essential.This paper makes comprehensive review on research results about repeated sprint ability at home and abroad.The main purpose of this paper is to summarize physiological basis,test methods and impact factors of repeated sprint ability and provide theoretical guidance for team ball games scientific training.

  16. Longitudinal study of repeated sprint performance in youth soccer players of contrasting skeletal maturity status

    NARCIS (Netherlands)

    Valente-dos-Santos, Joao; Coelho-e-Silva, Manuel J.; Severino, Vitor; Duarte, Joao; Martins, Raul S.; Figueiredo, Antonio J.; Seabra, Andre T.; Philippaerts, Renaat M.; Cumming, Sean P.; Elferink-Gemser, Marije; Malina, Robert M.

    The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11-13 years at baseline was assessed annually. Stature,

  17. Longitudinal study of repeated sprint performance in youth soccer players of contrasting maturity status

    NARCIS (Netherlands)

    V. Duarte; A. Seabra; A. Figueiredo; S. Cumming; R. Martins; R. Philippaerts; M. Coelho e Silva; J. Valente dos Santos; V. Severino; Marije Elferink-Gemser

    2012-01-01

    The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11- 13 years at baseline was assessed annually.

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. Effect of endurance training on performance and muscle reoxygenation rate during repeated-sprint running.

    Science.gov (United States)

    Buchheit, Martin; Ufland, Pierre

    2011-02-01

    The aim of the present study was to examine the effect of an 8-week endurance training program on repeated-sprint (RS) performance and post-sprints muscle reoxygenation rate in 18 moderately trained males (34 ± 5 years). Maximal aerobic speed (MAS), 10 km running and RS (2 × 15-s shuttle-sprints, interspersed with 15 s of passive recovery) performance were assessed before and after the training intervention. Total distance covered (TD) and the percentage of distance decrement (%Dec) were calculated for RS. Between-sprints muscle reoxygenation rate (Reoxy rate) was assessed with near-infrared spectroscopy during RS before and after training. After training, MAS (+9.8 ± 5.8%, with 100% chances to observe a substantial improvement), 10 km time (-6.2 ± 5.3%, 99%), TD (+9.6 ± 7.7%, 98%), %Dec (-25.6 ± 73.6%, 93%) and Reoxy rate (+152.4 ± 308.1%, 95%) were improved. The improvement of Reoxy rate was largely correlated with improvements in MAS [r = 0.63 (90% CL, 0.31;-0.82)] and %Dec [r = -0.52 (-0.15;-0.76)]. Present findings confirm the beneficial effect of endurance training on post-sprint muscle reoxygenation rate, which is likely to participate in the improvement of repeated-sprint ability after training. These data also confirm the importance of aerobic conditioning in sports, where repeating high-intensity/maximal efforts within a short time-period are required.

  2. Effects of two different half-squat training programs on fatigue during repeated cycling sprints in soccer players.

    Science.gov (United States)

    Bogdanis, Gregory C; Papaspyrou, Aggeliki; Souglis, Athanasios G; Theos, Apostolos; Sotiropoulos, Aristomenis; Maridaki, Maria

    2011-07-01

    This study compared the effects of two different half-squat training programs on the repeated-sprint ability of soccer players during the preseason. Twenty male professional soccer players were divided into 2 groups: One group (S-group) performed 4 sets of 5 repetitions with 90% of their 1-repetition maximum (1RM), and the other group (H-group) performed 4 sets of 12 repetitions with 70% of 1RM, 3 times per week for 6 weeks, in addition to their common preseason training program. Repeated-sprint ability was assessed before and after training by 10 × 6-second cycle ergometer sprints separated by 24 seconds of passive recovery. Maximal half-squat strength increased significantly in both groups (p < 0.01), but this increase was significantly greater in the S-group compared with the H-group (17.3 ± 1.9 vs. 11.0 ± 1.9%, p < 0.05). Lean leg volume (LLV) increased only in the H-group. Total work over the 10 sprints improved in both groups after training, but this increase was significantly greater in the second half (8.9 ± 2.6%) compared with the first half of the sprint test (3.2 ± 1.7%) only in the S-group. Mean power output (MPO) expressed per liter of LLV was better maintained during the last 6 sprints posttraining only in the S-group, whereas there was no change in MPO per LLV in the H-group over the 10 sprints. These results suggest that resistance training with high loads is superior to a moderate-load program, because it increases strength without a change in muscle mass and also results in a greater improvement in repeated sprint ability. Therefore, resistance training with high loads may be preferable when the aim is to improve maximal strength and fatigue during sprinting in professional soccer players.

  3. The effects of repeated-sprint training on field-based fitness measures: a meta-analysis of controlled and non-controlled trials.

    Science.gov (United States)

    Taylor, Jonathan; Macpherson, Tom; Spears, Iain; Weston, Matthew

    2015-06-01

    Repeated-sprint training appears to be an efficient and practical means for the simultaneous development of different components of fitness relevant to team sports. Our objective was to systematically review the literature and meta-analyse the effect of repeated-sprint training on a selection of field-based measures of athletic performance, i.e. counter-movement jump, 10 m sprint, 20 m sprint, 30 m sprint, repeated-sprint ability and high-intensity intermittent running performance. The SPORTDiscus, PubMed, MEDLINE and Web of Science databases were searched for original research articles. Search terms included 'repeated-sprint training', 'sprint training', 'aerobic endurance', 'repeated-sprint ability', 'counter-movement jump' and 'sprint performance'. Inclusion criteria included intervention consisting of a series of ≤10 s sprints with ≤60 s recovery; trained participants; intervention duration of 2-12 weeks; field-based fitness measures; running- or cycling-based intervention; published up to, and including, February 2014. Our final dataset included six trials for counter-movement jump (two controlled trials), eight trials for 10 m sprint, four trials for 20 m sprint (three controlled trials), two trials for 30 m sprint, eight trials for repeated-sprint ability and three trials for high-intensity intermittent running performance. Analyses were conducted using comprehensive meta-analysis software. Uncertainty in the meta-analysed effect of repeated-sprint training was expressed as 95% confidence limits (CL), along with the probability that the true value of the effect was trivial, beneficial or harmful. Magnitude-based inferences were based on standardised thresholds for small, moderate and large changes of 0.2, 0.6 and 1.2 standard deviations, respectively. Repeated-sprint training had a likely small beneficial effect in non-controlled counter-movement jump trials (effect size 0.33; 95% CL ±0.30), with a possibly moderate beneficial effect in controlled

  4. Repeated sprint performance and metabolic recovery curves: effects of aerobic and anaerobic characteristics.

    Science.gov (United States)

    de Aguiar, Rafael Alves; Turnes, Tiago; Santos de Oliveira Cruz, Rogério; Salvador, Amadeo Félix; Caputo, Fabrizio

    2015-05-01

    To examine the influence of aerobic and anaerobic indices on repeated sprint (RS) performance and ability (RSA), 8 sprinters (SPR), 8 endurance runners (END), and 8 active participants (ACT) performed the following tests: (i) incremental test; (ii) 1-min test to determine first decay time constant of pulmonary oxygen uptake off-kinetics and parameters related to anaerobic energy supply, lactate exchange, and removal abilities from blood lactate kinetics; and (iii) RS test (ten 35-m sprints, departing every 20 s) to determine best (RSbest) and mean (RSmean) sprint times and percentage of sprint decrement (%Dec). While SPR had a 98%-100% likelihood of having the fastest RSbest (Cohen's d of 1.8 and 1.4 for ACT and END, respectively) and RSmean (2.1 and 0.9 for ACT and END, respectively), END presented a 97%-100% likelihood of having the lowest %Dec (0.9 and 2.2 for ACT and SPR, respectively). RSmean was very largely correlated with RSbest (r=0.85) and moderately correlated with estimates of anaerobic energy supply (r=-0.40 to -0.49). RSmean adjusted for RSbest (which indirectly reflects RSA) was largely correlated with lactate exchange ability (r=0.55). Our results confirm the importance of locomotor- and anaerobic-related variables to RS performance, and highlight the importance of disposal of selected metabolic by-products to RSA.

  5. Performance and physiological responses to repeated-sprint and jump sequences.

    Science.gov (United States)

    Buchheit, Martin

    2010-11-01

    In this study, the performance and selected physiological responses to team-sport specific repeated-sprint and jump sequence were investigated. On four occasions, 13 team-sport players (22 ± 3 year) performed alternatively six repeated maximal straight-line or shuttle-sprints interspersed with a jump ([RS(+j), 6 × 25 m] or [RSS(+j), 6 × (2 × 12.5 m)]) or not ([RS, 6 × 25 m] or [RSS, 6 × (2 × 12.5 m)]) within each recovery period. Mean running time, rate of perceived exertion (RPE), pulmonary oxygen uptake (V(O)₂), blood lactate ([La](b)), and vastus lateralis deoxygenation ([HHb]) were obtained for each condition. Mean sprint times were greater for RS(+j) versus RS (4.14 ± 0.17 vs. 4.09 ± 0.16 s, with the qualitative analysis revealing a 82% chance of RS(+j) times to be greater than RS) and for RSS(+j) versus RSS (5.43 ± 0.18 vs. 5.29 ± 0.17 s; 99% chance of RSS(+j) to be >RSS). The correlation between sprint and jump abilities were large-to-very-large, but below 0.71 for RSSs. Jumps increased RPE (Cohen's d ± 90% CL: +0.7 ± 0.5; 95% chance for RS(+j) > RS and +0.7 ± 0.5; 96% for RSS(+j) > RSS), V(O)₂(+0.4 ± 0.5; 80% for RS(+j) > RS and +0.5 ± 0.5; 86% for RSS(+j) > RSS), [La](b) (+0.5 ± 0.5; 59% for RS(+j) > RS and +0.2 ± 0.5; unclear for RSS(+j) > RSS), and [HHb] (+0.5 ± 0.5; 86% for RS(+j) > RS and +0.5 ± 0.5; 85% for RSS(+j) > RSS). To conclude, repeated- sprint and jump abilities could be considered as specific qualities. The addition of a jump within the recovery periods during repeated-sprint running sequences impairs sprinting performance and might be an effective training practice for eliciting both greater systemic and vastus lateralis physiological loads.

  6. Relationship Between Repeated Sprint Performance and both Aerobic and Anaerobic Fitness.

    Science.gov (United States)

    Dardouri, Wajdi; Selmi, Mohamed Amin; Sassi, Radhouane Haj; Gharbi, Zied; Rebhi, Ahmed; Yahmed, Mohamed Haj; Moalla, Wassim

    2014-03-27

    The aims of this study were firstly, to examine the relationship between repeated sprint performance indices and anaerobic speed reserve (AnSR), aerobic fitness and anaerobic power and secondly, to identify the best predictors of sprinting ability among these parameters. Twenty nine subjects (age: 22.5 ± 1.6 years, body height: 1.8 ± 0.1 m, body mass: 68.8 ± 8.5 kg, body mass index (BMI): 22.2 ± 2.1 kg•m-2, fat mass: 11.3 ± 2.9 %) participated in this study. All participants performed a 30 m sprint test (T30) from which we calculated the maximal anaerobic speed (MAnS), vertical and horizontal jumps, 20m multi-stage shuttle run test (MSRT) and repeated sprint test (10 × 15 m shuttle run). AnSR was calculated as the difference between MAnS and the maximal speed reached in the MSRT. Blood lactate sampling was performed 3 min after the RSA protocol. There was no significant correlation between repeated sprint indices (total time (TT); peak time (PT), fatigue index (FI)) and both estimated VO2max and vertical jump performance). TT and PT were significantly correlated with T30 (r=0.63, p=0.001 and r=0.62, p=0.001; respectively), horizontal jump performance (r = -0.47, p = 0.001 and r = -0.49, p = 0.006; respectively) and AnSR (r=-0.68, p= 0.001 and r=-0.70, p=0.001, respectively). Significant correlations were found between blood lactate concentration and TT, PT, and AnSR (r=-0.44, p=0.017; r=-0.43, p=0.018 and r=0.44, p=0.016; respectively). Stepwise multiple regression analyses demonstrated that AnSR was the only significant predictor of the TT and PT, explaining 47% and 50% of the shared variance, respectively. Our findings are of particular interest for coaches and fitness trainers in order to predict repeated sprint performance by using AnSR that can easily identify the respective upper performance limits supported by aerobic and anaerobic power of a player involved in multi-sprint team sports.

  7. Relationship Between Repeated Sprint Performance and both Aerobic and Anaerobic Fitness

    Science.gov (United States)

    Dardouri, Wajdi; Selmi, Mohamed Amin; Sassi, Radhouane Haj; Gharbi, Zied; Rebhi, Ahmed; Yahmed, Mohamed Haj; Moalla, Wassim

    2014-01-01

    The aims of this study were firstly, to examine the relationship between repeated sprint performance indices and anaerobic speed reserve (AnSR), aerobic fitness and anaerobic power and secondly, to identify the best predictors of sprinting ability among these parameters. Twenty nine subjects (age: 22.5 ± 1.6 years, body height: 1.8 ± 0.1 m, body mass: 68.8 ± 8.5 kg, body mass index (BMI): 22.2 ± 2.1 kg•m-2, fat mass: 11.3 ± 2.9 %) participated in this study. All participants performed a 30 m sprint test (T30) from which we calculated the maximal anaerobic speed (MAnS), vertical and horizontal jumps, 20m multi-stage shuttle run test (MSRT) and repeated sprint test (10 × 15 m shuttle run). AnSR was calculated as the difference between MAnS and the maximal speed reached in the MSRT. Blood lactate sampling was performed 3 min after the RSA protocol. There was no significant correlation between repeated sprint indices (total time (TT); peak time (PT), fatigue index (FI)) and both estimated VO2max and vertical jump performance). TT and PT were significantly correlated with T30 (r=0.63, p=0.001 and r=0.62, p=0.001; respectively), horizontal jump performance (r = −0.47, p = 0.001 and r = −0.49, p = 0.006; respectively) and AnSR (r=−0.68, p= 0.001 and r=−0.70, p=0.001, respectively). Significant correlations were found between blood lactate concentration and TT, PT, and AnSR (r=−0.44, p=0.017; r=−0.43, p=0.018 and r=0.44, p=0.016; respectively). Stepwise multiple regression analyses demonstrated that AnSR was the only significant predictor of the TT and PT, explaining 47% and 50% of the shared variance, respectively. Our findings are of particular interest for coaches and fitness trainers in order to predict repeated sprint performance by using AnSR that can easily identify the respective upper performance limits supported by aerobic and anaerobic power of a player involved in multi-sprint team sports. PMID:25031682

  8. High-intensity interval training vs. repeated-sprint training in tennis.

    Science.gov (United States)

    Fernandez-Fernandez, Jaime; Zimek, Rico; Wiewelhove, Thimo; Ferrauti, Alexander

    2012-01-01

    The aim of this study was to compare the effects of high-intensity interval training (HIIT) and repeated-sprint training (RST) on aerobic fitness, tennis-specific endurance, linear and repeated-sprint ability (RSA), and jumping ability. Thirty-one competitive male tennis players took part in a training intervention of 6 weeks. The players were matched into 3 groups, HIIT (n = 11), RST (n = 12), or control group (CON, n = 9). The results showed significant time × intervention interactions for VO(2)peak, with a significant increase in the VO(2)peak level of 6.0% in HIIT (p = 0.008) and 4.9% in RST (p = 0.010), whereas no changes occurred in CON. However, the following differences were found between the intervention groups: The HIIT-induced greater improvements in tennis-specific endurance (HIIT 28.9% vs. RST 14.5%; p training strategy induced any effects on jumping and sprinting abilities. Both training interventions showed similar improvements in general aerobic fitness. Also, the present results suggest that RST represents a time-efficient stimulus for a simultaneous improvement of general and tennis-specific aerobic fitness as well for RSA.

  9. A Comparison of Two Reading Fluency Methods: Repeated Readings to a Fluency Criterion and Interval Sprinting

    Science.gov (United States)

    Kostewicz, Douglas E.; Kubina, Richard M., Jr.

    2010-01-01

    Teachers have used the method of repeated readings to build oral reading fluency in students with and without special needs. A new fluency building intervention called interval sprinting uses shorter timing intervals (i.e., sprints) across a passage. This study used an alternating treatment design to compare repeated readings and interval…

  10. Effect of the number of sprint repetitions on the variation of blood lactate concentration in repeated sprint sessions.

    Science.gov (United States)

    Gharbi, Z; Dardouri, W; Haj-Sassi, R; Castagna, C; Chamari, K; Souissi, N

    2014-06-01

    The aim of the present study was to examine the effect of number of sprint repetitions on the variation of blood lactate concentration (blood [La]) during different repeated-sprint sessions in order to find the appropriate number of sprint repetitions that properly simulates the physiological demands of team sport competitions. Twenty male team-sport players (age, 22.2 ± 2.9 years) performed several repeated-sprint sessions (RSS) consisting of 1, 2, 3, 4, 5, 9, or 10 repetitions of 30 m shuttle sprints (2 × 15 m) with 30 s recovery in between. The blood [La] was obtained after 3 min of recovery at the end of each RSS. The present study showed that for RSS of 3 sprints (RSS3) there was a high increase (psprints (9.6±1.4 and 10.5±1.9 mmol · l(-1), p=0.96 and 0.26, respectively). After RSS9 and RSS10 blood [La] further significantly increased to 12.6 and 12.7 mmol · l(-1), psprint speed decrement (Sdec) (1.5±1.2; 2.0±1.1 and 2.6±1.4%, respectively). There was also no significant difference between RSS9 and RSS10 for Sdec (3.9±1.3% and 4.5±1.4%, respectively). In conclusion, the repeated-sprint protocol composed of 5 shuttle sprint repetitions is more representative of the blood lactate demands of the team sports game intensity.

  11. 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.

  12. The effects of 20-m repeated sprint training on aerobic capacity in college volleyball players

    Directory of Open Access Journals (Sweden)

    Kaynak Kerimhan

    2017-02-01

    Full Text Available Study aim: The purpose of this study was to examine the effects of a repeated sprint training program in addition to volleyball training on the aerobic capacity of college volleyball players.

  13. Importance of muscle power variables in repeated and single sprint performance in soccer players.

    Science.gov (United States)

    López-Segovia, Manuel; Dellal, Alexandre; Chamari, Karim; González-Badillo, Juan José

    2014-03-27

    This study examined the relationship between lower body power and repeated as well as single sprint performance in soccer players. The performance of nineteen male soccer players was examined. The first testing session included the countermovement jump (CMJL) and the progressive full squat (FSL), both with external loads. Power in the CMJL and FSL was measured with each load that was lifted. The second session included a protocol of 40-m repeated sprints with a long recovery period (2 min). The number of sprints executed until there was a 3% decrease in performance for the best 40-m sprint time was recorded as a repeated sprint index (RSI). The RSI was moderately associated with power output relative to body mass in the CMJL and FSL (r = 0.53/0.54, p ≤ 0.05). The most and least powerful players (determined by FSL) showed significant differences in the RSI (9.1 ± 4.2 vs. 6.5 ± 1.6) and 10 m sprint time (p ± 0.01). Repeated and single sprints are associated with relatively lower body power in soccer players.

  14. Smaller muscle ATP reduction in women than in men by repeated bouts of sprint exercise.

    Science.gov (United States)

    Esbjörnsson-Liljedahl, Mona; Bodin, Kristina; Jansson, Eva

    2002-09-01

    It was hypothesized that the reduction of high-energy phosphates in muscle after repeated sprints is smaller in women than in men. Fifteen healthy and physically active women and men with an average age of 25 yr (range of 19-42 yr) performed three 30-s cycle sprints (Wingate test) with 20 min of rest between sprints. Repeated blood and muscle samples were obtained. Freeze-dried pooled muscle fibers of types I and II were analyzed for high-energy phosphates and their breakdown products and for glycogen. Accumulation of plasma ATP breakdown products, plasma catecholamines, and blood lactate, as well as glycogen reduction in type I fibers, was all lower in women than in men during sprint exercise. Repeated sprints induced smaller reduction of ATP and smaller accumulation of IMP and inosine in women than in men in type II muscle fibers, with no gender differences in changes of ATP and its breakdown products during the bouts of exercise themselves. This indicates that the smaller ATP reduction in women than in men during repeated sprints was created during recovery periods between the sprint exercises and that women possess a faster recovery of ATP via reamination of IMP during these recovery periods.

  15. Repeated high-intensity running and sprinting in elite women’s soccer competition

    OpenAIRE

    Gabbett, Tim J; Wiig, Håvard; Spencer, Matt

    2013-01-01

    Background: To the authors’ knowledge, no study has investigated the concurrent repeated, high-intensity (RHIA) and repeated-sprint activity (RSA) of intermittent team-sport competition. Purpose: In this study, they report on the RSA of elite women’s football competition. In addition, they describe the nature of RHIA (eg, striding and sprinting activities) that involve a high energy cost and are associated with short (ie, ≤20 s) recovery periods. Methods: Thirteen elite women soccer players u...

  16. The effect of heavy resistance exercise on repeated sprint performance in youth athletes.

    Science.gov (United States)

    Low, Daniel; Harsley, Paul; Shaw, Matthew; Peart, Daniel

    2015-01-01

    This investigation assessed whether prior heavy resistance exercise would improve the repeated sprint performance of 16 trained youth soccer players (Age 17.05 ± 0.65 years; height 182.6 ± 8.9 cm; body mass 77.8 ± 8.2 kg). In session 1, individual 1 repetition max was measured utilising a squat movement. In sessions 2 and 3, participants performed a running-based repeated anaerobic sprint test with and without prior heavy resistance exercise of 91% of their 1 repetition max. Times were recorded for each of the 6 sprints performed in the repeated sprint test and summed to provide total time. T-tests compared the two exercise conditions via differences in corresponding sprint times and total time. Analysis revealed significantly reduced total time with use of heavy resistance exercise (33.48 (±1.27) vs. 33.59 (±1.27); P = 0.01). Sprints 1 (P = 0.05) and 2 (P = 0.02) were also faster in the heavy resistance exercise condition (5.09 (±0.16) vs. 5.11 (±0.16) and 5.36 (±0.24) vs. 5.45 (±0.26) seconds respectively) although no other differences were shown. Findings demonstrate improved sprint times of trained adolescent soccer players after heavy resistance exercise although benefits appear not as sustained as in adult participants.

  17. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury.

    Science.gov (United States)

    Røksund, Ola D; Kristoffersen, Morten; Bogen, Bård E; Wisnes, Alexander; Engeseth, Merete S; Nilsen, Ann-Kristin; Iversen, Vegard V; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    strain injury. The maximal speed, leg strength, ability to produce maximal power, endurance capacity, and hamstring flexibility was similar for both groups. Thus, a repeated sprint test consisting of 8 × 20 m could be used as a field-based diagnostic tool to identify players in need of reconditioning programs to ensure complete post-injury rehabilitation.

  18. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

    Science.gov (United States)

    Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    strain injury. The maximal speed, leg strength, ability to produce maximal power, endurance capacity, and hamstring flexibility was similar for both groups. Thus, a repeated sprint test consisting of 8 × 20 m could be used as a field-based diagnostic tool to identify players in need of reconditioning programs to ensure complete post-injury rehabilitation. PMID:28190999

  19. Effects of weighted sled towing with heavy versus light load on sprint acceleration ability.

    Science.gov (United States)

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

    2014-10-01

    Weighted sled towing is used by athletes to improve sprint acceleration ability. The typical coaching recommendation is to use relatively light loads, as excessively heavy loads are hypothesized to disrupt running mechanics and be detrimental to sprint performance. However, this coaching recommendation has not been empirically tested. This study compared the effects of weighted sled towing with 2 different external loads on sprint acceleration ability. Twenty-one physically active men were randomly allocated to heavy- (n = 10) or light-load weighted sled towing (n = 11) groups. All subjects participated in 2 training sessions per week for 8 weeks. The subjects in the heavy and light groups performed weighted sled towing using external loads that reduced sprint velocity by approximately 30 and 10%, respectively. Before and after the training, the subjects performed a 10-m sprint test, in which split time was measured at 5 and 10 m from the start. The heavy group significantly improved both the 5- and 10-m sprint time by 5.7 ± 5.7 and 5.0 ± 3.5%, respectively (P sprint time was improved significantly by 3.0 ± 3.5% (P sprint time from pre- to posttraining. These results question the notion that training loads that induce greater than 10% reduction in sprint velocity would negatively affect sprint performance and point out the potential benefit of using a heavier load for weighted sled towing.

  20. Effect of Small-Sided Games and Repeated Shuffle Sprint Training on Physical Performance in Elite Handball Players.

    Science.gov (United States)

    Dello Iacono, Antonio; Ardigò, Luca P; Meckel, Yoav; Padulo, Johnny

    2016-03-01

    This study was designed to compare the effects of small-sided games (SSGs) and repeated shuffle sprint (RSS) training on repeated sprint ability (RSA) and countermovement jump (CMJ) tests performances of elite handball players. Eighteen highly trained players (24.8 ± 4.4 years) were assigned to either SSG or RSS group training protocols twice a week for 8 weeks. The SSG training consisted of 5 small-sided handball games with 3-a-side teams excluding goalkeepers. The RSS consisted of 2 sets of 14-17 of 20-m shuttle sprints and 9-m jump shots interspersed by 20-second recoveries. Before and after training, the following performance variables were assessed: speed on 10-m and 20-m sprint time, agility and RSA time, CMJ height, standing throw, and jump shot speed. Significant pre-to-post treatment improvements were found in all the assessed variables following both training protocols (multivariate analysis of variance, p ≤ 0.05). There was a significantly greater improvement on 10-m sprint, CMJ, and jump shooting, after the RSS in comparison with SSG training (+4.4% vs. +2.4%, +8.6% vs. +5.6%, and +5.5% vs. +2.7%, respectively). Conversely, agility and standing throwing showed lower improvements after RSS in comparison with SSG (+1.0% vs. +7.8% and +1.6% vs. +9.0%, respectively). These results indicate that these training methods are effective for fitness development among elite adult handball players during the last period of the competitive season. Specifically, SSG seems to be more effective in improving agility and standing throw, whereas RSS seems preferable in improving 10-m sprint, CMJ, and jump shot.

  1. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting

    Science.gov (United States)

    Girard, Olivier; Brocherie, Franck; Millet, Grégoire P.

    2016-01-01

    We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s “all-out” sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; “fast” instruction) and maximal (~5 s; “hard” instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, −50, −100, and −200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P sprint decrement score and a shorter (P sprints occurred in HA (−8 ± 4% and 178 ± 11 m) but not in LA (−7 ± 3% and 181 ± 10 m) compared to NM (−5 ± 2% and 183 ± 9 m). Compared to NM (−9 ± 7%), a larger (P 0.05). Irrespectively of condition (P > 0.05), peak RTD (−6 ± 11%; P 0.05), whereas it increased (P repeated-sprint ability and post-exercise MVC decrease were greater at high altitude than in normoxia or at low altitude. However, the post-exercise alterations in RTD were similar between normoxia and low-to-high hypoxia. PMID:27014095

  2. In-season effect of a combined repeated sprint and explosive strength training program on elite junior tennis players.

    Science.gov (United States)

    Fernandez-Fernandez, Jaime; Sanz-Rivas, David; Kovacs, Mark S; Moya, Manuel

    2015-02-01

    The aim of this study was to analyze the effects of a combined explosive strength (ExpS) and repeated sprint (RS)-training program (2 times per week) on performance (sprint, jumping ability, and RS ability [RSA]) in young elite tennis players during a competitive period. Eight competitive internationally ranked male junior tennis players participated in an 8-week training intervention. After training, except for percentage of decrement in the RS test (p = 0.72) and maximal aerobic performance (p = 1.0), all performance variables (i.e., sprint, countermovement jump, and RSA) were significantly improved (p ≤ 0.05; effect sizes ranging from 0.56 to 1.12). Although one can expect greater effects of ExpS or RS training programs alone than a combined program, the results obtained here show that the inclusion of a combined ExpS and RS training program seems to be an effective training tool to improve neuromuscular performance (i.e., changes in jumping ability and single sprint) as well as RSA in high-level tennis players.

  3. The Effect of Passive versus Active Recovery on Power Output over Six Repeated Wingate Sprints

    Science.gov (United States)

    Lopez, Egla-Irina D.; Smoliga, James M.; Zavorsky, Gerald S.

    2014-01-01

    Purpose: The aim of this study was to examine the effect of active versus passive recovery on 6 repeated Wingate tests (30-s all-out cycling sprints on a Velotron ergometer). Method: Fifteen healthy participants aged 29 (SD = 8) years old (body mass index = 23 [3] kg/m[superscript 2]) participated in 3 sprint interval training sessions separated…

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

    Science.gov (United States)

    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.

  5. LONGITUDINAL STUDY OF REPEATED SPRINT PERFORMANCE IN YOUTH SOCCER PLAYERS OF CONTRASTING SKELETAL MATURITY STATUS

    Directory of Open Access Journals (Sweden)

    João Valente-dos-Santos

    2012-09-01

    Full Text Available The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11- 13 years at baseline was assessed annually. Stature, body mass, 7x34.2-m sprint protocol (25-s active recovery, 20-m multi-stage continuous shuttle endurance run and counter-movement jump (CMJ without the use of the arms were measured. Fat-free mass (FFM was determined by age and gender- specific formulas. Developmental changes in total sprint time across ages were predicted using multilevel modeling. Corresponding measurements were performed on an independent cross-sectional subsample of 52 youth soccer players 11-17 years to evaluate the predictive model. CA, CA2, maturational status (SA-CA, body size (mass and stature, FFM, aerobic endurance, lower limb explosive strength and annual volume training significantly improved the statistical fit of the RSA multilevel model. In 'late' maturing athletes, the best model for predicting change in RSA was expressed by the following equation: 86.54 - 2.87 x CA + 0.05 x CA2 - 0.25 x FFM + 0.15 x body mass + 0.05 x stature - 0.05 x aerobic endurance - 0.09 x lower limb explosive strength - 0.01 x annual volume training. The best fitting models for players who were 'on time' and 'early' maturing were identical to the best model for late maturing players, less 0.64 seconds and 1.74 seconds, respectively. Multilevel modeling provided performance curves that permitted the prediction of individual RSA performance across adolescent years in regional level soccer players

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

    DEFF Research Database (Denmark)

    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...... 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.......-out exercise, and 8 × 30 s of all-out sprint was evaluated before and after the intervention. Following at least 8 weeks of wash-out, the subjects crossed over and repeated the procedure. Incremental peak power output was similar after both interventions [LHTL: 375 ± 74 vs. 369 ± 70 W (pre-vs-post), placebo...

  7. The effects of oral creatine supplementation on performance in single and repeated sprint swimming.

    Science.gov (United States)

    Peyrebrune, M C; Nevill, M E; Donaldson, F J; Cosford, D J

    1998-04-01

    We studied the effects of oral creatine supplementation on sprint swimming performance in 14 elite competitive male swimmers. The subjects performed a single sprint (1 x 50 yards [45.72 m]) and repeated sprint set (8 x 50 yards at intervals of 1 min 30 s) before and after a 5 day period of either creatine (9 g creatine + 4.5 g maltodextrin + 4.5 g glucose day(-1)) or placebo (18 g glucose day(-1); double-blind protocol) supplementation. Venous and capillary blood samples were taken for the determination of plasma ammonia, blood pH and lactate. Mean times recorded for the single 50 yard sprint were unchanged as a result of supplementation (creatine vs control, N.S.). During the repeated sprint test, mean times increased (Pcreatine supplementation (sprints 1-8: control pre-, 23.35+/-0.68 to 26.32+/-1.34 s; control post-, 23.59+/-0.66 to 26.19+/-1.48 s; creatine pre-, 23.20+/-0.67 to 26.85+/-0.42 s; creatine post-, 23.39+/-0.54 to 25.73+/-0.26 s; P creatine supplementation (control, 12.7+/-5.7% vs 11.0+/-5.5%; creatine, 15.7+/-4.3% vs 10.0+/-2.5%; Pcreatine in this group of swimmers after an identical supplementation regimen. In summary, our results suggest that ingesting 9 g creatine per day for 5 days can improve swimming performance in elite competitors during repeated sprints, but appears to have no effect on a single 50 yard sprint.

  8. 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.

  9. Sex alters impact of repeated bouts of sprint exercise on neuromuscular activity in trained athletes.

    Science.gov (United States)

    Billaut, François; Smith, Kurt

    2009-08-01

    This study characterized the effect of sex on neuromuscular activity during repeated bouts of sprint exercise. Thirty-three healthy male and female athletes performed twenty 5-s cycle sprints separated by 25 s of rest. Mechanical work and integrated electromyograhs (iEMG) of 4 muscles of the dominant lower limb were calculated in every sprint. The iEMG signals from individual muscles were summed to represent overall electrical activity of these muscles (sum-iEMG). Neuromuscular efficiency (NME) was calculated as the ratio of mechanical work and sum-iEMG for every sprint. Arterial oxygen saturation was estimated (SpO2) with pulse oximetry throughout the protocol. The sprint-induced work decrement (18.9% vs. 29.6%; p women than for the men. However, the sprints decreased NME (10.1%; p men, R2 = 0.87; women, R2 = 0.91; all p sprint exercise is not likely to be explained by a difference in muscle contractility impairment in men and women, but may be due to a sex difference in muscle recruitment strategy. We speculate that women would be less sensitive to arterial O2 desaturation than men, which may trigger lower neuromuscular adjustments to exhaustive exercise.

  10. Effects of leg contrast strength training on sprint, agility and repeated change of direction performance in male soccer players.

    Science.gov (United States)

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

    2017-11-01

    Contrast training is a popular technique among individuals who are involved in dynamic sports, having as its goal an increase in dynamic muscular performance. It is characterized by the use of high and low loads in the same strength training session. The present investigation aimed to determine the effects of adding 8 weeks of contrast strength training (CSTP) to regular soccer practice in U-17 male soccer players during the competitive season. We hypothesized that CSTP would enhance their performance. Subjects were divided randomly between a control group (CG, N.=12) and a contrast strength group (CSG, N.=19). The 2 groups trained together; controls followed the regular soccer program, which was replaced by a contrast strength training program for the experimental group. Performance was assessed before and after training, using 10 measures: 5-10-, 20- 30-, and 40-m sprints, a 4x5 m sprint (S4x5), a 9-3-6-3-9 m sprint with 180° turns (S180), a 9-3-6-3-9 m sprint with backward and forward running (SBF), a Repeated-Shuttle-Sprint Ability Test (RSSA), and a Repeated Change of Direction Test (RCOD). CSG showed gains relative to controls in 5-m (Psprints. There were also significant gains in S180°, SBF, and S4 x 5 agility tests (P<0.01), and all RCOD parameters (P<0.05) except RCOD-FI (P=0.055) but no significant change in any RSSA parameters. We conclude that biweekly contrast strength training can be commended to U-17 male soccer players as a means of improving many important components of athletic performance relative to standard in-season training.

  11. Repeated-sprint performance and vastus lateralis oxygenation: effect of limited O₂ availability.

    Science.gov (United States)

    Billaut, F; Buchheit, M

    2013-06-01

    This study examined the influence of muscle deoxygenation and reoxygenation on repeated-sprint performance via manipulation of O2 delivery. Fourteen team-sport players performed 10 10-s sprints (30-s recovery) under normoxic (NM: FI O2 0.21) and acute hypoxic (HY: FI O2 0.13) conditions in a randomized, single-blind fashion and crossover design. Mechanical work was calculated and arterial O2 saturation (Sp O2 ) was estimated via pulse oximetry for every sprint. Muscle deoxyhemoglobin concentration ([HHb]) was monitored continuously by near-infrared spectroscopy. Differences between NM and HY data were analyzed for practical significance using magnitude-based inferences. HY reduced Sp O2 (-10.7 ± 1.9%, with chances to observe a higher/similar/lower value in HY of 0/0/100%) and mechanical work (-8.2 ± 2.1%; 0/0/100%). Muscle deoxygenation increased during sprints in both environments, but was almost certainly higher in HY (12.5 ± 3.1%, 100/0/0%). Between-sprint muscle reoxygenation was likely more attenuated in HY (-11.1 ± 11.9%; 2/7/91%). The impairment in mechanical work in HY was very largely correlated with HY-induced attenuation in muscle reoxygenation (r = 0.78, 90% confidence limits: 0.49; 0.91). Repeated-sprint performance is related, in part, to muscle reoxygenation capacity during recovery periods. These results extend previous findings that muscle O2 availability is important for prolonged repeated-sprint performance, in particular when the exercise is taken in hypoxia.

  12. Physiological correlates of multiple-sprint ability and performance in international-standard squash players.

    Science.gov (United States)

    Wilkinson, Michael; Cooke, Matthew; Murray, Stafford; Thompson, Kevin G; St Clair Gibson, Alan; Winter, Edward M

    2012-02-01

    From measures on a battery of fitness tests in elite-standard squash players on different tiers of a national performance program, we examined the relationships among test scores and player rank, and fitness factors important for squash-specific multiple-sprint ability. Thirty-one (20 men, 11 women) squash players from the England Squash performance program participated: n = 12 senior; n = 7 transition; n = 12 talented athlete scholarship scheme (TASS) players. In 1 test session and in a fixed order, the players completed a battery of tests to assess countermovement jump height, reactive strength, change-of-direction speed, and multiple-sprint ability on squash-specific tests and endurance fitness. Two-way analysis of variance compared senior, transition, and TASS players by sex on all measures except jump height where only senior and transition players were compared. Effect size (ES) was calculated for all comparisons. Pearson's correlation examined relationships among test scores and multiple-sprint ability. Spearman's ρ investigated relationships among test scores and players' rank in men and women separately. Regardless of sex, seniors outperformed TASS players on all except the endurance test (p sprint ability than did transition players (p Men outperformed women in all tests at all performance program tiers (p men, rank was related to multiple-sprint ability, fastest-multiple-sprint-test repetition, and change-of-direction speed (ρ = 0.78, 0.86, 0.59, respectively). In women, rank was related to fastest multiple-sprint-test repetition (ρ = 0.65). In men and women, multiple-sprint ability was related to change-of-direction speed (r = 0.9 and 0.84) and fastest-multiple-sprint-test repetition (r = 0.96 for both) and to reactive strength in men (r = -0.71). The results confirm that high-intensity variable-direction exercise capabilities are important for success in elite squash.

  13. The effect of combined resisted agility and repeated sprint training vs. strength training on female elite soccer players.

    Science.gov (United States)

    Shalfawi, Shaher A I; Haugen, Thomas; Jakobsen, Tore A; Enoksen, Eystein; Tønnessen, Espen

    2013-11-01

    The aim of this study was to compare the effects of in-season combined resisted agility and repeated sprint training with strength training on soccer players' agility, linear single sprint speed, vertical jump, repeated sprint ability (RSA), and aerobic capacity. Twenty well-trained elite female soccer players of age ± SD 19.4 ± 4.4 years volunteered to participate in this study. The participants were randomly assigned to either the agility and repeated sprint training group or to the strength training group. All the participants were tested before and after a 10-week specific conditioning program. The pretest and posttest were conducted on 3 separate days with 1 day of low-intensity training in between. Test day 1 consisted of squat jump (SJ), countermovement jump (CMJ), and RSA. Test day 2 consisted of a 40-m maximal linear sprint and an agility test, whereas a Beep test was conducted on test day 3 to assess aerobic capacity. The agility and repeated sprint training implemented in this study did not have a significant effect on agility, although there was a tendency for moderate improvements from 8.23 ± 0.32 to 8.06 ± 0.21 seconds (d = 0.8). There was a significant (p < 0.01) and moderate-positive effect on Beep-test performance from level 9.6 ± 1.4 to level 10.8 ± 1.0, and only a trivial small effect on all other physical variables measured in this study. The strength training group had a positive, moderate, and significant (p < 0.01) effect on Beep-test performance from level 9.7 ± 1.3 to level 10.9 ± 1.2 (d = 1.0) and a significant (p < 0.05) but small effect (d = 0.5) on SJ performance (25.9 ± 2.7 to 27.5 ± 4.1 cm). Furthermore, the strength training implemented in this study had a trivial and negative effect on agility performance (d = -0.1). No between-group differences were observed. The outcome of this study indicates the importance of a well-planned program of conditioning that does not result in a decreased performance of the players, the

  14. Squat jump training at maximal power loads vs. heavy loads: effect on sprint ability.

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    Harris, Nigel K; Cronin, John B; Hopkins, Will G; Hansen, Keir T

    2008-11-01

    Training at a load maximizing power output (Pmax) is an intuitively appealing strategy for enhancement of performance that has received little research attention. In this study we identified each subject's Pmax for an isoinertial resistance training exercise used for testing and training, and then we related the changes in strength to changes in sprint performance. The subjects were 18 well-trained rugby league players randomized to two equal-volume training groups for a 7-week period of squat jump training with heavy loads (80% 1RM) or with individually determined Pmax loads (20.0-43.5% 1RM). Performance measures were 1RM strength, maximal power at 55% of pretraining 1RM, and sprint times for 10 and 30 m. Percent changes were standardized to make magnitude-based inferences. Relationships between changes in these variables were expressed as correlations. Sprint times for 10 m showed improvements in the 80% 1RM group (-2.9 +/- 3.2%) and Pmax group (-1.3 +/- 2.2%), and there were similar improvements in 30-m sprint time (-1.9 +/- 2.8 and -1.2 +/- 2.0%, respectively). Differences in the improvements in sprint time between groups were unclear, but improvement in 1RM strength in the 80% 1RM group (15 +/- 9%) was possibly substantially greater than in the Pmax group (11 +/- 8%). Small-moderate negative correlations between change in 1RM and change in sprint time (r approximately -0.30) in the combined groups provided the only evidence of adaptive associations between strength and power outputs, and sprint performance. In conclusion, it seems that training at the load that maximizes individual peak power output for this exercise with a sample of professional team sport athletes was no more effective for improving sprint ability than training at heavy loads, and the changes in power output were not usefully related to changes in sprint ability.

  15. The Effect of Standard Strength vs. Contrast Strength Training on the Development of Sprint, Agility, Repeated Change of Direction, and Jump in Junior Male Soccer Players.

    Science.gov (United States)

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

    2017-04-01

    Hammami, M, Negra, Y, Shephard, RJ, and Chelly, MS. The effect of standard strength vs. contrast strength training on the development of sprint, agility, repeated change of direction, and jump in junior male soccer players. J Strength Cond Res 31(4): 901-912, 2017-The aim was to compare the impact of 2 differing strength training (ST) programs on the athletic performance of junior male soccer players at a critical phase during their competitive season. Participants aged 16.0 ± 0.5 years were randomly assigned between control (C, n = 12), standard ST (n = 16), and contrast strength training (CST, n = 16), each performed twice a week. Athletic performance was assessed before and after the intervention using 8 tests: 40-m sprint, 4 × 5-m sprint (S4 × 5), 9-3-6-3-9 m sprint with 180° turns (S180°), 9-3-6-3-9 m sprint with backward and forward running (SBF), repeated shuttle sprint ability (RSSA), repeated change of direction (RCOD), squat jump (SJ), and countermovement jump (CMJ). The control group's (CG) performance tended to improve in some tests and decrease in others, but these changes were not statistically significant. Both training programs enhanced all sprint performances relative to controls (p ≤ 0.05). The strength training group (SG) and the CST group (CSG) increased significantly in S180°, SBF, and S4 × 5 relative to CG, although the S4 × 5 also increased in CSG relative to SG (p ≤ 0.05). No intergroup difference of RSSA performance was observed. The RCOD parameters increased significantly in CSG relative to both SG and CG (p ≤ 0.05). The SJ and CMJ height increased significantly in both experimental groups (p < 0.000). We conclude that during the competitive season, some measures of athletic performance in male soccer players were increased more by 8 weeks of CST than by ST.

  16. Changes in spring-mass model characteristics during repeated running sprints.

    Science.gov (United States)

    Girard, Olivier; Micallef, Jean-Paul; Millet, Grégoire P

    2011-01-01

    This study investigated fatigue-induced changes in spring-mass model characteristics during repeated running sprints. Sixteen active subjects performed 12 × 40 m sprints interspersed with 30 s of passive recovery. Vertical and anterior-posterior ground reaction forces were measured at 5-10 m and 30-35 m and used to determine spring-mass model characteristics. Contact (P Stride frequency (P  0.05) increased with time. As a result, vertical stiffness decreased (P  0.05). Changes in vertical stiffness were correlated (r > 0.7; P stride frequency. When compared to 5-10 m, most of ground reaction force-related parameters were higher (P stride frequency, vertical and leg stiffness were lower (P run-based sprints are repeated, which alters impact parameters. Maintaining faster stride frequencies through retaining higher vertical stiffness is a prerequisite to improve performance during repeated sprinting.

  17. High altitude increases alteration in maximal torque but not in rapid torque development in knee extensors after repeated treadmill sprinting

    Directory of Open Access Journals (Sweden)

    Olivier eGIRARD

    2016-03-01

    Full Text Available We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 x 5-s all-out sprints (passive recovery = 25 s on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%, at low (LA; FiO2 = 16.6% and high (HA; FiO2 = 13.3% normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively. Explosive (∼1 s; fast instruction and maximal (∼5 s; hard instruction voluntary isometric contractions (MVC of the knee extensors, with concurrent electromyographic (EMG activity recordings of the vastus lateralis (VL and rectus femoris (RF muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD and EMG (i.e., Root Mean Square or RMS rise from 0 to 30, -50, -100 and -200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P>0.05 in all conditions. A larger (P0.05. Irrespectively of condition (P>0.05, peak RTD (-6±11%; P0.05, whereas it increased (P<0.05 for RF muscle during all epochs post-exercise, independently of the conditions. In summary, alteration in repeated-sprint ability and post-exercise MVC decrease were greater at high altitude than in normoxia or at low altitude. However, the post-exercise alterations in RTD were similar between normoxia and low-to-high hypoxia.

  18. Mechanical work accounts for sex differences in fatigue during repeated sprints.

    Science.gov (United States)

    Billaut, François; Bishop, David J

    2012-04-01

    To investigate whether the larger reduction in mechanical work observed during repeated-sprint exercise (RSE) in men versus women represents a true, physiological sex dimorphism or is the consequence of the higher initial mechanical work performed by men. Male and female team-sport athletes (n = 35) performed 20, 5-s cycle sprints interspersed with 25 s of rest. Mechanical work and surface electromyograms (EMG) of four muscles were recorded in every sprint. Mechanical work achieved in one sprint (20.7%, P = 0.0006), total work accumulated over the 20 sprints (21.1%, P = 0.009) and percent work decrement (32.2%, P = 0.008) were larger in men than in women. When both sexes were plotted together, there was a positive relationship between the initial-sprint work and the work decrement across sprint repetitions (r = 0.89, P = 0.002). The RSE induced larger (P = 0.009) absolute EMG amplitude changes in men (-155.2 ± 60.3 mVs) than in women (-102.5 ± 45.1 mVs). Interestingly, in a subset of men and women (n = 7 per group) matched for initial-sprint work, the sex difference in percent work decrement (men: -29.5 ± 1.5%; women: -27.2 ± 3.2%; P = 0.72) and EMG changes (men: -17.7 ± 6.9% vs. women: -15.3 ± 7.1%; P = 0.69) no longer persisted. Results show that the proposed greater fatigue in men is likely to be a consequence of their greater absolute initial-sprint performance, rather than a sex difference in fatigue resistance per se. We conclude that, on the basis of the absolute mechanical work completed, women are not more fatigue resistant than men and use comparable muscle recruitment strategies to perform RSE.

  19. Repeated sprint swimming performance after low- or high-intensity active and passive recoveries.

    Science.gov (United States)

    Toubekis, Argyris G; Adam, Georgios V; Douda, Helen T; Antoniou, Panagiotis D; Douroundos, Ioannis I; Tokmakidis, Savvas P

    2011-01-01

    The purpose of this study was to examine the effects on sprint swimming performance after low- and high-intensity active recovery (AR) as compared to passive recovery. Ten male competitive swimmers (age: 17.9 ± 2.3 years; body mass: 73.2 ± 4.0 kg; height: 1.81 ± 0.04 m, 100-m best time: 54.90 ± 1.96 seconds) performed 8 × 25-m sprints with 120-second rest intervals followed by a 50-m sprint 6 minutes later. During the 120-second and the 6-minute interval periods swimmers rested passively (PAS) or swam at an intensity of 40% (ACT40; 36 ± 8% of the V(O2)max) and 60% (ACT60; 59 ± 7% of the V(O2)max) of their individual 100-m velocity. Performance time of the 8 × 25-m after ACT60 was slower compared with PAS and ACT40, but no difference was observed between ACT40 and PAS conditions (PAS: 12.15 ± 0.48, ACT40: 12.23 ± 0.54, ACT60: 12.35 ± 0.57 seconds, p sprint was no different between conditions (PAS: 26.45 ± 0.91; ACT40: 26.30 ± 1.18; ACT60: 26.21 ± 1.19 seconds; p > 0.05). Blood lactate concentration was not different between PAS, ACT40, and ACT60 after the 8 × 25-m and the 50-m sprints (p > 0.05). Passive recovery, or low intensity of AR (40% of the 100-m velocity), is advised to maintain repeated 25-m sprint swimming performance when a 2-minute interval period is provided. Active recovery at an intensity corresponding to 60% of the 100-m velocity decreases performance during the 25-m repeated sprints without affecting the performance time on a subsequent longer duration sprint (i.e., 50 m).

  20. Effects of red bull energy drink on repeated sprint performance in women athletes.

    Science.gov (United States)

    Astorino, Todd A; Matera, Angela J; Basinger, Jency; Evans, Mindy; Schurman, Taylor; Marquez, Rodney

    2012-05-01

    Energy drinks are frequently consumed by athletes prior to competition to improve performance. This study examined the effect of Red Bull™ on repeated sprint performance in women athletes. Fifteen collegiate soccer players participated, with mean age, height, and body mass equal to 19.5±1.1 year, 168.4±5.8 cm, and 63.4±6.1 kg, respectively. After performing a familiarization trial, subjects performed three sets of eight bouts of the modified t test after ingestion of 255 mL of placebo or Red Bull 1 h pre-exercise in a randomized, placebo-controlled crossover design. Throughout testing, sprint time, heart rate (HR), and rating of perceived exertion (RPE) were continuously obtained. Repeated measures analysis of variance was used to examine differences in variables between drink conditions. Across athletes, t test time ranged from 10.4 to 12.7 s. Mean sprint time was similar (p>0.05) between Red Bull (11.31±0.61 s) and placebo (11.35±0.61 s). HR and RPE increased (p0.05) of Red Bull on either variable versus placebo. Findings indicate that 255 mL of Red Bull containing 1.3 mg/kg of caffeine and 1 g of taurine does not alter repeated sprint performance, RPE, or HR in women athletes versus placebo. One serving of this energy drink provides no ergogenic benefit for women athletes engaging in sprint-based exercise.

  1. 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

  2. Efecto de un calentamiento con estiramientos estáticos y dinámicos sobre el salto horizontal y la capacidad para repetir esprint con cambio de dirección. [Effect of warm-up with static and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction].

    Directory of Open Access Journals (Sweden)

    Javier Sánchez-Sánchez

    2017-01-01

    Full Text Available El objetivo de este trabajo ha sido comparar el efecto de tres calentamientos diferentes (calentamiento aeróbico de baja intensidad, estiramiento estático y estiramiento dinámico sobre el salto horizontal y la capacidad de repetir esprint con cambios de dirección. Diecisiete practicantes de deportes de equipo de 20.8±1.1 años realizaron 3 tipos de calentamiento (10 min: ejercicio aeróbico sin estiramiento (CAE, con estiramiento estático (CAES y con estiramiento dinámico (CAED. Se estudió el efecto agudo de cada calentamiento sobre el rendimiento en una prueba de salto horizontal (SH y un test de repetición de esprint con cambio de dirección (RSCOD. No se obtuvieron diferencias significativas (p>0,05 en ninguna de las variables en función del calentamiento realizado. El tamaño del efecto (TE indicó que probablemente el RSCODmejor sea más sensible al CAE que al CAES (TE: 0,52 y al CAED (TE: 0,44. El escaso efecto de los estiramientos estáticos sobre el rendimiento en SH y RSCOD puede ser debido a la dosis, la intensidad y el tiempo de recuperación empleado. Los estiramientos dinámicos no mejoraron el rendimiento en SH y RSCOD. Abstract The purpose of this study was to compare the effect of three different warm-ups (low intensity aerobic warm-up, static stretching and dynamic stretching on the horizontal jump and repeated sprint ability with changes of direction. Seventeen players of team sports whose age was 20.8±1.1 years old performed three types of warm up (10 minutes: aerobic exercise without stretching (WU, with static stretching (WUSS and with dynamic stretching (WUDS. The acute effect of each warming over performance was studied in a test of horizontal jump (HJ and repeat sprint test with change of direction (RSCD. No significant differences were obtained (p>0.05 in any of the variables studied according to the warming developed. The effect size (ES indicated that probably RSCDbest was more sensitive to WU than WUDS (ES

  3. 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 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, with a similar fatigue pattern across conditions during subsequent repeated sprints in normoxia. PMID:26441679

  4. Adaptation to Damaging Dance and Repeated-Sprint Activity in Women.

    Science.gov (United States)

    Brown, Meghan A; Howatson, Glyn; Keane, Karen M; Stevenson, Emma J

    2016-09-01

    Brown, MA, Howatson, G, Keane, KM, and Stevenson, EJ. Adaptation to damaging dance and repeated-sprint activity in women. J Strength Cond Res 30(9): 2574-2581, 2016-The repeated bout effect (RBE) refers to the prophylactic effect from damaging exercise after a single previous bout of exercise. There is a paucity of data examining the RBE in women, and investigations using exercise paradigms beyond isolated eccentric contractions are scarce. In light of the limited literature, this investigation aimed to determine whether 2 different sport-specific exercise bouts would elicit a RBE in women. Twenty-one female dancers (19 ± 1 years) completed either a dance-specific protocol (n = 10) or sport-specific repeated-sprint protocol (n = 11). Delayed-onset muscle soreness (DOMS), limb girths, creatine kinase (CK), countermovement jump height, reactive strength index, maximal voluntary contraction, and 30-meter sprint time were recorded before and 0, 24, 48, and 72 hours after exercise. An identical exercise bout was conducted approximately 4 weeks after the initial bout, during which time the subjects maintained habitual training and dietary behaviors. DOMS and 30-meter sprint time decreased after a second bout of both activities (p = 0.003; (Equation is included in full-text article.)= 0.38 and p = 0.008; and (Equation is included in full-text article.)= 0.31, respectively). Circulating CK was also lower at 24, 48, and 72 hours after the second bout, independent of group (p = 0.010 and (Equation is included in full-text article.)= 0.23). Compared with the repeated-sprint protocol, the magnitude of change in DOMS was greater after a subsequent bout of the dance protocol (p = 0.010 and (Equation is included in full-text article.)= 0.19). These data are the first to demonstrate that dance and repeated-sprint activity resulting in muscle damage in women confers a protective effect against muscle damage after a subsequent bout.

  5. Comparison of Two Types of Warm-Up Upon Repeated-Sprint Performance in Experienced Soccer Players.

    Science.gov (United States)

    van den Tillaar, Roland; von Heimburg, Erna

    2016-08-01

    van den Tillaar, R and von Heimburg, E. Comparison of two types of warm-up upon repeated-sprint performance in experienced soccer players. J Strength Cond Res 30(8): 2258-2265, 2016-The aim of the study was to compare the effects of a long warm-up and a short warm-up upon repeated-sprint performance in soccer players. Ten male soccer players (age, 21.9 ± 1.9 years; body mass, 77.7 ± 8.3 kg; body height, 1.85 ± 0.03 m) conducted 2 types of warm-ups with 1 week in between: a long warm-up (20 minutes: LWup) and a short warm-up (10 minutes: SWup). Each warm-up was followed by a repeated-sprint test consisting of 8 × 30 m sprints with a new start every 30th second. The best sprint time, total sprinting time, and % decrease in time together with heart rate, lactate, and rate of perceived exertion (RPE) were measured. No significant differences in performance were found for the repeated-sprint test parameters (total sprint time: 35.99 ± 1.32 seconds [LWup] and 36.12 ± 0.96 seconds [SWup]; best sprint time: 4.32 ± 0.13 seconds [LWup] and 4.30 ± 0.10 seconds [SWup]; and % sprint decrease: 4.16 ± 2.15% [LWup] and 5.02 ± 2.07% [SWup]). No differences in lactate concentration after the warm-up and after the repeated-sprint test were found. However, RPE and heart rate were significantly higher after the long warm-up and the repeated-sprint test compared with the short warm-up. It was concluded that a short warm-up is as effective as a long warm-up for repeated sprints in soccer. Therefore, in regular training, less warm-up time is needed; the extra time could be used for important soccer skill training.

  6. 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%; 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

  7. Impact of 6 consecutive days of sprint training in hypoxia on performance in competitive sprint runners.

    Science.gov (United States)

    Kasai, Nobukazu; Mizuno, Sahiro; Ishimoto, Sayuri; Sakamoto, Etsuko; Maruta, Misato; Kurihara, Toshiyuki; Kurosawa, Yuko; Goto, Kazushige

    2017-04-18

    The purpose of the present study was to determine the effects of 6 successive days of repeated sprint training in moderate hypoxia on anaerobic capacity in 100-200-m sprint runners. Eighteen male sprint runners (age, 20.0 ± 0.3 years; height, 175.9 ± 1.1 cm; body mass, 65.0 ± 1.2 kg) performed repeated cycling sprints for 6 consecutive days in either normoxic (NOR; fraction of inspired oxygen [FiO2], 20.9%; n = 9) or hypoxic conditions (HYPO; FiO2, 14.5%; n = 9). The repeated sprint ability (10 × 6-s sprints), 30-s maximal sprint ability, maximal oxygen uptake (VO2max), and 60-m running time on the track were measured before and after the training period. Intramuscular PCr content (quadriceps femoris muscle) was measured by P-magnetic resonance spectroscopy (P-MRS) before and after the training period. Both groups showed similar improvements in repeated sprint ability after the training period (Psprint test and VO2max did not change significantly after the training period in either group. Running time for 0-10m improved significantly after the training period in the HYPO only (before, 1.39 ± 0.01s; after, 1.34 ± 0.02s, Psprint training for 6 consecutive days in hypoxia or normoxia improved repeated sprint ability in competitive sprint runners.

  8. 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.

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

    Science.gov (United States)

    Morrison, Jaime; McLellan, Chris; Minahan, Clare

    2015-12-01

    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 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 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. Key pointsThe RSR444 is a practical, multiple-set repeated-sprint running protocol designed for team-sport athletes.During performance of the RSR444 in hypoxia (FiO2 = 0.140), amateur team-sport athletes were unable to replicate the peak speed, distance covered or

  10. Effects of Carbohydrate Ingestion and Carbohydrate Mouth Rinse on Repeat Sprint Performance.

    Science.gov (United States)

    Krings, Ben M; Peterson, Timothy J; Shepherd, Brandon D; McAllister, Matthew J; Smith, JohnEric W

    2017-06-01

    The purpose of this investigation was to examine to the influence of carbohydrate ingestion (CHOI) and carbohydrate mouth rinse (CHOR) on acute repeat maximal sprint performance. Fourteen healthy males (age: 21.7 ± 1.8 years, mass: 82.3 ± 12.3 kg) completed a total of five 15-s maximal repeat sprints on a cycle ergometer against 0.075 kg ・ kg(-1) body mass each separated by 4 min of active recovery. Subjects completed four experimental trials and were randomly assigned one of four treatments: (1) CHOI, (2) CHOR, (3) placebo mouth rinse (PLAR), (4) placebo ingestion (PLAI). Subjects rinsed or ingested six 50 mL 10% CHO solutions throughout each trial. Performance variables measured included rating of perceived exertion, peak heart rate, peak and mean power output, fatigue index, and total work. Significant treatment main effects were observed for mean power output (p = 0.026), total work (p = 0.020), fatigue index (p = 0.004), and heart rate (p = 0.013). Overall mean power output and total work were significantly greater with CHOI (659.3 ± 103.0 watts, 9849.8 ± 1598.8 joules) compared with CHOR (645.8 ± 99.7 watts, 9447.5 ± 1684.9 joules, p PLAI, and PLAR. Athletes required to complete repeat bouts of high intensity exercise may benefit from CHOI.

  11. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an ‘hypoxic to normoxic recovery’ approach

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    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

  12. Diurnal variations of plasma homocysteine, total antioxidant status, and biological markers of muscle injury during repeated sprint: effect on performance and muscle fatigue--a pilot study.

    Science.gov (United States)

    Hammouda, Omar; Chtourou, Hamdi; Chahed, Henda; Ferchichi, Salyma; Kallel, Choumous; Miled, Abdelhedi; Chamari, Karim; Souissi, Nizar

    2011-12-01

    The aim of this study was (i) to evaluate whether homocysteine (Hcy), total antioxidant status (TAS), and biological markers of muscle injury would be affected by time of day (TOD) in football players and (ii) to establish a relationship between diurnal variation of these biomarkers and the daytime rhythm of power and muscle fatigue during repeated sprint ability (RSA) exercise. In counterbalanced order, 12 football (soccer) players performed an RSA test (5 x[6 s of maximal cycling sprint + 24 s of rest]) on two different occasions: 07:00-08:30 h and 17:00-18:30 h. Fasting blood samples were collected from a forearm vein before and 3-5 min after each RSA test. Core temperature, rating of perceived exertion, and performances (i.e., Sprint 1, Sprint 2, and power decrease) during the RSA test were significantly higher at 17:00 than 07:00 h (p RSA test. However, biomarkers of antioxidant status' resting levels (i.e., total antioxidant status, uric acid, and total bilirubin) were higher in the morning. This TOD effect was suppressed after exercise for TAS and uric acid. In conclusion, the present study confirms diurnal variation of Hcy, selected biological markers of cellular damage, and antioxidant status in young football players. Also, the higher performances and muscle fatigue showed in the evening during RSA exercise might be due to higher levels of biological markers of muscle injury and lower antioxidant status at this TOD.

  13. Comparison of the effect of repeated-sprint training combined with two different methods of strength training on young soccer players.

    Science.gov (United States)

    Campos-Vazquez, Miguel A; Romero-Boza, Sergio; Toscano-Bendala, Francisco J; Leon-Prados, Juan A; Suarez-Arrones, Luis J; Gonzalez-Jurado, Jose A

    2015-03-01

    The aim of this study was to assess the effect of combining repeated-sprint training with 2 different methods of muscle strength training on physical performance variables in young players. Twenty-one soccer players with mean (± SD) age of 18.1 (± 0.8) years, weight 69.9 (± 6.5) kg, and height 177.1 (± 5.7) cm, and competing in U-19 category, were randomly assigned to 2 experimental groups: squat group (SG: n = 10) and take-off group (TG: n = 11). Intervention in both groups consisted of the combination of a weekly session of repeated-sprint training (the same for both groups), with 2 weekly sessions of strength training (different for each group), for 8 weeks in the final period of the season. The strength sessions for the SG consisted of conducting a series of full squats executed at maximum velocity in the concentric phase. Intervention in the TG was the performance of 2 specific strength exercises (take-offs and change of direction), with measurements taken before and after consideration of the following variables: repeated-sprint ability (RSA), yo-yo intermittent recovery test level 1 (YYIRT1), countermovement jump (CMJ), and average velocity in full squat progressive loads test. The SG improved CMJ height in 5.28% (p ≤ 0.05) and FS37.5-47.5-67.5 (p ≤ 0.05), whereas the TG improved FS17.5-27.5-37.5-47.5-67.5 (p ≤ 0.05). There were no significant changes in the values of RSA or YYIRT1 in either group. The results seem to show that the combination of a weekly session of repeated-sprint training with 2 weekly sessions of strength training could be an insufficient stimulus to improve RSA in the final period of the season.

  14. Effects of Beetroot Juice on Recovery of Muscle Function and Performance between Bouts of Repeated Sprint Exercise

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    Tom Clifford

    2016-08-01

    Full Text Available This study examined the effects of beetroot juice (BTJ on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA (2 × 250 mL for 3 days after an initial repeated sprint test (20 × 30 m; RST1 and after a second repeated sprint test (RST2, performed 72 h later. Maximal isometric voluntary contractions (MIVC, countermovement jumps (CMJ, reactive strength index (RI, pressure-pain threshold (PPT, creatine kinase (CK, C-reactive protein (hs-CRP, protein carbonyls (PC, lipid hydroperoxides (LOOH and the ascorbyl free radical (A•− were measured before, after, and at set times between RST1 and RST2. CMJ and RI recovered quicker in BTJ compared to PLA after RST1: at 72 h post, CMJ and RI were 7.6% and 13.8% higher in BTJ vs. PLA, respectively (p < 0.05. PPT was 10.4% higher in BTJ compared to PLA 24 h post RST2 (p = 0.012 but similar at other time points. No group differences were detected for mean and fastest sprint time or fatigue index. MIVC, or the biochemical markers measured (p > 0.05. BTJ reduced the decrement in CMJ and RI following and RST but had no effect on sprint performance or oxidative stress.

  15. Effects of Beetroot Juice on Recovery of Muscle Function and Performance between Bouts of Repeated Sprint Exercise.

    Science.gov (United States)

    Clifford, Tom; Berntzen, Bram; Davison, Gareth W; West, Daniel J; Howatson, Glyn; Stevenson, Emma J

    2016-08-18

    This study examined the effects of beetroot juice (BTJ) on recovery between two repeated-sprint tests. In an independent groups design, 20 male, team-sports players were randomized to receive either BTJ or a placebo (PLA) (2 × 250 mL) for 3 days after an initial repeated sprint test (20 × 30 m; RST1) and after a second repeated sprint test (RST2), performed 72 h later. Maximal isometric voluntary contractions (MIVC), countermovement jumps (CMJ), reactive strength index (RI), pressure-pain threshold (PPT), creatine kinase (CK), C-reactive protein (hs-CRP), protein carbonyls (PC), lipid hydroperoxides (LOOH) and the ascorbyl free radical (A(•-)) were measured before, after, and at set times between RST1 and RST2. CMJ and RI recovered quicker in BTJ compared to PLA after RST1: at 72 h post, CMJ and RI were 7.6% and 13.8% higher in BTJ vs. PLA, respectively (p sprint time or fatigue index. MIVC, or the biochemical markers measured (p > 0.05). BTJ reduced the decrement in CMJ and RI following and RST but had no effect on sprint performance or oxidative stress.

  16. Acute effects of a caffeine-taurine energy drink on repeated sprint performance of American college football players.

    Science.gov (United States)

    Gwacham, Nnamdi; Wagner, Dale R

    2012-04-01

    Consumption of energy drinks is common among athletes; however, there is a lack of research on the efficacy of these beverages for short-duration, intense exercise. The purpose of this research was to investigate the acute effects of a low-calorie caffeine-taurine energy drink (AdvoCare Spark) on repeated sprint performance and anaerobic power in National Collegiate Athletic Association Division I football players. Twenty football players (age 19.7 ± 1.8 yr, height 184.9 ± 5.3 cm, weight 100.3 ± 21.7 kg) participated in a double-blind, randomized crossover study in which they received the energy drink or an isoenergetic, isovolumetric, non-caffeinated placebo in 2 trials separated by 7 days. The Running Based Anaerobic Sprint Test, consisting of six 35-m sprints with 10 s of rest between sprints, was used to assess anaerobic power. Sprint times were recorded with an automatic electronic timer. The beverage treatment did not significantly affect power (F = 3.84, p = .066) or sprint time (F = 3.06, p = .097). However, there was a significant interaction effect between caffeine use and the beverage for sprint times (F = 4.62, p = .045), as well as for anaerobic power (F = 5.40, p = .032), indicating a confounding effect. In conclusion, a caffeine-taurine energy drink did not improve the sprint performance or anaerobic power of college football players, but the level of caffeine use by the athletes likely influenced the effect of the drink.

  17. 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

  18. Changes in repeated-sprint performance in relation to change in locomotor profile in highly-trained young soccer players.

    Science.gov (United States)

    Buchheit, Martin; Mendez-Villanueva, Alberto

    2014-01-01

    The aim of this study was to examine the effects of changes in maximal aerobic (MAS) and sprinting (MSS) speeds and the anaerobic reserve (ASR) on repeated-sprint performance. Two hundred and seventy highly-trained soccer players (14.5 ± 1.6 year) completed three times per season (over 5 years) a maximal incremental running test to approach MAS, a 40-m sprint with 10-m splits to assess MSS and a repeated-sprint test (10 × 30-m sprints), where best (RSb) and mean (RSm) sprint times, and percentage of speed decrement (%Dec) were calculated. ASR was calculated as MSS-MAS. While ∆RSb were related to ∆MSS and ∆body mass (r(2) = 0.42, 90%CL[0.34;0.49] for the overall multiple regression, n = 334), ∆RSm was also correlated with ∆MAS and ∆sum of 7 skinfolds (r(2) = 0.43 [0.35;0.50], n = 334). There was a small and positive association between ∆%Dec and ∆MAS (r(2) = 0.02 [-0.07;0.11], n = 334). Substantial ∆MSS and ∆MAS had a predictive value of 70 and 55% for ∆RSm, respectively. Finally, ∆ASR per se was not predictive of ∆RSm (Cohen's = +0.8 to -0.3 with increased ASR), but the greater magnitude of ∆RSm improvement was observed when MSS, MAS and ASR increased together (0.8 vs. +0.4 with ASR increased vs. not, additionally to MSS and MAS). Low-cost field tests aimed at assessing maximal sprinting and aerobic speeds can be used to monitor ∆RS performance.

  19. 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.

  20. Arterial oxygen desaturation response to repeated bouts of sprint exercise in healthy young women.

    Science.gov (United States)

    Kuniyoshi, Shimpei; Endoh, Yumiko; Kobayashi, Minoru; Endoh, Hiroshi

    2010-01-01

    The decline in arterial oxygen saturation of hemoglobin during exercise has been termed exercise-induced arterial hypoxemia (EIAH). We examined whether repeated bouts of sprint exercise (SprE) would induce EIAH in healthy young men and women. Ten men and 11 women (20.4 +/- 0.3 year) performed an anaerobic power test (three bouts of 10 s cycling with 120 s intervals) using a cycle ergometer. Arterial oxygen saturation of hemoglobin measured by pulse oximeter (SpO(2)), heart rate (HR), rate perceived exertion (RPE), and the blood lactate concentration ([La](b)) were assessed at rest, during, and 5 min after repeated bouts of SprE. Women exhibited a lower maximal anaerobic power (MAnP) compared to men (498 +/- 23 vs. 759 +/- 22 watts, respectively, p women were comparable with those in men throughout the test. However, the only significant decline in SpO(2) after a single bout of SprE (95.5 +/- 0.7%) from the resting value (97.9 +/- 0.2%) was observed in women, and further declines occurred following heavier SprE (women, mild to moderate EIAH developed, whereas only 2 men showed mild EIAH. Thus, these findings suggest that repeated bouts of SprE might induce mild EIAH in young women but not men.

  1. Interaction of central and peripheral factors during repeated sprints at different levels of arterial O2 saturation.

    Directory of Open Access Journals (Sweden)

    François Billaut

    Full Text Available PURPOSE: To investigate the interaction between the development of peripheral locomotor muscle fatigue, muscle recruitment and performance during repeated-sprint exercise (RSE. METHOD: In a single-blind, randomised and cross-over design, ten male team-sport athletes performed two RSE (fifteen 5-s cycling sprints interspersed with 25 s of rest; power self-selected in normoxia and in acute moderate hypoxia (FIO2 0.138. Mechanical work, total electromyographic intensity (summed quadriceps electromyograms, RMSsum and muscle (vastus lateralis and pre-fontal cortex near-infrared spectroscopy (NIRS parameters were calculated for every sprint. Blood lactate concentration ([Lac(-] was measured throughout the protocol. Peripheral quadriceps fatigue was assessed via changes in potentiated quadriceps twitch force (ΔQtw,pot pre- versus post-exercise in response to supra-maximal magnetic femoral nerve stimulation. The central activation ratio (QCAR was used to quantify completeness of quadriceps activation. RESULTS: Compared with normoxia, hypoxia reduced arterial oxygen saturation (-13.7%, P=0.001, quadriceps RMSsum (-13.7%, P=0.022, QCAR (-3.3%, P=0.041 and total mechanical work (-8.3%, P=0.019. However, the magnitude of quadriceps fatigue induced by RSE was similar in the two conditions (ΔQtw,pot: -53.5% and -55.1%, P=0.71. The lower cycling performance in hypoxia occurred despite similar metabolic (muscle NIRS parameters and blood [Lac(-] and functional (twitch and M-wave muscle states. CONCLUSION: Results suggest that the central nervous system regulates quadriceps muscle recruitment and, thereby, performance to limit the development of muscle fatigue during intermittent, short sprints. This finding highlights the complex interaction between muscular perturbations and neural adjustments during sprint exercise, and further supports the presence of pacing during intermittent sprint exercise.

  2. SHORT DURATIONS OF STATIC STRETCHING WHEN COMBINED WITH DYNAMIC STRETCHING DO NOT IMPAIR REPEATED SPRINTS AND AGILITY

    Directory of Open Access Journals (Sweden)

    Del P. Wong

    2011-06-01

    Full Text Available This study aimed to compare the effect of different static stretching durations followed by dynamic stretching on repeated sprint ability (RSA and change of direction (COD. Twenty-five participants performed the RSA and COD tests in a randomized order. After a 5 min aerobic warm up, participants performed one of the three static stretching protocols of 30 s, 60 s or 90 s total duration (3 stretches x 10 s, 20 s or 30 s. Three dynamic stretching exercises of 30 s duration were then performed (90 s total. Sit-and-reach flexibility tests were conducted before the aerobic warm up, after the combined static and dynamic stretching, and post- RSA/COD test. The duration of static stretching had a positive effect on flexibility with 36.3% and 85.6% greater sit-and-reach scores with the 60 s and 90 s static stretching conditions respectively than with the 30 s condition (p < 0.001. However there were no significant differences in RSA and COD performance between the 3 stretching conditions. The lack of change in RSA and COD might be attributed to a counterbalancing of static and dynamic stretching effects. Furthermore, the short duration (< 90 s static stretching may not have provided sufficient stimulus to elicit performance impairments

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

    Science.gov (United States)

    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 (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.

  4. Effects of a Ten Week Training Programme on Repeated Short Sprints among Football Referees of Malaysia

    Directory of Open Access Journals (Sweden)

    Subramaniam Nathan

    2014-07-01

    Full Text Available The objective of this study was to investigate whether a ten week training programme would improve repeated short sprints of football referees in Malaysia. Sixty national football referees were randomly assigned into 3 groups (n=20 namely the control group, experimental one and experimental two. Experimental one followed a 10 week training programme (duration of training 4 days in a week, each session=90 minutes and time 5 pm supervised by a physical education lecturer and his assistants. Experimental two reported for training at a different venue and trained on their own (duration, frequency and time as for experimental one. Pre-test and post-test results were used to determine whether there was an improvement. SPANOVA results rejected the null hypothesis [F (2, 57 =75.86 p<0.05].  Pillai’s Trace indicated there was a significant difference between pre-test and post-test results and significant interaction effect. Tukey Pair Wise Comparison indicated best performance by experimental one and the control group the poorest. The results indicated that the training programme was acceptable.

  5. Physiological and Neuromuscular Response to a Simulated Sprint-Distance Triathlon: Effect of Age Differences and Ability Level.

    Science.gov (United States)

    García-Pinillos, Felipe; Cámara-Pérez, José C; González-Fernández, Francisco T; Párraga-Montilla, Juan A; Muñoz-Jiménez, Marcos; Latorre-Román, Pedro Á

    2016-04-01

    This study aimed to describe the acute impact of a simulated sprint-distance triathlon at physiological and neuromuscular levels and to determine whether age and athletic performance influenced the response in triathletes. Nineteen triathletes performed a sprint-distance triathlon under simulated conditions. Cardiovascular response was monitored during the race. Rate of perceived exertion along with muscular performance parameters (countermovement jump [CMJ], squat jump [SJ], and handgrip strength test [HS]) were tested at pre- and posttest and during every transition, while a 20-m sprint test (S20m) was performed before and after the race. Blood lactate was recorded postrace. A repeated measures analysis of variance showed that the neuromuscular response-in terms of CMJ, SJ, and HS-was unchanged (p ≥ 0.05), while S20m performance was impaired at posttest (p triathlon were similar.

  6. Multidirectional sprints and small-sided games training effect on agility and change of direction abilities in youth soccer.

    Science.gov (United States)

    Chaouachi, Anis; Chtara, Moktar; Hammami, Raouf; Chtara, Hichem; Turki, Olfa; Castagna, Carlo

    2014-11-01

    The aim of this study was to compare the training effects of a small-sided game (SSG) and multidirectional sprint intervention on agility and change of direction (COD) ability in young male soccer players. Thirty-six soccer players (age: 14.2 ± 0.9 years; height: 167.2 ± 5.7 cm; body mass: 54.1 ± 6.3 kg, body fat: 12.5 ± 2.2%) participated in a short-term (6 weeks) randomized parallel fully controlled training study, with pre-to-post measurements. Players were randomly assigned to 2 experimental groups: training with preplanned COD drills (CODG, n = 12) or using SSGs (SSGG, n = 12) and to a control group (CONG, n = 12). Pre- and post-training players completed a test battery involving linear sprinting (15- and 30-m sprint), COD sprinting (COD: 15 m, ball: 15 m, 10-8-8-10 m, zigzag: 20 m), reactive agility test (RAT, RAT-ball), and vertical and horizontal jumping (countermovement jump and 5-jump, respectively). A significant (p ≤ 0.05) group × time effect was detected for all variables in CODG and SSGG. Improvements in sprint, agility without ball, COD, and jumping performances, were higher in CODG than in the other groups. The SSGG improved significantly more (p ≤ 0.05) than other groups in agility tests with the ball. The CONG showed significant improvements (p ≤ 0.05) on linear sprinting over a distance longer than 10 m and in all the agility and COD tests used in this study. It is concluded that in young male soccer players, agility can be improved either using purpose-built SSG or preplanned COD sprints. However, the use of specifically designed SSG may provide superior results in match-relevant variables.

  7. No Improved Performance With Repeated-Sprint Training in Hypoxia Versus Normoxia: A Double-Blind and Crossover Study.

    Science.gov (United States)

    Montero, David; Lundby, Carsten

    2017-02-01

    Few recent studies indicate that short-term repeated-sprint (RS) training in hypoxia (RSH) improves RS performance compared with identical training under normoxic conditions (RSN) in endurance-trained subjects. To determine the effects of RSH against RSN on RS performance under normoxic and moderate hypoxic conditions, using a randomized, doubleblind, crossover experimental design. Fifteen endurance-trained male subjects (age 25 ± 4 y) performed 4 wk of RS training (3 sessions/wk) in normobaric hypoxia (RSH, FiO2 = 13.8%) and normoxia (RSN, FiO2 = 20.9%) in a crossover manner. Before and after completion of training, RS tests were performed on a cycle ergometer with no prior exercise (RSNE), after an incremental exercise test (RSIE), and after a time-trial test (RSTT) in normoxia and hypoxia. Peak power outputs at the incremental exercise test and time-trial performance were unaltered by RSH in normoxia and hypoxia. RS performance was generally enhanced by RSH, as well as RSN, but there were no additional effects of RSH over RSN on peak and mean sprint power output and the number of repeated sprints performed in the RSNE, RSIE, and RSTT trials under normoxic and hypoxic conditions. The present double-blind crossover study indicates that RSH does not improve RS performance compared with RSN in normoxic and hypoxic conditions in endurance-trained subjects. Therefore, caution should be exercised when proposing RSH as an advantageous method to improve exercise performance.

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

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    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.

  9. Short Durations of Static Stretching when Combined with Dynamic Stretching do not Impair Repeated Sprints and Agility

    Science.gov (United States)

    Wong, Del P.; Chaouachi, Anis; Lau, Patrick W.C.; Behm, David G.

    2011-01-01

    This study aimed to compare the effect of different static stretching durations followed by dynamic stretching on repeated sprint ability (RSA) and change of direction (COD). Twenty-five participants performed the RSA and COD tests in a randomized order. After a 5 min aerobic warm up, participants performed one of the three static stretching protocols of 30 s, 60 s or 90 s total duration (3 stretches x 10 s, 20 s or 30 s). Three dynamic stretching exercises of 30 s duration were then performed (90 s total). Sit-and-reach flexibility tests were conducted before the aerobic warm up, after the combined static and dynamic stretching, and post- RSA/COD test. The duration of static stretching had a positive effect on flexibility with 36.3% and 85.6% greater sit-and-reach scores with the 60 s and 90 s static stretching conditions respectively than with the 30 s condition (p ≤ 0.001). However there were no significant differences in RSA and COD performance between the 3 stretching conditions. The lack of change in RSA and COD might be attributed to a counterbalancing of static and dynamic stretching effects. Furthermore, the short duration (≤ 90 s) static stretching may not have provided sufficient stimulus to elicit performance impairments. Key points The duration of combined static and dynamic stretching had a positive effect on flexibility with 36.3% and 85.6% greater sit and reach scores with the 60 s and 90 s static stretching conditions respectively than with the 30 s condition (p ≤ 0.001). No significant differences in RSA and COD between the 3 stretching conditions. The lack of change in RSA and COD might be attributed to a counterbalancing of static and dynamic stretching effects. The short duration (≤ 90 s) static stretching may not have provided sufficient stimulus to elicit performance impairments. PMID:24149890

  10. Relationships Between Sprint, Jumping and Strength Abilities, and 800 M Performance in Male Athletes of National and International Levels

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    Bachero-Mena Beatriz

    2017-08-01

    Full Text Available This study analysed the relationships between sprinting, jumping and strength abilities, with regard to 800 m running performance. Fourteen athletes of national and international levels in 800 m (personal best: 1:43-1:58 min:ss completed sprint tests (20 m and 200 m, a countermovement jump, jump squat and full squat test as well as an 800 m race. Significant relationships (p < 0.01 were observed between 800 m performance and sprint tests: 20 m (r = 0.72 and 200 m (r = 0.84. Analysing the 200 m run, the magnitude of the relationship between the first to the last 50 m interval times and the 800 m time tended to increase (1st 50 m: r = 0.71; 2nd 50 m: r = 0.72; 3rd 50 m: r = 0.81; 4th 50 m: r = 0.85. Performance in 800 m also correlated significantly (p < 0.01-0.05 with strength variables: the countermovement jump (r = -0.69, jump squat (r = -0.65, and full squat test (r = -0.58. Performance of 800 m in high-level athletes was related to sprint, strength and jumping abilities, with 200 m and the latest 50 m of the 200 m being the variables that most explained the variance of the 800 m performance.

  11. Repeated-sprint cycling does not induce respiratory muscle fatigue in active adults: measurements from the powerbreathe® inspiratory muscle trainer.

    Science.gov (United States)

    Minahan, Clare; Sheehan, Beth; Doutreband, Rachel; Kirkwood, Tom; Reeves, Daniel; Cross, Troy

    2015-03-01

    This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., 'S-Index') before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP) values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p Repeated-sprint cycling had no effect on respiratory muscle strength as measured by the POWERbreathe® (p > 0.99) and during the Mueller maneuver (p > 0.99). The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults. Key pointsThe S-Index as measured by the POWERbreathe® is a reliable measure of respiratory muscle strengthThe S-Index does not accurately reflect maximal inspiratory pressure obtained from a Mueller maneuverRepeated-sprint cycling does not induce respiratory muscle fatigue as measured by the POWERbreathe® and the Manometer.

  12. Emotional responses during repeated sprint intervals performed on level, downhill and uphill surfaces.

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    Baron, Bertrand; Guilloux, Bertrand; Begue, Mylène; Uriac, Stéphane

    2015-01-01

    The purpose of this study was to test emotional responses during sprint intervals performed on a level, down and up surface. Fifty trained participants performed a maximal effort during a 60-m sprint and 10 repetitions of 60 m running sprints on a level, down and up surface on a 5.9% slope. Running speeds, emotional responses and heart rate were measured. Self-selected speeds were correlated with the rating of perceived exertion, the affective balance, the desire to stop and the resources needed for the task in all conditions whereas the pleasure, the desire to continue and the capacity to realise the task were correlated with speeds only during level and uphill running. Mean values of emotional parameters were significantly different (P < 0.05) during running on a flat surface, downhill and uphill. When the gradient of running surface is changed, the pattern of emotional responses was just translated, i.e. most of the slope between the evolution of emotional parameters and the repetitions were not significantly different whereas Y-intercepts were different. Consented effort is highly correlated with the resources needed for the task (P < 0.001, r(2) = 0.72). We propose that the difference in the resources needed for the task between level, downhill and uphill running (F 2, 1499 = 166.5, P < 0.001, Eta(2) = 0.18) is the most important key that explains our results.

  13. EFFECT OF PRE-COOLING ON REPEAT-SPRINT PERFORMANCE IN SEASONALLY ACCLIMATISED MALES DURING AN OUTDOOR SIMULATED TEAM-SPORT PROTOCOL IN WARM CONDITIONS

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    Carly J. Brade

    2013-09-01

    Full Text Available Whether precooling is beneficial for exercise performance in warm climates when heat acclimatised is unclear. The purpose of this study was to determine the effect of precooling on repeat-sprint performance during a simulated team-sport circuit performed outdoors in warm, dry field conditions in seasonally acclimatised males (n = 10. They performed two trials, one with precooling (PC; ice slushy and cooling jacket and another without (CONT. Trials began with a 30-min baseline/cooling period followed by an 80 min repeat-sprint protocol, comprising 4 x 20-min quarters, with 2 x 5-min quarter breaks and a 10-min half-time recovery/cooling period. A clear and substantial (negative; PC slower effect was recorded for first quarter circuit time. Clear and trivial effects were recorded for overall circuit time, third and fourth quarter sprint times and fourth quarter best sprint time, otherwise unclear and trivial effects were recorded for remaining performance variables. Core temperature was moderately lower (Cohen's d=0.67; 90% CL=-1.27, 0.23 in PC at the end of the precooling period and quarter 1. No differences were found for mean skin temperature, heart rate, thermal sensation, or rating of perceived exertion, however, moderate Cohen's d effect sizes suggested a greater sweat loss in PC compared with CONT. In conclusion, repeat- sprint performance was neither clearly nor substantially improved in seasonally acclimatised players by using a combination of internal and external cooling methods prior to and during exercise performed in the field in warm, dry conditions. Of practical importance, precooling appears unnecessary for repeat-sprint performance if athletes are seasonally acclimatised or artificially acclimated to heat, as it provides no additional benefit

  14. Short-term effects of complex and contrast training in soccer players' vertical jump, sprint, and agility abilities.

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    Maio Alves, José Manuel Vilaça; Rebelo, António Natal; Abrantes, Catarina; Sampaio, Jaime

    2010-04-01

    The purpose of this study was to analyze the short-term effects of complex and contrast training (CCT) on vertical jump (squat and countermovement jump), sprint (5 and 15 m), and agility (505 Agility Test) abilities in soccer players. Twenty-three young elite Portuguese soccer players (age 17.4 +/- 0.6 years) were divided into 2 experimental groups (G1, n = 9, and G2, n = 8) and 1 control group (G3, n = 6). Groups G1 and G2 have done their regular soccer training along with a 6-week strength training program of CCT, with 1 and 2 training sessions.wk, respectively. G3 has been kept to their regular soccer training program. Each training session from the CCT program was organized in 3 stations in which a general exercise, a multiform exercise, and a specific exercise were performed. The load was increased by 5% from 1 repetition maximum each 2 weeks. Obtained results allowed identifying (a) a reduction in sprint times over 5 and 15 m (9.2 and 6.2% for G1 and 7.0 and 3.1%, for G2; p < 0.05) and () an increase on squat and jump (12.6% for G1 and 9.6% for G2; p < 0.05). The results suggested that the CCT induced the performance increase in 5 and 15 m sprint and in squat jump. Vertical jump and sprint performances after CCT program were not influenced by the number of CCT sessions per week (1 or 2 sessions.wk). From the obtained results, it was suggested that the CCT is an adequate training strategy to develop soccer players' muscle power and speed.

  15. Repeated sprints, high-intensity interval training, small-sided games: theory and application to field sports.

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    Hoffmann, James J; Reed, Jacob P; Leiting, Keith; Chiang, Chieh-Ying; Stone, Michael H

    2014-03-01

    Due to the broad spectrum of physical characteristics necessary for success in field sports, numerous training modalities have been used develop physical preparedness. Sports like rugby, basketball, lacrosse, and others require athletes to be not only strong and powerful but also aerobically fit and able to recover from high-intensity intermittent exercise. This provides coaches and sport scientists with a complex range of variables to consider when developing training programs. This can often lead to confusion and the misuse of training modalities, particularly in the development of aerobic and anaerobic conditioning. This review outlines the benefits and general adaptations to 3 commonly used and effective conditioning methods: high-intensity interval training, repeated-sprint training, and small-sided games. The goals and outcomes of these training methods are discussed, and practical implementations strategies for coaches and sport scientists are provided.

  16. Long-term glycine propionyl-l-carnitine supplemention and paradoxical effects on repeated anaerobic sprint performance

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    Goldstein Erica R

    2010-10-01

    Full Text Available Abstract Background It has been demonstrated that acute GPLC supplementation produces enhanced anaerobic work capacity with reduced lactate production in resistance trained males. However, it is not known what effects chronic GPLC supplementation has on anaerobic performances or lactate clearance. Purpose The purpose of this study was to examine the long-term effects of different dosages of GPLC supplementation on repeated high intensity stationary cycle sprint performance. Methods Forty-five resistance trained men participated in a double-blind, controlled research study. All subjects completed two testing sessions, seven days apart, 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. Following completion of the second test session, the 45 subjects were randomly assigned to receive 1.5 g, 3.0 g, or 4.5 g GPLC per day for a 28 day period. Subjects completed a third test session following the four weeks of GPLC supplementation using the same testing protocol. Values of peak power (PP, mean power (MP and percent decrement of power (DEC were determined per bout and standardized relative to body mass. Heart rate (HR and blood lactate (LAC were measured prior to, during and following the five sprint bouts. Results There were no significant effects of condition or significant interaction effects detected for PP and MP. However, results indicated that sprint bouts three, four and five produced 2 - 5% lower values of PP and 3 - 7% lower values of MP with GPLC at 3.0 or 4.5 g per day as compared to baseline values. Conversely, 1.5 g GPLC produced 3 - 6% higher values of PP and 2 -5% higher values of MP compared with PL baseline values. Values of DEC were significantly greater (15-20% greater across the five sprint bouts with 3.0 g or 4.5 g GPLC, but the 1.5 g GPLC

  17. Effect of pre-cooling on repeat-sprint performance in seasonally acclimatised males during an outdoor simulated team-sport protocol in warm conditions.

    Science.gov (United States)

    Brade, Carly J; Dawson, Brian T; Wallman, Karen E

    2013-01-01

    Whether precooling is beneficial for exercise performance in warm climates when heat acclimatised is unclear. The purpose of this study was to determine the effect of precooling on repeat-sprint performance during a simulated team-sport circuit performed outdoors in warm, dry field conditions in seasonally acclimatised males (n = 10). They performed two trials, one with precooling (PC; ice slushy and cooling jacket) and another without (CONT). Trials began with a 30-min baseline/cooling period followed by an 80 min repeat-sprint protocol, comprising 4 x 20-min quarters, with 2 x 5-min quarter breaks and a 10-min half-time recovery/cooling period. A clear and substantial (negative; PC slower) effect was recorded for first quarter circuit time. Clear and trivial effects were recorded for overall circuit time, third and fourth quarter sprint times and fourth quarter best sprint time, otherwise unclear and trivial effects were recorded for remaining performance variables. Core temperature was moderately lower (Cohen's d=0.67; 90% CL=-1.27, 0.23) in PC at the end of the precooling period and quarter 1. No differences were found for mean skin temperature, heart rate, thermal sensation, or rating of perceived exertion, however, moderate Cohen's d effect sizes suggested a greater sweat loss in PC compared with CONT. In conclusion, repeat- sprint performance was neither clearly nor substantially improved in seasonally acclimatised players by using a combination of internal and external cooling methods prior to and during exercise performed in the field in warm, dry conditions. Of practical importance, precooling appears unnecessary for repeat-sprint performance if athletes are seasonally acclimatised or artificially acclimated to heat, as it provides no additional benefit. Key PointsPre-cooling did not improve repeated sprint performance during a prolonged team-sport circuit in field conditions.If individuals are already heat acclimatised/acclimated, pre-cooling is

  18. Analysis of a simulated sprint competition in classical cross country skiing.

    Science.gov (United States)

    Stöggl, T; Lindinger, S; Müller, E

    2007-08-01

    The objectives of this project were first to analyze the physiological response of a classical cross country (XC) skiing sprint competition, second, to examine the relationships of kinematic and physiological variables with sprint performance and third, to test the hypothesis that maximal speed in double poling (DP) and diagonal stride (DIAG) predicts sprint performance. Twelve elite skiers performed a treadmill-based simulation of a sprint competition that included two maximal speed tests (DP, DIAG), a test and three sprint heats over a 3.5-h period. VO(2), lactate, heart rate (HR) and kinematic variables were measured. Maximal DP and DIAG speed, the level of repeatedly produced lactate values and skiing technical aspects positively correlated with sprint performance. Fastest skiers produced longer cycle lengths in all techniques at equal poling frequency. VO(2) variables showed no correlation to sprint performance. VO(2), tidal volume (VT), and lactate decreased over the heats. XC-sprint performance in classical style depends on speed abilities, technique use, fatigue resistance, and anaerobic capacity. The relationship of maximal speed with sprint performance suggests (a) integrating maximal speed tests in XC sprint diagnostics and (b) emphasizing training models for XC skiing-specific speed abilities to improve performance in XC skiing sprint.

  19. Repeated Dribbling Ability in Young Soccer Players: Reproducibility and Variation by the Competitive Level

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    Duarte João P.

    2016-12-01

    Full Text Available The intermittent nature of match performance in youth soccer supports relevance of ability to repeatedly produce high-intensity actions with short recovery periods. This study was aimed to examine the reproducibility of a repeated dribbling ability protocol and, additionally, to estimate the contribution of concurrent tests to explain inter-individual variability in repeated dribbling output. The total sample comprised 98 players who were assessed as two independent samples: 31 players were assessed twice to examine reliability of the protocol; and 67 juveniles aged 16.1 ± 0.6 years were compared by the competitive level (local, n = 34; national, n = 33 to examine construct validity. All single measurements appeared to be reasonably reliable: total (ICC = 0.924; 95%CI: 0.841 to 0.963; ideal (ICC = 0.913; 95%CI: 0.820 to 0.958; worst (ICC = 0.813; 95%CI: 0.611 to 0.910. In addition, the percentage of the coefficient of variation was below the critical value of 5% for total (%CV = 3.84; TEM = 2.51 s; ideal (%CV = 3.90, TEM = 2.48 s. Comparisons between local and national players suggested magnitude effects as follows: moderate (d-value ranged from 0.63 to 0.89 for all repeated sprint ability scores; large for total (d = 1.87, ideal (d = 1.72, worst (d = 1.28 and moderate for composite scores: the fatigue index (d = 0.69 and the decrement score (d = 0.67. In summary, the dribbling protocol presented reasonable reproducibility properties and output extracted from the protocol seemed to be independent from biological maturation.

  20. The use of portable NIRS to measure muscle oxygenation and haemodynamics during a repeated sprint running test.

    Science.gov (United States)

    Jones, Ben; Hesford, Catherine M; Cooper, Chris E

    2013-01-01

    Portable near-infrared spectroscopy (NIRS) devices were originally developed for use in exercise and sports science by Britton Chance in the 1990s (the RunMan and microRunman series). However, only recently with the development of more robust, and wireless systems, has the routine use in elite sport become possible. As with the medical use of NIRS, finding applications of the technology that are relevant to practitioners is the key issue. One option is to use NIRS to track exercise training-induced adaptations in muscle. Portable NIRS devices enable monitoring during the normal 'field' routine uses to assess fitness, such as repeat sprint shuttle tests. Knowledge about the acute physiological responses to these specific tests has practical applications within team sport training prescription, where development of both central and peripheral determinants of high-intensity intermittent exercise needs to be considered. The purpose of this study was to observe NIRS-detected parameters during a repeat sprint test. We used the PortaMon, a two wavelength spatially resolved NIR spectrometer manufactured by Artinis Inc., to assess NIR changes in the gastrocnemius muscle of both the left and right leg during high-intensity running. Six university standard rugby players were assessed (age 20 ± 1.5 years; height 183 ± 1.0 cm; weight 89.4 ± 5.8 kg; body fat 12.2 ± 3.0 %); the subjects completed nine repeated shuttle runs, which incorporated forward, backward and change of direction movements. Individual sprint time, total time to complete test, blood lactate response (BL), heart rate values (HR) and haemoglobin variables (ΔHHb, ΔtHb, ΔHbO2 and ΔTSI%) were measured. Total time to complete the test was 260 ± 20 s, final blood lactate was 14.3 ± 2.8 mM, and maximal HR 182 ± 5 bpm. NIRS variables displayed no differences between right and left legs. During the test, the group-averaged data showed a clear decrease in HbO2 (max. decrease 11.41 ± 4.95 μM), increase in HHb

  1. Effects of seated and standing cold water immersion on recovery from repeated sprinting.

    Science.gov (United States)

    Leeder, Jonathan D C; van Someren, Ken A; Bell, Phillip G; Spence, John R; Jewell, Andrew P; Gaze, David; Howatson, Glyn

    2015-01-01

    This study investigated the effects of two different hydrostatic pressures (seated or standing) during cold water immersion at attenuating the deleterious effects of strenuous exercise on indices of damage and recovery. Twenty four male well-trained games players (age 23 ± 3 years; body mass 81.4 ± 8.7 kg: [Formula: see text]O2max 57.5 ± 4.9 ml∙kg(-1)∙min(-1)) completed the Loughborough Intermittent Shuttle Test (LIST) and were randomly assigned to either a control, seated cold water immersion or a standing cold water immersion (14 min at 14°C). Maximal isometric voluntary contraction, counter-movement jump, creatine kinase, C-reactive protein, interleukin-6 and delayed onset muscle soreness (DOMS) were measured before and up to 72 h following the LIST. All dependent variables showed main effects for time (P cold water immersion interventions. Seated cold water immersion was associated with lower DOMS than standing cold water immersion (effect size = 1.86; P = 0.001). These data suggest that increasing hydrostatic pressure by standing in cold water does not provide an additional recovery benefit over seated cold water immersion, and that both seated and standing immersions have no benefit in promoting recovery following intermittent sprint exercise.

  2. Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric "Live High-Train Low": a double-blind placebo-controlled cross-over study.

    Science.gov (United States)

    Bejder, Jacob; Andersen, Andreas Breenfeldt; Buchardt, Rie; Larsson, Tanja Hultengren; Olsen, Niels Vidiendal; Nordsborg, Nikolai Baastrup

    2017-05-01

    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-out exercise, and 8 × 30 s of all-out sprint was evaluated before and after the intervention. Following at least 8 weeks of wash-out, the subjects crossed over and repeated the procedure. Incremental peak power output was similar after both interventions [LHTL: 375 ± 74 vs. 369 ± 70 W (pre-vs-post), placebo: 385 ± 60 vs. 364 ± 79 W (pre-vs-post)]. Likewise, mean power output was similar between treatments as well as before and after each intervention for time trial [LHTL: 257 ± 49 vs. 254 ± 54 W (pre-vs-post), placebo: 267 ± 57 vs. 267 ± 52 W (pre-vs-post)], and 3-min all-out [LHTL: 366 ± 68 vs. 369 ± 72 W (pre-vs-post), placebo: 365 ± 66 vs. 355 ± 71 W (pre-vs-post)]. Furthermore, peak- and mean power output during repeated sprint exercise was similar between groups at all time points (n = 5). In conclusion, 6 weeks of normobaric LHTL using altitude tents simulating altitudes of 2500-3500 m 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.

  3. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.

    Science.gov (United States)

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2011-03-01

    This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

  4. 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 women (R 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.

  5. Repeated-Sprint Cycling Does Not Induce Respiratory Muscle Fatigue in Active Adults: Measurements from The Powerbreathe® Inspiratory Muscle Trainer

    Directory of Open Access Journals (Sweden)

    Clare Minahan, Beth Sheehan, Rachel Doutreband, Tom Kirkwood, Daniel Reeves, Troy Cross

    2015-03-01

    Full Text Available This study examined respiratory muscle strength using the POWERbreathe® inspiratory muscle trainer (i.e., ‘S-Index’ before and after repeated-sprint cycling for comparison with maximal inspiratory pressure (MIP values obtained during a Mueller maneuver. The S-Index was measured during six trials across two sessions using the POWERbreathe® and MIP was measured during three trials in a single session using a custom-made manometer in seven recreationally active adults. Global respiratory muscle strength was measured using both devices before and after the performance of sixteen, 6-s sprints on a cycle ergometer. Intraclass correlation coefficients for the POWERbreathe® S-index indicated excellent (p 0.99 and during the Mueller maneuver (p > 0.99. The POWERbreathe® S-Index is a moderately reliable, but not equivalent, measure of MIP determined during a Mueller maneuver. Furthermore, repeated-sprint cycling does not induce globalized respiratory muscle fatigue in recreationally-active adults.

  6. Effects of partial sleep deprivation on proinflammatory cytokines, growth hormone, and steroid hormone concentrations during repeated brief sprint interval exercise.

    Science.gov (United States)

    Abedelmalek, Salma; Souissi, Nizar; Chtourou, Hamdi; Denguezli, Meriam; Aouichaoui, Chirine; Ajina, Monia; Aloui, Asma; Dogui, Mohamed; Haddouk, Samy; Tabka, Zouhair

    2013-05-01

    The purpose of this study was to evaluate the effects of partial sleep deprivation (PSD) on circulating concentrations of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in relation to the secretory profiles of growth hormone (GH), cortisol, and testosterone during a repeated brief sprint interval exercise. Thirty healthy football players (mean age: 21.1 [range: 18-24] years; body mass index [BMI]: 22.6 [range: 18.47-24.46] Kg/m(2)) completed two test sessions at 08:00 h, one scheduled after a baseline night (bedtime: from 22:30 to 07:00 h) and the other after a PSD night caused by an early awakening (bedtime: from 22:30 to 03:00 h). During each session, participants performed 4 × 250-m run on a treadmill at a constant intensity of 80% of the personal maximal speed with a 3-min recovery in between. Tests session were performed at 08:00 h. Blood samples were collected before, immediately after the first and the fourth 250-m run, and 60 min after the exercise. The results showed that cortisol concentrations were not affected by the PSD. However, GH and testosterone concentrations were higher (p exercise during PSD in comparison with baseline. Likewise, plasma concentrations of IL-6 and TNF-α were higher (p exercise (i.e., the first and the fourth run) and remained elevated during the recovery period (i.e., 60 min after the exercise). In conclusion, these results showed that sleep restriction increases the proinflammatory cytokine, GH, and testosterone concentrations after physical exercise but did not affect the cortisol responses.

  7. The Effects of a Single Whole-Body Cryotherapy Exposure on Physiological, Performance, and Perceptual Responses of Professional Academy Soccer Players After Repeated Sprint Exercise.

    Science.gov (United States)

    Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian J; Bracken, Richard M; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P

    2017-02-01

    Russell, M, Birch, J, Love, T, Cook, CJ, Bracken, RM, Taylor, T, Swift, E, Cockburn, E, Finn, C, Cunningham, D, Wilson, L, and Kilduff, LP. The effects of a single whole-body cryotherapy exposure on physiological, performance, and perceptual responses of professional academy soccer players after repeated sprint exercise. J Strength Cond Res 31(2): 415-421, 2017-In professional youth soccer players, the physiological, performance, and perceptual effects of a single whole-body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counterbalanced, and crossover design, 14 habituated English Premier League academy soccer players performed 15 × 30 m sprints (each followed by a 10 m forced deceleration) on 2 occasions. Within 20 minutes of exercise cessation, players entered a WBC chamber (Cryo: 30 seconds at -60° C, 120 seconds at -135° C) or remained seated (Con) indoors in temperate conditions (∼25° C). Blood and saliva samples, peak power output (countermovement jump), and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2-hour and 24-hour postexercise. When compared with Con, a greater testosterone response was observed at 2-hour (+32.5 ± 32.3 pg·ml, +21%) and 24-hour (+50.4 ± 48.9 pg·ml, +28%) postexercise (both P = 0.002) in Cryo (trial × treatment interaction: P = 0.001). No between-trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and creatine kinase), performance (peak power output), or perceptual (recovery or soreness) markers (all trial × treatment interactions: P > 0.05); all of which were influenced by exercise (time effects: all P ≤ 0.05). A single session of WBC performed within 20 minutes of repeated sprint exercise elevated testosterone concentrations for 24 hours but did not affect any other performance, physiological, or perceptual measurements taken. Although unclear, WBC may be

  8. Kinematic analysis of sprinting pickup acceleration versus maximum sprinting speed

    Directory of Open Access Journals (Sweden)

    S. MANZER

    2016-10-01

    Full Text Available Pickup acceleration and maximum sprinting speed are two essential phases of the 100-m sprint with variant sprinting speed, step length, frequency and technique. The aim of the study was to describe and compare the kinematic parameters of both sprint variants. Hypothetically it was assumed to find differences in sprinting speed, step length, flight and contact times as well as between the body angles of different key positions. From 8 female and 8 male (N=16 track and field junior athletes a double stride of both sprint variants was filmed (200 Hz from a sagittal position and the 10-m-sprint time was measured using triple light barriers. Kinematic data for sprinting speed and angles of knee, hip and ankle were compared with an analysis of variance with repeated measures. The sprinting speed was 7.7 m/s and 8.0 m/s (female and 8.4 m/s and 9.2 m/s (male with significantly higher values of step length, flight time and shorter ground contact time during maximum sprinting speed. Because of the longer flight time, it is possible to place the foot closer to the body but with a more extended knee on the ground. These characteristics can be used as orientation for technique training.

  9. Sprint vs. interval training in football.

    Science.gov (United States)

    Ferrari Bravo, D; Impellizzeri, F M; Rampinini, E; Castagna, C; Bishop, D; Wisloff, U

    2008-08-01

    The aim of this study was to compare the effects of high-intensity aerobic interval and repeated-sprint ability (RSA) training on aerobic and anaerobic physiological variables in male football players. Forty-two participants were randomly assigned to either the interval training group (ITG, 4 x 4 min running at 90 - 95 % of HRmax; n = 21) or repeated-sprint training group (RSG, 3 x 6 maximal shuttle sprints of 40 m; n = 21). The following outcomes were measured at baseline and after 7 weeks of training: maximum oxygen uptake, respiratory compensation point, football-specific endurance (Yo-Yo Intermittent Recovery Test, YYIRT), 10-m sprint time, jump height and power, and RSA. Significant group x time interaction was found for YYIRT (p = 0.003) with RSG showing greater improvement (from 1917 +/- 439 to 2455 +/- 488 m) than ITG (from 1846 +/- 329 to 2077 +/- 300 m). Similarly, a significant interaction was found in RSA mean time (p = 0.006) with only the RSG group showing an improvement after training (from 7.53 +/- 0.21 to 7.37 +/- 0.17 s). No other group x time interactions were found. Significant pre-post changes were found for absolute and relative maximum oxygen uptake and respiratory compensation point (p RSA training protocol used in this study can be an effective training strategy for inducing aerobic and football-specific training adaptations.

  10. Neurophysiological Mechanisms of Fatigue Résistance during Repeated Sprints in Hot and Hypoxic Environments: Application to Team Sports

    OpenAIRE

    Brocherie, Franck

    2016-01-01

    In team sports, characterising fatigue is complex, with the underlying processes (e.g., metabolic energy supply, intramuscular accumulation of metabolic by-products, hyperthermia, dehydration) developing as match proceeds to ultimately manifest as a decline in physical performance. Using acute and chronic manipulations of environmental stress (i.e., heat or hypoxia) and unique tools (i.e., instrumented sprint treadmill, 45-m long hypoxic marquee), the main intention of this work was to better...

  11. Free radicals and sprint exercise in humans.

    Science.gov (United States)

    Morales-Alamo, D; Calbet, J A L

    2014-01-01

    Sprint exercise ability has been critical for survival. The remarkably high-power output levels attained during sprint exercise are achieved through strong activation of anaerobic, and to a lesser extent, aerobic energy supplying metabolic reactions, which generate reactive oxygen and nitrogen species (RONS). Sprint exercise may cause oxidative stress leading to muscle damage, particularly when performed in severe acute hypoxia. However, with training oxidative stress is reduced. Paradoxically, total plasma antioxidant capacity increases during the subsequent 2 h after a short sprint due to the increase in plasma urate concentration. The RONS produced during and immediately after sprint exercise play a capital role in signaling the adaptive response to sprint. Antioxidant supplementation blunts the normal AMPKα and CaMKII phosphorylation in response to sprint exercise. However, under conditions of increased glycolytic energy turnover and muscle acidification, as during sprint exercise in severe acute hypoxia, AMPKα phosphorylation is also blunted. This indicates that an optimal level of RONS-mediated stimulation is required for the normal signaling response to sprint exercise. Although RONS are implicated in fatigue, most studies convey that antioxidants do not enhance sprint performance in humans. Although currently controversial, it has been reported that antioxidant ingestion during training may jeopardize some of the beneficial adaptations to sprint training.

  12. 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…

  13. Effect of carbohydrate mouth rinsing on multiple sprint performance

    Science.gov (United States)

    2013-01-01

    Background Research suggests that carbohydrate mouth rinsing (CMR) improves endurance performance; yet, little is known regarding the effect of CMR on multiple sprint efforts. As many sports involve multiple sprinting efforts, followed by periods of recovery, the aim of our current study was to investigate the influence of CMR on multiple sprint performance. Methods We recruited eight active males (Age; 22 ± 1 y; 75.0 ± 8.8 kg; estimated VO2max 52.0 ± 3.0 ml/kg/min) to participate in a randomly assigned, double-blind, counterbalanced study administering a CMR (6.4% Maltodextrin) or similarly flavoured placebo solution. Primary outcomes for our study included: (a) time for three repeated sprint ability tests (RSA) and (b) the Loughborough Intermittent Shuttle Test (LIST). Time was expressed in seconds (sec). Secondary outcomes included ratings of perceived exertion (RPE) and blood glucose concentration. Tertiary outcomes included two psychological assessments designed to determine perceived activation (i.e., arousal) and pleasure-displeasure after each section of the LIST. We analysed our data using a two-way analysis of variance (ANOVA) for repeated measures, a Bonferroni adjusted post hoc t-test to determine significant differences in treatment, and a liberal 90% confidence interval between treatment conditions. Effect sizes were calculated between trials and interpreted as ≤ 0.2 trivial, > 0.2 small, > 0.6 moderate, > 1.2 large, > 2 very large and > 4 extremely large. Data are means ± SD. Overall statistical significance was set as P repeated, intermittent, sprint efforts. PMID:24066731

  14. On the Training of Final Sprint Ability in the Middle Distance Race%中长跑最后冲刺能力训练探讨

    Institute of Scientific and Technical Information of China (English)

    张建辉

    2015-01-01

    In recent years, the training of middle distance running not only requires endurance, but also needs speed which has caused many coaches and athletes’ further attention. The most critical element for the middle and long distance runners is the last few meters or tens of meters, so the speed is very critical, which can show the athletes’ final sprint ability and is becoming an important link and key to get a good grade. This paper analyzes the speed ability of middle and long distance runners, putting forward that the speed training for the middle and long distance runners should be strengthened, which is very critical for middle and long distance runners. This paper also analyzes the training of the final sprint ability for middle and long distance runners.%近年来,中长跑的训练不仅要求耐力,而且在速度上也引起不少教练员、运动员的进一步重视。中长跑运动员在比赛中最关键的是最后几米或几十米才能见高下,所以说速度的快慢是非常关键的,也是运动员最后冲刺能力的体现,更是在取得名次重要的一个环节和重点。文章对此进行了简短梳理和探讨,对中长跑运动员的速度能力进行了研究并提出加强中长跑运动员的速度训练,这对中长跑运动员来说是非常关键的。通过研究分析对中长跑训练中的最后冲刺能力训练做一些研究与探讨。

  15. Influence of Dehydration on Intermittent Sprint Performance.

    Science.gov (United States)

    Davis, Jon-Kyle; Laurent, C Matt; Allen, Kimberly E; Green, J Matt; Stolworthy, Nicola I; Welch, Taylor R; Nevett, Michael E

    2015-09-01

    This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

  16. Shuttle-run sprint training in hypoxia for youth elite soccer players: a pilot study.

    Science.gov (United States)

    Gatterer, Hannes; Philippe, Marc; Menz, Verena; Mosbach, Florian; Faulhaber, Martin; Burtscher, Martin

    2014-12-01

    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. Key PointsShuttle-run sprint training is feasible in hypoxic chambers of limited size (i

  17. Endurance and sprint benefits of high-intensity and supramaximal interval training.

    Science.gov (United States)

    Cicioni-Kolsky, Daniel; Lorenzen, Christian; Williams, Morgan David; Kemp, Justin Guy

    2013-01-01

    This study examined the effect of two different interval training programs-high-intensity interval training (HIT) and supramaximal interval training (SMIT)-on measures of sprint and endurance performance. Physically active individuals (Females: n=32; age 19.3, s=2.2 years; mass 67.6, s=9.1 kg; stature 172.7, s=6.6 cm. Males: n=23; age 20.0, s=2.7 years; mass 71.3, s=8.3 kg; stature 176.6, s=5.8 cm) completed pre-testing that comprised (1) 3000 m time-trial, (2) 40 m sprint, and (3) repeated sprint ability (RSA-6×40 m sprints, 24 s active recovery) performance. Participants were then matched for average 3000 m running velocity (AV) and randomly assigned to one of three groups: (i) HIT, n=19, 4 min at 100% AV, 4 min passive recovery, 4-6 bouts per session; (ii) SMIT, n=20, 30 s at 130% AV, 150 s passive recovery, 7-12 bouts per session; and (iii) control group, n=16, 30 min continuous running at 75% AV. Groups trained three times per week for six weeks. When time to complete each test were compared among groups: (i) improvements in 3000 m time trial performance were greater following SMIT than continuous running, and (ii) improvements in 40 m sprint and RSA performance were greater following SMIT than HIT and continuous running. In addition, a gender effect was observed for the 3000 m time trial only, where females changed more following the training intervention than males. In summary, for concurrent improvements in endurance, sprint and repeated sprint performance, SMIT provides the greatest benefits for physically active individuals.

  18. Sprint performance under heat stress: A review.

    Science.gov (United States)

    Girard, O; Brocherie, F; Bishop, D J

    2015-06-01

    Training and competition in major track-and-field events, and for many team or racquet sports, often require the completion of maximal sprints in hot (>30 °C) ambient conditions. Enhanced short-term (heat exposure (muscle temperature rise), can be attributed to improved muscle contractility. Under heat stress, elevations in skin/core temperatures are associated with increased cardiovascular and metabolic loads in addition to decreasing voluntary muscle activation; there is also compelling evidence to suggest that large performance decrements occur when repeated-sprint exercise (consisting of brief recovery periods between sprints, usually 39 °C). Here we also discuss strategies (heat acclimatization, precooling, hydration strategies) employed by "sprint" athletes to mitigate the negative influence of higher environmental temperatures.

  19. A2 Milk Enhances Dynamic Muscle Function Following Repeated Sprint Exercise, a Possible Ergogenic Aid for A1-Protein Intolerant Athletes?

    Science.gov (United States)

    Kirk, Ben; Mitchell, Jade; Jackson, Matthew; Amirabdollahian, Farzad; Alizadehkhaiyat, Omid; Clifford, Tom

    2017-01-01

    Hyperaminoacidemia following ingestion of cows-milk may stimulate muscle anabolism and attenuate exercise-induced muscle damage (EIMD). However, as dairy-intolerant athletes do not obtain the reported benefits from milk-based products, A2 milk may offer a suitable alternative as it lacks the A1-protein. This study aimed to determine the effect of A2 milk on recovery from a sports-specific muscle damage model. Twenty-one male team sport players were allocated to three independent groups: A2 milk (n = 7), regular milk (n = 7), and placebo (PLA) (n = 7). Immediately following muscle-damaging exercise, participants consumed either A2 milk, regular milk or PLA (500 mL each). Visual analogue scale (muscle soreness), maximal voluntary isometric contraction (MVIC), countermovement jump (CMJ) and 20-m sprint were measured prior to and 24, 48, and 72 h post EIMD. At 48 h post-EIMD, CMJ and 20-m sprint recovered quicker in A2 (33.4 ± 6.6 and 3.3 ± 0.1, respectively) and regular milk (33.1 ± 7.1 and 3.3 ± 0.3, respectively) vs. PLA (29.2 ± 3.6 and 3.6 ± 0.3, respectively) (p < 0.05). Relative to baseline, decrements in 48 h CMJ and 20-m sprint were minimised in A2 (by 7.2 and 5.1%, respectively) and regular milk (by 6.3 and 5.2%, respectively) vs. PLA. There was a trend for milk treatments to attenuate decrements in MVIC, however statistical significance was not reached (p = 0.069). Milk treatments had no apparent effect on muscle soreness (p = 0.152). Following muscle-damaging exercise, ingestion of 500 mL of A2 or regular milk can limit decrements in dynamic muscle function in male athletes, thus hastening recovery and improving subsequent performance. The findings propose A2 milk as an ergogenic aid following EIMD, and may offer an alternative to athletes intolerant to the A1 protein. PMID:28134840

  20. Caffeine supplementation and multiple sprint running performance.

    Science.gov (United States)

    Glaister, Mark; Howatson, Glyn; Abraham, Corinne S; Lockey, Richard A; Goodwin, Jon E; Foley, Paul; McInnes, Gillian

    2008-10-01

    The aim of this study was to examine the effects of caffeine supplementation on multiple sprint running performance. Using a randomized double-blind research design, 21 physically active men ingested a gelatin capsule containing either caffeine (5 mg x kg(-1) body mass) or placebo (maltodextrin) 1 h before completing an indoor multiple sprint running trial (12 x 30 m; repeated at 35-s intervals). Venous blood samples were drawn to evaluate plasma caffeine and primary metabolite concentrations. Sprint times were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate pretest and posttest lactate concentrations. Heart rate was monitored continuously throughout the tests, with RPE recorded after every third sprint. Relative to placebo, caffeine supplementation resulted in a 0.06-s (1.4%) reduction in fastest sprint time (95% likely range = 0.04-0.09 s), which corresponded with a 1.2% increase in fatigue (95% likely range = 0.3-2.2%). Caffeine supplementation also resulted in a 3.4-bpm increase in mean heart rate (95% likely range = 0.1-6.6 bpm) and elevations in pretest (+0.7 mmol x L(-1); 95% likely range = 0.1-1.3 mmol x L(-1)) and posttest (+1.8 mmol x L(-1); 95% likely range = 0.3-3.2 mmol x L(-1)) blood lactate concentrations. In contrast, there was no significant effect of caffeine supplementation on RPE. Although the effect of recovery duration on caffeine-induced responses to multiple sprint work requires further investigation, the results of the present study show that caffeine has ergogenic properties with the potential to benefit performance in both single and multiple sprint sports.

  1. 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.

  2. EFFECTS OF BLOOD LACTATE ON OXYGEN UPTAKE KINETICS DURING RECOVERY AFTER SPRINT IN HUMANS

    Directory of Open Access Journals (Sweden)

    Tokuo Yano

    2012-07-01

    Full Text Available The purpose of this study was to examine the effects of blood lactate level (La on oxygen uptake ( ·VO2 kinetics during recovery after short-term exercise with maximal effort (sprint. Three sprints were performed on a cycle ergometer with a load of 8% f body weight at maximal rotation rate. ·VO2 kinetics and oxygen debt were determined after three sprint tests: one 10-s cycling sprint, five repeated 10-s cycling sprints with 6-min intervals and one 30-s cycling sprint. There was no significant difference between peak power outputs in the 10-s sprint and five sprints. There was no difference in ·VO2 kinetics during recovery from one sprint and during recovery after five sprints. La peaked at 5 min. The peak value of La was significantly lower in one sprint (4.41 ± 0.9 mM than in five sprints (7.01 ± 2.2 mM. Thus, despite a difference in La, there was no difference between ·VO2 kinetics during recovery after one sprint and after five sprints. There was a significant difference in ·VO2 between the five sprints and 30-s sprint from 70 s to 320 s during recovery, but there were no significant differences in La after 5 min of recovery. There were two phases in ·VO2. They consisted of fast oxygen debt and slow oxygen debt. There were also no differences in slow and fast oxygen debts between the two 10-s sprints despite significant differences in blood lactate during recovery. Peak La in the five sprints was not significantly different from that in the 30-s sprint (8.68 ± 1.2 mM. However, slow oxygen debt was significantly greater in the 30-s sprint than in the five sprints. It is concluded that ·VO2 kinetics during recovery are not affected by an increase in blood lactate.

  3. VARIATION IN FOOTBALL PLAYERS' SPRINT TEST PERFORMANCE ACROSS DIFFERENT AGES AND LEVELS OF COMPETITION

    Directory of Open Access Journals (Sweden)

    Jaime Sampaio

    2004-11-01

    Full Text Available The purpose of this study was to compare sprint test performance performed by football players of different ages and levels of competition. One hundred and forty six Portuguese players from different teams completed the test (seven maximal sprints interspersed with 25 s active recovery. A 6 (level of competition: 1st national division, 2nd national division, 1st regional division, sub 16, sub 14, sub 12 7 (sprint trial: sprint 1, sprint 2, sprint 3, sprint 4, sprint 5, sprint 6, sprint 7 repeated measures ANOVA was carried out on subjects sprint times. The main effect of level of competition was statistically significant, F(5, 140 = 106.28, p < 0.001. Subjects from 1st national division were significantly faster than subjects from 2nd national division; subjects from 1st regional division obtained similar performances when compared to sub 16 and sub 14 level; subjects from sub 12 level were the slowest. The main effect of sprint trial was also statistically significant, F (6, 840 = 7.37, p < 0.001. Mean sprint times from the first trial were significantly slower than mean sprint times from the second, third and fourth trial. Results from the fifth, sixth and seventh trials were slower, denoting a decrement in performance. The two main effects were qualified by a significant level of competition x sprint trial interaction, F (30, 840 = 9.47 p < 0.001, identifying markedly different performance profiles. Coaches should be aware that normative data regarding this test can play a very important role if used frequently and consistently during the whole season.

  4. Sprint CEO遭殃

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 2007年10月8日,美国移动通信巨头Sprint Nextel公司董事会决定,罢免董事长兼首席执行官加里·福西(Gary Forsee).董事会抱怨称,自从福西实施大规模的Sprint-Nextel合并以来,公司财报结果一直不佳.

  5. Influence of Rest Intervals After Assisted Sprinting on Bodyweight Sprint Times in Female Collegiate Soccer Players.

    Science.gov (United States)

    Nealer, Austyn L; Dunnick, Dustin D; Malyszek, Kylie K; Wong, Megan A; Costa, Pablo B; Coburn, Jared W; Brown, Lee E

    2017-01-01

    Nealer, AL, Dunnick, DD, Malyszek, KK, Wong, MA, Costa, PB, Coburn, JW, and Brown, LE. Influence of rest intervals after assisted sprinting on bodyweight sprint times in female collegiate soccer players. J Strength Cond Res 31(1): 88-94, 2017-Speed is a crucial element an athlete must possess to be successful. In soccer, the ability to accelerate faster than your opponent can result in being first to reach a ball on a breakaway or stopping a counter attack. A unique way to train explosive movements is to evoke postactivation potentiation (PAP) in the working muscles. Traditionally, an overload stimulus with a long rest period is used, but a model using an overspeed stimulus with shorter rest periods is less understood. Therefore, the purpose of this study was to determine the acute effects of varied rest intervals after assisted sprinting on bodyweight sprint time. Twenty-four female soccer players were split into 2 groups: recreational (n:11; age:20 ± 1.67 year; ht:162.30 ± 4.35 cm; mass:61.02 ± 8.78 kg) and collegiate athletes (n:13; age:19.76 ± 0.83 year; ht:166.85 ± 5.98 cm; mass:61.23 ± 3.77 kg). All participants attended 5 separate sessions, performed a dynamic warm up, then executed one 20 m sprint (with 5 m splits) at 30% bodyweight assistance (BWA). They then rested for 30 seconds, 1, 2, or 4 minutes in random order, followed by one bodyweight sprint with no BWA. Baseline sprint times were measured without BWA on the initial session of testing. Results revealed no difference in sprint time for the full 20 m distance in either group. However, sprint time was significantly decreased for the 0-5 m split only for the athletes after 1 minute (1.15 ± 0.06 second) and 2 minute (1.16 ± 0.06 second) rest compared with baseline (1.21 ± 0.04 second). Therefore, trained athletes should rest 1 or 2 minutes after 30% BWA supramaximal sprinting for increased bodyweight sprint speed.

  6. Effect of high-intensity intermittent cycling sprints on neuromuscular activity.

    Science.gov (United States)

    Billaut, F; Basset, F A; Giacomoni, M; Lemaître, F; Tricot, V; Falgairette, G

    2006-01-01

    High-intensity intermittent sprints induce changes in metabolic and mechanical parameters. However, very few data are available about electrical manifestations of muscle fatigue following such sprints. In this study, quadriceps electromyographic (EMG) responses to repeated all-out exercise bouts of short duration were assessed from maximal voluntary isometric contractions (MVC) performed before and after sprints. Twelve men performed ten 6-s maximal cycling sprints, separated by 30-s rest. The MVC were performed pre-sprints ( pre), post-sprints ( post), and 5 min post-sprints ( post5). Values of root-mean-square (RMS) and median frequency (MF) of vastus lateralis (VL) and vastus medialis (VM) were recorded during each MVC. During sprints, PPO decreased significantly in sprints 8, 9, and 10, compared to sprint 1 (- 8 %, - 10 %, and - 11 %, respectively, p MVC post (- 13 %, p MVC post5 (- 10.5 %, p MVC pre. The RMS value of VL muscle increased significantly after sprints (RMS pre vs. RMS post: + 15 %, p pattern of muscle fiber recruitment, and a decrease in conduction velocity of active fibers.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Anthropometric, Sprint, and High-Intensity Running Profiles of English Academy Rugby Union Players by Position.

    Science.gov (United States)

    Darrall-Jones, Joshua D; Jones, Ben; Till, Kevin

    2016-05-01

    The purpose of this study was to evaluate the anthropometric, sprint, and high-intensity running profiles of English academy rugby union players by playing positions, and to investigate the relationships between anthropometric, sprint, and high-intensity running characteristics. Data were collected from 67 academy players after the off-season period and consisted of anthropometric (height, body mass, sum of 8 skinfolds [∑SF]), 40-m linear sprint (5-, 10-, 20-, and 40-m splits), the Yo-Yo intermittent recovery test level 1 (Yo-Yo IRTL-1), and the 30-15 intermittent fitness test (30-15 IFT). Forwards displayed greater stature, body mass, and ∑SF; sprint times and sprint momentum, with lower high-intensity running ability and sprint velocities than backs. Comparisons between age categories demonstrated body mass and sprint momentum to have the largest differences at consecutive age categories for forwards and backs; whereas 20-40-m sprint velocity was discriminate for forwards between under 16s, 18s, and 21s. Relationships between anthropometric, sprint velocity, momentum, and high-intensity running ability demonstrated body mass to negatively impact on sprint velocity (10 m; r = -0.34 to -0.46) and positively affect sprint momentum (e.g., 5 m; r = 0.85-0.93), with large to very large negative relationships with the Yo-Yo IRTL-1 (r = -0.65 to -0.74) and 30-15 IFT (r = -0.59 to -0.79). These findings suggest that there are distinct anthropometric, sprint, and high-intensity running ability differences between and within positions in junior rugby union players. The development of sprint and high-intensity running ability may be impacted by continued increases in body mass as there seems to be a trade-off between momentum, velocity, and the ability to complete high-intensity running.

  9. Reliability and criterion-related validity of a new repeated agility test

    Directory of Open Access Journals (Sweden)

    MS Fessi

    2016-04-01

    Full Text Available The study aimed to assess the reliability and the criterion-related validity of a new repeated sprint T-test (RSTT that includes intense multidirectional intermittent efforts. The RSTT consisted of 7 maximal repeated executions of the agility T-test with 25 s of passive recovery rest in between. Forty-five team sports players performed two RSTTs separated by 3 days to assess the reliability of best time (BT and total time (TT of the RSTT. The intra-class correlation coefficient analysis revealed a high relative reliability between test and retest for BT and TT (>0.90. The standard error of measurement (<0.50 showed that the RSTT has a good absolute reliability. The minimal detectable change values for BT and TT related to the RSTT were 0.09 s and 0.58 s, respectively. To check the criterion-related validity of the RSTT, players performed a repeated linear sprint (RLS and a repeated sprint with changes of direction (RSCD. Significant correlations between the BT and TT of the RLS, RSCD and RSTT were observed (p<0.001. The RSTT is, therefore, a reliable and valid measure of the intermittent repeated sprint agility performance. As this ability is required in all team sports, it is suggested that team sports coaches, fitness coaches and sports scientists consider this test in their training follow-up.

  10. Heat stress impairs repeated jump ability after competitive elite soccer games

    DEFF Research Database (Denmark)

    Mohr, Magni; Krustrup, Peter

    2013-01-01

    ABSTRACT:: The present study examined the effect of environmental heat stress on repeated jump performance after elite competitive soccer games. Male elite soccer players (n=19) from two Scandinavian teams participated (age; 26.7±1.0 yrs, height; 181.7±1.1 cm, body mass; 75.8±1.0 kg). The players...

  11. Effects of limited peripheral vision on shuttle sprint performance of soccer players

    NARCIS (Netherlands)

    Lemmink, KAPM; Dijkstra, B; Visscher, C

    2005-01-01

    This study examined the effect of limited peripheral vision oil the shuttle sprint performance of soccer players. Participants were 14 male soccer players of a student soccer club (M age = 22.1 yr., SD = 1.3 yr.). They performed a repeated shuttle sprint with full and limited peripheral vision. Mean

  12. Identifying the Limits of an Integrated Training Environment Using Human Abilities and Affordance Theory

    Science.gov (United States)

    2014-06-01

    Speed Wrist-Finger Speed The ability to make fast, simple, repeated movements of the fingers, hands, and wrists. Psychomotor-Reaction Time and Speed...muscle force to propel oneself (as in jumping or sprinting ), or to throw an object. Physical-Strength Dynamic Strength The ability to exert muscle force...public release; distribution is unlimited IDENTIFYING THE LIMITS OF AN INTEGRATED TRAINING ENVIRONMENT USING HUMAN ABILITIES AND AFFORDANCE

  13. Sprint conditioning of junior soccer players: effects of training intensity and technique supervision.

    Directory of Open Access Journals (Sweden)

    Thomas Haugen

    Full Text Available The aims of the present study were to compare the effects of 1 training at 90 and 100% sprint velocity and 2 supervised versus unsupervised sprint training on soccer-specific physical performance in junior soccer players. Young, male soccer players (17 ± 1 yr, 71 ± 10 kg, 180 ± 6 cm were randomly assigned to four different treatment conditions over a 7-week intervention period. A control group (CON, n = 9 completed regular soccer training according to their teams' original training plans. Three training groups performed a weekly repeated-sprint training session in addition to their regular soccer training sessions performed at A 100% intensity without supervision (100UNSUP, n = 13, B 90% of maximal sprint velocity with supervision (90SUP, n = 10 or C 90% of maximal sprint velocity without supervision (90UNSUP, n=13. Repetitions x distance for the sprint-training sessions were 15 x 20 m for 100UNSUP and 30 x 20 m for 90SUP and 90UNSUP. Single-sprint performance (best time from 15 x 20 m sprints, repeated-sprint performance (mean time over 15 x 20 m sprints, countermovement jump and Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1 were assessed during pre-training and post-training tests. No significant differences in performance outcomes were observed across groups. 90SUP improved Yo-Yo IR1 by a moderate margin compared to controls, while all other effect magnitudes were trivial or small. In conclusion, neither weekly sprint training at 90 or 100% velocity, nor supervised sprint training enhanced soccer-specific physical performance in junior soccer players.

  14. Sprint conditioning of junior soccer players: effects of training intensity and technique supervision.

    Science.gov (United States)

    Haugen, Thomas; Tønnessen, Espen; Øksenholt, Øyvind; Haugen, Fredrik Lie; Paulsen, Gøran; Enoksen, Eystein; Seiler, Stephen

    2015-01-01

    The aims of the present study were to compare the effects of 1) training at 90 and 100% sprint velocity and 2) supervised versus unsupervised sprint training on soccer-specific physical performance in junior soccer players. Young, male soccer players (17 ± 1 yr, 71 ± 10 kg, 180 ± 6 cm) were randomly assigned to four different treatment conditions over a 7-week intervention period. A control group (CON, n = 9) completed regular soccer training according to their teams' original training plans. Three training groups performed a weekly repeated-sprint training session in addition to their regular soccer training sessions performed at A) 100% intensity without supervision (100UNSUP, n = 13), B) 90% of maximal sprint velocity with supervision (90SUP, n = 10) or C) 90% of maximal sprint velocity without supervision (90UNSUP, n=13). Repetitions x distance for the sprint-training sessions were 15 x 20 m for 100UNSUP and 30 x 20 m for 90SUP and 90UNSUP. Single-sprint performance (best time from 15 x 20 m sprints), repeated-sprint performance (mean time over 15 x 20 m sprints), countermovement jump and Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) were assessed during pre-training and post-training tests. No significant differences in performance outcomes were observed across groups. 90SUP improved Yo-Yo IR1 by a moderate margin compared to controls, while all other effect magnitudes were trivial or small. In conclusion, neither weekly sprint training at 90 or 100% velocity, nor supervised sprint training enhanced soccer-specific physical performance in junior soccer players.

  15. Reliability and criterion-related validity of a new repeated agility test

    Science.gov (United States)

    Makni, E; Jemni, M; Elloumi, M; Chamari, K; Nabli, MA; Padulo, J; Moalla, W

    2016-01-01

    The study aimed to assess the reliability and the criterion-related validity of a new repeated sprint T-test (RSTT) that includes intense multidirectional intermittent efforts. The RSTT consisted of 7 maximal repeated executions of the agility T-test with 25 s of passive recovery rest in between. Forty-five team sports players performed two RSTTs separated by 3 days to assess the reliability of best time (BT) and total time (TT) of the RSTT. The intra-class correlation coefficient analysis revealed a high relative reliability between test and retest for BT and TT (>0.90). The standard error of measurement (repeated linear sprint (RLS) and a repeated sprint with changes of direction (RSCD). Significant correlations between the BT and TT of the RLS, RSCD and RSTT were observed (prepeated sprint agility performance. As this ability is required in all team sports, it is suggested that team sports coaches, fitness coaches and sports scientists consider this test in their training follow-up. PMID:27274109

  16. On the relationship between upper-body strength, power, and sprint performance in ice sledge hockey.

    Science.gov (United States)

    Skovereng, Knut; Ettema, Gertjan; Welde, Boye; Sandbakk, Øyvind

    2013-12-01

    Ice sledge hockey is a popular paralympic team sport where players rely entirely on their upper body to propel themselves rapidly across the ice surface. The isolated and repetitive poling movements provide a good model for examining upper-body sprint ability and the related movement and strength characteristics. Therefore, the purpose of the present study was to investigate the relationship between upper-body maximal strength, power, and sprint performance in ice sledge hockey. Thirteen male ice sledge hockey players from the Norwegian national team performed three 30-m maximal sprint tests recorded by fixed light sensors. The best 30-m time for each subject was used for further analyses, and the sprint was analyzed more in detail for the first and last 10-m split times and kinematics (cycle length and rate) using photocells and 2-dimensional video analysis. One repetition maximum (1RM) strength and peak power were assessed in the bench press, bench pull, and pull-down exercises using a barbell and a linear encoder. Both 1RM strength and peak power for all the 3 strength exercises correlated significantly with the total sprint time (-0.75 sprint test. There were no significant relationships between sprint kinematics and 1RM strength and peak power. Overall, these results demonstrate that there are close relationships between upper-body strength, power, and sprint performance in highly trained athletes and that the ability to produce propulsion and high frequency in combination is important for the sprint abilities in ice sledge hockey.

  17. Biomechanics of the sprint start.

    Science.gov (United States)

    Harland, M J; Steele, J R

    1997-01-01

    Many variables have been studied pertaining to the block sprint start. Research suggests that the adoption of a medium block spacing is preferred, with front and rear knee angles in the set position approximating 90 and 130 degrees, respectively, with the hips held moderately high. The sprinter must be capable of developing a high force rate combined with a high maximum force, especially in the horizontal direction. This ability to create high force underlies other important indicators of starting performance such as minimum block clearance time, maximum block leaving velocity and maximum block leaving acceleration. Once the sprinter has projected him/herself from the blocks at a low angle (40 to 45 degrees) relative to the ground, the following 2 post-block steps should occur with the total body centre of gravity ahead of the contacting foot at foot strike to minimise potential horizontal braking forces.

  18. Exposure to hot and cold environmental conditions does not affect the decision making ability of soccer referees following an intermittent sprint protocol.

    Directory of Open Access Journals (Sweden)

    Lee eTaylor

    2014-05-01

    Full Text Available Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g. Moscow ~ -5oC, Madrid ~30oC. Effects of these temperatures on player performance are well documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold (COLD; 5oC, 40% relative humidity (RH, hot (HOT; 30oC, 40% RH and temperate (CONT; 18oC, 40% RH conditions on decision making during soccer specific exercise. On separate occasions within each condition, thirteen physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion and thermal sensation were recorded throughout the protocol. There was no significant difference between conditions for decision making (p > 0.05 despite significant differences in measured physiological variables (skin temperature = HOT 34.5 ± 5.1°C; CONT 31.2 ± 0.1°C and COLD 26.7 ± 0.5°C; p < 0.05. It is hypothesised that the lack of difference observed in decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.

  19. Assessment of the upper body contribution to multiple-sprint cycling in men and women.

    Science.gov (United States)

    Grant, Marie Clare; Watson, Hugh; Baker, Julien S

    2015-07-01

    The aim of this study was to investigate the effect of repeated cycling sprints on power profiles while assessing upper body muscle contraction. Eighteen physically active participants performed 8 × 10 s repeated sprints while muscle activity was recorded via surface electromyography (sEMG) from the brachioradialis (BR), biceps brachii (BB), triceps brachii (TB) and upper trapezius (UT). Measurements were obtained at rest, during a functional maximum contraction (FMC) while participants were positioned in a seated position on the cycle ergometer and during the repeated sprint protocol. Results suggest that mainly type I muscle fibres (MFs) are being recruited within the upper body musculature due to the submaximal and intermittent nature of the contractions. Subsequently, there is no evidence of upper body fatigue across the sprints, which is reflected in the lack of changes in the median frequency of the power spectrum (P<0·05).

  20. Triumph Sprint RS

    Institute of Scientific and Technical Information of China (English)

    周才鸿

    2005-01-01

    我独自骑乘着Triumph Sprint RS,如图1、图2所示,在西班牙连绵的公路上奔驰了几个小时,试图抓住这辆新型Triumph跑车的感觉,但是事情好像有点不大对劲,不知道是什么原因,我无法将我的感觉与思绪整合起来。

  1. Lower leg musculoskeletal geometry and sprint performance.

    Science.gov (United States)

    Karamanidis, Kiros; Albracht, Kirsten; Braunstein, Bjoern; Moreno Catala, Maria; Goldmann, Jan-Peter; Brüggemann, Gert-Peter

    2011-05-01

    The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N=11, 10.30±0.07s; slow: N=7, 10.70±0.08s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p>0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.

  2. Combined glucose ingestion and mouth rinsing improves sprint cycling performance.

    Science.gov (United States)

    Chong, Edwin; Guelfi, Kym J; Fournier, Paul A

    2014-12-01

    This study investigated whether combined ingestion and mouth rinsing with a carbohydrate solution could improve maximal sprint cycling performance. Twelve competitive male cyclists ingested 100 ml of one of the following solutions 20 min before exercise in a randomized double-blinded counterbalanced order (a) 10% glucose solution, (b) 0.05% aspartame solution, (c) 9.0% maltodextrin solution, or (d) water as a control. Fifteen min after ingestion, repeated mouth rinsing was carried out with 11 × 15 ml bolus doses of the same solution at 30-s intervals. Each participant then performed a 45-s maximal sprint effort on a cycle ergometer. Peak power output was significantly higher in response to the glucose trial (1188 ± 166 W) compared with the water (1036 ± 177 W), aspartame (1088 ± 128 W) and maltodextrin (1024 ± 202 W) trials by 14.7 ± 10.6, 9.2 ± 4.6 and 16.0 ± 6.0% respectively (p sprint was significantly higher in the glucose trial compared with maltodextrin (p sprinting did not differ significantly between treatments (p > .05). These findings suggest that combining the ingestion of glucose with glucose mouth rinsing improves maximal sprint performance. This ergogenic effect is unlikely to be related to changes in blood glucose, sweetness, or energy sensing mechanisms in the gastrointestinal tract.

  3. Muscle metabolism and performance improvement after two training programmes of sprint running differing in rest interval duration.

    Science.gov (United States)

    Saraslanidis, Ploutarchos; Petridou, Anatoli; Bogdanis, Gregory C; Galanis, Nikiforos; Tsalis, George; Kellis, Spiros; Mougios, Vassilis

    2011-08-01

    Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval.

  4. Comparison of the Capacity of Different Jump and Sprint Field Tests to Detect Neuromuscular Fatigue.

    Science.gov (United States)

    Gathercole, Rob J; Sporer, Ben C; Stellingwerff, Trent; Sleivert, Gord G

    2015-09-01

    Different jump and sprint tests have been used to assess neuromuscular fatigue, but the test with optimal validity remains to be established. The current investigation examined the suitability of vertical jump (countermovement jump [CMJ], squat jump [SJ], drop jump [DJ]) and 20-m sprint (SPRINT) testing for neuromuscular fatigue detection. On 6 separate occasions, 11 male team-sport athletes performed 6 CMJ, SJ, DJ, and 3 SPRINT trials. Repeatability was determined on the first 3 visits, with subsequent 3 visits (0-, 24-, and 72-hour postexercise) following a fatiguing Yo-Yo running protocol. SPRINT performance was most repeatable (mean coefficient of variation ≤2%), whereas DJ testing (4.8%) was significantly less repeatable than CMJ (3.0%) and SJ (3.5%). Each test displayed large decreases at 0-hour (33 of 49 total variables; mean effect size = 1.82), with fewer and smaller decreases at 24-hour postexercise (13 variables; 0.75), and 72-hour postexercise (19 variables; 0.78). SPRINT displayed the largest decreases at 0-hour (3.65) but was subsequently unchanged, whereas SJ performance recovered by 72-hour postexercise. In contrast, CMJ and DJ performance displayed moderate (12 variables; 1.18) and small (6 variables; 0.53) reductions at 72-hour postexercise, respectively. Consequently, the high repeatability and immediate and prolonged fatigue-induced changes indicated CMJ testing as most suitable for neuromuscular fatigue monitoring.

  5. 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.

  6. Sprint Running Performance Monitoring: Methodological and Practical Considerations.

    Science.gov (United States)

    Haugen, Thomas; Buchheit, Martin

    2016-05-01

    The aim of this review is to investigate methodological concerns associated with sprint performance monitoring, more specifically the influence and magnitude of varying external conditions, technology and monitoring methodologies not directly related to human physiology. The combination of different starting procedures and triggering devices can cause up to very large time differences, which may be many times greater than performance changes caused by years of conditioning. Wind, altitude, temperature, barometric pressure and humidity can all combine to yield moderate time differences over short sprints. Sprint performance can also be affected by the athlete's clothing, principally by its weight rather than its aerodynamic properties. On level surfaces, the track compliance must change dramatically before performance changes larger than typical variation can be detected. An optimal shoe bending stiffness can enhance performance by a small margin. Fully automatic timing systems, dual-beamed photocells, laser guns and high-speed video are the most accurate tools for sprint performance monitoring. Manual timing and single-beamed photocells should be avoided over short sprint distances (10-20 m) because of large absolute errors. The validity of today's global positioning systems (GPS) technology is satisfactory for long distances (>30 m) and maximal velocity in team sports, but multiple observations are still needed as reliability is questionable. Based on different approaches used to estimate the smallest worthwhile performance change and the typical error of sprint measures, we have provided an assessment of the usefulness of speed evaluation from 5 to 40 m. Finally, we provide statistical guidelines to accurately assess changes in individual performance; i.e. considering both the smallest worthwhile change in performance and the typical error of measurement, which can be reduced while repeating the number of trials.

  7. Long-term strength training effects on change-of-direction sprint performance.

    Science.gov (United States)

    Keiner, Michael; Sander, Andre; Wirth, Klaus; Schmidtbleicher, Dietmar

    2014-01-01

    The requirement profiles for sports such as soccer, football, tennis, and rugby demonstrate the importance of strength and speed-strength abilities, in addition to other conditional characteristics. During a game, the athletes complete a large number of strength and speed-strength actions. In addition to the linear sprints, athletes perform sprints while changing the direction (change-of-direction sprint [COD]). Therefore, this study aims to clarify the extent to which there is a strength training intervention effect on COD. Further, this investigation analyzes the possible correlations between the 1-Repetition Maximum/body mass (SREL) in the front and back squats and COD. The subjects (n = 112) were at pretest between 13 and 18 years of age and were divided into 2 groups with 4 subgroups (A = under 19 years of age, B = under 17 years of age, and C = under 15 years of age). For approximately 2 years, 1 group (control group [CG]) only participated in routine soccer training, and the other group (strength training group [STG]) participated in an additional strength training program with the routine soccer training. Additionally, the performances in the COD of 34 professional soccer players of the first and second divisions in Germany were measured as a standard of high-level COD. For the analysis of the performance development within a group and pairwise comparisons between 2 groups, an analysis of variance with repeated measures was calculated with the factors group and time. Relationships between the COD and SREL were calculated for the normal distributed data using a plurality of bivariate correlations by Pearson. Our data show that additional strength training over a period of 2 years significantly affects the performance in the COD. The STG in all subcohorts reached significantly (p strength training improves the performance of the COD. Therefore, a long-term resistance training is recommended as early as in childhood and adolescence.

  8. The Effect of Repeated Listenings on Ability to Recognize the Structural Elements of Music and the Influence of this Ability on Affective Shift. Final Report.

    Science.gov (United States)

    Bartlett, Dale L.

    This study, conducted over a period of three weeks at the University of Kansas, attempted to determine whether knowledge of musical structure would effect greater understanding and, eventually, enjoyment of music. Experimental and control groups comprising freshmen who were not enrolled in a music course listened repeatedly to excerpts of…

  9. The relationships among sprint performance, voluntary swimming activity, and social dominance in juvenile rainbow trout.

    Science.gov (United States)

    McDonald, D G; Keeler, R A; McFarlane, W J

    2007-01-01

    The specific objectives of this study were to determine whether sprint performance in juvenile rainbow trout is correlated with either voluntary swimming activity or aggressive behaviors and to determine the reciprocal: the effect of swimming activity and aggression on sprint performance. Sprint performance was assessed by rapidly accelerating trout (5-7-cm fork length) to a fixed velocity (40, 42, or 45 cm s(-1)) and then holding them at that velocity until fatigue. There was considerable interindividual variation in sprint performance not explained by variations in body size, but intraindividual performance was highly repeatable over at least 2 mo. Voluntary swimming was measured as the frequency of transits (voluntary transit activity, VTA) between two identical tanks via a connecting channel with two different flow regimes: zero or minimum velocity (0 or 2.5 cm s(-1)) and high velocity (84 cm s(-1)). There was a strong correlation between sprint performance and VTA in minimal current but no correlation in high current. Furthermore, sprint performance did not predict the outcome of dominance encounters. Experience with rapid acceleration, especially when voluntary, led to a pronounced improvement in sprint performance in proportion to the number of acceleration events. Social dominance encounters had a more complex effect: a significant reduction in sprint performance in previously high-performance sprinters and the reverse for low performers. We propose that there are four independent axes of interindividual variation in juvenile rainbow trout: spontaneous and rheotaxis-stimulated locomotor activity, aggressive activity, and the trainability of sprint performance. The independence of these axes has the potential to produce a much larger diversity in behavioral and ultimately physiological phenotypes than would be produced if the axes were linked.

  10. Muscle coordination changes during intermittent cycling sprints.

    Science.gov (United States)

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-03

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, Pcycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue.

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

    Science.gov (United States)

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

    2016-03-01

    and finish line sprint.An 8-week low-intensity endurance training program of either cycling or running training combined with additional routine training improves classical aerobic characteristics (17% increase of VO2 peak), as well as values for acceleration and speed.Athletes who trained in the running group demonstrated a higher reliance on the fat metabolism in the sport-specific post-testing.The significant reduction in anaerobic ATP turnover during repeated sprints appears to be partially compensated by an increase in VO2 in subsequent sprint. The results revealed a close relationship between the aerobic capacity and sprint performance in inline speed skating.

  12. Sprint-based exercise and cognitive function in adolescents.

    Science.gov (United States)

    Cooper, Simon B; Bandelow, Stephan; Nute, Maria L; Dring, Karah J; Stannard, Rebecca L; Morris, John G; Nevill, Mary E

    2016-12-01

    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.

  13. 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.

  14. 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...... 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...... in men (P adipose tissue. However, the fractional extraction (a...

  15. Relationship Between Jump Rope Double Unders and Sprint Performance in Elementary Schoolchildren.

    Science.gov (United States)

    Miyaguchi, Kazuyoshi; Demura, Shinichi; Omoya, Masashi

    2015-11-01

    According to dynamic analyses of muscle contraction, jump rope is a typical stretch-shortening cycle (SSC) movement. It has been reported that the relationship with SSC is higher in double unders than in single unders (basic jumps); however, the relationship between jump rope and sprint performances has not been extensively studied. To clarify this relationship in elementary schoolchildren, we compared the sprint speed and SSC ability of children who were grouped according to gender and ability. The subjects were 143 elementary fifth and sixth graders (78 boys, 65 girls). The consecutive maximal number of double unders, reactivity index (index of SSC ability) by Myotest, and 20-m sprint time were measured. According to the mean of jump rope records, the children were divided into a superior ability group (more than average + 0.5 SD) and an inferior ability group (less than average - 0.5 SD) for each gender. In both genders, a significant difference was found in the 20-m sprint time between the inferior and superior ability groups. The times for the superior ability groups (boys, 3.75 ± 0.23 seconds; girls, 4.02 ± 0.24 seconds) were excellent compared with the inferior ability groups (boys, 4.17 ± 0.32 seconds; girls, 4.23 ± 0.21 seconds). This effect size was higher in boys (1.44) than in girls (0.93). The reactivity index in the superior ability group was excellent compared with that in the inferior ability group. In conclusion, children who perform better in double unders are also faster during a 20-m sprint run. This tendency may be higher in boys. Classic jump rope training, such as double unders, should be effective as elementary plyometrics for improving the sprint ability of children.

  16. 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.

  17. Modeling Longitudinal Changes in 5 m Sprinting Performance Among Young Male Tennis Players.

    Science.gov (United States)

    Kramer, Tamara; Valente-Dos-Santos, João; Coelho-E-Silva, Manuel J; Malina, Robert M; Huijgen, Barbara C H; Smith, Joanne; Elferink-Gemser, Marije T; Visscher, Chris

    2016-02-01

    Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players were classified as elite or sub-elite. To account for the repeated measurements within the individual nature of longitudinal data, multilevel random effects regression analyses were used. Sprint performance improved with age at each additional 1 year of age, thus predicting ∼.016 sec improvement in five-meter sprint time by all variables of the model. It was possible to predict the performance of elite tennis players in the 5-m sprint (sec) for elite players (1.1493 - (0.0159 ċ centered age) - (0.009 ċ BM) - (0.044 ċ LLES) and sub-elite players (1.1493 - (0.0159 ċ centered age) + 0.0135 - (0.009 ċ BM) - (0.044 ċ LLES) - (0.0557 ċ centered age). Sprint performance differences between elite and sub-elite players was related to longitudinal changes in body size and lower limb strength up until age 13.

  18. 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.

  19. Validity and reliability of hand and electronic timing for 40-yd sprint in college football players.

    Science.gov (United States)

    Mann, J Bryan; Ivey, Pat J; Brechue, William F; Mayhew, Jerry L

    2015-06-01

    The 40-yd sprint is the premier event for evaluating sprint speed among football players at all competitive levels. Some questions remain concerning the validity of hand timing compared with electronic timing, as well as the lack of assessment and reliability of each method. The purpose of this study was to evaluate the validity of hand timing by experienced and novice timers compared with electronic timing and to establish the reliability and smallest worthwhile difference (SWD) of each method for the 40-yd sprint. National Collegiate Athletic Association (NCAA) Division I college football players (n = 81) ran two 40-yd sprint trials, with each being timed electronically (touch pad start and infrared beam stop) and with hand-held stopwatches by 2 experienced and 4 novice timers. There was no significant difference between trials timed electronically or by experienced and novice timers. Hand timing (experienced = 4.90 ± 0.34 seconds; novice = 4.86 ± 0.33 seconds) produced a significantly faster 40-yd sprint time than electronic timing (5.12 ± 0.35 seconds) by 0.22 ± 0.07 and 0.26 ± 0.08 seconds, respectively. Relative reliability was extremely high for all comparisons with intraclass correlation coefficient >0.987. The SWD was 0.12 seconds with electronic timing and 0.14 seconds with hand timing. In conclusion, hand timing produces faster sprint times than electronic timing in college football players, independent of timer experience. Repeated 40-yd sprint trials have high relative reliability regardless of timing method. A meaningful change in 40-yd sprint performance is dependent on timing method used.

  20. Sprinting patterns of National Rugby League competition.

    Science.gov (United States)

    Gabbett, Tim J

    2012-01-01

    The purpose of this study was to investigate the sprinting demands of National Rugby League (NRL) competition and characterize the sprinting patterns of different rugby league playing positions. Thirty-seven elite rugby league players (mean ± SE age: 23.6 ± 0.5 years) underwent global positioning satellite analysis during 104 NRL appearances. The majority (67.5%) of sprint efforts were across distances of rugby league playing positions for the nature of sprint efforts and the typical distances covered during these efforts. Furthermore, the activities preceding and the recovery periods after sprint efforts were different among playing positions. These findings suggest that rugby league sprint training should be tailored to meet the individual demands of specific playing positions.

  1. Effect of betaine supplementation on cycling sprint performance

    Directory of Open Access Journals (Sweden)

    Pryor J Luke

    2012-04-01

    Full Text Available Abstract Purpose To examine the effect of betaine supplementation on cycling sprint performance. Methods Sixteen recreationally active subjects (7 females and 9 males completed three sprint tests, each consisting of four 12 sec efforts against a resistance equal to 5.5% of body weight; efforts were separated by 2.5 min of cycling at zero resistance. Test one established baseline; test two and three were preceded by seven days of daily consumption of 591 ml of a carbohydrate-electrolyte beverage as a placebo or a carbohydrate-electrolyte beverage containing 0.42% betaine (approximately 2.5 grams of betaine a day; half the beverage was consumed in the morning and the other half in the afternoon. We used a double blind random order cross-over design; there was a 3 wk washout between trials two and three. Average and maximum peak and mean power were analyzed with one-way repeated measures ANOVA and, where indicated, a Student Newman-Keuls. Results Compared to baseline, betaine ingestion increased average peak power (6.4%; p Conclusions One week of betaine ingestion improved cycling sprint power in recreationally active males and females.

  2. Tail autotomy affects bipedalism but not sprint performance in a cursorial Mediterranean lizard

    Science.gov (United States)

    Savvides, Pantelis; Stavrou, Maria; Pafilis, Panayiotis; Sfenthourakis, Spyros

    2017-02-01

    Running is essential in all terrestrial animals mainly for finding food and mates and escaping from predators. Lizards employ running in all their everyday functions, among which defense stands out. Besides flight, tail autotomy is another very common antipredatory strategy within most lizard families. The impact of tail loss to sprint performance seems to be species dependent. In some lizard species, tail shedding reduces sprint speed, in other species, increases it, and, in a few species, speed is not affected at all. Here, we aimed to clarify the effect of tail autotomy on the sprint performance of a cursorial lizard with particular adaptations for running, such as bipedalism and spike-like protruding scales (fringes) on the toepads that allow high speed on sandy substrates. We hypothesized that individuals that performed bipedalism, and have more and larger fringes, would achieve higher sprint performance. We also anticipated that tail shedding would affect sprint speed (though we were not able to define in what way because of the unpredictable effects that tail loss has on different species). According to our results, individuals that ran bipedally were faster; limb length and fringe size had limited effects on sprint performance whereas tail autotomy affected quadrupedal running only in females. Nonetheless, tail loss significantly affected bipedalism: the ability for running on hindlimbs was completely lost in all adult individuals and in 72.3% of juveniles.

  3. Influence of Strength, Sprint Running, and Combined Strength and Sprint Running Training on Short Sprint Performance in Young Adults.

    Science.gov (United States)

    Marques, M C; Gabbett, T J; Marinho, D A; Blazevich, A J; Sousa, A; van den Tillaar, R; Izquierdo, M

    2015-10-01

    The purpose of this study was to assess the degree of transference of 6 weeks of full squat vs. full squat plus sprint running training to short (ranged from 0-10 to 0-30 m) sprint running performance in non-athletes. We hypothesized that a speed-full-squat training regimen could enhance squat strength and power with simultaneous improvements in short sprint performance. 122 physically active adults (age: 20.5±2.5 years; body mass: 65.8±6.1 kg; height: 1.71±0.08 m) were randomly divided into 4 groups: full squat training (n=36), combined full squat and sprint training (n=32), speed training only (n=34) and non-training control group (n=20). Each training group completed 2 sessions per week over 6 weeks, while the control group performed only their normal physical activity. Sprint performance was improved after sprint running or full squat training alone (1.7% and 1.8% Psprint training intervention. These results suggest that in recreationally active adults, combined full squat and sprint training provides a greater stimulus for improving sprint performance than either modality alone.

  4. Selected determinants of acceleration in the 100m sprint.

    Science.gov (United States)

    Maćkała, Krzysztof; Fostiak, Marek; Kowalski, Kacper

    2015-03-29

    The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1-repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01).

  5. Selected Determinants of Acceleration in the 100m Sprint

    Directory of Open Access Journals (Sweden)

    Maćkała Krzysztof

    2015-03-01

    Full Text Available The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m and secondary (30 m acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start, strength (back squat, back extension, and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1- repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72, and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85, but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01.

  6. Selected Determinants of Acceleration in the 100m Sprint

    Science.gov (United States)

    Maćkała, Krzysztof; Fostiak, Marek; Kowalski, Kacper

    2015-01-01

    The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1-repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01). PMID:25964817

  7. What Research Tells the Coach About Sprinting.

    Science.gov (United States)

    Dintiman, George B.

    This booklet on sprinting is divided into four chapters. Chapter 1 "Introduction," provides an analysis of the 100-meter dash, summarizes world records, and discusses the reliability of timing the sprint race. Chapter 2, "Describing the Sprinter," discusses the following topics: anatomical characteristics, flexibility, reaction, strength/power,…

  8. 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 sprint and lower for the remainder of the sprint compared with the PLA trial (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

  9. 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.

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

    Science.gov (United States)

    Martínez-Valencia, María Asunción; Romero-Arenas, Salvador; Elvira, José L.L.; González-Ravé, José María; Navarro-Valdivielso, Fernando; Alcaraz, Pedro E.

    2015-01-01

    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. PMID:26240657

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

    Science.gov (United States)

    Martínez-Valencia, María Asunción; Romero-Arenas, Salvador; Elvira, José L L; González-Ravé, José María; Navarro-Valdivielso, Fernando; Alcaraz, Pedro E

    2015-06-27

    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.

  12. Different responses of skeletal muscle following sprint training in men and women.

    Science.gov (United States)

    Esbjörnsson Liljedahl, M; Holm, I; Sylvén, C; Jansson, E

    1996-01-01

    Six male and ten female physically active students performed 30-s sprint training on a cycle ergometer three times a week for 4 weeks, to investigate the training responses of skeletal muscle and to evaluate possible sex differences in this respect. Three repeated sprint tests with a 20-min rest in between were performed and muscle biopsies from the vastus lateralis muscle were taken before and after the training period. Mean power (average of sprint I-III) and type IIB cross-sectional fibre area increased only in the women (7% and 25% respectively) following sprint training, resulting in a decreased sex difference. There was an increase in total lactate dehydrogenase (LD) activity following sprint training in both sexes, although the levels were lower in the women both before and after training. Glycogen content increased and the activity of LD iso-enzyme 1 decreased in the women, but not in men. It was hypothesised that both the smaller areas of type II fibres and lower activity of LD generally seen in women may be due in part to less frequent activation of type II fibres in women than in men. If this were the case, the women should respond to sprint training (a type of training that activates type II fibres) to a relatively greater extent than men. That the observed increase in type IIB fibre area in response to sprint training was greater in the women than in men supported the hypothesis of the study. However, the results for LD activity, which showed a similar response in the men and the women, did not support the hypothesis.

  13. Effects of sprint and plyometrics training on field sport acceleration technique.

    Science.gov (United States)

    Lockie, Robert G; Murphy, Aron J; Callaghan, Samuel J; Jeffriess, Matthew D

    2014-07-01

    The mechanisms for speed performance improvement from sprint training and plyometrics training, especially relating to stance kinetics, require investigation in field sport athletes. This study determined the effects of sprint training and plyometrics training on 10-m sprint time (0-5, 5-10, and 0-10 m intervals), step kinematics (step length and frequency, contact and flight time), and stance kinetics (first, second, and last contact relative vertical [VF, VI], horizontal [HF, HI], and resultant [RF, RI] force and impulse; resultant ground reaction force angle [RFθ]; ratio of horizontal to resultant force [RatF]) during a 10-m sprint. Sixteen male field sport athletes were allocated into sprint training (ST) and plyometrics training (PT) groups according to 10-m sprint time; independent samples t-tests (p ≤ 0.05) indicated no between-group differences. Training involved 2 sessions per week for 6 weeks. A repeated measures analysis of variance (p ≤ 0.05) determined within- and between-subject differences. Both groups decreased 0-5 and 0-10 m time. The ST group increased step length by ∼15%, which tended to be greater than step length gains for the PT group (∼7%). The ST group reduced first and second contact RFθ and RatF, and second contact HF. Second contact HI decreased for both groups. Results indicated a higher post-training emphasis on VF production. Vertical force changes were more pronounced for the PT group for the last contact, who increased or maintained last contact VI, RF, and RI to a greater extent than the ST group. Sprint and plyometrics training can improve acceleration, primarily through increased step length and a greater emphasis on VF.

  14. Biomechanics of sprint running. A review.

    Science.gov (United States)

    Mero, A; Komi, P V; Gregor, R J

    1992-06-01

    Understanding of biomechanical factors in sprint running is useful because of their critical value to performance. Some variables measured in distance running are also important in sprint running. Significant factors include: reaction time, technique, electromyographic (EMG) activity, force production, neural factors and muscle structure. Although various methodologies have been used, results are clear and conclusions can be made. The reaction time of good athletes is short, but it does not correlate with performance levels. Sprint technique has been well analysed during acceleration, constant velocity and deceleration of the velocity curve. At the beginning of the sprint run, it is important to produce great force/power and generate high velocity in the block and acceleration phases. During the constant-speed phase, the events immediately before and during the braking phase are important in increasing explosive force/power and efficiency of movement in the propulsion phase. There are no research results available regarding force production in the sprint-deceleration phase. The EMG activity pattern of the main sprint muscles is described in the literature, but there is a need for research with highly skilled sprinters to better understand the simultaneous operation of many muscles. Skeletal muscle fibre characteristics are related to the selection of talent and the training-induced effects in sprint running. Efficient sprint running requires an optimal combination between the examined biomechanical variables and external factors such as footwear, ground and air resistance. Further research work is needed especially in the area of nervous system, muscles and force and power production during sprint running. Combining these with the measurements of sprinting economy and efficiency more knowledge can be achieved in the near future.

  15. Enhanced ability of TRPV1 channels in regulating glutamatergic transmission after repeated morphine exposure in the nucleus accumbens of rat.

    Science.gov (United States)

    Zhang, Haitao; Jia, Dong; Wang, Yuan; Qu, Liang; Wang, Xuelian; Song, Jian; Heng, Lijun; Gao, Guodong

    2017-04-01

    Glutamatergic projections to nucleus accumbens (NAc) drive drug-seeking behaviors during opioids withdrawal. Modulating glutamatergic neurotransmission provides a novel pharmacotherapeutic avenue for treatment of opioids dependence. Great deals of researches have verified that transient receptor potential vanilloid 1 (TRPV1) channels alters synaptic transmitter release and regulate neural plasticity. In the present study, whole-cell patch clamp recordings were adopted to examine the activity of TRPV1 Channels in regulating glutamate-mediated excitatory postsynaptic currents (EPSCs) in NAc of rat during morphine withdrawal for 3days and 3weeks. The data showed that the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) and the amplitudes of evoked excitatory postsynaptic currents (eEPSCs) were increased during morphine withdrawal after applied with capsaicin (TRPV1 agonist). Capsaicin decreased the paired pulse ratio (PPR) and increased sEPSCs frequency but not their amplitudes suggesting a presynaptic locus of action during morphine withdrawal. All these effects were fully blocked by the TRPV1 antagonist Capsazepine. Additionally, In the presence of AM251 (CB1 receptor antagonist), depolarization-induced release of endogenous cannabinoids activated TRPV1 channels to enhance glutamatergic neurotransmission during morphine withdrawal. The functional enhancement of TRPV1 Channels in facilitating glutamatergic transmission was not recorded in dorsal striatum. Our findings demonstrate the ability of TRPV1 in regulating excitatory glutamatergic transmission is enhanced during morphine withdrawal in NAc, which would deepen our understanding of glutamatergic modulation during opioids withdrawal.

  16. Maximal Strength Training Improves Surfboard Sprint and Endurance Paddling Performance in Competitive and Recreational Surfers.

    Science.gov (United States)

    Coyne, Joseph O C; Tran, Tai T; Secomb, Josh L; Lundgren, Lina E; Farley, Oliver R L; Newton, Robert U; Sheppard, Jeremy M

    2017-01-01

    Coyne, JOC, Tran, TT, Secomb, JL, Lundgren, LE, Farley, ORL, Newton, RU, and Sheppard, JM. Maximal strength training improves surfboard sprint and endurance paddling performance in competitive and recreational surfers. J Strength Cond Res 31(1): 244-253, 2017-Upper-body (UB) strength has very high correlations with faster surfboard paddling speeds. However, there is no research examining the effects of improving UB strength has on surfboard paddling ability. This study aimed to determine the influence that improvements in UB closed-kinetic chain maximal strength have on surfboard paddling in both competitive and recreational surfers. Seventeen competitive and recreational male surfers (29.7 ± 7.7 years, 177.4 ± 7.4 cm, 76.7 ± 9.9 kg) participated in a repeated-measures, parallel control study design. Anthropometry; 5-, 10-, and 15-m sprint; and 400-m endurance surfboard paddling tests along with pull-up and dip 1 repetition maximum strength tests were assessed pre- and postintervention. Subjects in the training group performed 5 weeks of maximal strength training in the pull-up and dip. Differences between the training and control groups were examined postintervention. The training group increased their speed over the 5-, 10-, and 15-m sprint, whereas the control group became slower (d = 0.71, 0.51, and 0.4, respectively). The training group also displayed faster endurance paddling performance compared with the control group (d = 0.72). Short-term exposure to maximal strength training elicits improvements in paddling performance measures. However, the magnitude of performance increases seems to be dependent on initial strength levels with differential responses between strong and weaker athletes. Although a longer maximal strength training period may have produced more significant paddling improvements in stronger subjects, practitioners are unlikely to have any more than 5 weeks in an uninterrupted block with competitive surfing athletes. This study reveals

  17. 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....... The STT was repeated four times on a 1300-m simulated sprint course including three flat (1°) double poling (DP) sections interspersed with two uphill (7°) diagonal stride (DS) sections. Treadmill velocity and VO2 were monitored continuously during the four STTs and data were averaged. Supramaximal GE...... 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...

  18. Metatarsophalangeal joint function during sprinting: a comparison of barefoot and sprint spike shod foot conditions.

    Science.gov (United States)

    Smith, Grace; Lake, Mark; Lees, Adrian

    2014-04-01

    The metatarsophalangeal joint is an important contributor to lower limb energetics during sprint running. This study compared the kinematics, kinetics and energetics of the metatarsophalangeal joint during sprinting barefoot and wearing standardized sprint spikes. The aim of this investigation was to determine whether standard sprinting footwear alters the natural motion and function of the metatarsophalangeal joint exhibited during barefoot sprint running. Eight trained sprinters performed maximal sprints along a runway, four sprints in each condition. Three-dimensional high-speed (1000 Hz) kinematic and kinetic data were collected at the 20 m point. Joint angle, angular velocity, moment, power and energy were calculated for the metatarsophalangeal joint. Sprint spikes significantly increase sprinting velocity (0.3 m/s average increase), yet limit the range of motion about the metatarsophalangeal joint (17.9% average reduction) and reduce peak dorsiflexion velocity (25.5% average reduction), thus exhibiting a controlling affect over the natural behavior of the foot. However, sprint spikes improve metatarsophalangeal joint kinetics by significantly increasing the peak metatarsophalangeal joint moment (15% average increase) and total energy generated during the important push-off phase (0.5 J to 1.4 J). The results demonstrate substantial changes in metatarsophalangeal function and potential improvements in performance-related parameters due to footwear.

  19. A physical model of sprinting.

    Science.gov (United States)

    Gaudet, S

    2014-09-22

    A new physical model of all-out sprinting is presented. The first models for the applied forces in the block, drive and maintenance phases, as well as for braking forces, are proposed and are based on experimental observations. The applied forces and the aerodynamic drag forces along with the speed and position of the sprinter are calculated by the model as functions of time. The model's unknown parameters are physically relevant and are quantitatively comparable to quantities measured experimentally. A novel mathematical method, not based on curve fitting, is proposed along with the model which requires two observable quantities, time of first step and start of maintenance phase, and four time splits. The model was validated by modeling several elite sprints from available split data, as well as measured splits for non-elite sprinters, over 100 m and 200 m distances. Excellent agreement between the split times and the simulated times was obtained and the model was shown to accurately predict 100 m times from 60 m splits for non-elite runners and 200 m times from 100 m splits for elite sprinters. The model was also applied to the study of wind and altitude effects for elite sprinters in 100 and 200 m sprints. The model presented in this paper may also be useful as a coaching tool for non-elite sprinters by enabling comparisons with elite sprinters, the identification of weaknesses (comparing phases, braking coefficient) and by allowing predictions of 100 m times based on 60 m (indoor) performances and 200 m times based on 100 m splits.

  20. Use of NIRS to assess effect of training on peripheral muscle oxygenation changes in elite rugby players performing repeated supramaximal cycling tests.

    Science.gov (United States)

    Jones, Benjamin; Cooper, C E

    2014-01-01

    In most team sports, intermittent high intensity sprint efforts combined with short recovery periods have been identified as a key factor of physical performance; the ability to repeat these efforts at a sustained level is of great importance. Near-infrared spectroscopy (NIRS) has been proposed as a tool to monitor muscle oxygenation changes during such sprint efforts. The purpose of this study was to observe muscle reoxygenation rate (reoxy rate) (% s⁻¹) between sprint efforts in a repeat sprint cycle test. A two wavelength spatially resolved NIR spectrometer (Portamon, Artinis Inc.) was used to assess reoxy rate changes in the vastus lateralis of the dominant leg before and after a training stimulus. Eight UK premiership academy level rugby players were assessed (age 20.6 ± 0.9) years; height 187 ± 0.6 cm; weight 109.5 ± 8.6 kg; quadriceps skin fold 16.6 ± 4.5 mm); the subjects completed ten repeated 10-s cycle sprints interspersed with 40 s recovery, upon a Wattbike Pro cycle. Hemoglobin variables (ΔHHb, ΔtHb, ΔO₂Hb, ΔTSI %) during the sprint and the post-sprint reoxygenation rate (%TSI s⁻¹) were measured. During both cycle tests all subjects experienced a drop in muscle oxygen saturation (Pre-Δ - 12.39 ± 6.01 %), Post-Δ - 14.83 ± 3.88 %). Post-training, there was an increase in the extent of desaturation (drop in TSI %) in the group means, both for the biggest single change and the average of all ten changes. Seven out of eight players showed an increase based on the maximum change and six based on the average of their ten tests. Additionally, seven out of eight players showed a significant increase in ΔHHb (Pre-Δ + 76.80 ± 61.92, Post-Δ + 121.28 ± 69.76) (p < 0.01) (including the one player who did not show a significant effect on the TSI measure). Players who exercised at the highest power tended to decrease their muscle oxygenation to a greater extent. The number of bike training sessions undertaken correlated with improvements in

  1. Mechanical determinants of 100-m sprint running performance.

    Science.gov (United States)

    Morin, Jean-Benoît; Bourdin, Muriel; Edouard, Pascal; Peyrot, Nicolas; Samozino, Pierre; Lacour, Jean-René

    2012-11-01

    Sprint mechanics and field 100-m performances were tested in 13 subjects including 9 non-specialists, 3 French national-level sprinters and a world-class sprinter, to further study the mechanical factors associated with sprint performance. 6-s sprints performed on an instrumented treadmill allowed continuous recording of step kinematics, ground reaction forces (GRF), and belt velocity and computation of mechanical power output and linear force-velocity relationships. An index of the force application technique was computed as the slope of the linear relationship between the decrease in the ratio of horizontal-to-resultant GRF and the increase in velocity. Mechanical power output was positively correlated to mean 100-m speed (P 100-m performance (r (s) > 0.683; P 100-m performance (positively for the former, negatively for the two latter, all P  0.21). Last, anthropometric data of body mass index and lower-limb-to-height ratio showed no significant correlation with 100-m performance. We concluded that the main mechanical determinants of 100-m performance were (1) a "velocity-oriented" force-velocity profile, likely explained by (2) a higher ability to apply the resultant GRF vector with a forward orientation over the acceleration, and (3) a higher step frequency resulting from a shorter contact time.

  2. Effects of six warm-up protocols on sprint and jump performance.

    Science.gov (United States)

    Vetter, Rheba E

    2007-08-01

    The purpose of this study was to compare the effects of 6 warm-up protocols, with and without stretches, on 2 different power maneuvers: a 30-m sprint run and a vertical countermovement jump (CJ). The 6 protocols were: (a) walk plus run (WR); (b) WR plus exercises including small jumps (EJ); (c) WR plus dynamic active stretch plus exercises with small jumps (DAEJ); (d) WR plus dynamic active stretch (DA); (e) WR plus static stretch plus exercises with small jumps (SSEJ); and (f) WR plus static stretch (SS). Twenty-six college-age men (n = 14) and women (n = 12) performed each of 6 randomly ordered exercise routines prior to randomly ordered sprint and vertical jump field tests; each routine and subsequent tests were performed on separate days. A 2 x 6 repeated measures analysis of variance revealed a significant overall linear trend (p hoc analysis pairwise comparisons showed the WR protocol produced higher jumps than did SS (p = 0.003 protocols on sprint run performance (p > or = 0.05). No significant interaction occurred between gender and protocol. There were significant differences between men and women on CJ and sprint trials; as expected, in general men ran faster and jumped higher than the women did. The data indicate that a warm-up including static stretching may negatively impact jump performance, but not sprint time.

  3. IMPACT OF EXERCISE INDUCED MUSCLE DAMAGE ON SPRINT AND AGILITY PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Şengül AKDENİZ

    2012-08-01

    Full Text Available Purpose: The purpose of this study was to investigate the impact of exercise induced muscle damage on sprint and agility performance.Methods: Eleven healthy male soccer players [( ±SD age: 21.63 ± 1.91 years; stature: 176.63 ± 5.31cm; body mass: 70.36 ± 3.72kg] who did not perform any high intensity physical training during last 3 months volunteered to participate in this study. Agility and sprint running times were measured, following determination of athletes muscle soreness level using visual analog scale (VAS, before (baseline and at 1st, 24th, 48th, 72nd and 96th hours after muscle damaging exercise protocol. Five sets of 20 repetitions drop jumps were performed as a muscle damage exercise protocol. Repeated measure ANOVA was used for statistical analysis.Results: Repeated measures ANOVA showed significant changes in muscle soreness [F(5-50= 196.65, p≤0.01], agility [F(5-50= 32.034, p≤0.01] and sprint running times [F(5-50= 9.28, p≤0.01] relevant with time intervals. Muscle soreness and agility test times were significantly (p≤0.05 higher than baseline values at all time intervals (1st, 24th, 48th, 72nd and 96th hours. Sprint running time was significantly (p≤0.05 increased at 1st, 24th, and 48th hours compared to baseline values.Conclusion: Consequently, results of the study revealed that exercise induced muscle damage affect agility and sprint performance negatively. The respondents should be careful in including unfamiliar exercises and exercises including intense eccentric contractions during the process of training planning for sports branches, where agility and sprint are important features.

  4. Effect of Different Sprint Training Methods on Sprint Performance Over Various Distances: A Brief Review.

    Science.gov (United States)

    Rumpf, Michael C; Lockie, Robert G; Cronin, John B; Jalilvand, Farzad

    2016-06-01

    Rumpf, MC, Lockie, RG, Cronin, JB, and Jalilvand, F. Effect of different sprint training methods on sprint performance over various distances: a brief review. J Strength Cond Res 30(6): 1767-1785, 2016-Linear sprinting speed is an essential physical quality for many athletes. There are a number of different training modalities that can be used to improve sprint performance. Strength and conditioning coaches must select the most appropriate modalities for their athletes, taking into consideration the sprint distances that typically occur during competition. The study purpose was to perform a brief review as to the effect of specific (free sprinting; resisted sprinting by sleds, bands, or incline running; assisted sprinting with a towing device or a downhill slope), nonspecific (resistance and plyometric training), and combined (a combination of specific and nonspecific) training methods on different sprint distances (0-10, 0-20, 0-30, and 31+ m). A total of 48 studies fulfilled the inclusion criteria, resulting in 1,485 subjects from a range of athletic backgrounds. The training effects associated with specific sprint training were classified as moderate (effect size [ES] = -1.00; %change = -3.23). Generally, the effect of specific sprint training tended to decrease with distance, although the largest training effects were observed for the 31+ m distance. The greatest training effects (ES = -0.43; %change = -1.65) of nonspecific training were observed for the 31+ m distance. The combined training revealed greatest effects (ES = -0.59; %change = -2.81) for the 0-10 m distance. After this review, specific sprint training methods seem the most beneficial over the investigated distances. However, the implementation of nonspecific training methods (e.g., strength and power training) could also benefit speed and athletic performance.

  5. Effect of oral creatine supplementation on single-effort sprint performance in elite swimmers.

    Science.gov (United States)

    Burke, L M; Pyne, D B; Telford, R D

    1996-09-01

    Oral supplementation with creatine monohydrate (Cr.H2O) has been reported to increase muscle creatine phosphate levels. The aim of the present study was to determine the effect of such supplementation on performance of a single-effort sprint by elite swimmers. Thirty-two elite swimmers (M = 18, F = 14; age = 17-25 years) from the Australian Institute of Sport were tested on two occasions, 1 week apart. Tests performed were 25-m, 50-m, and 100-m maximal effort sprints (electronically timed with dive start, swimmers performing their best stroke), each with approximately 10 min active recovery. A 10-s maximal leg ergometry test was also undertaken. Swimmers were divided into two groups matched for sex, stroke/event, and sprint time over 50 m, and groups were randomly assigned to 5 days of Cr.H2O supplementation (4 . day-1 x 5 g Cr.H2O + 2 g sucrose, n = 16) or placebo (4 . day-1 x 5 g Polycose + 2 g sucrose, n = 16) prior to the second trial. Results revealed no significant differences between the group means for sprint times or between 10-s maximal leg ergometry power and work. This study does not support the hypothesis that creatine supplementation enhances single-effort sprint ability of elite swimmers.

  6. Effect of four different starting stances on sprint time in collegiate volleyball players.

    Science.gov (United States)

    Johnson, Trevor M; Brown, Lee E; Coburn, Jared W; Judelson, Daniel A; Khamoui, Andy V; Tran, Tai T; Uribe, Brandon P

    2010-10-01

    Starting stance plays an important role in influencing short-distance sprint speed and, therefore, the ability to reach a ball during sport play. The purpose of this study was to evaluate 4 different starting stances on sprint time. Twenty-six male and female collegiate volleyball players volunteered to participate in 1 testing session. Each subject performed 3 15-ft sprint trials at each of 4 different starting stances (P-parallel, FS-false step, S-staggered, and SFS-staggered false step) in random order. Analysis of variance revealed that there was no significant interaction of sex by stance, but there were main effects for sex (men were faster than women) and stance. The FS (1.18 ± 0.10 seconds), S (1.16 ± 0.07 seconds), and SFS (1.14 ± 0.06 seconds) stances were faster than the P (1.25 ± 0.09 seconds) stance, and the SFS stance was faster than the FS stance. This indicates that starting with a staggered stance (regardless of stepping back) produced the greatest sprinting velocity over the initial 15 feet. Although taking a staggered stance seems counterproductive, the resultant stretch-shortening cycle action and forward body lean likely increase force production of the push-off phase and place the total body center of mass ahead of the contacting foot, thereby, decreasing sprint time.

  7. The I2020T Leucine-rich repeat kinase 2 transgenic mouse exhibits impaired locomotive ability accompanied by dopaminergic neuron abnormalities

    Directory of Open Access Journals (Sweden)

    Maekawa Tatsunori

    2012-04-01

    Full Text Available Abstract Background Leucine-rich repeat kinase 2 (LRRK2 is the gene responsible for autosomal-dominant Parkinson’s disease (PD, PARK8, but the mechanism by which LRRK2 mutations cause neuronal dysfunction remains unknown. In the present study, we investigated for the first time a transgenic (TG mouse strain expressing human LRRK2 with an I2020T mutation in the kinase domain, which had been detected in the patients of the original PARK8 family. Results The TG mouse expressed I2020T LRRK2 in dopaminergic (DA neurons of the substantia nigra, ventral tegmental area, and olfactory bulb. In both the beam test and rotarod test, the TG mice exhibited impaired locomotive ability in comparison with their non-transgenic (NTG littermates. Although there was no obvious loss of DA neurons in either the substantia nigra or striatum, the TG brain showed several neurological abnormalities such as a reduced striatal dopamine content, fragmentation of the Golgi apparatus in DA neurons, and an increased degree of microtubule polymerization. Furthermore, the tyrosine hydroxylase-positive primary neurons derived from the TG mouse showed an increased frequency of apoptosis and had neurites with fewer branches and decreased outgrowth in comparison with those derived from the NTG controls. Conclusions The I2020T LRRK2 TG mouse exhibited impaired locomotive ability accompanied by several dopaminergic neuron abnormalities. The TG mouse should provide valuable clues to the etiology of PD caused by the LRRK2 mutation.

  8. Effect of pre-performance lower-limb massage on thirty-meter sprint running.

    Science.gov (United States)

    Goodwin, Jon E; Glaister, Mark; Howatson, Glyn; Lockey, Richard A; McInnes, Gillian

    2007-11-01

    Massage is a commonly utilized therapy within sports, frequently intended as an ergogenic aid prior to performance. However, evidence as to the efficacy of massage in this respect is lacking, and massage may in some instances reduce force production. The aim of this study was to investigate the effect of massage on subsequent 30-m sprint running performance. Male university level repeat sprint sports players volunteered for the study (n = 37). After each of 3 treatment conditions, subjects completed a standardized warm-up followed by three 30-m sprint trials in a counterbalanced crossover design. Treatment conditions were 15 minutes of lower-limb massage (M), 15 minutes of placebo ultrasound (PU), and rest (R). Thirty-meter sprint times were recorded (including 10-m split times) for the 3 trials under each condition. Best times at 10 m (M: 1.85 +/- 0.09 seconds, PU: 1.84 +/- 0.11 seconds, R: 1.83 +/- 0.10 seconds) and 30 m (M: 4.41 +/- 0.27 seconds, PU: 4.39 +/- 0.28 seconds, R: 4.39 +/- 0.28 seconds) were not significantly different (p > 0.05). There was no significant treatment, trial, or interaction effect for 10- or 30-m sprint times (p > 0.05). No difference was seen in the location of subjects' best times across the 3 trials (p > 0.05). Relative to placebo or control, the results of this study showed that a controlled 15-minute lower-limb massage administered prior to warm-up had no significant effect on subsequent 30-m sprint performance. Massage remains indicated prior to performance where other benefits, such as reduced muscle spasm and psychological stress, might be served to the athlete.

  9. Rest interval duration does not influence adaptations in acid/base transport proteins following 10 wk of sprint-interval training in active women.

    Science.gov (United States)

    McGinley, Cian; Bishop, David J

    2017-05-01

    The removal of protons (H(+)) produced during intense exercise is important for skeletal muscle function, yet it remains unclear how best to structure exercise training to improve muscle pH regulation. We investigated whether 4 wk of work-matched sprint-interval trining (SIT), performed 3 days/wk, with either 1 (Rest-1; n = 7) or 5 (Rest-5; n = 7) min of rest between sprints, influenced adaptations in acid/base transport protein content, nonbicarbonate muscle buffer capacity (βmin vitro), and exercise capacity in active women. Following 1 wk of posttesting, comprising a biopsy, a repeated-sprint ability (RSA) test, and a graded-exercise test, maintenance of adaptations was then studied by reducing SIT volume to 1 day/wk for a further 5 wk. After 4 wk of SIT, there was increased protein abundance of monocarboxylate transporter (MCT)-1, sodium/hydrogen exchanger (NHE)-1, and carbonic anhydrase (CA) XIV for both groups, but rest interval duration did not influence the adaptive response. In contrast, greater improvements in total work performed during the RSA test after 4 wk of SIT were evident for Rest-5 compared with Rest-1 (effect size: 0.51; 90% confidence limits ±0.37), whereas both groups had similarly modest improvements in V̇o2peak When training volume was reduced to 1 day/wk, enhanced acid/base transport protein abundance was maintained, although NHE1 content increased further for Rest-5 only. Finally, our data support intracellular lactate as a signaling molecule for inducing MCT1 expression, but neither lactate nor H(+) accumulation appears to be important signaling factors in MCT4 regulation. Copyright © 2017 the American Physiological Society.

  10. Sprint and vertical jump performances are not affected by six weeks of static hamstring stretching.

    Science.gov (United States)

    Bazett-Jones, David M; Gibson, Mark H; McBride, Jeffrey M

    2008-01-01

    The purpose of this study was to investigate whether 6 weeks of static hamstring stretching effects range of motion (ROM), sprint, and vertical jump performances in athletes. Twenty-one healthy division III women's track and field athletes participated in the study. Subjects were tested for bilateral knee ROM; 55-m sprint time; and vertical jump height before, at 3 weeks, and after the 6-week flexibility program. Subjects were randomly assigned to treatment and control groups and warmed up with a 10-minute jog on a track before a hamstring stretching protocol. The stretching protocol consisted of four repetitions held for 45 seconds, 4 days per week. Four variables (left and right leg ROM, 55-m sprint time, vertical jump) were analyzed using a repeated-measures analysis of variance design. No significant differences (P stretching and control groups. Six weeks of a static hamstring stretching protocol did not improve knee ROM or sprint and vertical jump performances in women track and field athletes. The use of static stretching should be restricted to post practice or competition because of the detrimental effects reported throughout the literature. Based on the current investigation, it does not seem that chronic static stretching has a positive or negative impact on athletic performance. Thus, the efficacy of utilizing this practice is questionable and requires further investigation.

  11. Combined Plyometric & Strength Training Improves Ice-hockey Players` On-ice Sprint.

    Science.gov (United States)

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

    2016-12-05

    Combined plyometric and strength training have previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training has not been previously been compared to the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with strength training only. Eighteen participants were randomly assigned to two groups that completed 5 strength-training sessions per week for 8 weeks. One group included plyometric exercises at the start of three sessions per week (PLY+ST), whereas 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 training for 8 weeks was superior to strength training alone on improving 10 m on-ice sprint performance in high-level ice hockey players.

  12. Anthropometric-based selection and sprint kayak training in children.

    Science.gov (United States)

    Aitken, D A; Jenkins, D G

    1998-08-01

    A 12 week kayak training programme was evaluated in children who either had or did not have the anthropometric characteristics identified as being unique to senior elite sprint kayakers. Altogether, 234 male and female school children were screened to select 10 children with and 10 children without the identified key anthropometric characteristics. Before and after training, the children completed an all-out 2 min kayak ergometer simulation test; measures of oxygen consumption, plasma lactate and total work accomplished were recorded. In addition, a 500 m time trial was performed at weeks 3 and 12. The coaches were unaware which 20 children possessed those anthropometric characteristics deemed to favour development of kayak ability. All children improved in both the 2 min ergometer simulation test and 500 m time trial. However, boys who were selected according to favourable anthropometric characteristics showed greater improvement than those without such characteristics in the 2 min ergometer test only. In summary, in a small group of children selected according to anthropometric data unique to elite adult kayakers, 12 weeks of intensive kayak training did not influence the rate of improvement of on-water sprint kayak performance.

  13. Effects of static and dynamic stretching on sprint and jump performance in boys and girls.

    Science.gov (United States)

    Paradisis, Giorgos P; Pappas, Panagiotis T; Theodorou, Apostolos S; Zacharogiannis, Elias G; Skordilis, Emmanouil K; Smirniotou, Athanasia S

    2014-01-01

    The aim of this study was to investigate the acute effects of static (SS) and dynamic stretching (DS) on explosive power, flexibility, and sprinting ability of adolescent boys and girls and to report possible gender interactions. Forty-seven active adolescent boys and girls were randomly tested after SS and DS of 40 seconds on quadriceps, hamstrings, hip extensors, and plantar flexors; no stretching was performed at the control condition. Pretreatment and posttreatment tests examined the effects of stretching on 20-m sprint run (20 m), countermovement jump (CMJ) height, and sit and reach flexibility test. In terms of performance, SS hindered 20 m and CMJ in boys and girls by 2.5 and 6.3%, respectively. Dynamic stretching had no effect on 20 m in boys and girls but impaired CMJ by 2.2%. In terms of flexibility, both SS and DS improved performance with SS being more beneficial (12.1%) compared with DS (6.5%). No gender interaction was found. It can therefore be concluded that SS significantly negates sprinting performance and explosive power in adolescent boys and girls, whereas DS deteriorates explosive power and has no effect on sprinting performance. This diversity of effects denotes that the mode of stretching used in adolescent boys and girls should be task specific.

  14. Agile Learning: Sprinting through the Semester

    Science.gov (United States)

    Lang, Guido

    2017-01-01

    This paper introduces agile learning, a novel pedagogical approach that applies the processes and principles of agile software development to the context of learning. Agile learning is characterized by short project cycles, called sprints, in which a usable deliverable is fully planned, designed, built, tested, reviewed, and launched. An…

  15. Effects of sled towing on sprint starts.

    Science.gov (United States)

    Cottle, Casey A; Carlson, Lara A; Lawrence, Michael A

    2014-05-01

    Sled towing is a popular method of sprint training. Researchers have struggled to identify a loading scheme that is most appropriate to improve sprint performance in the acceleration phase. The purpose of this study was to determine if loads of 10% body weight (BWT) or 20% BWT produced significantly greater propulsive ground reaction force (GRF) impulse, peak propulsive GRF, or a greater propulsive rate of force development (RFD) than an unweighted sprint start. Seventeen healthy court and field athletes (10 men, 7 women; 20.9 ± 1.1 years) completed 5 starts of each condition (unweighted, 10% BWT, 20% BWT). Participants began each start in an upright staggered stance. Propulsive GRF impulse was greater in the 20% BWT condition than the unweighted condition in both limbs and greater in the 20% BWT condition than the 10% BWT condition in the front leg only, and vertical GRF impulse was greater in the 20% BWT than the unweighted condition. In summary, our results suggest that a 10% BWT load is not sufficient to increase propulsive GRF impulse. A loading scheme of 20% BWT is sufficient to increase propulsive GRF impulse. Coaches seeking to improve sprint starts may observe improvements using a load of 20% BWT during training while towing a sled.

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

    Science.gov (United States)

    Esbjörnsson, Mona; Bülow, Jens; Norman, Barbara; Simonsen, Lene; Nowak, Jacek; Rooyackers, Olav; Kaijser, Lennart; Jansson, Eva

    2006-12-01

    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 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 in men (P women than in men (P sprint exercise (2.2 +/- 0.7 and 1.6 +/- 0.8, respectively) compared with the value at rest (1.2 +/- 0.6), suggesting a reaction of the extracted NH(3) 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.

  17. Application of the Copenhagen Soccer Test in high-level women players - locomotor activities, physiological response and sprint performance

    DEFF Research Database (Denmark)

    Bendiksen, Mads; Pettersen, Svein Arne; Ingebrigtsen, Jørgen;

    2013-01-01

    We evaluated the physiological response, sprint performance and technical ability in various phases of the Copenhagen Soccer Test for Women (CSTw) and investigated whether the locomotor activities of the CSTw were comparable to competitive match-play (CM). Physiological measurements and physical/...

  18. The effect of resisted sprint training on maximum sprint kinetics and kinematics in youth.

    Science.gov (United States)

    Rumpf, Michael C; Cronin, John B; Mohamad, Ikhwan N; Mohamad, Sharil; Oliver, Jon L; Hughes, Michael G

    2015-01-01

    Resisted sled towing is a popular and efficient training method to improve sprint performance in adults, however, has not been utilised in youth populations. The purpose therefore was to investigate the effect of resisted sled towing training on the kinematics and kinetics of maximal sprint velocity in youth of different maturation status. Pre- and post-intervention 30 metre sprint performance of 32 children, 18 pre-peak height velocity (PHV) and 14 mid-/post-PHV, were tested on a non-motorised treadmill. The 6-week intervention consisted of ∼12 sessions for pre-PHV and 14 for mid-/post-PHV of resisted sled towing training with each sessions comprised of 8-10 sprints covering 15-30 metres with a load of 2.5, 5, 7.5 or 10% body mass. Pre-PHV participants did not improve sprint performance, while the mid-/post-PHV participants had significant (P sprint time (-5.76, -0.74), relative leg stiffness (-45.0, -2.16) and relative vertical stiffness (-17.4, -0.76) and a significant increase in average velocity (5.99, 0.76), average step rate (5.65, 0.53), average power (6.36, 0.31), peak horizontal force (9.70, 0.72), average relative vertical forces (3.45, 1.70) and vertical displacement (14.6, 1.46). It seems that sled towing may be a more suitable training method in mid-/post-PHV athletes to improve 30 metre sprint performance.

  19. 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

  20. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    Science.gov (United States)

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration

  1. Heat acclimation improves intermittent sprinting in the heat but additional pre-cooling offers no further ergogenic effect.

    Science.gov (United States)

    Castle, Paul; Mackenzie, Richard W; Maxwell, Neil; Webborn, Anthony D J; Watt, Peter W

    2011-08-01

    The aim of this study was to determine the effect of 10 days of heat acclimation with and without pre-cooling on intermittent sprint exercise performance in the heat. Eight males completed three intermittent cycling sprint protocols before and after 10 days of heat acclimation. Before acclimation, one sprint protocol was conducted in control conditions (21.8 ± 2.2°C, 42.8 ± 6.7% relative humidity) and two sprint protocols in hot, humid conditions (33.3 ± 0.6°C, 52.2 ± 6.8% relative humidity) in a randomized order. One hot, humid condition was preceded by 20 min of thigh pre-cooling with ice packs (-16.2 ± 4.5°C). After heat acclimation, the two hot, humid sprint protocols were repeated. Before heat acclimation, peak power output declined in the heat (P < 0.05) but pre-cooling prevented this. Ten days of heat acclimation reduced resting rectal temperature from 37.8 ± 0.3°C to 37.4 ± 0.3°C (P < 0.01). When acclimated, peak power output increased by ∼2% (P < 0.05, main effect) and no reductions in individual sprint peak power output were observed. Additional pre-cooling offered no further ergogenic effect. Unacclimated athletes competing in the heat should pre-cool to prevent reductions in peak power output, but heat acclimate for an increased peak power output.

  2. 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

  3. Kinematics of transition during human accelerated sprinting

    Directory of Open Access Journals (Sweden)

    Ryu Nagahara

    2014-07-01

    Full Text Available This study investigated kinematics of human accelerated sprinting through 50 m and examined whether there is transition and changes in acceleration strategies during the entire acceleration phase. Twelve male sprinters performed a 60-m sprint, during which step-to-step kinematics were captured using 60 infrared cameras. To detect the transition during the acceleration phase, the mean height of the whole-body centre of gravity (CG during the support phase was adopted as a measure. Detection methods found two transitions during the entire acceleration phase of maximal sprinting, and the acceleration phase could thus be divided into initial, middle, and final sections. Discriminable kinematic changes were found when the sprinters crossed the detected first transition—the foot contacting the ground in front of the CG, the knee-joint starting to flex during the support phase, terminating an increase in step frequency—and second transition—the termination of changes in body postures and the start of a slight decrease in the intensity of hip-joint movements, thus validating the employed methods. In each acceleration section, different contributions of lower-extremity segments to increase in the CG forward velocity—thigh and shank for the initial section, thigh, shank, and foot for the middle section, shank and foot for the final section—were verified, establishing different acceleration strategies during the entire acceleration phase. In conclusion, there are presumably two transitions during human maximal accelerated sprinting that divide the entire acceleration phase into three sections, and different acceleration strategies represented by the contributions of the segments for running speed are employed.

  4. Effects of three types of resisted sprint training devices on the kinematics of sprinting at maximum velocity.

    Science.gov (United States)

    Alcaraz, Pedro E; Palao, José M; Elvira, José L L; Linthorne, Nicholas P

    2008-05-01

    Resisted sprint running 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 purpose of this study was to compare the kinematics of sprinting at maximum velocity to the kinematics of sprinting when using three of types of resisted sprint training devices (sled, parachute, and weight belt). Eleven men and 7 women participated in the study. Flying sprints greater than 30 m were recorded by video and digitized with the use of biomechanical analysis software. The test conditions were compared using a 2-way analysis of variance with a post-hoc Tukey test of honestly significant differences. We found that the 3 types of resisted sprint training devices are appropriate devices for training the maximum velocity phase in sprinting. These devices exerted a substantial overload on the athlete, as indicated by reductions in stride length and running velocity, but induced only minor changes in the athlete's running technique. When training with resisted sprint training devices, the coach should use a high resistance so that the athlete experiences a large training stimulus, but not so high that the device induces substantial changes in sprinting technique. We recommend using a video overlay system to visually compare the movement patterns of the athlete in unloaded sprinting to sprinting with the training device. In particular, the coach should look for changes in the athlete's forward lean and changes in the angles of the support leg during the ground contact phase of the stride.

  5. Comparison of lower body strength, power, acceleration, speed, agility, and sprint momentum to describe and compare playing rank among professional rugby league players.

    Science.gov (United States)

    Baker, Daniel G; Newton, Robert U

    2008-01-01

    Success in rugby league football seems heavily reliant on players possessing an adequate degree of various physical fitness qualities, such as strength, power, speed, agility, and endurance, as well as the individual skills and team tactical abilities. The purpose of this study was to describe and compare the lower body strength, power, acceleration, maximal speed, agility, and sprint momentum of elite first-division national rugby league (NRL) players (n = 20) to second-division state league (SRL) players (n = 20) players from the same club. Strength and maximal power were the best discriminators of which players were in the NRL or SRL squads. None of the sprinting tests, such as acceleration (10-m sprint), maximal speed (40-m sprint), or a unique 40-m agility test, could distinguish between the NRL or SRL squads. However, sprint momentum, which was a product of 10-m velocity and body mass, was better for discriminating between NRL and SRL players as heavier, faster players would possess better drive forward and conversely be better able to repel their opponents' drive forward. Strength and conditioning specialists should therefore pay particular attention to increasing lower body strength and power and total body mass through appropriate resistance training while maintaining or improving 10-m sprint speed to provide their players with the underlying performance characteristics of play at the elite level in rugby leagues.

  6. 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

    to road, path, and forest running and sprinting performance, as well as running economy, velocity at anaerobic threshold, and VO2peak from treadmill assessments. RESULTS: During SJs and CMJs, elites demonstrated superior relative peak forces, time-to-peak forces, and pre-stretch augmentation albeit lower......-stretch augmentation and forest running velocities. Pre-stretch augmentation and time-to-peak forces were moderately correlated to VO2peak. Correlations between running economy and jumping or hopping were small or trivial. CONCLUSIONS: Overall, our elites exhibited superior stretch-shortening cycle utilization...... 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....

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

    Science.gov (United States)

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

    2017-04-01

    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. The STT was repeated four times on a 1300-m simulated sprint course including three flat (1°) double poling (DP) sections interspersed with two uphill (7°) diagonal stride (DS) sections. Treadmill velocity and VO2 were monitored continuously during the four STTs and data were averaged. Supramaximal GE 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 contribution was 18 ± 5%, with an accumulated O2 deficit of 45 ± 13 mL/kg. Block-wise multiple regression revealed that VO2 , O2 deficit, and GE explained 30%, 15%, and 53% of the variance in STT time, respectively (all P < 0.05). This novel GE-based method of estimating the O2 deficit in simulated sprint-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Multi-Directional Sprint Training Improves Change-Of-Direction Speed and Reactive Agility in Young Highly Trained Soccer Players

    Science.gov (United States)

    Born, Dennis-Peter; Zinner, Christoph; Düking, Peter; Sperlich, Billy

    2016-01-01

    The aim of this study was to evaluate the effect of a repeated sprint training with multi-directional change-of-direction (COD) movements (RSmulti) compared to repeated shuttle sprints (RSS) on variables related to COD speed and reactive agility. Nineteen highly-trained male U15 soccer players were assigned into two groups performing either RSmulti or RSS. For both groups, each training session involved 20 repeated 15 s sprints interspersed with 30 s recovery. With RSmulti the COD movements were randomized and performed in response to a visual stimulus, while the RSS involved predefined 180° COD movements. Before and following the six training sessions, performance in the Illinois agility test (IAT), COD speed in response to a visual stimulus, 20 m linear sprint time and vertical jumping height were assessed. Both groups improved their performance in the IAT (p sprint time (P=0.73, ES = 0.07; p = 0.14, ES = 0.28) or vertical jumping height (p = 0.46, ES = 0.11; p = 0.29, ES = 0.12) for the RSmulti and RSS, respectively. In conclusion, performance in the IAT improved with the RSmulti as well as RSS. With the RSmulti however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility in young highly trained soccer players. Key points During soccer, the players perform repeated sprints involving multi-directional COD movements, while most of these turns and twists are not pre-planned but executed in response to an external stimulus, such as ball movement, several interacting opponents and changing game situations. Both groups improved performance in the IAT. With the RSmulti on the Speedcourt however, the COD movements are performed in response to a visual stimulus, which may result in specific adaptations that improve COD speed and reactive agility. The Speedcourt could serve as a valuable method to design and individualize specific conditioning drills for young highly

  9. Stride characteristics progress in a 40-m sprinting test executed by male preadolescent, adolescent and adult athletes

    Directory of Open Access Journals (Sweden)

    IOANNIS CHATZILAZARIDIS,

    2012-01-01

    Full Text Available The purpose of the present study was to examine the progress of sprint running velocity (SRV during the acceleration and initial constant velocity phases in prepubescent (PPS, adolescent (ADS and adult (AS sprinters by comparing the progress of the magnitude of the stride length (SL and stride frequency (SF. SRV, SL and SF progress for each 10-m interval of a 40-m sprinting test were examined with a video-analysis method for a total of thirty-one athletes. A 24 (age group 10-m interval ANOVA with repeated measures on the second factor revealed that SRV was developed similarly in ADS and AS (p >.05 and it was differentiated (p .73, p < .05 for the entire distance of the sprinting test for AS and PPS. On the contrary, SF was the maincontributor for SRV development in the 10-30m segment for ADS. In conclusion, SRV improvement seemed to be attributed to the increment of SL and SF, which were differently developed during the 40-m sprint performed by prepubertal, adolescent and adult sprinters.

  10. Effects of Warm-Up Stretching Exercises on Sprint Performance

    Science.gov (United States)

    Makaruk, Hubert; Makaruk, Beata; Kedra, Stanislaw

    2008-01-01

    Study aim: To assess direct effects of warm-up consisting of static and dynamic stretching exercises on sprint results attained by students differing in sprint performance. Material and methods: A group of 24 male and 19 female physical education students, including 12 and 9 sprinters, respectively. They performed warm-ups consisting of dynamic…

  11. Effects of Warm-Up Stretching Exercises on Sprint Performance

    Science.gov (United States)

    Makaruk, Hubert; Makaruk, Beata; Kedra, Stanislaw

    2008-01-01

    Study aim: To assess direct effects of warm-up consisting of static and dynamic stretching exercises on sprint results attained by students differing in sprint performance. Material and methods: A group of 24 male and 19 female physical education students, including 12 and 9 sprinters, respectively. They performed warm-ups consisting of dynamic…

  12. The Effect of Sprint Start Speed on Lower-limb Stiffness in Sprint Runners

    Directory of Open Access Journals (Sweden)

    Mansour Eslami

    2015-09-01

    Full Text Available Objective: Lower extremity stiffness is associated with variables such as the frequency and length of running steps, the amount of muscle force and power production. Previous studies showed contradictory findings regarding the relationship between lower extremities joints stiffness and start velocity. Sprint start can be highly affected by two key components of lower limb stiffness, namely, force and time. However, no research has yet investigated the effect of start velocity changes on lower–limb stiffness during sprint start. To test the effect of velocity changes on lower-limb stiffness during sprint start. Method: 15 male members of track and field were selected for this study. Leg stiffness was calculated dividing peak ground reaction force by the leg length. Joint stiffness was also estimated dividing the muscle moment of force by joint angular displacement. Subjects performed a start with three different speeds. Results: From low to high start velocity, means of leg stiffness, knee stiffness and ankle stiffness increased by 67.53%, 41.9% and 39.03% respectively. Conclusion: The findings show that lower-limb stiffness could be a key factor in changing runners' acceleration during sprint start.

  13. Current and Future Treatment of Hypertension in the SPRINT Era.

    Science.gov (United States)

    Phillips, Robert A

    2015-01-01

    Based on the SPRINT trial, it is highly likely that new SPRINT-era guidelines will establish a blood pressure (BP) goal of SPRINT demonstrated that assignment to an intensive-treatment systolic BP (SBP) goal of SPRINT-era guidelines in the elderly, African Americans, and patients with uncomplicated essential hypertension, diabetes, chronic kidney disease, cardiovascular disease, and coronary artery disease. Specific attention is paid to BP goals and preferred pharmacological antihypertensive therapy in these populations, and an algorithm that incorporates the SPRINT trial results is presented. Inhibitors of the renin-angiotensin-aldosterone system as well as calcium channel blockers are universally accepted as first-line therapy in uncomplicated hypertension, but controversy exists over the role of thiazide diuretics and beta blockers. This review also discusses a physiologically and outcomes-based approach to combination therapy for treatment of hypertension.

  14. The effect of ego depletion on sprint start reaction time.

    Science.gov (United States)

    Englert, Chris; Bertrams, Alex

    2014-10-01

    In the current study, we consider that optimal sprint start performance requires the self-control of responses. Therefore, start performance should depend on athletes' self-control strength. We assumed that momentary depletion of self-control strength (ego depletion) would either speed up or slow down the initiation of a sprint start, where an initiation that was sped up would carry the increased risk of a false start. Applying a mixed between- (depletion vs. nondepletion) and within- (before vs. after manipulation of depletion) subjects design, we tested the start reaction times of 37 sport students. We found that participants' start reaction times decelerated after finishing a depleting task, whereas it remained constant in the nondepletion condition. These results indicate that sprint start performance can be impaired by unrelated preceding actions that lower momentary self-control strength. We discuss practical implications in terms of optimizing sprint starts and related overall sprint performance.

  15. Contribution of trunk muscularity on sprint run.

    Science.gov (United States)

    Kubo, T; Hoshikawa, Y; Muramatsu, M; Iida, T; Komori, S; Shibukawa, K; Kanehisa, H

    2011-03-01

    This study aimed to investigate how the trunk muscularity is related to sprint running performance. In 23 youth soccer players, the cross-sectional images at the mid level of each of L1-L2, L2-L3, L3-L4, L4-L5, and L5-S1 were obtained using magnetic resonance imaging to determine the cross-sectional areas (CSAs) of rectus abdominis, oblique, psoas major, quadratus lumborum and erector spinae muscles. The times taken to sprint over 20 m were measured, and the mean velocity of running was calculated for each of the 2 distances (V (10 m) and V (20 m)) and for the distance from 10 m to 20 m (V (10-20 m)). The CSA values of the 5 slice levels for all muscles except for the quadratus lumborum and those of the 3 slice levels (L1-L2, L2-L3 and L3-L4) for the quadratus lumborum were averaged and expressed relative to the two-third power of body mass (CSA/BM (2/3)). The CSA/BM (2/3) values of the erector spinae and quadratus lumborum were selected as significant contributors to predict V (10 m) ( R(2)=0.450), V (20 m) ( R(2)=0.504) and V (10-20 m) ( R(2)=0.420). The current results indicate that the muscularity of the erector spinae and quadratus lumborum contributes to achieving a high performance in sprint running over distances of less than 20 m.

  16. Methods for quantifying training in sprint kayak.

    Science.gov (United States)

    Borges, Thiago Oliveira; Bullock, Nicola; Duff, Christine; Coutts, Aaron J

    2014-02-01

    The aims of this study were to determine the validity of the session rating of perceived exertion (session-RPE) method by comparing 3 different scales of perceived exertion with common measures of training load (TL). A secondary aim was to verify the relationship between TLs, fitness, and performance in Sprint Kayak athletes. After laboratory assessment of maximal oxygen uptake (V[Combining Dot Above]O2peak) and lactate threshold, the athletes performed on water time trials over 200 and 1,000 m. Training load was quantified for external (distance and speed) and internal (session-RPE: 6-20, category ratio [CR]-10 and CR-100 scales, training impulse [TRIMP], and individual TRIMP). Ten (6 male, 4 female) well-trained junior Sprint Kayak athletes (age 17.1 ± 1.2 years; V[Combining Dot Above]O2peak 4.2 ± 0.7 L·min) were monitored over a 7-week period. There were large-to-very large within-individual correlations between the session distance and the various heart rate (HR) and RPE-based methods for quantifying TL (0.58-0.91). Correlations between the mean session speed and various HR- and RPE-based methods for quantifying TL were small to large (0.12-0.50). The within-individual relationships between the various objective and subjective methods of internal TL were large to very large (0.62-0.94). Moderate-to-large inverse relationships were found between mean session-RPE TL and various aerobic fitness variables (-0.58 to -0.37). Large-to-very large relationships were found between mean session-RPE TL and on water performance (0.57-0.75). In conclusion, session-RPE is a valid method for monitoring TL for junior Sprint Kayak athletes, regardless of the RPE scale used. The session-RPE TL relates to fitness and performance, supporting the use of session-RPE in Sprint Kayak training.

  17. 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.

  18. Is there an ACE ID - ACTN3 R577X polymorphisms interaction that influences sprint performance?

    Science.gov (United States)

    Eynon, N; Alves, A J; Yamin, C; Sagiv, M; Duarte, J A; Oliveira, J; Ayalon, M; Goldhammer, E; Sagiv, M; Meckel, Y

    2009-12-01

    Functional R577X (rs.1815739) and ID (rs.5186) polymorphisms in the alpha-actinin-3 ( ACTN3) and the angiotensin converting enzyme (ACE) genes, respectively, have been associated with sprint performance. The aim of this study was to determine their effect on sprint performance among 81 Israeli sprinters and 240 healthy controls. Results revealed that the ACE II genotype+ ACTN3 R allele (P=0.003 for sprinters vs. controls), and the ACTN3 RR genotype +ACE I allele (P=0.001 for sprinters vs. controls) might be the genotype for sprinters. In the whole cohort the probability of ACTN3 RR genotype+ ACE I allele being a sprinter (odds ratio 2.67, 95% confidence interval 1.45-4.93) and of ACE II genotype+ ACTN3 R allele being a sprinter (odds ratio 3.57, 95% confidence interval 1.78-7.15) was significantly higher than that in the controls. In conclusion, the above data suggest that ACE ID/ ACTN3 R577X genotype combination is associated with sprint ability. However, ACE ID/ ACTN3 R577X genotype combination is not related to the level of performance.

  19. Acute Response of Well-Trained Sprinters to a 100-m Race: Higher Sprinting Velocity Achieved With Increased Step Rate Compared With Speed Training.

    Science.gov (United States)

    Otsuka, Mitsuo; Kawahara, Taisuke; Isaka, Tadao

    2016-03-01

    This study aimed to clarify the contribution of differences in step length and step rate to sprinting velocity in an athletic race compared with speed training. Nineteen well-trained male and female sprinters volunteered to participate in this study. Sprinting motions were recorded for each sprinter during both 100-m races and speed training (60-, 80-, and 100-m dash from a block start) for 14 days before the race. Repeated-measures analysis of covariance was used to compare the step characteristics and sprinting velocity between race and speed training, adjusted for covariates including race-training differences in the coefficients of restitution of the all-weather track, wind speed, air temperature, and sex. The average sprinting velocity to the 50-m mark was significantly greater in the race than in speed training (8.26 ± 0.22 m·s vs. 8.00 ± 0.70 m·s, p sprinters achieve higher sprinting velocity and can run with higher exercise intensity and more rapid motion during a race than during speed training, even if speed training was performed at perceived high intensity.

  20. Physiological Demands of Competitive Sprint and Distance Performance in Elite Female Cross-Country Skiing.

    Science.gov (United States)

    Carlsson, Magnus; Carlsson, Tomas; Wedholm, Lars; Nilsson, Mattias; Malm, Christer; Tonkonogi, Michail

    2016-08-01

    Carlsson, M, Carlsson, T, Wedholm, L, Nilsson, M, Malm, C, and Tonkonogi, M. Physiological demands of competitive sprint and distance performance in elite female cross-country skiing. J Strength Cond Res 30(8): 2138-2144, 2016-The purpose was to investigate the relationship between elite females' competitive performance capability in sprint and distance cross-country skiing and the variables of gross efficiency (GE), work rate at the onset of blood-lactate accumulation (OBLA4mmol), maximal oxygen uptake (V[Combining Dot Above]O2max), maximal speed (Vmax), and peak upper-body oxygen uptake (V[Combining Dot Above]O2peak). Ten elite female cross-country skiers (age 24.5 ± 2.8 years) completed treadmill roller-skiing tests to determine GE, OBLA4mmol, and V[Combining Dot Above]O2max using the diagonal-stride technique as well as Vmax and V[Combining Dot Above]O2peak using the double-poling technique. International Ski Federations ranking points for sprint (FISsprint) and distance (FISdist) races were used as competitive performance data. There were correlations between the FISsprint and the V[Combining Dot Above]O2max expressed absolutely (p = 0.0040), Vmax (p = 0.012), and V[Combining Dot Above]O2peak expressed absolutely (p cross-country skiing. In addition, the ability to generate a high Vmax indicates the performance in sprint races, whereas the skier's OBLA4mmol reflects the performance capability in distance races. Based on the results, when evaluating the performance capacity of elite female cross-country skiers, it is recommended to use physiological variables that reflect competitive performance.

  1. Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

    Science.gov (United States)

    Feng, Weiwei; Wu, Huiyu; Li, Qian; Zhou, Zhaoxiang; Chen, Yao; Zhao, Ting; Feng, Yun; Mao, Guanghua; Li, Fang; Yang, Liuqing; Wu, Xiangyang

    2015-11-01

    Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

  2. Exercise-induced muscle damage following dance and sprint-specific exercise in females.

    Science.gov (United States)

    Brown, Meghan A; Howatson, Glyn; Keane, Karen; Stevenson, Emma J

    2016-11-01

    There is a paucity of studies investigating exercise-induced muscle damage (EIMD) in females and only one in response to dance-type exercise. This study sought to firstly elucidate the physiological profile of EIMD following a dance-specific protocol, and second to compare the magnitude of damage to that experienced following a sport-specific protocol in physically active females. Twenty-nine female recreational dancers (19±1 years) were recruited. Participants completed either a dance-specific protocol (DPFT; N.=15) or sport-specific repeated sprint protocol (SSRS; N.=14). Muscle soreness, limb girths, creatine kinase (CK), countermovement jump height (CMJ), reactive strength index (RSI), maximal voluntary contraction (MVC) and 30 m sprint time were recorded pre, 0-, 24-, 48-, and 72 h post exercise. The DPFT induced muscle damage, with significant time effects for all variables except RSI. However the response was acute, and muscle function returned to near-baseline levels by 48 h. Although no group differences existed, there were significant interaction effects; notably in CMJ (P=0.038) where the decline at 0 h (-6.9%) was smaller and recovery was greater at 72 h (which exceeded pre-exercise levels by 3.7%) post DPFT compared to post SSRS. The results offer new information showing that dance-specific activity results in EIMD in females. In addition, the magnitude of damage was similar to repeated sprint exercise and demonstrated that, in this population, recovery from these strenuous activities takes several days. These data have important implications for understanding the consequences of dance activity and other strenuous exercise in females.

  3. The effects of ten weeks of resistance and combined plyometric/sprint training with the Meridian Elyte athletic shoe on muscular performance in women.

    Science.gov (United States)

    Ratamess, Nicholas A; Kraemer, William J; Volek, Jeff S; French, Duncan N; Rubin, Martyn R; Gómez, Ana L; Newton, Robert U; Maresh, Carl M

    2007-08-01

    The purpose of this investigation was to examine the combined effects of resistance and sprint/plyometric training with or without the Meridian Elyte athletic shoe on muscular performance in women. Fourteen resistance-trained women were randomly assigned to one of 2 training groups: (a) an athletic shoe (N = 6) (AS) group or (b) the Meridian Elyte (N = 8) (MS) group. Training was performed for 10 weeks and consisted of resistance training for 2 days per week and 2 days per week of sprint/plyometric training. Linear periodized resistance training consisted of 5 exercises per workout (4 lower body, 1 upper body) for 3 sets of 3-12 repetition maximum (RM). Sprint/plyometric training consisted of 5-7 exercises per workout (4-5 plyometric exercises, 40-yd and 60-yd sprints) for 3-6 sets with gradually increasing volume (8 weeks) followed by a 2-week taper phase. Assessments for 1RM squat and bench press, vertical jump, broad jump, sprint speed, and body composition were performed before and following the 10-week training period. Significant increases were observed in both AS and MS groups in 1RM squat (12.0 vs. 14.6 kg), bench press (6.8 vs. 7.4 kg), vertical jump height (3.3 vs. 2.3 cm), and broad jump (17.8 vs. 15.2 cm). Similar decreases in peak 20-, 40-, and 60-m sprint times were observed in both groups (20 m: 0.14 vs. 0.11 seconds; 40 m: 0.29 vs. 0.34 seconds; 60 m: 0.45 vs. 0.46 seconds in AS and MS groups, respectively). However, when sprint endurance (the difference between the fastest and slowest sprint trials) was analyzed, there was a significantly greater improvement at 60 m in the MS group. These results indicated that similar improvements in peak sprint speed and jumping ability were observed following 10 weeks of training with either shoe. However, high-intensity sprint endurance at 60 m increased to a greater extent during training with the Meridian Elyte athletic shoe.

  4. Running sprint interval training induces fat loss in women.

    Science.gov (United States)

    Hazell, Tom J; Hamilton, Craig D; Olver, T Dylan; Lemon, Peter W R

    2014-08-01

    Data on whether sprint interval training (SIT) (repeated supermaximal intensity, short-duration exercise) affects body composition are limited, and the data that are available suggest that men respond more favourably than do women. Moreover, most SIT data involve cycling exercise, and running may differ because of the larger muscle mass involved. Further, running is a more universal exercise type. This study assessed whether running SIT can alter body composition (air displacement plethysmography), waist circumference, maximal oxygen consumption, peak running speed, and (or) the blood lipid profile. Fifteen recreationally active women (age, 22.9 ± 3.6 years; height, 163.9 ± 5.1 cm; mass, 60.8 ± 5.2 kg) completed 6 weeks of running SIT (4 to 6, 30-s "all-out" sprints on a self-propelled treadmill separated by 4 min of rest performed 3 times per week). Training decreased body fat mass by 8.0% (15.1 ± 3.6 to 13.9 ± 3.4 kg, P = 0.002) and waist circumference by 3.5% (80.1 ± 4.2 to 77.3 ± 4.4 cm, P = 0.048), whereas it increased fat-free mass by 1.3% (45.7 ± 3.5 to 46.3 ± 2.9 kg, P = 0.05), maximal oxygen consumption by 8.7% (46 ± 5 to 50 ± 6 mL/(kg·min), P = 0.004), and peak running speed by 4.8% (16.6 ± 1.7 to 17.4 ± 1.4 km/h, P = 0.026). There were no differences in food intake assessed by 3-day food records (P > 0.329) or in blood lipids (P > 0.595), except for a slight decrease in high-density lipoprotein concentration (1.34 ± 0.28 to 1.24 ± 0.24 mmol/L, P = 0.034). Running SIT is a time-efficient strategy for decreasing body fat while increasing aerobic capacity, peak running speed, and fat-free mass in healthy young women.

  5. Assisted and resisted sprint training in swimming.

    Science.gov (United States)

    Girold, Sébastien; Calmels, Paul; Maurin, Didier; Milhau, Nicolas; Chatard, Jean-Claude

    2006-08-01

    This study was undertaken to determine whether the resisted-sprint in overstrength (OSt) or the assisted-sprint in overspeed (OSp) could be efficient training methods to increase 100-m front crawl performance. Thirty-seven (16 men, 21 women) competition-level swimmers (mean +/- SD: age 17.5 +/- 3.5 years, height 173 +/- 14 cm, weight 63 +/- 14 kg) were randomly divided into 3 groups: OSt, OSp, and control (C). All swimmers trained 6 days per week for 3 weeks, including 3 resisted or assisted training sessions per week for the groups OSt and OSp respectively. Elastic tubes were used to generate swimming overstrength and overspeed. Three 100-m events were performed before, during, and after the training period. Before each 100-m event, strength of the elbow flexors and extensors was measured with an isokinetic dynamometer. Stroke rate and stroke length were evaluated using the video-recorded 100-m events. In the OSt group, elbow extensor strength, swimming velocity, and stroke rate significantly increased (p < 0.05), while stroke length remained unchanged after the 3-week training period. In the OSp group, stroke rate significantly increased (p < 0.05) and stroke length significantly decreased (p < 0.05) without changes in swimming velocity. No significant variations in the C group were observed. Both OSt and OSp proved to be more efficient than the traditional training program. However, the OSt training program had a larger impact on muscle strength, swimming performance, and stroke technique than the OSp program.

  6. No effect of acute ingestion of Thai ginseng (Kaempferia parviflora) on sprint and endurance exercise performance in humans.

    Science.gov (United States)

    Wasuntarawat, Chanchira; Pengnet, Sirinat; Walaikavinan, Nutchanon; Kamkaew, Natakorn; Bualoang, Tippaporn; Toskulkao, Chaivat; McConell, Glenn

    2010-09-01

    Thai ginseng, Kaempferia parviflora, is widely believed among the Mong hill tribe to reduce perceived effort and improve physical work capacity. Kaempferia parviflora is consumed before their daily work. Therefore, we conducted an acute study on the effects of K. parviflora on repeated bouts of sprint exercise and on endurance exercise time to exhaustion. Two studies were conducted in college males using a randomized, double-blind, crossover design. Ninety minutes after consumption of K. parviflora or a starch placebo, participants in study 1 (n = 19) completed three consecutive maximum 30-s sprint cycling Wingate tests, separated by 3 min recovery, while participants in study 2 (n = 16) performed submaximal cycling exercise to exhaustion. Peak and mean power output decreased with successive Wingate tests, while percent fatigue and blood lactate concentration increased after the third Wingate test (P parviflora. There was also no effect of K. parviflora on time to exhaustion, rating of perceived exertion or heart rate during submaximal exercise. Our results indicate that acute ingestion of K. parviflora failed to improve exercise performance during repeated sprint exercise or submaximal exercise to exhaustion. However, chronic effects or actions in other populations cannot be excluded.

  7. Enhanced sarcoplasmic reticulum Ca(2+) release following intermittent sprint training

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Lunde, Per; Levin, Kasper

    2000-01-01

    To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after...... the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% (P training. The 5-wk sprint training induced a significantly higher (P ...-977) arbitrary units Ca(2+). g protein(-1). min(-1) (after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% (P

  8. Enhanced sarcoplasmic reticulum Ca(2+) release following intermittent sprint training

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Lunde, Per; Levin, Kasper

    2000-01-01

    To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after...... the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% (P training. The 5-wk sprint training induced a significantly higher (P ...-977) arbitrary units Ca(2+). g protein(-1). min(-1) (after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% (P

  9. 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

  10. Acute consumption of p-synephrine does not enhance performance in sprint athletes.

    Science.gov (United States)

    Gutiérrez-Hellín, Jorge; Salinero, Juan José; Abían-Vicen, Javier; Areces, Francisco; Lara, Beatriz; Gallo, Cesar; Puente, Carlos; Del Coso, Juan

    2016-01-01

    P-Synephrine is a protoalkaloid widely used as an ergogenic aid in sports. This substance has been included in the World Anti-Doping Agency monitoring program, although scientific information about its effects on performance and athletes' well-being is scarce. The purpose of this investigation was to determine the effectiveness of p-synephrine to increase performance in sprint athletes. In a randomized and counterbalanced order, 13 experienced sprinters performed 2 acute experimental trials after the ingestion of p-synephrine (3 mg·kg(-1)) or after the ingestion of a placebo (control trial). Forty-five minutes after the ingestion of the substances, the sprinters performed a squat jump, a countermovement jump, a 15-s repeated jump test, and subsequently performed 60-m and 100-m simulated sprint competitions. Self-reported questionnaires were used to assess side-effect prevalence. In comparison with the control trial, the ingestion of p-synephrine did not change countermovement jump height (37.4 ± 4.2 vs 36.7 ± 3.3 cm, respectively; P = 0.52), squat jump height (34.4 ± 3.6 vs 33.9 ± 3.7 cm; P = 0.34), or average 15-s repeated jumps height (31.8 ± 4.1 vs 32.2 ± 3.6 cm; P = 0.18). P-Synephrine did not modify maximal running speed during the 60-m (9.0 ± 0.5 vs 9.0 ± 0.4 m·s(-1), respectively; P = 0.55) and 100-m sprint competitions (8.8 ± 0.5 vs 8.8 ± 0.5 m·s(-1), respectively; P = 0.92). The ingestion of p-synephrine did not alter the prevalence of headache, gastrointestinal discomforts, muscle pain, or insomnia during the hours following the tests. Acute consumption of 3 mg·kg(-1) of p-synephrine was ineffective to increase performance in competitive sprint athletes. Moreover, p-synephrine did not increase the occurrence of side effects after the competition.

  11. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    National Research Council Canada - National Science Library

    Yanci, J; Granados, C; Otero, M; Badiola, A; Olasagasti, J; Bidaurrazaga-Letona, I; Iturricastillo, A; Gil, Sm

    ...; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89...

  12. Effect of two different long-sprint training regimens on sprint performance and associated metabolic responses.

    Science.gov (United States)

    Hanon, Christine; Bernard, Olivier; Rabate, Mathieu; Claire, Thomas

    2012-06-01

    The purpose of this study was to analyze 2 different long-sprint training programs (TPs) of equal total work load, completed either with short recovery (SR) or long recovery (LR) between sets and to compare the effects of 6 long-sprint training sessions (TSs) conducted over a 2-week period on a 300-m performance. Fourteen trained subjects performed 3 pretraining maximal sprints (50-, 100-, and 300-m), were paired according to their 300-m performance, and randomly allocated to an LR or SR group, which performed 6 TSs consisting of sets of 150, 200, or 250 m. The recovery in the LR group was double that of the SR group. During the third TS and the 300-m pretest and posttest, blood pH, bicarbonate concentration ([HCO₃⁻]), excess-base (EB), and lactate concentration were recorded. Compared with a similar TS performed with SR, the LR training tends to induce a greater alteration of the acid-base balance: pH: 7.09 ± 0.08 (LR) and 7.14 ± 0.05 (SR) (p = 0.10), [HCO₃⁻]: 7.8 ± 1.9 (LR) and 9.6 ± 2.7 (SR) (p = 0.04), and EB: -21.1 ± 3.8 (LR) and -17.7 ± 2.8 (SR) (p = 0.11). A significant improvement in the 300-m performance between pre-TP and post-TP (42.45 ± 2.64 vs. 41.52 ± 2.45, p = 0.01) and significant decreases in pH (p < 0.01), EB (p < 0.001) and increase in [La] (p < 0.001) have been observed post-TP compared with those pre-TP. Although sprint training with longer recovery induces higher metabolic disturbances, both sprint training regimens allow a similar 300-m performance improvement with no concomitant significant progress in the 50- and 100-m performance.

  13. Hypertension up to date: SPRINT to SPYRAL.

    Science.gov (United States)

    Kulenthiran, Saarraaken; Ewen, Sebastian; Böhm, Michael; Mahfoud, Felix

    2017-07-01

    Hypertension is the most common chronic cardiovascular condition with increasing prevalence all over the world. Treatment of patients at risk requires a multimodal therapeutic concept to adjust blood pressure, including systematic identification of secondary causes of hypertension or pseudo-resistance, lifestyle modification, polypharmacy, and as well as accompanying risk factors and comorbidities. The present review discusses recent studies on patients with increased cardiovascular risk potentially influencing future treatment strategies. It covers blood pressure targets in patients at risk (SPRINT), novel treatment options such as angiotensin receptor neprilysin inhibitors, discusses the treatment of patients with impaired glucose tolerance, and appreciates novelties in controlling therapy-resistant hypertension by fourth-line pharmacotherapies (PATHWAY), as well as new interventional approaches.

  14. Acute plasma volume change with high-intensity sprint exercise.

    Science.gov (United States)

    Bloomer, Richard J; Farney, Tyler M

    2013-10-01

    When exercise is of long duration or of moderate to high intensity, a decrease in plasma volume can be observed. This has been noted for both aerobic and resistance exercise, but few data are available with regard to high-intensity sprint exercise. We measured plasma volume before and after 3 different bouts of acute exercise, of varying intensity, and/or duration. On different days, men (n = 12; 21-35 years) performed aerobic cycle exercise (60 minutes at 70% heart rate reserve) and 2 different bouts of cycle sprints (five 60-second sprints at 100% maximum wattage obtained during graded exercise testing (GXT) and ten 15-second sprints at 200% maximum wattage obtained during GXT). Blood was collected before and 0, 30, and 60 minutes postexercise and analyzed for hematocrit and hemoglobin and plasma volume was calculated. Plasma volume decreased significantly for all exercise bouts (p sprint bouts (∼19%) compared with aerobic exercise bouts (∼11%). By 30 minutes postexercise, plasma volume approached pre-exercise values. We conclude that acute bouts of exercise, in particular high-intensity sprint exercise, significantly decrease plasma volume during the immediate postexercise period. It is unknown what, if any negative implications these transient changes may have on exercise performance. Strength and conditioning professionals may aim to rehydrate athletes appropriately after high-intensity exercise bouts.

  15. Gait asymmetry: composite scores for mechanical analyses of sprint running.

    Science.gov (United States)

    Exell, T A; Gittoes, M J R; Irwin, G; Kerwin, D G

    2012-04-01

    Gait asymmetry analyses are beneficial from clinical, coaching and technology perspectives. Quantifying overall athlete asymmetry would be useful in allowing comparisons between participants, or between asymmetry and other factors, such as sprint running performance. The aim of this study was to develop composite kinematic and kinetic asymmetry scores to quantify athlete asymmetry during maximal speed sprint running. Eight male sprint trained athletes (age 22±5 years, mass 74.0±8.7 kg and stature 1.79±0.07 m) participated in this study. Synchronised sagittal plane kinematic and kinetic data were collected via a CODA motion analysis system, synchronised to two Kistler force plates. Bilateral, lower limb data were collected during the maximal velocity phase of sprint running (velocity=9.05±0.37 ms(-1)). Kinematic and kinetic composite asymmetry scores were developed using the previously established symmetry angle for discrete variables associated with successful sprint performance and comparisons of continuous joint power data. Unlike previous studies quantifying gait asymmetry, the scores incorporated intra-limb variability by excluding variables from the composite scores that did not display significantly larger (pcomposite scores and the magnitude of asymmetry observed for each measure varied on an individual participant basis. The new composite scores indicated the inter-participant differences that exist in asymmetry during sprint running and may serve to allow comparisons between overall athlete asymmetry with other important factors such as performance.

  16. 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.

  17. Different Starting Distances Affect 5-m Sprint Times.

    Science.gov (United States)

    Altmann, Stefan; Hoffmann, Marian; Kurz, Gunther; Neumann, Rainer; Woll, Alexander; Haertel, Sascha

    2015-08-01

    The purpose of this study was to quantify the effect of different starting distances on 5-m sprint time and the accuracy of the initial timing gate. A single-beam timing gate system (1 m high) was used to measure 5-m sprint time in 13 male sports students. Each subject performed 3 valid trials for 3 starting distances: 0.3, 0.5, and 1.0 m from the initial timing lights, respectively. A high-speed video camera was used to track a reflective marker placed on the subjects' hip within a field of view around the initial timing gate. Accuracy of the initial timing gate was defined as the time between the initial timing light trigger and passing of the reflective marker by the initial timing gate. Sprint times were significantly faster for the 1.0-m starting distance (0.98 ± 0.06 seconds) than for the 0.5-m (1.05 ± 0.07 seconds) and the 0.3-m (1.09 ± 0.08 seconds) starting distances (p sprint times but not the accuracy of the initial timing gate. Researchers and coaches should consider the effect of starting distance on 5-m sprint time and ensure consistent testing protocols. Based on the results of this study, we recommend a starting distance of 0.3 m that should be used for all sprint performance tests.

  18. Effect of Number of Sprints in an SIT Session on Change in V˙O2max: A Meta-analysis.

    Science.gov (United States)

    Vollaard, Niels B J; Metcalfe, Richard S; Williams, Sean

    2017-06-01

    Recent meta-analyses indicate that sprint interval training (SIT) improves cardiorespiratory fitness (V˙O2max), but the effects of various training parameters on the magnitude of the improvement remain unknown. The present meta-analysis examined the modifying effect of the number of sprint repetitions in an SIT session on improvements in V˙O2max. The databases PubMed and Web of Science were searched for original studies that have examined pre- and posttraining V˙O2max in adults after ≥2 wk of training consisting of repeated (≥2) Wingate-type cycle sprints, published up to May 1, 2016. Articles were excluded if they were not in English; if they involved patients, athletes, or participants with a mean baseline V˙O2max of >55 mL·kg·min or a mean age SIT trial was combined with another intervention or used intervals shorter than 10 s. A total of 38 SIT trials from 34 studies were included in the meta-analysis. Probabilistic magnitude-based inferences were made to interpret the outcome of the analysis. The meta-analysis revealed a likely large effect of a typical SIT intervention on V˙O2max (mean ± 90% confidence limits = 7.8% ± 4.0%) with a possibly small modifying effect of the maximum number of sprint repetitions in a training session (-1.2% ± 0.8% decrease per two additional sprint repetitions). Apart from possibly small effects of baseline V˙O2max and age, all other modifying effects were unclear or trivial. We conclude that the improvement in V˙O2max with SIT is not attenuated with fewer sprint repetitions, and possibly even enhanced. This means that SIT protocols can be made more time efficient, which may help SIT to be developed into a viable strategy to impact public health.

  19. 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.

  20. Method for the rapid determination of protein in meats using the CEM Sprint protein analyzer: collaborative study.

    Science.gov (United States)

    Moser, Cindy; Herman, Kathy

    2011-01-01

    A collaborative study was conducted to determine the protein content of raw and processed meat products by a protein-tagging and colorimetric technique. Meat products were prepared following AOAC Official Method 983.18 and analyzed using CEM Corporation's Sprint Rapid Protein Analyzer. Sprint provides protein results by combining an accurately weighed test portion with a known amount of dye-binding agent. The dye-binding agent binds with the lysine, histidine, and arginine, as well as the n-terminus of the proteins commonly found in raw meat and processed meat products. Results are displayed and reported by the Sprint as a percentage (g/100 g) of protein. Ten blind duplicate study samples were sent to 10 collaborating laboratories in the United States. The within-laboratory (repeatability) relative standard deviation (RSD(r)) ranged from 0.91 to 3.04%, and between-laboratories (reproducibility) relative standard deviation (RSDR) ranged from 1.50 to 3.41% for protein. The method is recommended for Official First Action.

  1. Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2017-10-07

    We aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterising intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly-most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely-very likely greater mean propulsive force during the initial four steps and possibly-very likely larger mean net anterior-posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior-posterior force during initial and middle acceleration.

  2. Exercise training comprising of single 20-s cycle sprints does not provide a sufficient stimulus for improving maximal aerobic capacity in sedentary individuals.

    Science.gov (United States)

    Songsorn, P; Lambeth-Mansell, A; Mair, J L; Haggett, M; Fitzpatrick, B L; Ruffino, J; Holliday, A; Metcalfe, R S; Vollaard, N B J

    2016-08-01

    Sprint interval training (SIT) provides a potent stimulus for improving maximal aerobic capacity ([Formula: see text]), which is among the strongest markers for future cardiovascular health and premature mortality. Cycling-based SIT protocols involving six or more 'all-out' 30-s Wingate sprints per training session improve [Formula: see text], but we have recently demonstrated that similar improvements in [Formula: see text] can be achieved with as few as two 20-s sprints. This suggests that the volume of sprint exercise has limited influence on subsequent training adaptations. Therefore, the aim of the present study was to examine whether a single 20-s cycle sprint per training session can provide a sufficient stimulus for improving [Formula: see text]. Thirty sedentary or recreationally active participants (10 men/20 women; mean ± SD age: 24 ± 6 years, BMI: 22.6 ± 4.0 kg m(-2), [Formula: see text]: 33 ± 7 mL kg(-1) min(-1)) were randomised to a training group or a no-intervention control group. Training involved three exercise sessions per week for 4 weeks, consisting of a single 20-s Wingate sprint (no warm-up or cool-down). [Formula: see text] was determined prior to training and 3 days following the final training session. Mean [Formula: see text] did not significantly change in the training group (2.15 ± 0.62 vs. 2.22 ± 0.64 L min(-1)) or the control group (2.07 ± 0.69 vs. 2.08 ± 0.68 L min(-1); effect of time: P = 0.17; group × time interaction effect: P = 0.26). Although we have previously demonstrated that regularly performing two repeated 20-s 'all-out' cycle sprints provides a sufficient training stimulus for a robust increase in [Formula: see text], our present study suggests that this is not the case when training sessions are limited to a single sprint.

  3. Dissimilar Physiological and Perceptual Responses Between Sprint Interval Training and High-Intensity Interval Training.

    Science.gov (United States)

    Wood, Kimberly M; Olive, Brittany; LaValle, Kaylyn; Thompson, Heather; Greer, Kevin; Astorino, Todd A

    2016-01-01

    High-intensity interval training (HIIT) and sprint interval training (SIT) elicit similar cardiovascular and metabolic adaptations vs. endurance training. No study, however, has investigated acute physiological changes during HIIT vs. SIT. This study compared acute changes in heart rate (HR), blood lactate concentration (BLa), oxygen uptake (VO2), affect, and rating of perceived exertion (RPE) during HIIT and SIT. Active adults (4 women and 8 men, age = 24.2 ± 6.2 years) initially performed a VO2max test to determine workload for both sessions on the cycle ergometer, whose order was randomized. Sprint interval training consisted of 8 bouts of 30 seconds of all-out cycling at 130% of maximum Watts (Wmax). High-intensity interval training consisted of eight 60-second bouts at 85% Wmax. Heart rate, VO2, BLa, affect, and RPE were continuously assessed throughout exercise. Repeated-measures analysis of variance revealed a significant difference between HIIT and SIT for VO2 (p HIIT (209.3 ± 40.3 kcal) vs. SIT (193.5 ± 39.6 kcal). During HIIT, subjects burned significantly more calories and reported lower perceived exertion than SIT. The higher VO2 and lower BLa in HIIT vs. SIT reflected dissimilar metabolic perturbation between regimens, which may elicit unique long-term adaptations. If an individual is seeking to burn slightly more calories, maintain a higher oxygen uptake, and perceive less exertion during exercise, HIIT is the recommended routine.

  4. Effect of Caffeine Contained in Sports Drink on Hormones Producing Energy Following Sprint Test Performance in Male Soccer Players

    Directory of Open Access Journals (Sweden)

    Mohammad Fayiz Abumoh'd

    2016-05-01

    Full Text Available This study investigated the effect of caffeine contained in sports drink on hormones producing energy and sprint test performance in male soccer players. Twelve participants (25.97 ± 2.70 y performed the test under thre e conditions (one week apart: caffeine with sports drink (SD-CAF, sports drink (SD, and placebo (PLA. Using a double-blind, placebo-controlled, randomized, crossover protocol, participants performed SD-CAF trial (5 mg/kg of caffeine contained in 300 ml of sports drink 30 minutes prior to sprinting test (7 × 30 m, SD trial (solely 300 ml of sports drink 30 minutes prior to sprinting test, or placebo. Blood analysis indicated significantly higher level of free thyroxine in SD-CAF (21.450 ± 3.048 compared to SD (18.742 ± 1.151 and PLA (16.983 ± 1.783. Similar findings existed regarding insulin (P 0.05. No significant differences were observed between trials in first–fourth repetitions (P > 0.05. Time of fifth-seventh repetitions were significantly lower in SD-CAF compared to SD and PLA (P < 0.05, and were significantly lower in SD than that in PLA (P < 0.05. The time of 7th repetition was (4.331 ± 0.210, 4.610 ± 0.197, 4.81 6 ± 0.171 s for SD-CAF, SD, and PLA, respectively; P < 0.05. In conclusion, caffeine interferes hormones that are responsible for producing energy which in turn have a positive effect on repeated sprint bouts.

  5. Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test

    Directory of Open Access Journals (Sweden)

    Mark ET Willems

    2016-08-01

    Full Text Available New Zealand blackcurrant (NZBC extract has been shown to enhance high-intensity intermittent treadmill running. We examined the effects of NZBC extract during the Loughborough Intermittent Shuttle Test (LIST which involves 5 × 15 min blocks with intermittent 15-m maximal sprints, interspersed by moderate and high-intensity running to simulate team sport activity, and a subsequent run to exhaustion. Thirteen males (age: 22 ± 1 year, V ˙ O 2 max : 50 ± 5 mL·kg−1·min−1 participated in three indoor sessions (T: 24 ± 3 °C, humidity: 52% ± 9%. In the first session, a multistage fitness test was completed to determine peak running speed and estimate V ˙ O 2 max . Participants consumed NZBC extract in capsules (300 mg·day−1 CurraNZ™ or placebo (PL (300 mg·day−1 microcrystalline cellulose M102 for seven days in a double-blind, randomized, cross-over design (wash-out at least seven days. NZBC extract did not affect average 15-m sprint times in each block. NZBC reduced slowing of the fastest sprint between block 1 and 5 (PL: 0.12 ± 0.07 s; NZBC: 0.06 ± 0.12 s; p < 0.05. NZBC extract had no effect on heart rate, vertical jump power, lactate and time to exhaustion (PL: 13.44 ± 8.09 min, NZBC: 15.78 ± 9.40 min, p > 0.05. However, eight participants had higher running times to exhaustion when consuming NZBC extract. New Zealand blackcurrant extract may enhance performance in team sports with repeated maximal sprints.

  6. Long-term training-induced changes in sprinting speed and sprint momentum in elite rugby union players.

    Science.gov (United States)

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

    2014-10-01

    Speed and sprint momentum are considered to be important physical qualities for rugby. The purpose of the study was to understand the development of these qualities in senior and junior international rugby players. In part 1 of the study, a group of senior (n = 38) and junior (n = 31) players were tested for speed over 40 m. Initial sprint velocity (ISV), maximal sprint velocity (MSV), initial sprint momentum (ISM), and maximal sprint momentum (MSM) were calculated using 10-m splits. In part 2 of the study, a group of junior (n = 12) and senior (n = 15) players were tracked over a 2-year period for body mass, ISV, MSV, ISM, and MSM. In part 1, senior backs and forwards were not found to have significantly greater ISV and MSV than junior players but were found to have greater ISM and MSM. Forwards were found to have significantly greater ISM and MSM than backs but significantly lower ISV and MSV than backs. In part 2, no significant differences were found over the 2 years between senior and junior players, but greater effect sizes for juniors were generally found when compared with seniors for improvements in ISV (d = 0.73 vs. 0.79), MSV (d = 1.09 vs. 0.68), ISM (d = 0.96 vs. 0.54), and MSM (d = 1.15 vs. 0.50). Sprint momentum is a key discriminator between senior and junior players, and large changes can be made by junior players as they transition into senior rugby. Speed appears to peak for players in their early 20s but sprint momentum appears to be more trainable.

  7. β-Alanine Supplementation Does Not Augment the Skeletal Muscle Adaptive Response to 6 Weeks of Sprint Interval Training.

    Science.gov (United States)

    Cochran, Andrew J R; Percival, Michael E; Thompson, Sara; Gillen, Jenna B; MacInnis, Martin J; Potter, Murray A; Tarnopolsky, Mark A; Gibala, Martin J

    2015-12-01

    Sprint interval training (SIT), repeated bouts of high-intensity exercise, improves skeletal muscle oxidative capacity and exercise performance. β-alanine (β-ALA) supplementation has been shown to enhance exercise performance, which led us to hypothesize that chronic β-ALA supplementation would augment work capacity during SIT and augment training-induced adaptations in skeletal muscle and performance. Twenty-four active but untrained men (23 ± 2 yr; VO2peak = 50 ± 6 mL · kg(-1) · min(-1)) ingested 3.2 g/day of β-ALA or a placebo (PLA) for a total of 10 weeks (n = 12 per group). Following 4 weeks of baseline supplementation, participants completed a 6-week SIT intervention. Each of 3 weekly sessions consisted of 4-6 Wingate tests, i.e., 30-s bouts of maximal cycling, interspersed with 4 min of recovery. Before and after the 6-week SIT program, participants completed a 250-kJ time trial and a repeated sprint test. Biopsies (v. lateralis) revealed that skeletal muscle carnosine content increased by 33% and 52%, respectively, after 4 and 10 weeks of β-ALA supplementation, but was unchanged in PLA. Total work performed during each training session was similar across treatments. SIT increased markers of mitochondrial content, including cytochome c oxidase (40%) and β-hydroxyacyl-CoA dehydrogenase maximal activities (19%), as well as VO2peak (9%), repeated-sprint capacity (5%), and 250-kJ time trial performance (13%), but there were no differences between treatments for any measure (p .05, interaction effects). The training stimulus may have overwhelmed any potential influence of β-ALA, or the supplementation protocol was insufficient to alter the variables to a detectable extent.

  8. 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.

  9. 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.…

  10. Physiological responses to an acute bout of sprint interval cycling.

    Science.gov (United States)

    Freese, Eric C; Gist, Nicholas H; Cureton, Kirk J

    2013-10-01

    Sprint interval training has been shown to improve skeletal muscle oxidative capacity, V[Combining Dot Above]O2max, and health outcomes. However, the acute physiological responses to 4-7 maximal effort intervals have not been determined. To determine the V[Combining Dot Above]O2, cardiorespiratory responses, and energy expenditure during an acute bout of sprint interval cycling (SIC), health, college-aged subjects, 6 men and 6 women, completed 2 SIC sessions with at least 7 days between trials. Sprint interval cycling was performed on a cycle ergometer and involved a 5-minute warm-up followed by four 30-second all-out sprints with 4-minute active recovery. Peak oxygen uptake (ml·kg·min) during the 4 sprints were 35.3 ± 8.2, 38.8 ± 10.1, 38.8 ± 10.6, and 36.8 ± 9.3, and peak heart rate (b·min) were 164 ± 17, 172 ± 10, 177 ± 12, and 175 ± 22. We conclude that an acute bout of SIC elicits submaximal V[Combining Dot Above]O2 and cardiorespiratory responses during each interval that are above 80% of estimated maximal values. Although the duration of exercise in SIC is very short, the high level of V[Combining Dot Above]O2 and cardiorespiratory responses are sufficient to potentially elicit adaptations to training associated with elevated aerobic energy demand.

  11. Effects of Psyching-Up on Sprint Performance.

    Science.gov (United States)

    Hammoudi-Nassib, Sarra; Nassib, Sabri; Chtara, Moktar; Briki, Walid; Chaouachi, Anis; Tod, David; Chamari, Karim

    2017-08-01

    Hammoudi-Nassib, S, Nassib, S, Chtara, M, Briki, W, Chaouachi, A, Tod, D, and Chamari, K. Effects of psyching-up on sprint performance. J Strength Cond Res 31(8): 2066-2074, 2017-The present research aimed at examining whether the psyching up (PU) strategies improve performance in 30-m sprinting. Sixteen male sprinters (age, 20.6 ± 1.3 years; body mass, 77.5 ± 7.1 kg; height, 180.8 ± 5.6 cm) participated in this study. Before each experimental session, the Hooper index was used to monitor the subject's feeling for the quality of sleep of the previous night, perceived quantity of stress, delayed onset muscle soreness, and fatigue. After completing general and specific warm-up, participants had to rate their degree of self-confidence. Then, they were asked to follow 1 of these 4 conditions: Imagery (experimental PU condition), Preparatory arousal (experimental PU condition), Attention placebo (control condition), and Distraction (control condition) during the final 30 seconds of the rest period right before performing a 30-m sprint. Participants separately and randomly performed all conditions. Results showed that although the imagery and preparatory arousal strategies contributed to increase the performance in the short-distance sprints (from 0 to 10 m), the imagery strategy contributed to increase the performance in the 30-m sprints. These findings support the general view that the PU strategies could improve athletic performance.

  12. Sprint swimming performance of wild bull trout (Salvelinus confluentus)

    Science.gov (United States)

    Mesa, M.G.; Phelps, J.; Weiland, L.K.

    2008-01-01

    We conducted laboratory experiments to determine the sprint swimming performance of wild juvenile and adult bull trout Salvelinus confluentus. Sprint swimming speeds were estimated using high-speed digital video analysis. Thirty two bull trout were tested in sizes ranging from about 10 to 31 cm. Of these, 14 fish showed at least one motivated, vigorous sprint. When plotted as a function of time, velocity of fish increased rapidly with the relation linear or slightly curvilinear. Their maximum velocity, or Vmax, ranged from 1.3 to 2.3 m/s, was usually achieved within 0.8 to 1.0 s, and was independent of fish size. Distances covered during these sprints ranged from 1.4 to 2.4 m. Our estimates of the sprint swimming performance are the first reported for this species and may be useful for producing or modifying fish passage structures that allow safe and effective passage of fish without overly exhausting them. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  13. Can cycle power predict sprint running performance?

    Science.gov (United States)

    van Ingen Schenau, G J; Jacobs, R; de Koning, J J

    1991-01-01

    A major criticism of present models of the energetics and mechanics of sprint running concerns the application of estimates of parameters which seem to be adapted from measurements of running during actual competitions. This study presents a model which does not perpetuate this solecism. Using data obtained during supra-maximal cycle ergometer tests of highly trained athletes, the kinetics of the anaerobic and aerobic pathways were modelled. Internal power wasted in the acceleration and deceleration of body limbs and the power necessary to overcome air friction was calculated from data in the literature. Assuming a mechanical efficiency as found during submaximal cycling, a power equation was constructed which also included the power necessary to accelerate the body at the start of movement. The differential equation thus obtained was solved through simulation. The model appeared to predict realistic times at 100 m (10.47 s), 200 m (19.63 s) and 400 m (42.99 s) distances. By comparison with other methods it is argued that power equations of locomotion should include the concept of mechanical efficiency.

  14. 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

    significant correlations were observed between maximal strength measures and jump ability. However, the correlations obtained between maximal strength and the sprint times ranged between -0,06 and -0,32, not being statistically significant. Correlations of 0,25 to 0,34 (n. s. were observed between maximal strength and ball velocity. In conclusion, the relationship between maximalstrength in squat exercise and jump ability in subject with little experience in strength training was moderate, whereas no relationships were observed between maximal strength and the sprint time or ball speed. Therefore, other aspects, such as kicking and/or running technique, should be considered as possibleperformance predictors in this population.

  15. Role of muscle mass on sprint performance: gender differences?

    Science.gov (United States)

    Perez-Gomez, Jorge; Rodriguez, German Vicente; Ara, Ignacio; Olmedillas, Hugo; Chavarren, Javier; González-Henriquez, Juan Jose; Dorado, Cecilia; Calbet, José A L

    2008-04-01

    The aim of this study was to determine if gender differences in muscle mass explain the gender differences in running and cycling sprint performance. Body composition (dual-energy X-ray absorptiometry), and running (30 and 300 m test) and cycling (Wingate test) sprint performance were assessed in 123 men and 32 women. Peak power (PP) output in the Wingate test expressed per kg of lower extremities lean mass (LM) was similar in males and females (50.4 +/- 5.6 and 50.5 +/- 6.2 W kg(-1), P = 0.88). No gender differences were observed in the slope of the linear relation between LM and PP or mean power output (MP). However, when MP was expressed per kg of LM, the males attained a 22% higher value (26.6 +/- 3.4 and 21.9 +/- 3.2 W kg(-1), P sprints, even when expressed as a percentage of the whole body mass.

  16. The effects of specific preconditioning activities on acute sprint performance.

    Science.gov (United States)

    Guggenheimer, Joshua D; Dickin, D Clark; Reyes, Gabriel F; Dolny, Dennis G

    2009-07-01

    Previous research suggests that specific preconditioning activities such as whole-body vibration (WBV) and resistance training may play an important role in ensuing dynamic activities. The purpose of this study was to examine the effects of 2 preconditioning activities, WBV and power cleans (PC), on acute sprint performance. Two studies were conducted in which 14 (WBV) and 9 (PC) male track and field athletes were subjects. The WBV treatment consisted of 4 bouts of 5 seconds of high-knee running on a vibrating platform at 0, 30, 40, or 50 Hz. The PC treatment consisted of 3 PC reps at 90% 1RM. In both cases, acute sprint performance was the dependent variable of interest. For WBV, split times were recorded at 10, 20, and 40 m. Reaction times (RXN) as well as 5-, 10-, and 40-m split times were recorded for the PC study. Results indicated no significant differences between treatment and nontreatment groups for both studies. However, significant correlations were present between RXN and 5-m splits (r = 0.65) and RXN and 10-m splits (r = 0.63), although they decreased as a function of sprint distance to r = 0.43 at 40 m. These results suggest little efficacy for the use of WBV and PC as a means of augmenting acute sprint performance. However, a trend within the 30-Hz protocol may suggest that WBV as part of a warm-up for sprinting activities greater than 40 m (i.e., 100 m) could potentially result in a decreased sprint time of nearly 1/10th of a second, which is worth future consideration.

  17. The Effects of Resisted Training Using Parachuteon Sprint Performance

    OpenAIRE

    KLIMENTINI MARTINOPOULOU; POLYXENI ARGEITAKI; GEORGIOS PARADISIS; CHRISTOS KATSIKAS,; ATHANASIA SMIRNIOTOU

    2011-01-01

    The purpose of this study was to examine the effects of resisted and unresisted sprint training programmes (STP) on acceleration and maximum speed performance. Sixteen sprint athletes divided into two groups (resisted group-RG and unresisted group-UG, n=8 each), age 25±4y, height 172±0.8 cm and weight 61.5±10.6kg. RG followed the STP towing a large size parachute and the UG followed a STP without resistance. Stride length (SL), stride frequency (SF), contact time (CT) and flight time (FT) wer...

  18. The Acute Potentiating Effects of Heavy Sled Pulls on Sprint Performance.

    Science.gov (United States)

    Winwood, Paul W; Posthumus, Logan R; Cronin, John B; Keogh, Justin W L

    2016-05-01

    This study examined the acute potentiating effects of heavy sprint-style sled pulls on sprint performance. Twenty-two experienced resistance-trained rugby athletes performed 2 heavy sprint-style sled pull training protocols on separate occasions using a randomized, crossover, and counterbalanced design. The protocols consisted of 2-baseline 15 m sprints followed by 15 m sprints at 4, 8, and 12 minutes after completing 15 and 7.5 m heavy sled pulls with loads of 75 and 150% body mass (respectively). A significantly faster (p ≤ 0.05) 15 m sprint time was observed at 12 minutes for the 75% body mass load. Small nonsignificant improvements (effect size [ES] = 0.22-0.33) in 5, 10, and 15 m sprint times were observed at 8 and 12 minutes after the 75% body mass sled pull. No significant changes were observed for any sprint time after the 150% body mass sled pull. Significant differences in the percentage of change in sprint times between the 2 sled pull conditions were observed at 4 (ES = 0.44-0.52), 8 (ES = 0.59), and 12 minutes (ES = 0.64). It would seem that the 75% body mass sled pull can be an effective preload stimulus for improving subsequent sprint performance provided that adequate recovery (8-12 minutes) is allowed. Practitioners should be advised that prescription of training load based on decrement in sprint velocity may be the best approach to determine loading for athletes.

  19. 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.

  20. A deterministic model based on evidence for the associations between kinematic variables and sprint kayak performance.

    Science.gov (United States)

    McDonnell, Lisa K; Hume, Patria A; Nolte, Volker

    2013-09-01

    The aim of this narrative review was to propose a deterministic model based on a review of previous research documenting the evidence for the associations between average kayak velocity and kinematic variables in sprint kayaking. Literature was reviewed after searching electronic databases using key words 'kayak,' 'biomechanics,' 'velocity,' 'kinematics,' and 'performance.' Our kinematic deterministic model for sprint kayaking performance shows that the average kayak velocity is determined by kayak stroke displacement and stroke time. Stroke time had the strongest correlation with 200-m race time (r = 0.86, p < 0.001), and stroke rate (inversely proportional to stroke time) was strongly correlated with average horizontal velocity over two consecutive strokes at race pace (r = -0.83, p < 0.05). Increased stroke rate via decreased absolute water phase time and increased relative water phase time were indicative of more elite performance. There was no significant relationship between stroke displacement and velocity; however, a large decrease in stroke displacement may be detrimental to performance. Individual characteristics may be responsible for a paddlers' ability to achieve and sustain a given stroke rate. Coaches should theoretically focus interventions on increasing stroke rate while maintaining stroke displacement; however this hypothesis should be confirmed with prospective studies.

  1. Relationship between Lower Limb Angular Kinematic Variables and the Effectiveness of Sprinting during the Acceleration Phase

    Directory of Open Access Journals (Sweden)

    Artur Struzik

    2016-01-01

    Full Text Available The ability to reach a high running velocity over a short distance is essential to a high playing performance in team games. The aim of this study was to determine the relationship between running time over a 10-meter section of a 30-meter sprint along a straight line and changes in the angle and angular velocity that were observed in the ankle, knee, and hip joints. The possible presence may help to optimize motion efficiency during acceleration sprint phase. Eighteen girls involved in team sports were examined in the study. The Fusion Smart Speed System was employed for running time measurements. The kinematic data were recorded using the Noraxon MyoMotion system. Statistically significant relationships were found between running time over a 10-meter section and the kinematic variables of hip and ankle joints. An excessively large flexion in hip joints might have an unfavorable effect on running time during the acceleration phase. Furthermore, in order to minimize running time during the acceleration phase, stride should be maintained along a line (a straight line rather than from side to side. It is also necessary to ensure an adequate range of motion in the hip and ankle joints with respect to the sagittal axis.

  2. Enzyme adaptations of human skeletal muscle during bicycle short-sprint training and detraining.

    Science.gov (United States)

    Linossier, M T; Dormois, D; Perier, C; Frey, J; Geyssant, A; Denis, C

    1997-12-01

    The effect of sprint training and detraining on supramaximal performances was studied in relation to muscle enzyme adaptations in eight students trained four times a week for 9 weeks on a cycle ergometer. The subjects were tested for peak oxygen uptake (VO2peak), maximal aerobic power (MAP) and maximal short-term power output (Wmax) before and after training and after 7 weeks of detraining. During these periods, biopsies were taken from vastus lateralis muscle for the determination of creatine kinase (CK), adenylate kinase (AK), glycogen phosphorylase (PHOS), hexokinase (HK), phosphofructokinase (PFK), lactate dehydrogenase (LDH) and its isozymes, 3-hydroxy-acyl-CoA dehydrogenase (HAD) and citrate synthase (CS) activities. Training induced large improvements in Wmax (28%) with slight increases (3%) in VO2peak (P power output as a result of a muscle glycogenolytic and glycolytic adaptation. A long interruption in training has negligible effects on short-sprint ability and muscle anaerobic potential. On the other hand, a persistent training stimulus is required to maintain high aerobic capacity and muscle oxidative potential. This may contribute to a rapid return to competitive fitness for sprinters and power athletes.

  3. 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.

  4. Data Sprints: A Collaborative Format in Digital Controversy Mapping

    DEFF Research Database (Denmark)

    Munk, Anders Kristian; Tommaso, Venturini; Meunier, Axel

    2017-01-01

    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...

  5. Reliability of power output during eccentric sprint cycling.

    Science.gov (United States)

    Brughelli, Matt; Van Leemputte, Marc

    2013-01-01

    The purpose of this study was to determine the reliability of power outputs during maximal intensity eccentric cycling over short durations (i.e., eccentric sprint cycling) on a "motor-driven" isokinetic ergometer. Fourteen physically active male subjects performed isokinetic eccentric cycling sprints at 40, 60, 80, 100, and 120 revolutions per minute (rpm) on 4 separate occasions (T1-T4). Each sprint lasted for 6 seconds, and absolute measures of mean power (MP) and peak power (PP) per revolution were recorded. Significant increases in MP and PP were observed between T1 and subsequent trials, but no significant differences were identified between T2, T3, and T4. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated to reflect within-subject and between-session reliability of MP and PP at each cadence. The CV improved to below 10% for cadences of 60, 80, 100, and 120 rpm between T3 and T4, and the majority of ICC values improved to above 0.90. The remaining ICC values remained in the moderate range between T3 and T4 (i.e., 0.82-0.89). Coefficient of variation and ICC values for the 40 rpm cadence remained at unacceptable levels throughout the 4 trials and thus should be avoided in future investigations. The results of this study indicate that reliable power outputs may be obtained after 2 familiarization sessions during eccentric sprint cycling at cadences ranging from 60 to 120 rpm.

  6. Evolution of the ID Process at Sprint: A Practitioner's Perspective.

    Science.gov (United States)

    Beard, Michael W.

    1999-01-01

    Provides instructional developers' (ID) insights and observations based on the experiences of a training and development organization, Sprint's University of Excellence (UE), as it evolved from a small group of 20-25 individuals in 1990 to a large business unit comprising almost 400 individuals in 1999. Discussion includes course development…

  7. Effects of active vs. passive recovery on repeated rugby-specific exercises.

    Science.gov (United States)

    Jougla, A; Micallef, J P; Mottet, D

    2010-05-01

    The aim of this study was to determine the effects of active vs. passive recovery on performance of a rugby-specific intermittent test in rugby union players. Seven male rugby players (20.6+/-0.5 yrs; 181.9+/-10.0 cm; 94.5+/-12.8 kg) performed in random order, over two separate sessions, a specific repeated-sprint rugby test, the Narbonne test (6 x 4 consecutive actions: 1, scrummaging; 2, agility sprinting; 3, tackling; 4, straight sprinting) with 30s of passive or active recovery (running at 50% of maximal aerobic speed). The Narbonne tests were completed before (pre-test) and after (post-test) a 30-min rugby match. During the Narbonne test, scrum forces, agility and sprint times, heart rate and rate of perceived exertion were measured. Scrum forces were lower in active (74.9+/-13.4 kg) than in passive recovery (90.4+/-20.9 kg), only during the post-test (p<0.05). Fatigue index (%) (p<0.05) and total sprint time (s) (p<0.01) were significantly greater in active than in passive recovery, both during the pre-test (11.5+/-5.7% vs. 6.7+/-4.5% and 18.1+/-1.3s vs. 16.9+/-0.9s) and the post-test (7.3+/-3.3% vs. 4.3+/-1.5% and 18.3+/-1.6s vs. 16.9+/-1.1s). Consequently, the results indicated that passive recovery enabled better performance during the Narbonne test. However, it is obviously impractical to suggest that players should stand still during and following repeated-sprint bouts: the players have to move to ensure they have taken an optimal position.

  8. Sprint running performance: comparison between treadmill and field conditions.

    Science.gov (United States)

    Morin, Jean-Benoît; Sève, Pierrick

    2011-08-01

    We investigated the differences in performance between 100-m sprints performed on a sprint treadmill recently validated versus on a standard track. To date, studies comparing overground and treadmill running have mainly focused on constant and not maximal "free" running speed, and compared running kinetics and kinematics over a limited number of steps, but not overall sprint performance. Eleven male physical education students including two sprinters performed one 100-m on the treadmill and one on a standard athletics track in a randomized order, separated by 30 min. Performance data were derived in both cases from speed-time relationships measured with a radar and with the instrumented sprint treadmill, which allowed subjects to run and produce speed "freely", i.e. with no predetermined belt speed imposed. Field and treadmill typical speed-distance curves and data of maximal and mean speed, 100-m time and acceleration/deceleration time constants were compared using t tests and field-treadmill correlations were tested. All the performance parameters but time to reach top speed and deceleration time constant differed significantly, by about 20% on average, between field and treadmill (e.g. top speed of 8.84 ± 0.51 vs. 6.90 ± 0.39 m s(-1)). However, significant correlations were found (r > 0.63; P 100-m sprint performances are different, despite the fact that subjects could freely accelerate the belt. However, the significant correlations found make it possible to investigate and interpret inter-individual differences in field performance from treadmill measurements.

  9. ASSESSMENT OF LINEAR SPRINTING PERFORMANCE: A THEORETICAL PARADIGM

    Directory of Open Access Journals (Sweden)

    Jaci L. VanHeest

    2004-12-01

    Full Text Available The purpose of this manuscript is to describe a theoretical paradigm from which to more accurately assess linear sprinting performance. More importantly, the model describes how to interpret test results in order to pinpoint weaknesses in linear sprinting performance and design subsequent training programs. A retrospective, quasi-experimental cross sectional analysis was performed using 86 Division I female soccer and lacrosse players. Linear sprinting performance was assessed using infrared sensors at 9.14, 18.28, 27.42, and 36.58 meter distances. Cumulative (9.14, 18.28, 27.42, and 36.58 meter and individual (1st, 2nd, 3rd, and 4th 9.14 meter split times were used to illustrate the theoretical paradigm. Sub-groups were identified from the sample and labelled as above average (faster, average, and below average (slower. Statistical analysis showed each sub-group was significantly different from each other (fast < average < slow. From each sub-group select individuals were identified by having a 36.58 meter time within 0.05 seconds of each other (n = 11, 13, and 7, respectively. Three phases of the sprint test were suggested to exist and called initial acceleration (0-9.14 m, middle acceleration (9.14-27.42 m, and metabolic-stiffness transition (27.42-36.58 m. A new model for assessing and interpreting linear sprinting performance was developed. Implementation of this paradigm should assist sport performance professionals identify weaknesses, minimize training errors, and maximize training adaptations.

  10. Scapula behavior associates with fast sprinting in first accelerated running.

    Science.gov (United States)

    Otsuka, Mitsuo; Ito, Taisuke; Honjo, Toyoyuki; Isaka, Tadao

    2016-01-01

    The arm-swing motion is important for coordinated lower limb movement during a fast sprint and is composed of three-dimensional scapulothoracic and glenohumeral joint motion. Here, we aimed to clarify the role of the scapula during the initiation of a sprint running when sprinter run with high horizontal acceleration. Ten sports-active students participated in four 5-m dashes, with scapular constraint using non-elastic therapy tape (constraint condition) and without scapular constraint (free condition). The sprinting kinematics was assessed by a 16-camera motion capture system. In the constraint condition, the 2-m sprint time was significantly longer than that in the free condition. At the instants of foot-contact and take-off during the first step, no significant difference in the humerothoracic flexion angle was seen between these two conditions. In contrast, at the instants of foot-contact and take-off during the first step, the humerothoracic extension angle in the constraint condition was significantly smaller than that in the free condition. The forward leaning vector angle of center of mass during the first step was significantly greater than that in the constraint condition. Although no significant difference in hip extension and foot forward leaning angles was seen at the instant of foot contact during the first step between the two conditions, at the instant of take-off, the hip extension and foot forward leaning angles in the constraint condition were significantly smaller than those in the free condition. Therefore, scapular behavior in first accelerated running contributes to larger upper- and lower-limb motions and facilitates coordinating whole-body balance for a fast sprint.

  11. Association of sprint performance with ground reaction forces during acceleration and maximal speed phases in a single sprint.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2017-09-27

    We aimed to clarify the mechanical determinants of sprinting performance during acceleration and maximal speed phases of a single sprint, using ground reaction forces (GRFs). While 18 male athletes performed a 60-m sprint, GRF was measured at every step over a 50-m distance from the start. Variables during the entire acceleration phase were approximated with a fourth-order polynomial. Subsequently, accelerations at 55%, 65%, 75%, 85%, and 95% of maximal speed, and running speed during the maximal speed phase were determined as sprinting performance variables. Ground reaction impulses and mean GRFs during the acceleration and maximal speed phases were selected as independent variables. Stepwise multiple regression analysis selected propulsive and braking impulses as contributors to acceleration at 55%-95% (β > 0.724) and 75%-95% (β > 0.176), respectively, of maximal speed. Moreover, mean vertical force was a contributor to maximal running speed (β = 0.481). The current results demonstrate that exerting a large propulsive force during the entire acceleration phase, suppressing braking force when approaching maximal speed, and producing a large vertical force during the maximal speed phase are essential for achieving greater acceleration and maintaining higher maximal speed, respectively.

  12. Systolic Blood Pressure Intervention Trial (SPRINT) and Target Systolic Blood Pressure in Future Hypertension Guidelines.

    Science.gov (United States)

    Egan, Brent M; Li, Jiexiang; Wagner, C Shaun

    2016-08-01

    The Systolic Blood Pressure (SBP, mm Hg) Intervention Trial (SPRINT) showed that targeting SBP SPRINT has 2 implicit assumptions that could impact future US hypertension guidelines: (1) standard therapy controlled SBP similarly to that in adults with treated hypertension and (2) intensive therapy produced a lower mean SBP than in adults with treated hypertension and SBP SPRINT-like participants aged ≥50 years; group 2 consisted of participants all aged ≥18 years; and group 3 consisted of participants aged ≥18 years excluding group 1 but otherwise similar to SPRINT-like participants except high cardiovascular risk. Mean SBPs in groups 1, 2, and 3 were 133.0, 130.1, and 124.6, with 66.2%, 72.2%, and 81.9%, respectively, controlled to SBP SPRINT-like group had higher mean SBP than comparison groups, yet lower than SPRINT standard treatment group and (2) among groups 1 to 3 with SBP SPRINT intensive treatment. SPRINT results suggest that treatment should be continued and not reduced when treated SBP is SPRINT-like subset. Furthermore, increasing the percentage of treated adults with SBP SPRINT intensive treatment SBP without lowering treatment goals.

  13. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  14. Effect of short burst activities on sprint and agility performance in 11- to 12-year-old boys.

    Science.gov (United States)

    Pettersen, Svein A; Mathisen, Gunnar E

    2012-04-01

    There are limited data on how coordinative sprint drills and maximal short burst activities affects children's sprint and agility performance. The purpose of the present study was to investigate the effect of short burst activities on sprint and agility performance in 11- to 12-year-old boys. A training group (TG) of 14 boys followed a 6-week, 1-hour·week(-1), training program consisting of different short burst competitive sprinting activities. Eleven boys of similar age served as controls (control group [CG]). Pre- and posttests assessed 10-m sprint, 20-m sprint, and agility performance. Results revealed significant performance improvement in all tests within TG (p sprint test. Furthermore, the relationships between the performances in straight-line sprint and agility showed a significant transfer effect (r = 0.68-0.75, p sprint and agility performance in 11- to 12-year-old boys.

  15. Efecto agudo del estiramiento sobre el sprint en jugadores de fútbol de división de honor juvenil. (Acute effect of stretching on sprint in honour division soccer players.

    Directory of Open Access Journals (Sweden)

    Pilar Sainz de Baranda Andújar

    2010-01-01

    Full Text Available ResumenSe valoró el efecto agudo del estiramiento sobre el rendimiento en la flexión máxima de tronco y sprint de 10 y 30 metros en jugadores de fútbol de división de honor. Se realizó un estudio aleatorio controlado de medidas repetidas, en el que participaron 28 varones jugadores de fútbol (edad 17,6 ± 0,8 años; peso 71,96 ± 7,9 kg; talla 177,66 ± 5,85 cm. Todos los sujetos fueron aleatoriamente distribuidos en 3 grupos: estiramientos estáticos-pasivos (n=9, estiramientos estáticos-activos (n=11 y estiramientos dinámicos (n=8. Todos los grupos realizaron un calentamiento estándar de 10 minutos de carrera, seguido de la valoración de la flexión máxima de tronco y del tiempo en el sprint de 10 y 30 metros parado y lanzado. Estas pruebas de valoración fueron repetidas después de que cada sujeto completase la rutina de estiramientos que previamente le fue asignada. Todos los grupos consiguieron un aumento de la distancia alcanzada en la flexión de tronco (p menor que 0.05, sin embargo, tan solo el grupo de estiramientos dinámicos no mostró un descenso en el rendimiento del sprint en cualquiera de sus variantes analizadas (p menor que 0.05. Por ello se recomienda la realización de estiramientos dinámicos como parte fundamental del calentamiento previo a una actuación deportiva.AbstractThe acute effect of stretching on maximum trunk flexion and 10 and 30 meters sprint performances was measured in honour division soccer players. A random controlled repeated measures design was used and 28 honour division soccer players participated in this study (age 17,6 ± 0,8 years; weight 71,96 ± 7,9 kg; height 177,66 ± 5,85 cm. All subjects were assigned randomly to 3 groups: passive static stretch (n=9, active-static stretch (n=11 and dynamic stretch (n=8. All groups performed a standard 10 minute jog warm-up, followed by maximum trunk flexion and stationary and flying 10 and 30 meters sprint time measurements. These measurement

  16. Energy and macronutrient intake in adolescent sprint athletes: a follow-up study.

    Science.gov (United States)

    Aerenhouts, Dirk; Deriemaeker, Peter; Hebbelinck, Marcel; Clarys, Peter

    2011-01-01

    Macronutrient intake, height, weight, and body composition of 60 adolescent sprint athletes were estimated every 6 months over 3 years. Seven-day food records were analysed based on the Belgian and Dutch food databanks. The age of participants at the start of the 3-year study was 14.8 ± 1.6 years for female athletes and 14.7 ± 1.9 years for male athletes. Girls and boys gained height (3.4 ± 4.6 cm and 5.9 ± 6.6 cm respectively) and weight (5.6 ± 3.5 kg and 8.7 ± 5.5 kg respectively), whereas percent body fat remained unchanged in both girls and boys (around 17.0% and 8.5% respectively). Mean protein intake of around 1.5 g · kg⁻¹ body weight was within recommendations on each occasion for both sexes. Carbohydrate intakes between 5 and 7 g · kg⁻¹ body weight support a training programme of moderate intensity. Total and saturated fat intakes were high at the start of the study (girls: 31.8 ± 3.5% and 12.2 ± 2.0% of energy intake; boys: 30.3 ± 4.6% and 12.0 ± 1.9% of energy intake) and it appeared to be difficult to achieve and maintain lower intakes. Consistent low fluid intakes around 40 ml · kg⁻¹ body weight were observed. General non-stringent advice for improvement of the diet resulted in significant favourable changes only for the consumption of wholegrain bread, vegetables, and soft drinks. Dietary habits of adolescent sprint athletes are not always according to guidelines and are relatively stable but repeated advice can induce moderate improvements.

  17. Caffeine-containing energy drink improves sprint performance during an international rugby sevens competition.

    Science.gov (United States)

    Del Coso, Juan; Portillo, Javier; Muñoz, Gloria; Abián-Vicén, Javier; Gonzalez-Millán, Cristina; Muñoz-Guerra, Jesús

    2013-06-01

    The aim of this study was to determine the effects of a caffeine-containing energy drink on physical performance during a rugby sevens competition. A second purpose was to investigate the post-competition urinary caffeine concentration derived from the energy drink intake. On two non-consecutive days of a friendly tournament, 16 women from the Spanish National rugby sevens Team (mean age and body mass = 23 ± 2 years and 66 ± 7 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink (Fure(®), ProEnergetics) or the same drink without caffeine (placebo). After 60 min for caffeine absorption, participants performed a 15-s maximal jump test, a 6 × 30 m sprint test, and then played three rugby sevens games against another national team. Individual running pace and instantaneous speed during the games were assessed using global positioning satellite (GPS) devices. Urine samples were obtained pre and post-competition. In comparison to the placebo, the ingestion of the energy drink increased muscle power output during the jump series (23.5 ± 10.1 vs. 25.6 ± 11.8 kW, P = 0.05), running pace during the games (87.5 ± 8.3 vs. 95.4 ± 12.7 m/min, P energy drink did not affect maximal running speed during the repeated sprint test (25.0 ± 1.5 vs. 25.0 ± 1.7 km/h). The ingestion of the energy drink resulted in a higher post-competition urine caffeine concentration than the placebo (3.3 ± 0.7 vs. 0.2 ± 0.1 μg/mL; P energy drink considerably enhanced physical performance during a women's rugby sevens competition.

  18. Effects of acute sprint interval cycling and energy replacement on postprandial lipemia.

    Science.gov (United States)

    Freese, Eric C; Levine, Ari S; Chapman, Donald P; Hausman, Dorothy B; Cureton, Kirk J

    2011-12-01

    High postprandial blood triglyceride (TG) levels increase cardiovascular disease risk. Exercise interventions may be effective in reducing postprandial blood TG. The purpose of this study was to determine the effects of sprint interval cycling (SIC), with and without replacement of the energy deficit, on postprandial lipemia. In a repeated-measures crossover design, six men and six women participated in three trials, each taking place over 2 days. On the evening of the first day of each trial, the participants either did SIC without replacing the energy deficit (Ex-Def), did SIC and replaced the energy deficit (Ex-Bal), or did not exercise (control). SIC was performed on a cycle ergometer and involved four 30-s all-out sprints with 4-min active recovery. In the morning of day 2, responses to a high-fat meal were measured. Venous blood samples were collected in the fasted state and at 0, 30, 60, 120, and 180 min postprandial. There was a trend toward a reduction with treatment in fasting TG (P = 0.068), but no significant treatment effect for fasting insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate (P > 0.05). The postprandial area under the curve (mmol·l(-1)·3 h(-1)) TG response was significantly lower in Ex-Def (21%, P = 0.006) and Ex-Bal (10%, P = 0.044) than in control, and significantly lower in Ex-Def (12%, P = 0.032) than in Ex-Bal. There was no treatment effect (P > 0.05) observed for area under the curve responses of insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate. SIC reduces postprandial lipemia, but the energy deficit alone does not fully explain the decrease observed.

  19. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test

    OpenAIRE

    Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

    2016-01-01

    Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer...

  20. Estimating Body Composition in Adolescent Sprint Athletes: Comparison of Different Methods in a 3 Years Longitudinal Design

    Science.gov (United States)

    Aerenhouts, Dirk

    2015-01-01

    A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 ± 1.5yrs in girls and 14.7 ± 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation. PMID:26317426

  1. Effect of Carbohydrate Ingestion on Sprint Performance Following Continuous Exercise

    Science.gov (United States)

    Siahkohian, M.; Farhadi, H.; Naghizadeh Baghi, A.; Valizadeh, A.

    The purpose of this study was to determine the effect of 5% carbohydrate ingestion on the sprint performance immediately following 90 min of running at 70-80% of maximal heart rate reserve. Thirty young active men were selected as subjects and allocated randomly to two carbohydrate (CHO, N = 15) and placebo (PL, N = 15) groups. Pre-test 200 m dash, 90 min running and post-test 200 m dash took place, respectively. Exercise heart rate monitored during 90 min running by a cardio frequency meter. Significant differences were found between the CHO and PL post-test 200 m dash records (pBlood glucose was found to be significantly higher at the end of the 90 min running for the CHO group than for the PL group (pexercise inhibits failing of Sprint performance of young active men.

  2. Data Sprints: A Collaborative Format in Digital Controversy Mapping

    DEFF Research Database (Denmark)

    Munk, Anders Kristian; Tommaso, Venturini; Meunier, Axel

    2017-01-01

    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...... 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...

  3. Effect of starting stance on initial sprint performance.

    Science.gov (United States)

    Cronin, John B; Green, Jonathon P; Levin, Gregory T; Brughelli, Matt E; Frost, David M

    2007-08-01

    The effect of different starting stances from a standing position on short sprint times and the subsequent variability in times was investigated in this study. A dual-beam timing light system was used to measure 5- and 10-m times for 3 different standing starts commonly found in the sporting environment: parallel (feet parallel to the start line), split (lead left foot on start line, right leg back), and false (initial parallel start, right leg drops back to split start when movement initiated). The parallel start was found to be significantly (alpha men and women. The split and false start seem to offer the best option as a movement strategy for minimizing short-distance sprint times. However, the benefits of these 2 starts are less clear if total movement time is the variable of interest.

  4. Sprint Nextel的4G战略——WiMAX

    Institute of Scientific and Technical Information of China (English)

    山石

    2006-01-01

    Sprint Nextel最近宣布将把移动WiMAX技术作为4G无线技术,并投入30亿美元。而实际上,作为2.5GHzMMDS频段的最大拥有者,Sprint公司在上世纪90年代已经推出了无线宽带业务。Sprint Nextel此次携手Intel、摩托罗拉和三星电子的目的不单单是为了在全国的范围内建设一张移动WiMAX网络,也是为了通过对个人多媒体移动业务的支持来推动移动WiMAX产业的发展和创新。

  5. URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    I. Bezrati-Benayed

    2014-07-01

    Full Text Available Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC was significantly lower in sprinters than controls (34±30 vs. 74±3 μmol/mmol creatinine, p<0.05. UC was inversely correlated with body mass (r=-0.34, p<0.01 and lean mass (r=- 0.30, p<0.05, and positively correlated with fat mass (r=0.32, p<0.05. After acute exercise, urinary creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes.

  6. Urinary creatine at rest and after repeated sprints in athletes: a pilot study.

    Science.gov (United States)

    Bezrati-Benayed, I; Nasrallah, F; Feki, M; Chamari, K; Omar, S; Alouane-Trabelsi, L; Ben Mansour, A; Kaabachi, N

    2014-03-01

    Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC) was significantly lower in sprinters than controls (34±30 vs. 74±3 µmol/mmol creatinine, p sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes.

  7. Genes for elite power and sprint performance: ACTN3 leads the way.

    Science.gov (United States)

    Eynon, Nir; Hanson, Erik D; Lucia, Alejandro; Houweling, Peter J; Garton, Fleur; North, Kathryn N; Bishop, David J

    2013-09-01

    The ability of skeletal muscles to produce force at a high velocity, which is crucial for success in power and sprint performance, is strongly influenced by genetics and without the appropriate genetic make-up, an individual reduces his/her chances of becoming an exceptional power or sprinter athlete. Several genetic variants (i.e. polymorphisms) have been associated with elite power and sprint performance in the last few years and the current paradigm is that elite performance is a polygenic trait, with minor contributions of each variant to the unique athletic phenotype. The purpose of this review is to summarize the specific knowledge in the field of genetics and elite power performance, and to provide some future directions for research in this field. Of the polymorphisms associated with elite power and sprint performance, the α-actinin-3 R577X polymorphism provides the most consistent results. ACTN3 is the only gene that shows a genotype and performance association across multiple cohorts of elite power athletes, and this association is strongly supported by mechanistic data from an Actn3 knockout mouse model. The angiotensin-1 converting enzyme insertion/deletion polymorphism (ACE I/D, registered single nucleotide polymorphism [rs]4646994), angiotensinogen (AGT Met235Thr rs699), skeletal adenosine monophosphate deaminase (AMPD1) Gln(Q)12Ter(X) [also termed C34T, rs17602729], interleukin-6 (IL-6 -174 G/C, rs1800795), endothelial nitric oxide synthase 3 (NOS3 -786 T/C, rs2070744; and Glu298Asp, rs1799983), peroxisome proliferator-activated receptor-α (PPARA Intron 7 G/C, rs4253778), and mitochondrial uncoupling protein 2 (UCP2 Ala55Val, rs660339) polymorphisms have also been associated with elite power performance, but the findings are less consistent. In general, research into the genetics of athletic performance is limited by a small sample size in individual studies and the heterogeneity of study samples, often including athletes from multiple

  8. Physical Demands of Sprinting in Professional Road Cycling.

    Science.gov (United States)

    Menaspà, P; Quod, M; Martin, D T; Peiffer, J J; Abbiss, C R

    2015-11-01

    The aim of this study was to quantify the demands of road competitions ending with sprints in male professional cycling. 17 races finished with top-5 results from 6 male road professional cyclists (age, 27.0±3.8 years; height, 1.76±0.03 m; weight, 71.7±1.1 kg) were analysed. SRM power meters were used to monitor power output, cadence and speed. Data were averaged over the entire race, different durations prior to the sprint (60, 10, 5 and 1 min) and during the actual sprint. Variations in power during the final 10 min of the race were quantified using exposure variation analysis. This observational study was conducted in the field to maximize the ecological validity of the results. Power, cadence and speed were statistically different between various phases of the race (proad cycling and highlight the need for both aerobic and anaerobic fitness.

  9. The Effects of Resisted Training Using Parachuteon Sprint Performance

    Directory of Open Access Journals (Sweden)

    KLIMENTINI MARTINOPOULOU

    2011-01-01

    Full Text Available The purpose of this study was to examine the effects of resisted and unresisted sprint training programmes (STP on acceleration and maximum speed performance. Sixteen sprint athletes divided into two groups (resisted group-RG and unresisted group-UG, n=8 each, age 25±4y, height 172±0.8 cm and weight 61.5±10.6kg. RG followed the STP towing a large size parachute and the UG followed a STP without resistance. Stride length (SL, stride frequency (SF, contact time (CT and flight time (FT were also evaluated. The results showed that the RG improved running velocity (RV in all sections of acceleration phase (AP, while the UG in the run section 0-20m. A comparison between groups indicated that RV was significantly higher during run section 0-20m in the RG compared to the UG. For the maximum speed phase the resisted STP improved the RV in the 40-50m run section and the maximum speed between 40-47m, while un-resisted STP had no effect in any runsection. SL increased after resisted and un-resisted STP in AP, whereas SF increased only after resisted STP in maximum speed phase. It is concluded that resisted STP with large size parachute significantly improves RV during AP by increasing SL and during maximum speed phase by increasing SF in sprint athletes.

  10. 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.

  11. Changes in muscle coordination and power output during sprint cycling.

    Science.gov (United States)

    O'Bryan, Steven J; Brown, Nicholas A T; Billaut, François; Rouffet, David M

    2014-07-25

    This study investigated the changes in muscle coordination associated to power output decrease during a 30-s isokinetic (120rpm) cycling sprint. Modifications in EMG amplitude and onset/offset were investigated from eight muscles [gluteus maximus (EMGGMAX), vastus lateralis and medialis obliquus (EMGVAS), medial and lateral gastrocnemius (EMGGAS), rectus femoris (EMGRF), biceps femoris and semitendinosus (EMGHAM)]. Changes in co-activation of four muscle pairs (CAIGMAX/GAS, CAIVAS/GAS, CAIVAS/HAM and CAIGMAX/RF) were also calculated. Substantial power reduction (60±6%) was accompanied by a decrease in EMG amplitude for all muscles other than HAM, with the greatest deficit identified for EMGRF (31±16%) and EMGGAS (20±14%). GASonset, HAMonset and GMAXonset shifted later in the pedalling cycle and the EMG offsets of all muscles (except GASoffset) shifted earlier as the sprint progressed (Ppower reduction during fatiguing sprint cycling is accompanied by marked reductions in the EMG activity of bi-articular GAS and RF and co-activation level between GAS and main power producer muscles (GMAX and VAS). The observed changes in RF and GAS EMG activity are likely to result in a redistribution of the joint powers and alterations in the orientation of the pedal forces. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Morphological characteristics of Olympic sprint canoe and kayak paddlers.

    Science.gov (United States)

    Ackland, T R; Ong, K B; Kerr, D A; Ridge, B

    2003-09-01

    Canoe and kayak paddlers (n = 50 M & 20 F) who competed in the sprint events at the 2000 Olympic Games in Sydney were measured on a battery of 38 anthropometry dimensions prior to competition. The ensuing analysis aimed to identify common physical characteristics that provide these elite paddlers with a competitive advantage. This study demonstrated that participants in Olympic sprint paddling events can be considered homogeneous in shape and physical size; male and female paddlers have SAMs of 1.1 and 1.0 respectively. Compared to other athlete groups, the variance in stature and body mass of paddlers is generally low. Whilst sprint paddlers are not athletes with extreme proportionality profiles, they do possess unique characteristics not commonly observed in the general population. These include a lean body composition (Phantom z-scores for skinfolds range from -1.5 to -2.5 for most sites) with proportionally large upper body girths (z-scores > +1.0 for arm and chest girths), and narrow hips (for males). The morphology of elite paddlers appears to have altered during the past 25 years toward a more compact, robust physique. This trend is especially noticeable for the female competitors.

  13. An observational model for biomechanical assessment of sprint kayaking technique.

    Science.gov (United States)

    McDonnell, Lisa K; Hume, Patria A; Nolte, Volker

    2012-11-01

    Sprint kayaking stroke phase descriptions for biomechanical analysis of technique vary among kayaking literature, with inconsistencies not conducive for the advancement of biomechanics applied service or research. We aimed to provide a consistent basis for the categorisation and analysis of sprint kayak technique by proposing a clear observational model. Electronic databases were searched using key words kayak, sprint, technique, and biomechanics, with 20 sources reviewed. Nine phase-defining positions were identified within the kayak literature and were divided into three distinct types based on how positions were defined: water-contact-defined positions, paddle-shaft-defined positions, and body-defined positions. Videos of elite paddlers from multiple camera views were reviewed to determine the visibility of positions used to define phases. The water-contact-defined positions of catch, immersion, extraction, and release were visible from multiple camera views, therefore were suitable for practical use by coaches and researchers. Using these positions, phases and sub-phases were created for a new observational model. We recommend that kayaking data should be reported using single strokes and described using two phases: water and aerial. For more detailed analysis without disrupting the basic two-phase model, a four-sub-phase model consisting of entry, pull, exit, and aerial sub-phases should be used.

  14. Creatine supplementation does not improve sprint performance in competitive swimmers.

    Science.gov (United States)

    Mujika, I; Chatard, J C; Lacoste, L; Barale, F; Geyssant, A

    1996-11-01

    This study was conducted to examine the effects of creatine (Cr) supplementation on sprint swimming performance and energy metabolism. Twenty highly trained swimmers (9 female, 11 male) were tested for blood ammonia and for blood lactate after the 25-, 50-, and 100-m performance in their best stroke on two occasions 7 d apart. After the first trial, subjects were evenly and randomly assigned to either a creatine (5 g creatine monohydrate 4 times per day for 5 d) or a placebo group (same dosage of a lactose placebo) in a double-blind research design. No significant differences in performance times were observed between trials. Post-exercise blood ammonia concentration decreased in the 50- and 100-m trials in the creatine group and in the 50-m trial in the placebo group. The supplementation period had no effect on post-exercise blood lactate. Therefore, creatine supplementation cannot be considered as an ergogenic aid for sprint performance in highly trained swimmers although adenine nucleotide degradation may be reduced during sprint exercise after 5 d of creatine ingestion.

  15. Sprinting performance and resistance-based training interventions: a systematic review.

    Science.gov (United States)

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

    2015-04-01

    The purpose of this systematic review was to search the scientific literature for original research, addressing the effects different forms of resistance-based training have on sprinting performance in competitive sprinters. Specific key words (Sprinters OR Sprint) NOT (Rugby, Soccer, Cycling, Swimming, Paralympic, and Nutrition) were used to search relevant databases through November 2013 for related literature. Original research was reviewed using the Physiotherapy Evidence Database scale. Five studies met the inclusion criteria: actively competitive adult male sprinters who participated in a resistance-based intervention (>4 weeks), with outcome measures in the form of 10- to 100-m sprint times. Exclusion criteria included acute studies (100-m sprint times). Three of the 5 studies used both locomotor resistance and fixed plane resistance, whereas the remaining 2 studies used more fixed plane resistance, for example, squat and leg extension. Three of the studies showed a statistical improvement in sprinting performance measures, for example, a decrease in 30-m sprint time (p = 0.044), whereas 1 study showed a decrease in sprinting performance. The analysis concluded that resistance-based training has a positive effect on sprinting performance. Varied input of locomotor resistance and fixed plane resistance has resulted in similar percentage change for sprinting performance. This review adds to the body of knowledge by strongly highlighting the dearth of literature exploring the effects of resistance-based training on sprinting performance in competitive sprinters. The short duration and wide range of exercises implemented in studies to date are of concern, but coaches should not hesitate to implement well-planned resistance programs for their sprint athletes.

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

    Directory of Open Access Journals (Sweden)

    Emma Harris

    Full Text Available INTRODUCTION: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.

  17. Repeated high-intensity exercise in professional rugby union.

    Science.gov (United States)

    Austin, Damien; Gabbett, Tim; Jenkins, David

    2011-07-01

    The aim of the present study was to describe the frequency, duration, and nature of repeated high-intensity exercise in Super 14 rugby union. Time-motion analysis was used during seven competition matches over the 2008 and 2009 Super 14 seasons; five players from each of four positional groups (front row forwards, back row forwards, inside backs, and outside backs) were assessed (20 players in total). A repeated high-intensity exercise bout was considered to involve three or more sprints, and/or tackles and/or scrum/ruck/maul activities within 21 s during the same passage of play. The range of repeated high-intensity exercise bouts for each group in a match was as follows: 11-18 for front row forwards, 11-21 for back row forwards, 13-18 for inside backs, and 2-11 for outside backs. The durations of the most intense repeated high-intensity exercise bouts for each position ranged from 53 s to 165 s and the minimum recovery periods between repeated high-intensity exercise bouts ranged from 25 s for the back row forwards to 64 s for the front row forwards. The present results show that repeated high-intensity exercise bouts vary in duration and activities relative to position but all players in a game will average at least 10 changes in activity in the most demanding bouts and complete at least one tackle and two sprints. The most intense periods of activity are likely to last as long as 120 s and as little as 25 s recovery may separate consecutive repeated high-intensity exercise bouts. The present findings can be used by coaches to prepare their players for the most demanding passages of play likely to be experienced in elite rugby union.

  18. Evaluation of the reliability of two field hockey specific sprint and dribble tests in young field hockey players

    NARCIS (Netherlands)

    Lemmink, K.A.; Elferink-Gemser, M.T.; Visscher, C.

    2004-01-01

    OBJECTIVES: To determine the reliability of two field hockey specific tests: the shuttle sprint and dribble test (ShuttleSDT) and the slalom sprint and dribble test (SlalomSDT). METHODS: The shuttle sprint and dribble performances of 22 young male and 12 young female field hockey players were

  19. 78 FR 76097 - Request for Comment on Petition Filed by Sprint Corporation for Reconsideration of Certain Rules...

    Science.gov (United States)

    2013-12-16

    ... CTS Reform Order, published at 78 FR 53684, August 30, 2013, and codified at 47 CFR 64.604(c)(9), (11... COMMISSION 47 CFR Part 64 Request for Comment on Petition Filed by Sprint Corporation for Reconsideration of... Commission seeks comment on a Sprint Corporation (Sprint) petition requesting reconsideration of...

  20. Evaluation of the reliability of two field hockey specific sprint and dribble tests in young field hockey players

    NARCIS (Netherlands)

    Lemmink, K.A.; Elferink-Gemser, M.T.; Visscher, C.

    2004-01-01

    OBJECTIVES: To determine the reliability of two field hockey specific tests: the shuttle sprint and dribble test (ShuttleSDT) and the slalom sprint and dribble test (SlalomSDT). METHODS: The shuttle sprint and dribble performances of 22 young male and 12 young female field hockey players were assess

  1. 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…

  2. 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

    1991-01-01

    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

  3. Reference values for the sprint performance in male football players aged from 9–35 years

    Directory of Open Access Journals (Sweden)

    Nikolaidis Pantelis Theodoros

    2016-07-01

    Full Text Available Study aim: The aim of the present study was twofold: firstly, to examine the effect of age on a 20 m sprint performance; and secondly, to establish normative data for the 20 m sprint performance by age in football players.

  4. Modeling Longitudinal Changes in 5m Sprinting Performance Among Young Male Tennis Players

    NARCIS (Netherlands)

    Kramer, Tamara; Valente-Dos-Santos, Joao; Coelho-E-Silva, Manuel J.; Malina, Robert M.; Huijgen, Barbara C. H.; Smith, Joanne; Elferink-Gemser, Marije T.; Visscher, Chris

    2016-01-01

    Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players

  5. 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

    1991-01-01

    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

  6. Separate and combined influence of posture and sprint running on plasma volume changes.

    Science.gov (United States)

    Tsampoukos, Antonios; Stokes, Keith; Nevill, Mary

    2014-01-01

    It is currently unknown whether any changes in plasma volume (PV) after sprint running are inherent to sprint running per se or are due to other confounding factors such as changes in posture. The purpose of the present study was to examine the independent effects of sprint running on PV changes. Eight females completed two trials on separate days: (1) a 30-s sprint on a non-motorised treadmill and (2) a control trial where no exercise was undertaken but blood samples were taken at identical time points as in the exercise trial. Changes in PV were calculated using haematocrit and haemoglobin. Post-sprint PV reductions were greater in the sprint than the control trial (mean: -17.7, SD=3.1% vs. mean: -7.5, s = 4.9, Psprint than the control trial in most sampling points. These data show that sprint running of only 30 s induces transient reductions in PV independently of posture change. The present findings suggest that PV changes due to sprint running should be routinely reported as well as the posture and the exact time in this posture.

  7. 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…

  8. Force-Time Characteristics and Running Velocity of Male Sprinters During the Acceleration Phase of Sprinting.

    Science.gov (United States)

    Mero, Antti

    1988-01-01

    Investigation of the force-time characteristics of eight male sprinters during the acceleration phase of the sprint start suggested that the braking and propulsion phases occur immediately after the block phase and that muscle strength strongly affects running velocity in the sprint start. (Author/CB)

  9. Sex effect on catecholamine responses to sprint exercise in adolescents and adults.

    Science.gov (United States)

    Botcazou, Maïtel; Jacob, Christophe; Gratas-Delamarche, Arlette; Vincent, Sophie; Bentué-Ferrer, Danièle; Delamarche, Paul; Zouhal, Hassane

    2007-05-01

    The purpose of this study was to clarify the effect of sex on plasma catecholamine responses to sprint exercise in adolescents and adults. Thirty-six untrained participants took part in this study-9 girls and 10 boys (Tanner Stage 4) and 9 women and 8 men. Each participant performed a 6-s sprint test on a cycle ergometer. Plasma adrenaline (A) and noradrenaline (NA) concentrations were determined successively at rest (A0 and NA0), immediately after the 6-s sprint test (AEX and NAEX), and after 5 min of recovery (A5 and NA5). Peak power, expressed in absolute values or relative to body weight and fat-free mass, was significantly higher in boys than in girls and higher in men than in women (p sprint (p men than in women (p women than in girls (p men than in boys (p sprint exercise.

  10. BP Targets in Hypertension: What Should We Do Now That SPRINT Is Out?

    Science.gov (United States)

    Bhatt, Hemal; Ghazi, Lama; Calhoun, David; Oparil, Suzanne

    2016-10-01

    Systolic blood pressure (SBP) is an important predictor of cardiovascular disease (CVD) outcomes. Lowering SBP has been shown to reduce CVD morbidity and mortality, but the optimal SBP target continues to be a topic of intense debate. The Systolic Blood Pressure Intervention Trial (SPRINT) reported a significantly lower risk for CVD outcomes and all-cause mortality by targeting SBP SPRINT findings to other hypertensive populations that were excluded from the trial, including those with diabetes or prior stroke, SPRINT findings for appropriate BP targets in high-risk groups of hypertensive persons, including the elderly and those with chronic kidney disease (CKD). We will also address the cost-effectiveness of intensive BP treatment as implemented in SPRINT and the implications of SPRINT for health care policy and future BP guidelines.

  11. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Javier Yanci

    2014-11-01

    Full Text Available The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball agility (T-test and pick-up test strength (handgrip and maximal pass and endurance (Yo-Yo 10 m recovery test were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94. The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s and maximal pass (8.39 ± 1.77 m, players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB.

  12. Physiological characteristics of well-trained junior sprint kayak athletes.

    Science.gov (United States)

    Borges, Thiago Oliveira; Dascombe, Ben; Bullock, Nicola; Coutts, Aaron J

    2015-07-01

    This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n=21, VO2max 4.1±0.7 L/min, training experience 2.7±1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscle-oxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (-.5 to -.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (-.4 to -.7) with 200- and 1000-m performance. In addition, trivial to large correlations (-.11 to -.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (Pkayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation.

  13. MONITORING SWIMMING SPRINT PERFORMANCE DURING A TRAINING CYCLE

    Directory of Open Access Journals (Sweden)

    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.

  14. Sprint Start Kinetics of Amputee and Non-Amputee Sprinters

    OpenAIRE

    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 instrumen...

  15. PENINGKATAN HASIL PEMBELAJARAN LARI SPRINT 60 METER MELALUI METODE PERMAINAN SDN 009 TELUK PELALAWAN

    Directory of Open Access Journals (Sweden)

    Gevi Indra

    2014-09-01

    Full Text Available Penelitian ini bertujuan untuk meningkatkan minat siswa terhadap pembelajaran lari sprint dan hasil belajar keterampilan lari sprint 60 m melalui metode pendekatan permainan lari membawa gelang dan mangkok pada siswa kelas atas SD Negeri 009 Teluk Tahun Pelajaran 2013/2014 Kabupaten Pelalawan Riau. Penelitian ini adalah penelitian tindakan kelas atau classroom action research yang berlangsung dua siklus, setiap siklus terdiri dari dua kali pertemuan. Subjek penelitian adalah siswa kelas V SD Negeri 009 Teluk Kabupaten Pelalawan Riau yang berjumlah 24 orang siswa. Adapun metode pengumpulan data yang digunakan adalah observasi, angket, tes unjuk kerja dan analisis data. Hasil penelitian menunjukkan bahwa minat siswa terhadap pembelajaran lari sprint dan hasil belajar keterampilan lari sprint 60 m siswa mengalami peningkatan. Hasil pretest tentang minat siswa terhadap pembelajaran lari sprint 60 m sebesar 29% dan pada posttest meningkat sebesar 75% kategori berminat. Sedangkan hasil belajar keterampilan lari sprint 60 m siswa pada pretest dengan nilai rata-rata 60, pada siklus pertama pertemuan kedua meningkat dengan nilai rata-rata sebesar 64,58 dan siswa yang mencapai kriteria ketuntasan minimal 37% atau sebanyak 9 orang siswa. Siklus kedua, pertemuan kedua meningkat dengan nilai rata-rata sebesar 74,58 dan siswa yang mencapai kriteria ketuntasan minimal 100% atau 24 orang siswa. Kata kunci: Hasil belajar, lari sprint 60 m, bermain lari gelang dan mangkok.

  16. Ethnicity and spatiotemporal parameters of bilateral and unilateral transtibial amputees in a 100-m sprint.

    Science.gov (United States)

    Hobara, Hiroaki; Hashizume, Satoru; Kobayashi, Yoshiyuki; Usami, Yuko; Mochimaru, Masaaki

    2016-01-01

    Similar to able-bodied sprinters, most of the medals for the 100-m sprint in past Paralympic Games and IPC Athletics World Championships were dominated by West African (WA) and Caucasian (CC) amputee sprinters, not Asian (AS) sprinters. Although these results indicate differences in sprint performance due to ethnicity, little is known about the ethnicity and spatiotemporal parameters of the 100-m sprint for amputee sprinters. The purpose of this study was to investigate the differences in the spatiotemporal parameters of WA, CC and AS sprinters with bilateral and unilateral transtibial amputations during a 100-m sprint. We analyzed 6 WA, 28 CC, and 10 AS amputee sprinters from publicly available Internet broadcasts. For each sprinter's run, the average speed, average step length, and step frequency were calculated by using the number of steps in conjunction with the official race time. No significant differences were found in the spatiotemporal parameters of the 100-m sprint for the WA and CC groups. On the other hand, the average speed of the AS group was significantly lower because of its shorter step length during the 100-m sprint. The results suggest that WA and CC sprinters would perform similarly during a 100-m sprint, but AS sprinters would not.

  17. Human ankle plantar flexor muscle–tendon mechanics and energetics during maximum acceleration sprinting

    Science.gov (United States)

    Schache, Anthony G.; Brown, Nicholas A. T.; Pandy, Marcus G.

    2016-01-01

    Tendon elastic strain energy is the dominant contributor to muscle–tendon work during steady-state running. Does this behaviour also occur for sprint accelerations? We used experimental data and computational modelling to quantify muscle fascicle work and tendon elastic strain energy for the human ankle plantar flexors (specifically soleus and medial gastrocnemius) for multiple foot contacts of a maximal sprint as well as for running at a steady-state speed. Positive work done by the soleus and medial gastrocnemius muscle fascicles decreased incrementally throughout the maximal sprint and both muscles performed more work for the first foot contact of the maximal sprint (FC1) compared with steady-state running at 5 m s−1 (SS5). However, the differences in tendon strain energy for both muscles were negligible throughout the maximal sprint and when comparing FC1 to SS5. Consequently, the contribution of muscle fascicle work to stored tendon elastic strain energy was greater for FC1 compared with subsequent foot contacts of the maximal sprint and compared with SS5. We conclude that tendon elastic strain energy in the ankle plantar flexors is just as vital at the start of a maximal sprint as it is at the end, and as it is for running at a constant speed. PMID:27581481

  18. 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.

  19. Eight Weeks of Kettlebell Swing Training Does not Improve Sprint Performance in Recreationally Active Females

    Science.gov (United States)

    HOLMSTRUP, MICHAEL E.; JENSEN, BROCK T.; EVANS, WILLIAM S.; MARSHALL, EMILY C.

    2016-01-01

    The kettlebell swing (KBS), emphasizing cyclical, explosive hip extension in the horizontal plane, aligns with movement- and velocity-specificity of sprinting. The present study examined the effect of an eight-week KBS intervention on sprinting in recreationally-active females, in comparison to an eight-week intervention using the stiff-legged deadlift (SDL). Following a pre-testing session measuring 30 meter sprint and countermovement vertical jump performance, participants were divided evenly by sprint time into KBS (n=8) and SDL (n=10) cohorts. Following familiarization with the exercises, KBS met twice weekly to perform swings using the Tabata interval (20s work, 10s rest, 8 rounds), stressing a rapid, explosive tempo. In contrast, the SDL group performed their Tabata stiff-legged deadlifts at a conventional resistance training tempo (2 seconds concentric, 2 seconds eccentric). Following eight weeks and greater than 95% training adherence, the SDL group only had a slightly greater average training volume (~3%) than KBS. No significant differences in pre-test values, or changes were noted in sprint performance from pre- to post-intervention in either group. An improvement in vertical jump performance was noted across groups. Potential explanations for the lack of sprint improvement compared to previous studies include differences between recreationally-active and athletic females, and low exercise volume (~46% of a comparable study with improvements in vertical jump). Future studies should seek to determine the appropriate volume and intensity for KBS components of sprint programming. PMID:27766131

  20. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test

    Directory of Open Access Journals (Sweden)

    Frédérique Hintzy, Frédéric Grappe, Alain Belli

    2016-06-01

    Full Text Available Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis, in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg-1 friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal. Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint, maximal power (towards the middle, and maximal velocity (at the end of the sprint. Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05 when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance.

  1. Effect of postactivation potentiation on swimming starts in international sprint swimmers.

    Science.gov (United States)

    Kilduff, Liam P; Cunningham, Dan J; Owen, Nick J; West, Daniel J; Bracken, Richard M; Cook, Christian J

    2011-09-01

    The aim of this study was to investigate the effects of postactivation potentiation (PAP) on swim start performance (time to 15 m) in a group of international sprint swimmers. Nine international sprint swimmers (7 men and 2 women) volunteered and gave informed consent for this study, which was approved by the university ethics committee. Initially, swimmers performed a countermovement jump (CMJ) on a portable force platform (FP) at baseline and at the following time points ∼15 seconds, 4, 8, 12, and 16 minutes after a PAP stimulus (1 set of 3 repetitions at 87% 1 repetition maximum [RM]) to individually determine the recovery time required to observe enhanced muscle performance. On 2 additional days, swimmers performed a swim start to 15 m under 50-m freestyle race conditions, which was preceded by either their individualized race specific warm-up or a PAP stimulus (1 set of 3 repetitions at 87% 1RM). Both trials were recorded on 2 cameras operating at 50 Hz with camera 1 located at the start and camera 2 at the 15-m mark. Peak vertical force (PVF) and peak horizontal force (PHF) were measured during all swim starts from a portable FP placed on top of the swim block. A repeated measures analysis of variance revealed a significant time effect with regard to power output (PO) (F = 20.963, p < 0.01) and jump height (JH) (F = 14.634, p < 0.01) with a paired comparison indicating a significant increase in PO and JH after 8 minutes of recovery from the PAP stimulus. There was a significant increase in both PHF and PVF after the PAP stimulus compared to the swim-specific warm-up during the swim start (PHF 770 ± 228 vs. 814 ± 263 N, p = 0.018; PVF: 1,462 ± 280 vs. 1,518 ± 311 N, p = 0.038); however, time to 15 m was the same when both starts were compared (7.1 ± 0.8 vs. 7.1 ± 0.8 seconds, p = 0.447). The results from this study indicate that muscle performance during a CMJ is enhanced after a PAP stimulus providing adequate recovery (∼8 minutes) is given between

  2. Sprint starts and the minimum auditory reaction time.

    Science.gov (United States)

    Pain, Matthew T G; Hibbs, Angela

    2007-01-01

    The simple auditory reaction time is one of the fastest reaction times and is thought to be rarely less than 100 ms. The current false start criterion in a sprint used by the International Association of Athletics Federations is based on this assumed auditory reaction time of 100 ms. However, there is evidence, both anecdotal and from reflex research, that simple auditory reaction times of less than 100 ms can be achieved. Reaction time in nine athletes performing sprint starts in four conditions was measured using starting blocks instrumented with piezoelectric force transducers in each footplate that were synchronized with the starting signal. Only three conditions were used to calculate reaction times. The pre-motor and pseudo-motor time for two athletes were also measured across 13 muscles using surface electromyography (EMG) synchronized with the rest of the system. Five of the athletes had mean reaction times of less than 100 ms in at least one condition and 20% of all starts in the first two conditions had a reaction time of less than 100 ms. The results demonstrate that the neuromuscular-physiological component of simple auditory reaction times can be under 85 ms and that EMG latencies can be under 60 ms.

  3. Muscle - tendon unit mechanical and morphological properties and sprint performance.

    Science.gov (United States)

    Stafilidis, Savvas; Arampatzis, Adamantios

    2007-07-01

    The objective of this study was to determine whether sprint performance is related to the mechanical (elongation - force relationship of the tendon and aponeurosis, muscle strength) and morphological (fascicle length, pennation angle, muscle thickness) properties of the quadriceps femoris and triceps surae muscle - tendon units. Two groups of sprinters (slow, n = 11; fast, n = 17) performed maximal isometric knee extension and plantar flexion contractions on a dynamometer at 11 different muscle - tendon unit lengths. Elongation of the tendon and aponeurosis of the gastrocnemius medialis and the vastus lateralis was measured using ultrasonography. We observed no significant differences in maximal joint moments at the ankle and knee joints or morphological properties of the gastrocnemius medialis and vastus lateralis between groups (P > 0.05). The fast group exhibited greater elongation of the vastus lateralis tendon and aponeurosis at a given tendon force, and greater maximal elongation of the vastus lateralis tendon and aponeurosis during maximum voluntary contraction (P aponeurosis showed a significant correlation with 100-m sprint times (r = -0.567, P = 0.003). For the elongation - force relationship at the gastrocnemius medialis tendon and aponeurosis, the two groups recorded similar values. It is suggested that the greater elongation of the vastus lateralis tendon and aponeurosis of the fast group benefits energy storage and return as well as the shortening velocity of the muscle - tendon unit.

  4. A biomechanical analysis of four sprint start positions.

    Science.gov (United States)

    Schot, P K; Knutzen, K M

    1992-06-01

    The sprint starts of 12 skilled collegiate sprinter/hurdlers were filmed for four different sprint start conditions. Ground reaction forces were collected for the first step out of the blocks and velocities through a 2-m speed trap immediately following the first support phase were recorded. The subjects employed their preferred right-left leg placement in the blocks, while the anterior-posterior spacing of the front block with respect to the starting line and the amount of forward lean in the set position were varied. Four positions were constructed that accounted for anthropometric differences. The four positions consisted of combinations of two arm orientations (forward lean and perpendicular to ground) and two front block to starting line distances (bunched and elongated). Kinematic data were reduced to provide center of mass position and velocity measures and analyzed for critical periods throughout the starting action. Selected critical events from the first step kinetic records were also analyzed. The results indicated that the elongated starting positions resulted in greater horizontal displacement, greater propelling impulse, increased first step toe-off velocity, and greater average velocity through a 2-m speed trap. Arm orientation effects were less well defined. Forward lean tended to result in greater vertical velocity at block clearance and horizontal velocity at first step toe-off, whereas perpendicular arm positioning resulted in greater 2-m speed trap velocity.

  5. Effects of preload 4 repetition maximum on 100-m sprint times in collegiate women.

    Science.gov (United States)

    Linder, Elizabeth E; Prins, Jan H; Murata, Nathan M; Derenne, Coop; Morgan, Charles F; Solomon, John R

    2010-05-01

    The purpose of this study was to determine the effects of postactivation potentiation (PAP) on track-sprint performance after a preload set of 4 repetition maximum (4RM) parallel back half-squat exercises in collegiate women. All subjects (n = 12) participated in 2 testing sessions over a 3-week period. During the first testing session, subjects performed the Controlled protocol consisting of a 4-minute standardized warm-up, followed by a 4-minute active rest, a 100-m track sprint, a second 4-minute active rest, finalized with a second 100-m sprint. The second testing session, the Treatment protocol, consisted of a 4-minute standardized warm-up, followed by 4-minute active rest, sprint, a second 4-minute active rest, a warm-up of 4RM parallel back half-squat, a third 9-minute active rest, finalized with a second sprint. The results indicated that there was a significant improvement of 0.19 seconds (p sprint was preceded by a 4RM back-squat protocol during Treatment. The standardized effect size, d, was 0.82, indicating a large effect size. Additionally, the results indicated that it would be expected that mean sprint times would increase 0.04-0.34 seconds (p 0.05). The findings suggest that performing a 4RM parallel back half-squat warm-up before a track sprint will have a positive PAP affect on decreased track-sprint times. Track coaches, looking for the "competitive edge" (PAP effect) may re-warm up their sprinters during meets.

  6. The relationship between extension of the metatarsophalangeal joint and sprint time for 100 m Olympic athletes.

    Science.gov (United States)

    Krell, Jason B; Stefanyshyn, Darren J

    2006-02-01

    Selected kinematic variables of the foot segments and the metatarsophalangeal (MTP) joint were investigated in relation to sprinting performance among 100 m sprint athletes at the 2000 Summer Olympic Games. It was hypothesized that the kinematics of the MTP joint, and forefoot and rearfoot segments, are related to sprint performance for both male and female athletes. Kinematic sagittal plane data were collected using two digital video cameras recording at 120 fields per second. It was determined that faster male sprinters experienced higher maximal rates of MTP extension, and faster female sprinters touch down with higher posterior sole angles and take off with lower posterior sole angles.

  7. 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 

  8. 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...... bouts of 30-s sprint exercise were performed by healthy females (n=8) and males (n=6). Blood leucine and muscle leucine were collected over the exercise period. Basal arterial plasma and skeletal muscle leucine were 40% higher in males than females (P...

  9. Energy expenditure and habitual physical activities in adolescent sprint athletes.

    Science.gov (United States)

    Aerenhouts, Dirk; Zinzen, Evert; Clarys, Peter

    2011-01-01

    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. Key pointsThe activity diary and Sensewear armband provide comparable estimates of TEE in adolescent sprint athletes.A high inter-individual variation was observed in time spent in high-intensity physical activities, advocating an individual based assessment when coaching

  10. Effect of expertise on postmaximal long sprint blood metabolite responses.

    Science.gov (United States)

    Hanon, Christine; Rabate, Mathieu; Thomas, Claire

    2011-09-01

    The aim of this study was to describe and compare the blood metabolic responses obtained after a single maximal exercise in elite and less-successful athletes and to investigate whether these responses are related to sprint performance. Eleven elite (ELI) and 14 regional (REG) long sprint runners performed a 300-m running test as fast as possible. Blood samples were taken at rest and at 4 minutes after exercise for measurements of blood lactate concentration [La] and acid-base status. The blood metabolic responses of ELI subjects compared to those of REG subjects for pH (7.07 ± 0.05 vs. 7.14 ± 1.5), sodium bicarbonate concentration ([HCO(3)(-)], 8.1 ± 1.5 vs. 9.8 ± 1.8 mmol·L(-1)), hemoglobin O(2) saturation (SaO(2)) (94.7 ± 1.8 vs. 96.2 ± 1.6%) were significantly lower (p < 0.05), and [La] was significantly higher in ELI (21.1 ± 2.9 vs. 19.1 ± 1.2 mmol·L(-1), p < 0.05). The 300-m performance (in % world record) was negatively correlated with pH (r = -0.55, p < 0.01), SaO2 (r = -0.64, p < 0.001), [HCO(3)(-)] (r = -0.40, p < 0.05), and positively correlated with [La] (r = 0.44, p < 0.05). In conclusion, for the same quantity of work, the best athletes are able to strongly alter their blood acid-base balance compared to underperforming runners, with larger acidosis and lactate accumulation. To obtain the pH limits with acute maximal exercise, coaches must have their athletes perform a distance run with duration of exercise superior to 35 seconds. The blood lactate accumulation values (mmol·L(-1)·s(-1)) recorded in this study indicate that the maximal glycolysis rate obtained in the literature from short sprint distances is maintained, but not increased, until 35 seconds of exercise.

  11. The relationship between muscle strength and sprint kinematics in elite sprinters.

    Science.gov (United States)

    Alexander, M J

    1989-09-01

    Twenty-three elite sprinters, 9 females and 14 males, were filmed while performing a maximal sprint. Age, height, weight, and personal best 100 m time were also determined for each sprinter. Several kinematic variables were calculated for each athlete from the filmed sprint, including stride length, stride frequency, horizontal and vertical velocity of the CG, and the angular kinematics of the limbs. A Kin/Com isokinetic dynamometer was used to determine lower limb peak and average torque values. Correlation coefficients were calculated between each of the kinematic variables and each of the strength variables. Stepwise multiple regression analysis was also carried out for each set of kinematic and strength variables, to determine the best predictors of sprinting speed. Significant relationships were noted between sprinting times for the 100 m and peak torque scores (N.m/kg) for males for fast concentric knee extension and slow eccentric dorsiflexion, and for females for concentric dorsiflexion at both speeds, and slow eccentric dorsiflexion.

  12. Digital Collections Are a Sprint, Not a Marathon: Adapting Scrum Project Management Techniques to Library Digital Initiatives

    Directory of Open Access Journals (Sweden)

    Michael Dulock

    2015-12-01

    Full Text Available This article describes a case study in which a small team from the digital initiatives group and metadata services department at the University of Colorado Boulder (CU-Boulder Libraries conducted a pilot of the Scrum project management framework. The pilot team organized digital initiatives work into short, fixed intervals called sprints—a key component of Scrum. Over a year of working in the modified framework yielded significant improvements to digital collection work, including increased production of digital objects and surrogate records, accelerated publication of digital collections, and an increase in the number of concurrent projects. Adoption of sprints has improved communication and cooperation among participants, reinforced teamwork, and enhanced their ability to adapt to shifting priorities.

  13. Speed, force, and power values produced from nonmotorized treadmill test are related to sprinting performance.

    Science.gov (United States)

    Mangine, Gerald T; Hoffman, Jay R; Gonzalez, Adam M; Wells, Adam J; Townsend, Jeremy R; Jajtner, Adam R; McCormack, William P; Robinson, Edward H; Fragala, Maren S; Fukuda, David H; Stout, Jeffrey R

    2014-07-01

    The relationships between 30-m sprint time and performance on a nonmotorized treadmill (TM) test and a vertical jump test were determined in this investigation. Seventy-eight physically active men and women (22.9 ± 2.7 years; 73.0 ± 14.7 kg; 170.7 ± 10.4 cm) performed a 30-second maximal sprint on the curve nonmotorized TM after 1 familiarization trial. Pearson product-moment correlation coefficients produced significant (p ≤ 0.05) moderate to very strong relationships between 30-m sprint time and body mass (r = -0.37), %fat (r = 0.79), peak power (PP) (r = -0.59), relative PP (r = -0.42), time to peak velocity (r = -0.23) and TM sprint times at 10 m (r = 0.48), 20 m (r = 0.59), 30 m (r = 0.67), 40 m (r = 0.71), and 50 m (r = 0.75). Strong relationships between 30-m sprint time and peak (r = -0.479) and mean vertical jump power (r = -0.559) were also observed. Subsequently, stepwise regression was used to produce two 30-m sprint time prediction models from TM performance (TM1: body mass + TM data and TM2: body composition + TM data) in a validation group (n = 39), and then crossvalidated against another group (n = 39). As no significant differences were observed between these groups, data were combined (n = 72) and used to create the final prediction models (TM1: r = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r = 0.84, SEE = 0.22 seconds). These final movement-specific models seem to be more accurate in predicting 30-m sprint time than derived peak (r = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r = 0.31, SEE = 0.45 seconds) equations. Consequently, sprinting performance on the TM can significantly predict short-distance sprint time. It, therefore, may be used to obtain movement-specific measures of sprinting force, velocity, and power in a controlled environment from a single 30-second maximal sprinting test.

  14. Proposal of Implicit Coordination Model for Performance Enhancement Using Sprint Zero

    Directory of Open Access Journals (Sweden)

    M. Rizwan Jameel Qureshi

    2012-08-01

    Full Text Available Scrum model always welcome the new requirements from customer at any stage of software development. This situation creates problem for development team to meet estimated timelines. The Scrum development team is always under heavy workload and stress because of this situation. A high level of coordination among team members is required in order to overcome this work pressure and meet quality demands within estimated time and cost. Scrum model emphasis to coordinate through communication to cope with changing requirements. Scrum development is facing new challenges to meet high quality demands with critical timeline environment. The ability of a team to act intelligently in such situation is gaining key position for the survival and success of an organization. The goal of this paper is to highlight the role of implicit coordination helping the software development team members to act intelligently in time demand environment to achieve common goals. Implicit coordination among team members during sprint zero development can show significant improvement in team performance. This will help to achieve high quality product under heavy workload within estimated time period. A survey is conducted to validate the research i.e., implicit coordination has strong impact for successful implementation of Scrum methodology.

  15. The force, power, and energy of the 100 meter sprint

    Science.gov (United States)

    Helene, O.; Yamashita, M. T.

    2010-03-01

    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 et al. [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 et al. to model Bolt's velocity time dependence for the Beijing 2008 and Berlin 2009 records. We deduce the maximum force, the maximum power, and the total mechanical energy produced by Bolt in both races. Surprisingly, we conclude that all of these values were smaller in 2009 than in 2008.

  16. The force, power and energy of the 100-meter sprint

    CERN Document Server

    Helene, O

    2009-01-01

    At the 2008 Summer Olympics in Beijing, Jamaican athlete 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 et al. studied Usain Bolt's performance and predicted that the record could be about one-tenth of second faster, which was confirmed in Berlin. In this paper we extend the analysis of Ref. [1] to model Bolt's velocity profile for the Beijing 2008 and Berlin 2009 records. From the results we obtained, we were able to deduce the maximum force, the maximum power and the total mechanical energy produced by the athlete in both races. Surprisingly, we concluded that all of these values were smaller in 2009 than in 2008.

  17. On the performance of Usain Bolt in the 100 metre sprint

    CERN Document Server

    Gómez, J J Hernández; Gómez, R W

    2013-01-01

    A theoretical model of the performance of the 100 m world record sprint of Usain Bolt during the 2009 World Championships at Berlin is developed, assuming a drag force proportional to $v$ and to $v^2$. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Amateur of Athletics Federations that recorded Bolt's position with a LAVEG (laser velocity guard) device. It is worth to note that our model works only for short sprints.

  18. 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 test