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Sample records for endurance running performance

  1. Effects of Heavy Strength Training on Running Performance and Determinants of Running Performance in Female Endurance Athletes

    Science.gov (United States)

    Vikmoen, Olav; Raastad, Truls; Seynnes, Olivier; Bergstrøm, Kristoffer; Ellefsen, Stian; Rønnestad, Bent R.

    2016-01-01

    Purpose The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes. We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors. Methods Nineteen female endurance athletes [maximal oxygen consumption (VO2max): 53±3 ml∙kg-1∙min-1, 5.8 h weekly endurance training] were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four leg exercises [3 x 4–10 repetition maximum (RM)], twice a week for 11 weeks. Muscle strength, 40 min all-out running distance, running performance determinants and patellar tendon stiffness were measured before and after the intervention. Results E+S increased 1RM in leg exercises (40 ± 15%) and maximal jumping height in counter movement jump (6 ± 6%) and squat jump (9 ± 7%, p running economy, fractional utilization of VO2max or VO2max. There were also no change in running distance during a 40 min all-out running test in neither of the groups. Conclusion Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only. PMID:26953893

  2. Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

    Science.gov (United States)

    Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

    2011-10-01

    The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as

  3. Endurance running performance in athletes with asthma.

    Science.gov (United States)

    Freeman, W; Williams, C; Nute, M G

    1990-01-01

    Laboratory assessment was made during maximal and submaximal exercise on 16 endurance trained male runners with asthma (aged 35 +/- 9 years) (mean +/- S.D.). Eleven of these asthmatic athletes had recent performance times over a half-marathon, which were examined in light of the results from the laboratory tests. The maximum oxygen uptake (VO2max) of the group was 61.8 +/- 6.3 ml kg-1 min-1 and the maximum ventilation (VEmax) was 138.7 +/- 24.7 l min-1. These maximum cardio-respiratory responses to exercise were positively correlated to the degree of airflow obstruction, defined as the forced expiratory volume in 1 s (expressed as a percentage of predicted normal). The half-marathon performance times of 11 of the athletes ranged from those of recreational to elite runners (82.4 +/- 8.8 min, range 69-94). Race pace was correlated with VO2max (r = 0.863, P less than 0.01) but the highest correlation was with the running velocity at a blood lactate concentration of 2 mmol l-1 (r = 0.971, P less than 0.01). The asthmatic athletes utilized 82 +/- 4% VO2max during the half-marathon, which was correlated with the %VO2max at 2 mmol l-1 blood lactate (r = 0.817, P less than 0.01). The results of this study suggest that athletes with mild to moderate asthma can possess high VO2max values and can develop a high degree of endurance fitness, as defined by their ability to sustain a high percentage of VO2max over an endurance race. In athletes with more severe airflow obstruction, the maximum ventilation rate may be reduced and so VO2max may be impaired. The athletes in the present study have adapted to this limitation by being able to sustain a higher %VO2max before the accumulation of blood lactate, which is an advantage during an endurance race. Therefore, with appropriate training and medication, asthmatics can successfully participate in endurance running at a competitive level.

  4. Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners

    DEFF Research Database (Denmark)

    Vorup Petersen, Jacob; Tybirk, Jonas; Gunnarsson, Thomas Petursson

    2016-01-01

    PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were rand...... and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.......PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were...... randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate...

  5. Should Body Size Categories Be More Common in Endurance Running Events?

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    Buresh, Robert

    2018-05-01

    Thousands of endurance running events are held each year in the United States, and most of them use age and sex categories to account for documented effects of those factors on running performance. However, most running events do not provide categories of body mass, despite abundant evidence that it, too, dramatically influences endurance running performance. The purposes of this article are to (1) discuss how body mass affects endurance running performance, (2) explain several mechanisms through which body mass influences endurance running performance, and (3) suggest possible ways in which body mass might be categorized in endurance running events.

  6. Calcaneus length determines running economy: implications for endurance running performance in modern humans and Neandertals.

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    Raichlen, David A; Armstrong, Hunter; Lieberman, Daniel E

    2011-03-01

    The endurance running (ER) hypothesis suggests that distance running played an important role in the evolution of the genus Homo. Most researchers have focused on ER performance in modern humans, or on reconstructing ER performance in Homo erectus, however, few studies have examined ER capabilities in other members of the genus Homo. Here, we examine skeletal correlates of ER performance in modern humans in order to evaluate the energetics of running in Neandertals and early Homo sapiens. Recent research suggests that running economy (the energy cost of running at a given speed) is strongly related to the length of the Achilles tendon moment arm. Shorter moment arms allow for greater storage and release of elastic strain energy, reducing energy costs. Here, we show that a skeletal correlate of Achilles tendon moment arm length, the length of the calcaneal tuber, does not correlate with walking economy, but correlates significantly with running economy and explains a high proportion of the variance (80%) in cost between individuals. Neandertals had relatively longer calcaneal tubers than modern humans, which would have increased their energy costs of running. Calcaneal tuber lengths in early H. sapiens do not significantly differ from those of extant modern humans, suggesting Neandertal ER economy was reduced relative to contemporaneous anatomically modern humans. Endurance running is generally thought to be beneficial for gaining access to meat in hot environments, where hominins could have used pursuit hunting to run prey taxa into hyperthermia. We hypothesize that ER performance may have been reduced in Neandertals because they lived in cold climates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Effects of a concurrent strength and endurance training on running performance and running economy in recreational marathon runners.

    Science.gov (United States)

    Ferrauti, Alexander; Bergermann, Matthias; Fernandez-Fernandez, Jaime

    2010-10-01

    The purpose of this study was to investigate the effects of a concurrent strength and endurance training program on running performance and running economy of middle-aged runners during their marathon preparation. Twenty-two (8 women and 14 men) recreational runners (mean ± SD: age 40.0 ± 11.7 years; body mass index 22.6 ± 2.1 kg·m⁻²) were separated into 2 groups (n = 11; combined endurance running and strength training program [ES]: 9 men, 2 women and endurance running [E]: 7 men, and 4 women). Both completed an 8-week intervention period that consisted of either endurance training (E: 276 ± 108 minute running per week) or a combined endurance and strength training program (ES: 240 ± 121-minute running plus 2 strength training sessions per week [120 minutes]). Strength training was focused on trunk (strength endurance program) and leg muscles (high-intensity program). Before and after the intervention, subjects completed an incremental treadmill run and maximal isometric strength tests. The initial values for VO2peak (ES: 52.0 ± 6.1 vs. E: 51.1 ± 7.5 ml·kg⁻¹·min⁻¹) and anaerobic threshold (ES: 3.5 ± 0.4 vs. E: 3.4 ± 0.5 m·s⁻¹) were identical in both groups. A significant time × intervention effect was found for maximal isometric force of knee extension (ES: from 4.6 ± 1.4 to 6.2 ± 1.0 N·kg⁻¹, p marathon running velocities (2.4 and 2.8 m·s⁻¹) and submaximal blood lactate thresholds (2.0, 3.0, and 4.0 mmol·L⁻¹). Stride length and stride frequency also remained unchanged. The results suggest no benefits of an 8-week concurrent strength training for running economy and coordination of recreational marathon runners despite a clear improvement in leg strength, maybe because of an insufficient sample size or a short intervention period.

  8. Relationship between Achilles tendon length and running performance in well-trained male endurance runners.

    Science.gov (United States)

    Ueno, Hiromasa; Suga, Tadashi; Takao, Kenji; Tanaka, Takahiro; Misaki, Jun; Miyake, Yuto; Nagano, Akinori; Isaka, Tadao

    2018-02-01

    This study aimed to determine the relationship between Achilles tendon (AT) length and running performance, including running economy, in well-trained endurance runners. We also examined the reasonable portion of the AT related to running performance among AT lengths measured in three different portions. The AT lengths at three portions and cross-sectional area (CSA) of 30 endurance runners were measured using magnetic resonance imaging. Each AT length was calculated as the distance from the calcaneal tuberosity to the muscle-tendon junction of the soleus, gastrocnemius medialis (GM AT ), and gastrocnemius lateralis, respectively. These AT lengths were normalized with shank length. The AT CSA was calculated as the average of 10, 20, and 30 mm above the distal insertion of the AT and normalized with body mass. Running economy was evaluated by measuring energy cost during three 4-minutes submaximal treadmill running trials at 14, 16, and 18 km/h, respectively. Among three AT lengths, only a GM AT correlated significantly with personal best 5000-m race time (r=-.376, P=.046). Furthermore, GM AT correlated significantly with energy cost during submaximal treadmill running trials at 14 km/h and 18 km/h (r=-.446 and -.429, respectively, Prunning performance. These findings suggest that longer AT, especially GM AT , may be advantageous to achieve superior running performance, with better running economy, in endurance runners. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Prevalence in running events and running performance of endurance runners following a vegetarian or vegan diet compared to non-vegetarian endurance runners: the NURMI Study.

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    Wirnitzer, Katharina; Seyfart, Tom; Leitzmann, Claus; Keller, Markus; Wirnitzer, Gerold; Lechleitner, Christoph; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat

    2016-01-01

    Beneficial and detrimental effects of various vegetarian and vegan diets on the health status are well known. Considering the growing background numbers of vegetarians and vegans, the number of vegetarian and vegan runners is likely to rise, too. Therefore, the Nutrition and Running High Mileage (NURMI) Study was designed as a comparative study to investigate the prevalence of omnivores, vegetarians, and vegans in running events and to detect potential differences in running performance comparing these three subgroups. The NURMI Study will be conducted in three steps following a cross-sectional design. Step 1 will determine epidemiological aspects of endurance runners (any distance) using a short standardized questionnaire. Step 2 will investigate dietary habits and running history from eligible participants (capable of running a half-marathon at least) using an extended standardized questionnaire. Step 3 will collect data after a running event on finishing time and final ranking as well as a post-race rating of perceived exertion, mood status, nutrient and fluid intake during the race. Our study will provide a major contribution to overcome the lack of data on the prevalence and running performance of vegetarian and vegan runners in endurance running events. We estimate the prevalence of vegetarians and vegans participating in a running event to be less compared to the respective proportion of vegetarians and vegans to the general population. Furthermore we will validate the subject's self-assessment of their respective diet. This comparative study may identify possible effects of dietary behavior on running performance und may detect possible differences between the respective subgroups: omnivorous, vegetarian and vegan runners. Trial registration Current controlled trials, ISRCTN73074080.

  10. Resting sympatho-vagal balance is related to 10 km running performance in master endurance athletes

    Directory of Open Access Journals (Sweden)

    Angelo Cataldo

    2018-02-01

    Full Text Available Relationships between heart rate recovery after exercise (HRR, baseline heart rate variability measures (HRV, and time to perform a 10Km running trial (t10Km were evaluated in "master" athletes of endurance to assess whether the measured indexes may be useful for monitoring the training status of the athletes. Ten “master” athletes of endurance, aged 40-60 years, were recruited. After baseline measures of HRV, the athletes performed a graded maximal test on treadmill and HRR was measured at 1 and 2 minutes from recovery. Subsequently they performed a 10Km running trial and t10Km was related to HRV and HRR indexes. The time to perform a 10Km running trial was significantly correlated with baseline HRV indexes. No correlation was found between t10Km and HRR. Baseline HRV measures, but not HRR, were significantly correlated with the time of performance on 10km running in “master” athletes. The enhanced parasympathetic function at rest appears to be a condition to a better performance on 10km running. HRV can be simple and useful measurements for monitoring the training stratus of athletes and their physical condition in proximity of a competition.

  11. Do Running Kinematic Characteristics Change over a Typical HIIT for Endurance Runners?

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    García-Pinillos, Felipe; Soto-Hermoso, Víctor M; Latorre-Román, Pedro Á

    2016-10-01

    García-Pinillos, F, Soto-Hermoso, VM, and Latorre-Román, PÁ. Do running kinematic characteristics change over a typical HIIT for endurance runners?. J Strength Cond Res 30(10): 2907-2917, 2016-The purpose of this study was to describe kinematic changes that occur during a common high-intensity intermittent training (HIIT) session for endurance runners. Twenty-eight male endurance runners participated in this study. A high-speed camera was used to measure sagittal-plane kinematics at the first and the last run during a HIIT (4 × 3 × 400 m). The dependent variables were spatial-temporal variables, joint angles during support and swing, and foot strike pattern. Physiological variables, rate of perceived exertion, and athletic performance were also recorded. No significant changes (p ≥ 0.05) in kinematic variables were found during the HIIT session. Two cluster analyses were performed, according to the average running pace-faster vs. slower, and according to exhaustion level reached-exhausted group vs. nonexhausted group (NEG). At first run, no significant differences were found between groups. As for the changes induced by the running protocol, significant differences (p ≤ 0.05) were found between faster and slower athletes at toe-off in θhip and θknee, whereas some changes were found in NEG in θhip during toe-off (+4.3°) and θknee at toe-off (-5.2°) during swing. The results show that a common HIIT session for endurance runners did not consistently or substantially perturb the running kinematics of trained male runners. Additionally, although some differences between groups have been found, neither athletic performance nor exhaustion level reached seems to be determinant in the kinematic response during a HIIT, at least for this group of moderately trained endurance runners.

  12. Effects of endurance training only versus same-session combined endurance and strength training on physical performance and serum hormone concentrations in recreational endurance runners.

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    Schumann, Moritz; Mykkänen, Olli-Pekka; Doma, Kenji; Mazzolari, Raffaele; Nyman, Kai; Häkkinen, Keijo

    2015-01-01

    This study investigated the effects of endurance training only (E, n = 14) and same-session combined training, when strength training is repeatedly preceded by endurance loading (endurance and strength training (E+S), n = 13) on endurance (1000-m running time during incremental field test) and strength performance (1-repetition maximum (1RM) in dynamic leg press), basal serum hormone concentrations, and endurance loading-induced force and hormone responses in recreationally endurance-trained men. E was identical in the 2 groups and consisted of steady-state and interval running, 4-6 times per week for 24 weeks. E+S performed additional mixed-maximal and explosive-strength training (2 times per week) immediately following an incremental running session (35-45 min, 65%-85% maximal heart rate). E and E+S decreased running time at week 12 (-8% ± 5%, p = 0.001 and -7% ± 3%, p force (-5% to -9%, p = 0.032 to 0.001) and testosterone and cortisol responses (18%-47%, p = 0.013 to p benefits when strength training was performed repeatedly after endurance training compared with endurance training only. This was supported by similar acute responses in force and hormonal measures immediately post-endurance loading after the training with sustained 1RM strength in E+S.

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

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

    2016-06-01

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

  14. Endurance capacity of mice selectively bred for high voluntary wheel running.

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    Meek, Thomas H; Lonquich, Brian P; Hannon, Robert M; Garland, Theodore

    2009-09-15

    Mice from four lines bred for high voluntary wheel activity run approximately 3-fold more revolutions per day and have elevated maximal oxygen consumption during forced treadmill exercise, as compared with four unselected control (C) lines. We hypothesized that these high runner (HR) lines would have greater treadmill endurance-running capacity. Ninety-six mice from generation 49 were familiarized with running on a motorized treadmill for 3 days. On days 4 and 5, mice were given an incremental speed test (starting at 20 m min(-1), increased 1.5 m min(-1) every 2 min) and endurance was measured as the total time or distance run to exhaustion. Blood samples were taken to measure glucose and lactate concentrations at rest during the photophase, during peak nightly wheel running, and immediately following the second endurance test. Individual differences in endurance time were highly repeatable between days (r=0.79), and mice tended to run longer on the second day (paired t-test, Pwheel running and treadmill endurance differed between the sexes, reinforcing previous studies that indicate sex-specific responses to selective breeding. HR mice appear to have a higher endurance capacity than reported in the literature for inbred strains of mice or transgenics intended to enhance endurance.

  15. Potential Relationship between Passive Plantar Flexor Stiffness and Running Performance.

    Science.gov (United States)

    Ueno, Hiromasa; Suga, Tadashi; Takao, Kenji; Tanaka, Takahiro; Misaki, Jun; Miyake, Yuto; Nagano, Akinori; Isaka, Tadao

    2018-02-01

    The present study aimed to determine the relationship between passive stiffness of the plantar flexors and running performance in endurance runners. Forty-eight well-trained male endurance runners and 24 untrained male control subjects participated in this study. Plantar flexor stiffness during passive dorsiflexion was calculated from the slope of the linear portion of the torque-angle curve. Of the endurance runners included in the present study, running economy in 28 endurance runners was evaluated by measuring energy cost during three 4-min trials (14, 16, and 18 km/h) of submaximal treadmill running. Passive stiffness of the plantar flexors was significantly higher in endurance runners than in untrained subjects. Moreover, passive plantar flexor stiffness in endurance runners was significantly correlated with a personal best 5000-m race time. Furthermore, passive plantar flexor stiffness in endurance runners was significantly correlated with energy cost during submaximal running at 16 km/h and 18 km/h, and a trend towards such significance was observed at 14 km/h. The present findings suggest that stiffer plantar flexors may help achieve better running performance, with greater running economy, in endurance runners. Therefore, in the clinical setting, passive stiffness of the plantar flexors may be a potential parameter for assessing running performance. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Short-term heat acclimation improves the determinants of endurance performance and 5-km running performance in the heat.

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    James, Carl A; Richardson, Alan J; Watt, Peter W; Willmott, Ashley G B; Gibson, Oliver R; Maxwell, Neil S

    2017-03-01

    This study investigated the effect of 5 days of controlled short-term heat acclimation (STHA) on the determinants of endurance performance and 5-km performance in runners, relative to the impairment afforded by moderate heat stress. A control group (CON), matched for total work and power output (2.7 W·kg -1 ), differentiated thermal and exercise contributions of STHA on exercise performance. Seventeen participants (10 STHA, 7 CON) completed graded exercise tests (GXTs) in cool (13 °C, 50% relative humidity (RH), pre-training) and hot conditions (32 °C, 60% RH, pre- and post-training), as well as 5-km time trials (TTs) in the heat, pre- and post-training. STHA reduced resting (p = 0.01) and exercising (p = 0.04) core temperature alongside a smaller change in thermal sensation (p = 0.04). Both groups improved the lactate threshold (LT, p = 0.021), lactate turnpoint (LTP, p = 0.005) and velocity at maximal oxygen consumption (vV̇O 2max ; p = 0.031) similarly. Statistical differences between training methods were observed in TT performance (STHA, -6.2(5.5)%; CON, -0.6(1.7)%, p = 0.029) and total running time during the GXT (STHA, +20.8(12.7)%; CON, +9.8(1.2)%, p = 0.006). There were large mean differences in change in maximal oxygen consumption between STHA +4.0(2.2) mL·kg -1 ·min -1 (7.3(4.0)%) and CON +1.9(3.7) mL·kg -1 ·min -1 (3.8(7.2)%). Running economy (RE) deteriorated following both training programmes (p = 0.008). Similarly, RE was impaired in the cool GXT, relative to the hot GXT (p = 0.004). STHA improved endurance running performance in comparison with work-matched normothermic training, despite equality of adaptation for typical determinants of performance (LT, LTP, vV̇O 2max ). Accordingly, these data highlight the ergogenic effect of STHA, potentially via greater improvements in maximal oxygen consumption and specific thermoregulatory and associated thermal perception adaptations absent in normothermic training.

  17. [Association between speed and endurance performance with sleep duration in children and adolescents].

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    Chen, T Q; Dong, B; Zhang, W J; Gao, D S; Dong, Y H; Ma, J; Ma, Y H

    2018-06-18

    To analyze the association between sleep duration and athletic performance, and provide scientific basis to improve the 50 m and endurance performance in children and adolescents. All the 119 462 subjects aged 9-15 years in both genders were sampled from 2014 National Physical Fitness and Health Surveillance by using stratified random cluster sampling method, to measure the height, weight, 50 meters and endurance performance and investigate sleep duration with questionnaire. Their body mass indexes (BMI) were calculated and the students' 50 m, endurance run scores and sleep durations were assessed. Binary Logistic regression was used to analyze the difference between the different sleep groups, and multifactor Logistic regression was used to analyze the relationship between the sleep condition and athletic performance. The prevalence of insufficient sleep was 94.67% in the total subjects, the prevalence was higher among the girls (95.26%)than the boys (94.09%, χ 2 =80.99, Pchildren with sufficient sleep had better performance in 50 m and endurance run scores( χ 2 50 m =10.10, P 50 m <0.01; χ 2 endurance run =21.76, Pchildren with adequate sleep showed better results(OR 50 m =1.14, 95%CI 50 m =1.05-1.23, P 50 m endurance run =1.21, 95%CI endurance run =1.11-1.31, P endurance run endurance run scores in the boys with adequate sleep were higher (Pendurance run excellent rates in the girls of different sleep conditions. The excellent rates of 50 m and endurance run in the urban children and the endurance rate in the rural children and adolescents with adequate sleep were higher than those with insufficient sleep (Psleep groups in rural areas. The 50 m and endurance run excellent rates of the children and adolescents with adequate sleep in each grade were higher than those of the children in the same grade with insufficient sleep (P primary students' endurance performance Children and adolescents with normal BMI and overweight who slept well had better

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

    Directory of Open Access Journals (Sweden)

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

    2016-03-01

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

  19. Increased Blood Lactate Level Deteriorates Running Economy in World Class Endurance Athletes.

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    Hoff, Jan; Støren, Øyvind; Finstad, Arnstein; Wang, Eivind; Helgerud, Jan

    2016-05-01

    Blood lactate accumulation is associated with development of muscle fatigue and negatively correlated to endurance performance. No research has quantified the effects of lactate presence at moderate levels of lactate accumulation. The purpose of this study was to test whether 2 moderate blood lactate concentration levels affect running economy (RE) when running at the individual lactate threshold (LT). Seven male world class endurance athletes with an average V[Combining Dot Above]O2max of 80.7 ± 2.7 ml·kg·min or 5.8 ± 0.5 L·min participated in this study. After the V[Combining Dot Above]O2max test, the subjects were resting or walking and in a random order tested for RE at their LT velocity when the blood lactate level reached either 3 mmol·L or 5 mmol·L. After a new 5-minute exercising period at maximal aerobic velocity, the crossover lactate value RE testing was performed. Running economy was significantly (p ≤ 0.05) deteriorated from 0.668 ± 0.044 to 0.705 ± 0.056 ml·kg·m or 5.5% (p ≤ 0.05) for blood lactate level of 3 mmol·L compared with 5 mmol·L, respectively. Increased lactate level from 3 to 5 mmol·L is thus accompanied by deteriorated RE at LT running velocity. The deteriorated RE at moderate levels of lactate concentration emphasizes the importance of avoiding intensities above LT in the early parts of a dominantly aerobic endurance competition. It also emphasizes the importance of a high V[Combining Dot Above]O2max for aerobic endurance athletes and may partly explain the V[Combining Dot Above]O2 slow component as impaired RE.

  20. 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.

    2016-01-01

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

  1. Endurance and age : evidence from long-distance running data

    NARCIS (Netherlands)

    Sterken, Elmer

    2001-01-01

    This paper analyzes the impact of aging on long-run endurance. We analyze the determinants of running speed on distances from 5K to the marathon. We model running speed as a function of distance, age, and sex. We find evidence for interaction between age and sex, but not between distance and sex.

  2. Five training sessions improves 3000 meter running performance.

    Science.gov (United States)

    Riiser, A; Ripe, S; Aadland, E

    2015-12-01

    The primary aim of the present study was to evaluate the effect of two weeks of endurance training on 3000-meter running performance. Secondary we wanted to assess the relationship between baseline running performance and change in running performance over the intervention period. We assigned 36 military recruits to a training group (N.=28) and a control group. The training group was randomly allocated to one of three sub-groups: 1) a 3000 meter group (test race); 2) a 4x4-minutes high-intensity interval group; 3) a continuous training group. The training group exercised five times over a two-week period. The training group improved its 3000 meter running performance with 50 seconds (6%) compared to the control group (P=0.003). Moreover, all sub-groups improved their performance by 37 to 73 seconds (4-8%) compared to the control group (Ptraining group. We conclude that five endurance training sessions improved 3000 meter running performance and the slowest runners achieved the greatest improvement in running performance.

  3. The effect of repeated periods of speed endurance training on performance, running economy, and muscle adaptations.

    Science.gov (United States)

    Skovgaard, C; Almquist, N W; Bangsbo, J

    2018-02-01

    The effect of repeated intense training interventions was investigated in eight trained male runners (maximum oxygen uptake [VO 2 -max]: 59.3±3.2 mL/kg/min, mean±SD) who performed 10 speed endurance training (SET; repeated 30-seconds "all-out" bouts) and 10 aerobic moderate-intensity training sessions during two 40-day periods (P1 and P2) separated by ~80 days of habitual training. Before and after both P1 and P2, subjects completed an incremental test to exhaustion to determine VO 2 -max and a repeated running test at 90% vVO 2 -max to exhaustion (RRT) to determine short-term endurance capacity. In addition, running economy (RE) was measured at 60% vVO 2 -max (11.9±0.5 km/h) and v10-km (14.3±0.9 km/h), a 10-km track-running test was performed, and a biopsy from m. vastus lateralis was collected. 10-km performance and VO 2 -max (mL/min) were the same prior to P1 and P2, whereas RE was better (P<.05) before P2 than before P1. During P1 and P2, 10-km performance (2.9% and 2.3%), VO 2 -max (2.1% and 2.6%), and RE (1.9% and 1.8% at 60% vVO 2 -max; 1.6% and 2.0% at v10-km) improved (P<.05) to the same extent, respectively. Performance in RRT was 20% better (P<.05) after compared to before P2, with no change in P1. No changes in muscle expression of Na + ,K + -ATPase α1, α2 and β1, NHE1, SERCA1 and SERCA2, actin, and CaMKII were found during neither P1 nor P2. Thus, the present study demonstrates that a second period of intense training leads to improved short-term performance and further improved RE, whereas 10-km performance and VO 2 -max improve to the same extent as during the first period. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Tenomodulin is Required for Tendon Endurance Running and Collagen I Fibril Adaptation to Mechanical Load

    Directory of Open Access Journals (Sweden)

    Sarah Dex

    2017-06-01

    Full Text Available Tendons are dense connective tissues that attach muscles to bone with an indispensable role in locomotion because of their intrinsic properties of storing and releasing muscle- generated elastic energy. Tenomodulin (Tnmd is a well-accepted gene marker for the mature tendon/ligament lineage and its loss-of -function in mice leads to a phenotype with distinct signs of premature aging on tissue and stem/progenitor cell levels. Based on these findings, we hypothesized that Tnmd might be an important factor in the functional performance of tendons. Firstly, we revealed that Tnmd is a mechanosensitive gene and that the C-terminus of the protein co-localize with collagen I-type fibers in the extracellular matrix. Secondly, using an endurance training protocol, we compared Tnmd knockout mice with wild types and showed that Tnmd deficiency leads to significantly inferior running performance that further worsens with training. In these mice, endurance running was hindered due to abnormal response of collagen I cross-linking and proteoglycan genes leading to an inadequate collagen I fiber thickness and elasticity. In sum, our study demonstrates that Tnmd is required for proper tendon tissue adaptation to endurance running and aids in better understanding of the structural-functional relationships of tendon tissues.

  5. Carbohydrate mouth rinse: does it improve endurance exercise performance?

    Directory of Open Access Journals (Sweden)

    Painelli Vitor

    2010-08-01

    Full Text Available Abstract It is well known that carbohydrate (CHO supplementation can improve performance in endurance exercises through several mechanisms such as maintenance of glycemia and sparing endogenous glycogen as well as the possibility of a central nervous-system action. Some studies have emerged in recent years in order to test the hypothesis of ergogenic action via central nervous system. Recent studies have demonstrated that CHO mouth rinse can lead to improved performance of cyclists, and this may be associated with the activation of brain areas linked to motivation and reward. These findings have already been replicated in other endurance modalities, such as running. This alternative seems to be an attractive nutritional tool to improve endurance exercise performance.

  6. Self-efficacy and enjoyment of middle school children performing the progressive aerobic cardiovascular endurance run (PACER).

    Science.gov (United States)

    Kane, Irene; Robertson, Robert J; Fertman, Carl I; Nagle, Elizabeth F; McConnaha, Wendell R; Rabin, Bruce S

    2013-10-01

    Self-efficacy and enjoyment were examined among 34 middle school children (M age = 12.5 yr.) performing the Progressive Aerobic Cardiovascular Endurance Run (PACER). Exercise self-efficacy (running) and physical activity enjoyment were measured after viewing a video illustrating the PACER, and subsequently following a PACER test. Significantly greater pre- than post-exercise self-efficacy was reported; enjoyment scores did not differ. Ratings of self-efficacy were higher before exercise than after, but enjoyment scores were not significantly different. A significant correlation was found between post-exercise self-efficacy and enjoyment, but not between pre-exercise self-efficacy and enjoyment. Although positive correlations were found between PACER laps and pre-/post-exercise self-efficacy, correlations with ratings of enjoyment were not significant. Exercise self-efficacy was associated with children's beliefs about the task-specific PACER aerobic exercise; however, exercise enjoyment was stable. Children's self-efficacy and enjoyment beliefs should be considered when developing interventional strategies to promote aerobic exercise participation.

  7. Born to run. Studying the limits of human performance

    Directory of Open Access Journals (Sweden)

    Murray Andrew

    2012-07-01

    Full Text Available Abstract It is recognised that regular physical activity and a high level of fitness are powerful predictors of positive health outcomes. There is a long and rich history of significant feats of human endurance with some, for example, the death of the first marathon runner, Pheidippides, associated with negative health outcomes. Early studies on endurance running used X-ray and interview techniques to evaluate competitors and comment on performance. Since then, comparatively few studies have looked at runners competing in distances longer than a marathon. Those that have, tend to show significant musculoskeletal injuries and a remarkable level of adaptation to this endurance load. The TransEurope Footrace Project followed ultra-endurance runners aiming to complete 4,500 Km of running in 64 days across Europe. This pioneering study will assess the impact of extreme endurance on human physiology; analysing musculoskeletal and other tissue/organ injuries, and the body's potential ability to adapt to extreme physiological stress. The results will be of interest not only to endurance runners, but to anyone interested in the limits of human performance. Please see related article: http://www.biomedcentral.com/1741-7015/10/78

  8. The effect of repeated periods of speed endurance training on performance, running economy and muscle adaptations

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Bangsbo, Jens

    2018-01-01

    sessions during two 40-day periods (P1 and P2) separated by ~80 days of habitual training. Before and after both P1 and P2, subjects completed an incremental test to exhaustion to determine VO2 -max and a repeated running test at 90% vVO2 -max to exhaustion (RRT) to determine short-term endurance capacity......, with no change in P1. No changes in muscle expression of Na(+) ,K(+) -ATPase α1, α2 and β1, NHE1, SERCA1 and SERCA2, actin and CamKII were found during neither P1 nor P2. Thus, the present study demonstrates that a second period of intense training leads to improved short-term performance and further improved RE...

  9. Passion and Pacing in Endurance Performance.

    Science.gov (United States)

    Schiphof-Godart, Lieke; Hettinga, Florentina J

    2017-01-01

    Endurance sports are booming, with sports passionates of varying skills and expertise battering city streets and back roads on their weekly or daily exercise rounds. The investments required for performing in endurance exercise are nevertheless considerable, and passion for their sport might explain the efforts endurance athletes are willing to make. Passion may be defined as a strong motivational force and as such might be related to the neurophysiological basis underlying the drive to exercise. A complex relationship between the brain and other systems is responsible for athletes' exercise behavior and thus performance in sports. We anticipate important consequences of athletes' short term choices, for example concerning risk taking actions, on long term outcomes, such as injuries, overtraining and burnout. We propose to consider athletes' type of passion, in combination with neurophysiological parameters, as an explanatory factor inunderstanding the apparent disparity in the regulation of exercise intensity during endurance sports. Previous research has demonstrated that athletes can be passionate toward their sport in either a harmonious or an obsessive way. Although both lead to considerable investments and therefore often to successful performances, obsessive passion may affect athlete well-being and performance on the long run, due to the corresponding inflexible exercise behavior. In this perspective we will thus examine the influence of passion in sport on athletes' short term and long term decision-making and exercise behavior, in particular related to the regulation of exercise intensity, and discuss the expected long term effects of both types of passion for sport.

  10. Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate.

    Science.gov (United States)

    Ping, Wong Chee; Keong, Chen Chee; Bandyopadhyay, Amit

    2010-07-01

    Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable. Nine heat adapted recreational Malaysian male runners (aged: 25.4+/-6.9 yr) who were nonusers of caffeine (23.7+/-12.6 mg per day) were recruited in this placebo--controlled double--blind randomized study. Caffeine (5 mg per kg of body weight) or placebo was ingested in the form of a capsule one hour prior to the running exercise trial at 70 per cent of VO2max on a motorised treadmill in a heat-controlled laboratory (31 degrees C, 70% relative humidity). Subjects drank 3 ml of cool water per kg of body weight every 20 min during the running trials to avoid the adverse effects of dehydration. Heart rate, core body temperature and rate of perceived exertion (RPE) were recorded at intervals of 10 min, while oxygen consumption was measured at intervals of 20 min. Running time to exhaustion was significantly (Pexercise from their respective resting values in both trials (P<0.001). Our study showed that ingestion of 5 mg of caffeine per kg of body weight improved the endurance running performance but did not impose any significant effect on other individual cardiorespiratory parameters of heat-acclimated recreational runners in hot and humid conditions.

  11. Effects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment

    Science.gov (United States)

    Ping, Fadzel Wong Chee; Keong, Chen Chee; Bandyopadhyay, Amit

    2011-01-01

    Background & objectives: Athletes in Malaysia need to perform in a hot and humid environment due to the climatic nature of the country. c0 hronic supplementation of Panax ginseng (PG) (a deciduous perennial plant belonging to the Araliaceae family) enhances physical performance. As the ergogenic effect of acute supplementation of PG on endurance performance has not been explored in the Malaysian population especially in a hot and humid condition this study was taken up. Methods: Nine heat adapted recreational runners (age : 25.4 ± 6.9 yr, body mass : 57.6 ± 8.4 kg; body height : 168.3 ± 7.6 cm) were recruited in this placebo-controlled double-blind randomized study. Subjects ingested 200 mg of PG one hour before the exercise test on treadmill at 70 per cent of their VO2max in a laboratory environment of 31 °C and 70 per cent relative humidity. They drank 3 ml/kg body weight of cool water every 20 min during the exercise to prevent adverse effects of dehydration. Blood samples were drawn every 20 min for the analysis of glucose, lactate, insulin and free fatty acids. Oxygen uptake was determined every 20 min while heart rate, body and skin temperatures, and ratings of perceived exertion (RPE) were recorded every 10 min during the trials. Results: Endurance running time to exhaustion did not differ between PG and placebo trials. Heart rate, skin temperature, core body temperature, oxygen uptake, RPE, plasma insulin, glucose, free fatty acid and lactate levels during the endurance exercise did not show any significant differences between the trials. Interpretation & conclusions: We conclude that acute supplementation of 200 mg of PG did not affect the endurance running performance of the heat-adapted male recreational runners in the heat. PMID:21321426

  12. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes

    DEFF Research Database (Denmark)

    Iaia, F. M.; Bangsbo, Jens

    2010-01-01

    the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing......The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain...... performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle...

  13. Life-long endurance running is associated with reduced glycation and mechanical stress in connective tissue

    DEFF Research Database (Denmark)

    Couppé, Christian; Svensson, René B; Grosset, Jean-Francois

    2014-01-01

    ) that is associated with aging and lifestyle-related diseases. We therefore examined two groups of healthy elderly men: 15 master athletes (64 ± 4 years) who had been engaged in life-long endurance running and 12 old untrained (66 ± 4 years) together with two groups of healthy young men; ten young athletes matched...... for running distance (26 ± 4 years), and 12 young untrained (24 ± 3 years). AGE cross-links (pentosidine) of the patellar tendon were measured biochemically, and in the skin, it was assessed by a fluorometric method. In addition, we determined mechanical properties and microstructure of the patellar tendon....... Life-long regular endurance runners (master athletes) had a 21 % lower AGE cross-link density compared to old untrained. Furthermore, both master athletes and young athletes displayed a thicker patellar tendon. These cross-sectional data suggest that life-long regular endurance running can partly...

  14. Heart rate variability in prediction of individual adaptation to endurance training in recreational endurance runners.

    Science.gov (United States)

    Vesterinen, V; Häkkinen, K; Hynynen, E; Mikkola, J; Hokka, L; Nummela, A

    2013-03-01

    The aim of this study was to investigate whether nocturnal heart rate variability (HRV) can be used to predict changes in endurance performance during 28 weeks of endurance training. The training was divided into 14 weeks of basic training (BTP) and 14 weeks of intensive training periods (ITP). Endurance performance characteristics, nocturnal HRV, and serum hormone concentrations were measured before and after both training periods in 28 recreational endurance runners. During the study peak treadmill running speed (Vpeak ) improved by 7.5 ± 4.5%. No changes were observed in HRV indices after BTP, but after ITP, these indices increased significantly (HFP: 1.9%, P=0.026; TP: 1.7%, P=0.007). Significant correlations were observed between the change of Vpeak and HRV indices (TP: r=0.75, PHRV among recreational endurance runners, it seems that moderate- and high-intensity training are needed. This study showed that recreational endurance runners with a high HRV at baseline improved their endurance running performance after ITP more than runners with low baseline HRV. © 2011 John Wiley & Sons A/S.

  15. Serotonin-mediated central fatigue underlies increased endurance capacity in mice from lines selectively bred for high voluntary wheel running.

    Science.gov (United States)

    Claghorn, Gerald C; Fonseca, Ivana A T; Thompson, Zoe; Barber, Curtis; Garland, Theodore

    2016-07-01

    Serotonin (5-hydroxytryptamine; 5-HT) is implicated in central fatigue, and 5-HT1A pharmaceuticals are known to influence locomotor endurance in both rodents and humans. We studied the effects of a 5-HT1A agonist and antagonist on both forced and voluntary exercise in the same set of mice. This cohort of mice was taken from 4 replicate lines of mice that have been selectively bred for high levels of voluntary wheel running (HR) as compared with 4 non-selected control (C) lines. HR mice run voluntarily on wheels about 3× as many revolutions per day as compared with C, and have greater endurance during forced treadmill exercise. We hypothesized that drugs targeting serotonin receptors would have differential effects on locomotor behavior of HR and C mice. Subcutaneous injections of a 5-HT1A antagonist (WAY-100,635), a combination of 5-HT1A agonist and a 5-HT1A/1B partial agonist (8-OH-DPAT+pindolol), or physiological saline were given to separate groups of male mice before the start of each of three treadmill trials. The same manipulations were used later during voluntary wheel running on three separate nights. WAY-100,635 decreased treadmill endurance in HR but not C mice (dose by linetype interaction, P=0.0014). 8-OH-DPAT+pindolol affected treadmill endurance (PWheel running was reduced in HR but not C mice at the highest dose of 8-OH-DPAT+pindolol (dose by linetype, P=0.0221), but was not affected by WAY-100,635 treatment. These results provide further evidence that serotonin signaling is an important determinant of performance during both forced and voluntary exercise. Although the elevated wheel running of HR mice does not appear related to alterations in serotonin signaling, their enhanced endurance capacity does. More generally, our results indicate that both forced and voluntary exercise can be affected by an intervention that acts (primarily) centrally. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Resveratrol Attenuates Exercise-Induced Adaptive Responses in Rats Selectively Bred for Low Running Performance

    OpenAIRE

    Hart, Nikolett; Sarga, Linda; Csende, Zsolt; Koch, Lauren G.; Britton, Steven L.; Davies, Kelvin J.A.; Radak, Zsolt

    2013-01-01

    Low capacity runner (LCR) rats have been developed by divergent artificial selection for treadmill endurance capacity to explore an aerobic biology-disease connection. The beneficial effects of resveratrol supplementation have been demonstrated in endurance running. In this study it was examined whether 12 weeks of treadmill exercise training and/or resveratrol can retrieve the low running performance of the LCR and impact mitochondrial biogenesis and quality control. Resveratrol regressed ru...

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

    Science.gov (United States)

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

    2018-03-01

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

  18. Study of speed endurance middle distance runners

    Directory of Open Access Journals (Sweden)

    R.V. Golovaschenko

    2013-12-01

    Full Text Available Purpose : To investigate the boost performance speed endurance runners who specialize in middle-distance running . Material and methods : The study involved team members Vinnytsia region in an amount of 44 people, whose average age was 20,2 ± 2,1 years. Classes are held during the 21-day mesocycle, 5 times a week, twice a day. Things were aimed at enhancing the development of indicators of special speed endurance. Results : The dynamics of the running speed of the model segments that characterize speed endurance athletes. Proved that the improved running 400 meter intervals helps reduce travel time competitive distance of 1500 meters. Conclusion : The use of the program contributes to higher speed endurance, which determines the result in the women's 1,500 meters.

  19. Effect of speed endurance training and reduced training volume on running economy and single muscle fiber adaptations in trained runners.

    Science.gov (United States)

    Skovgaard, Casper; Christiansen, Danny; Christensen, Peter M; Almquist, Nicki W; Thomassen, Martin; Bangsbo, Jens

    2018-02-01

    The aim of the present study was to examine whether improved running economy with a period of speed endurance training and reduced training volume could be related to adaptations in specific muscle fibers. Twenty trained male (n = 14) and female (n = 6) runners (maximum oxygen consumption (VO 2 -max): 56.4 ± 4.6 mL/min/kg) completed a 40-day intervention with 10 sessions of speed endurance training (5-10 × 30-sec maximal running) and a reduced (36%) volume of training. Before and after the intervention, a muscle biopsy was obtained at rest, and an incremental running test to exhaustion was performed. In addition, running at 60% vVO 2 -max, and a 10-km run was performed in a normal and a muscle slow twitch (ST) glycogen-depleted condition. After compared to before the intervention, expression of mitochondrial uncoupling protein 3 (UCP3) was lower (P economy at 60% vVO 2 -max (11.6 ± 0.2 km/h) and at v10-km (13.7 ± 0.3 km/h) was ~2% better (P economy with intense training may be related to changes in expression of proteins linked to energy consuming processes in primarily ST muscle fibers. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  20. Responsiveness of the Countermovement Jump and Handgrip Strength to an Incremental Running Test in Endurance Athletes: Influence of Sex.

    Science.gov (United States)

    García-Pinillos, Felipe; Delgado-Floody, Pedro; Martínez-Salazar, Cristian; Latorre-Román, Pedro Á

    2018-03-01

    The present study analyzed the acute effects of an incremental running test on countermovement jump (CMJ) and handgrip strength performance in endurance athletes, considering the effect of post-exercise recovery time and sex. Thirty-three recreationally trained long-distance runners, 20 men and 13 women, participated voluntarily in this study. The participants performed the Léger test, moreover, the CMJ and handgrip strength tests were carried out before and after the running test and during different stages of recovery (at the 1st min of recovery (posttest1), 5th min of recovery (posttest2), and 10th min of recovery (posttest3)). Two-way analysis of variance revealed a significant improvement in the CMJ (pre-posttest1, p = 0.001) and handgrip strength (pre-posttest2, p = 0.017) during recovery time. The Pearson's Chi-2 test showed no significant relationship ( p ≥ 0.05) between sex and post-activation potentiation (PAP). A linear regression analysis pointed to heart rate recovery as a predictive factor of CMJ improvement (PAP). In conclusion, despite significant fatigue reached during the Léger test, the long-distance runners did not experience an impaired CMJ and handgrip strength performance, either men or women, achieving an improvement (PAP) in posttest conditions. The results obtained showed no significant relationship between sex and PAP. Moreover, significant effect of recovery after running at high intensity on CMJ performance and handgrip strength was found. Finally, the data suggest that PAP condition can be predicted by heart rate recovery in endurance runners.

  1. Collagen gene interactions and endurance running performance

    African Journals Online (AJOL)

    to complete any of the individual components (3.8 km swim, 180 km bike or 42.2 km run) of the 226 km event. The major ... may affect normal collagen fibrillogenesis and alter the mechanical properties of ... using a XP Thermal Cycler (Block model XP-G, BIOER Technology Co.,. Japan). ..... New insights into the function of.

  2. Endurance performance and nocturnal HRV indices.

    Science.gov (United States)

    Nummela, A; Hynynen, E; Kaikkonen, P; Rusko, H

    2010-03-01

    The effects of endurance training on endurance performance characteristics and cardiac autonomic modulation during night sleep were investigated. Twenty-four sedentary subjects trained over four weeks two hours per week at an average running intensity of 76+/-4% of their heart rate reserve. The R to R ECG-intervals were recorded and heart rate variability indices including high frequency power (HFP) were calculated for the nights following the training days every week. The subjects were divided into responders and non-responders according to the improvements in the maximal velocity of the incremental treadmill test (v(max)). The responders improved their v(max) by 10.9+/-46 % (p < 0.001) while no changes were observed in the non-responders (1.6+/-3.0%), although there were no differences in any training load variables between the groups. In the responders nocturnal HFP was significantly higher during the fourth training week compared to the first training week (p=0.036). Furthermore, a significant correlation was observed between the change in v(max) and the change in nocturnal HFP (r=0.482, p=0.042). It was concluded that after similar training, an increase in cardiac vagal modulation was related to improved v(max) in the sedentary subjects. Georg Thieme Verlag KG Stuttgart.New York.

  3. The effects of creatine and glycerol hyperhydration on running economy in well trained endurance runners

    Directory of Open Access Journals (Sweden)

    Beis Lukas Y

    2011-12-01

    Full Text Available Abstract Background Ingestion of creatine (Cr and glycerol (Gly has been reported to be an effective method in expanding water compartments within the human body, attenuating the rise in heart rate (HR and core temperature (Tcore during exercise in the heat. Despite these positive effects, a substantial water retention could potentially impair endurance performance through increasing body mass (BM and consequently impacting negatively on running economy (RE. The objective of the present study was to investigate the effects of a combined Cr and Gly supplementation on thermoregulatory and cardiovascular responses and RE during running for 30 min at speed corresponding to 60% of maximal oxygen uptake (V˙O2max in hot and cool conditions. Methods Cr·H2O (11.4 g, Gly (1 g·kg-1 BM and Glucose polymer (75 g were administered twice daily to 15 male endurance runners during a 7-day period. Exercise trials were conducted pre- and post-supplementation at 10 and 35°C and 70% relative humidity. Results BM and total body water increased by 0.90 ± 0.40 kg (P P V˙O2 and therefore RE. Both HR and Tcore were attenuated significantly after supplementation (P Conclusions Combining Cr and Gly is effective in reducing thermal and cardiovascular strain during exercise in the heat without negatively impacting on RE.

  4. Mean platelet volume (MPV) predicts middle distance running performance.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Skafidas, Spyros; Tarperi, Cantor; Guidi, Gian Cesare; Schena, Federico

    2014-01-01

    performance. The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance.

  5. Mean platelet volume (MPV predicts middle distance running performance.

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    performance.The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance.

  6. Running Performance, VO2max, and Running Economy: The Widespread Issue of Endogenous Selection Bias.

    Science.gov (United States)

    Borgen, Nicolai T

    2018-05-01

    Studies in sport and exercise medicine routinely use samples of highly trained individuals in order to understand what characterizes elite endurance performance, such as running economy and maximal oxygen uptake VO 2max . However, it is not well understood in the literature that using such samples most certainly leads to biased findings and accordingly potentially erroneous conclusions because of endogenous selection bias. In this paper, I review the current literature on running economy and VO 2max , and discuss the literature in light of endogenous selection bias. I demonstrate that the results in a large part of the literature may be misleading, and provide some practical suggestions as to how future studies may alleviate endogenous selection bias.

  7. Running performance at high running velocities is impaired but V'O(₂max and peripheral endothelial function are preserved in IL-6⁻/⁻ mice.

    Directory of Open Access Journals (Sweden)

    Marta Wojewoda

    Full Text Available It has been reported that IL-6 knockout mice (IL-6⁻/⁻ possess lower endurance capacity than wild type mice (WT, however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6⁻/⁻ mice is linked to impaired maximal oxygen uptake (V'O(₂max, decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6⁻/⁻ mice than in WT mice (13.00±0.97 m·min⁻¹ vs. 16.89±1.15 m·min⁻¹, P<0.02, respectively. Moreover, the time to exhaustion during running at 12 m·min⁻¹ in IL-6⁻/⁻ mice was significantly shorter (P<0.05 than in WT mice. V'O(₂max in IL-6⁻/⁻ (n = 20 amounting to 108.3±2.8 ml·kg⁻¹·min⁻¹ was similar as in WT mice (n = 22 amounting to 113.0±1.8 ml·kg⁻¹·min⁻¹, (P = 0.16. No difference in maximal COX activity between the IL-6⁻/⁻ and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6⁻/⁻ mice. Surprisingly, plasma lactate concentration during running at 8 m·min⁻¹ as well at maximal running velocity in IL-6⁻/⁻ mice was significantly lower (P<0.01 than in WT mice. Interestingly, IL-6⁻/⁻ mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca²⁺-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6⁻/⁻ mice could not be explained by reduced V'O(₂max, endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance

  8. Running performance at high running velocities is impaired but V'O(₂max) and peripheral endothelial function are preserved in IL-6⁻/⁻ mice.

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    Wojewoda, Marta; Kmiecik, Katarzyna; Ventura-Clapier, Renée; Fortin, Dominique; Onopiuk, Marta; Jakubczyk, Justyna; Sitek, Barbara; Fedorowicz, Andrzej; Majerczak, Joanna; Kaminski, Karol; Chlopicki, Stefan; Zoladz, Jerzy Andrzej

    2014-01-01

    It has been reported that IL-6 knockout mice (IL-6⁻/⁻) possess lower endurance capacity than wild type mice (WT), however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6⁻/⁻ mice is linked to impaired maximal oxygen uptake (V'O(₂max)), decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6⁻/⁻ mice than in WT mice (13.00±0.97 m·min⁻¹ vs. 16.89±1.15 m·min⁻¹, P<0.02, respectively). Moreover, the time to exhaustion during running at 12 m·min⁻¹ in IL-6⁻/⁻ mice was significantly shorter (P<0.05) than in WT mice. V'O(₂max) in IL-6⁻/⁻ (n = 20) amounting to 108.3±2.8 ml·kg⁻¹·min⁻¹ was similar as in WT mice (n = 22) amounting to 113.0±1.8 ml·kg⁻¹·min⁻¹, (P = 0.16). No difference in maximal COX activity between the IL-6⁻/⁻ and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6⁻/⁻ mice. Surprisingly, plasma lactate concentration during running at 8 m·min⁻¹ as well at maximal running velocity in IL-6⁻/⁻ mice was significantly lower (P<0.01) than in WT mice. Interestingly, IL-6⁻/⁻ mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca²⁺-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6⁻/⁻ mice could not be explained by reduced V'O(₂max), endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance

  9. Running Performance at High Running Velocities Is Impaired but V′O2max and Peripheral Endothelial Function Are Preserved in IL-6−/− Mice

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    Wojewoda, Marta; Kmiecik, Katarzyna; Ventura-Clapier, Renée; Fortin, Dominique; Onopiuk, Marta; Jakubczyk, Justyna; Sitek, Barbara; Fedorowicz, Andrzej; Majerczak, Joanna; Kaminski, Karol; Chlopicki, Stefan; Zoladz, Jerzy Andrzej

    2014-01-01

    It has been reported that IL-6 knockout mice (IL-6−/−) possess lower endurance capacity than wild type mice (WT), however the underlying mechanism is poorly understood. The aim of the present work was to examine whether reduced endurance running capacity in IL-6−/− mice is linked to impaired maximal oxygen uptake (V′O2max), decreased glucose tolerance, endothelial dysfunction or other mechanisms. Maximal running velocity during incremental running to exhaustion was significantly lower in IL-6−/− mice than in WT mice (13.00±0.97 m.min−1 vs. 16.89±1.15 m.min−1, P<0.02, respectively). Moreover, the time to exhaustion during running at 12 m.min−1 in IL-6−/− mice was significantly shorter (P<0.05) than in WT mice. V′O2max in IL-6−/− (n = 20) amounting to 108.3±2.8 ml.kg−1.min−1 was similar as in WT mice (n = 22) amounting to 113.0±1.8 ml.kg−1.min−1, (P = 0.16). No difference in maximal COX activity between the IL-6−/− and WT mice in m. soleus and m. gastrocnemius was found. Moreover, no impairment of peripheral endothelial function or glucose tolerance was found in IL-6−/− mice. Surprisingly, plasma lactate concentration during running at 8 m.min−1 as well at maximal running velocity in IL-6−/− mice was significantly lower (P<0.01) than in WT mice. Interestingly, IL-6−/− mice displayed important adaptive mechanisms including significantly lower oxygen cost of running at a given speed accompanied by lower expression of sarcoplasmic reticulum Ca2+-ATPase and lower plasma lactate concentrations during running at submaximal and maximal running velocities. In conclusion, impaired endurance running capacity in IL-6−/− mice could not be explained by reduced V′O2max, endothelial dysfunction or impaired muscle oxidative capacity. Therefore, our results indicate that IL-6 cannot be regarded as a major regulator of exercise capacity but rather as a modulator of endurance performance. Furthermore, we

  10. Heat acclimation responses of an ultra-endurance running group preparing for hot desert-based competition.

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    Costa, Ricardo J S; Crockford, Michael J; Moore, Jonathan P; Walsh, Neil P

    2014-01-01

    Heat acclimation induces adaptations that improve exercise tolerance in hot conditions. Here we report novel findings into the effects of ultra-marathon specific exercise load in increasing hot ambient conditions on indices of heat acclimation. Six male ultra-endurance runners completed a standard pre-acclimation protocol at 20°C ambient temperature (T amb), followed by a heat acclimation protocol consisting of six 2 h running exercise-heat exposures (EH) at 60% VO2max on a motorised treadmill in an environmental chamber. Three EH were performed at 30°C T amb, followed by another three EH at 35°C T amb. EH were separated by 48 h within T amb and 72 h between T amb. Nude body mass (NBM), blood and urine samples were collected pre-exercise; while NBM and urine were collected post-exercise. Rectal temperature (T re), heart rate (HR), thermal comfort rating (TCR) and rating of perceived exertion were measured pre-exercise and monitored every 5 min during exercise. Water was provided ad libitum during exercise. Data were analysed using a repeated measures and one-way analysis of variance (ANOVA), with post hoc Tukey's HSD. Significance was accepted as Pheat acclimation in all ultra-endurance runners. Further, heat acclimation responses occurred with increasing EH to 35°C T amb. Preventing exertional heat illnesses and optimising performance outcomes in ultra-endurance runners may occur with exposure to at least 2 h of exercise-heat stress on at least two occasions in the days leading up to multi-stage ultra-marathon competition in the heat.

  11. The Acute Effect of Concurrent Training on Running Performance over 6 Days

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    Doma, Kenji; Deakin, Glen

    2015-01-01

    Purpose: This study examined the effects of strength training on alternating days and endurance training on consecutive days on running performance for 6 days. Methods: Sixteen male and 8 female moderately trained individuals were evenly assigned into concurrent-training (CCT) and strength-training (ST) groups. The CCT group undertook strength…

  12. Significant Effect of a Pre-Exercise High-Fat Meal after a 3-Day High-Carbohydrate Diet on Endurance Performance

    Directory of Open Access Journals (Sweden)

    Ikuma Murakami

    2012-06-01

    Full Text Available We investigated the effect of macronutrient composition of pre-exercise meals on endurance performance. Subjects consumed a high-carbohydrate diet at each meal for 3 days, followed by a high-fat meal (HFM; 1007 ± 21 kcal, 30% CHO, 55% F and 15% P or high-carbohydrate meal (HCM; 1007 ± 21 kcal, 71% CHO, 20% F and 9% P 4 h before exercise. Furthermore, just prior to the test, subjects in the HFM group ingested either maltodextrin jelly (M or a placebo jelly (P, while subjects in the HCM ingested a placebo jelly. Endurance performance was measured as running time until exhaustion at a speed between lactate threshold and the onset of blood lactate accumulation. All subjects participated in each trial, randomly assigned at weekly intervals. We observed that the time until exhaustion was significantly longer in the HFM + M (p < 0.05 than in HFM + P and HCM + P conditions. Furthermore, the total amount of fat oxidation during exercise was significantly higher in HFM + M and HFM + P than in HCM + P (p < 0.05. These results suggest that ingestion of a HFM prior to exercise is more favorable for endurance performance than HCM. In addition, HFM and maltodextrin ingestion following 3 days of carbohydrate loading enhances endurance running performance.

  13. "Functional" Inspiratory and Core Muscle Training Enhances Running Performance and Economy.

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    Tong, Tomas K; McConnell, Alison K; Lin, Hua; Nie, Jinlei; Zhang, Haifeng; Wang, Jiayuan

    2016-10-01

    Tong, TK, McConnell, AK, Lin, H, Nie, J, Zhang, H, and Wang, J. "Functional" inspiratory and core muscle training enhances running performance and economy. J Strength Cond Res 30(10): 2942-2951, 2016-We compared the effects of two 6-week high-intensity interval training interventions. Under the control condition (CON), only interval training was undertaken, whereas under the intervention condition (ICT), interval training sessions were followed immediately by core training, which was combined with simultaneous inspiratory muscle training (IMT)-"functional" IMT. Sixteen recreational runners were allocated to either ICT or CON groups. Before the intervention phase, both groups undertook a 4-week program of "foundation" IMT to control for the known ergogenic effect of IMT (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets per day, 6 days per week). The subsequent 6-week interval running training phase consisted of 3-4 sessions per week. In addition, the ICT group undertook 4 inspiratory-loaded core exercises (10 repetitions per set, 2 sets per day, inspiratory load set at 50% post-IMT P0) immediately after each interval training session. The CON group received neither core training nor functional IMT. After the intervention phase, global inspiratory and core muscle functions increased in both groups (p ≤ 0.05), as evidenced by P0 and a sport-specific endurance plank test (SEPT) performance, respectively. Compared with CON, the ICT group showed larger improvements in SEPT, running economy at the speed of the onset of blood lactate accumulation, and 1-hour running performance (3.04% vs. 1.57%, p ≤ 0.05). The changes in these variables were interindividually correlated (r ≥ 0.57, n = 16, p ≤ 0.05). Such findings suggest that the addition of inspiratory-loaded core conditioning into a high-intensity interval training program augments the influence of the interval program on endurance running performance and that this may be

  14. 5000 Meter Run Performance is not Enhanced 24 Hrs After an Intense Exercise Bout and Cold Water Immersion.

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    Stenson, Mary C; Stenson, Matthew R; Matthews, Tracey D; Paolone, Vincent J

    2017-06-01

    Cold water immersion (CWI) is used by endurance athletes to speed recovery between exercise bouts, but little evidence is available on the effects of CWI on subsequent endurance performance. The purpose of this study was to investigate the effects of CWI following an acute bout of interval training on 5000 m run performance 24 hrs after interval training, perceived muscle soreness (PMS), range of motion (ROM), thigh circumference (TC), and perceived exertion (RPE). Nine endurance-trained males completed 2 trials, each consisting of an interval training session of 8 repetitions of 1200 m at a running pace equal to 75% of VO 2 peak, either a control or CWI treatment, and a timed 5000 m run 24 hrs post interval training session. CWI was performed for 12 min at 12 degrees Celsius on the legs. Recovery treatments were performed in a counterbalanced design. Run time for 5000 m was not different between the CWI and control trials (CWI = 1317.33 ± 128.33 sec, control = 1303.44 ± 105.53 sec; p = 0.48). PMS increased significantly from baseline to immediately post exercise (BL = 1.17 ± 0.22, POST = 2.81 ± 0.52; p = 0.02) and remained elevated from baseline to 24 hrs post exercise (POST24 = 2.19 ± 0.32; p = 0.02), but no difference was observed between the treatments. No differences were observed for the interaction between time and treatment for TC (λ = 0.73, p = 0.15) and ROM (λ = 0.49; p = 0.10). CWI performed immediately following an interval training exercise bout did not enhance subsequent 5000 m run performance or reduce PMS. CWI may not provide a recovery or performance advantage when athletes are accustomed to the demands of the prior exercise bout.

  15. Differential satellite cell density of type I and II fibres with lifelong endurance running in old men

    DEFF Research Database (Denmark)

    Mackey, Abigail; Karlsen, A; Couppé, C

    2014-01-01

    AIM: To investigate the influence of lifelong endurance running on the satellite cell pool of type I and type II fibres in healthy human skeletal muscle. METHODS: Muscle biopsies were collected from 15 healthy old trained men (O-Tr) who had been running 43 ± 16 (mean ± SD) kilometres a week for 28...... ± 9 years. Twelve age-matched untrained men (O-Un) and a group of young trained and young untrained men were recruited for comparison. Frozen sections were immunohistochemically stained for Pax7, type I myosin and laminin, from which fibre area, the number of satellite cells, and the relationship......-Un. A strong positive relationship between fibre size and satellite cell content was detected in trained individuals. In line with a history of myofibre repair, a greater number of fibres with centrally located myonuclei were detected in O-Tr. CONCLUSION: Lifelong endurance training (i) does not deplete...

  16. Sympatho-adrenergic activation by endurance exercise: Effect on metanephrines spillover and its role in predicting athlete's performance.

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    Danese, Elisa; Tarperi, Cantor; Salvagno, Gian Luca; Guzzo, Alessandra; Sanchis-Gomar, Fabian; Festa, Luca; Bertinato, Luciano; Montagnana, Martina; Schena, Federico; Lippi, Giuseppe

    2018-03-20

    The sympatho-adrenergic activation during exercise is implicated in many cardiovascular respiratory and metabolic adaptations which have been thought to partially explain the different levels of performance observed between trained and untrained subjects. To date, no evidence exists about the association between competition performance and markers of "acute stress response". We designed this study to investigate; (i) the acute sympatho-adrenergic activation during endurance exercise in recreational runners by measuring plasma levels of free metanephrine (MN) and normethanephrine (NMN) before and after a half-marathon run; (ii) the association between the metanephrines levels and the running time. 26 amateur runners (15 males, 11 females) aged 30 to 63 years were enrolled. The quantification of MN and NMN was performed by LC-MS/MS. Anthropometric ergonomic and routine laboratory data were recorded. Statistical analyses included paired T -test, univariate and multivariate regressions. The post-run values of MN and NMN displayed a nearly 3.5 and 7 fold increase respectively compared to the baseline values ( p performance. No correlations were found for MN values. NMN is a reliable marker of sympatho-adrenergic activation by exercise and can predict endurance performance in the individual athlete. Adaptation phenomenon occurring not only in the adrenal medulla might represent the biological mechanism underlying this association. Further studies on sympatho-adrenergic activation, competition performance and training status should contemplate the measurement of these metabolites instead of their unstable precursors.

  17. Comparability and repeatability of three commonly used methods for measuring endurance capacity.

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    Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

    2017-12-01

    Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

  18. Consumo de aminoácidos de cadeia ramificada não afeta o desempenho de endurance Branched-chain amino acids ingestion does not affect endurance performance

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    Marco Carlos Uchida

    2008-02-01

    utilization, the subjects (n=17 were submitted to a prior exercise trial (one bout of running at 75% of VO2max for 40 min followed by two bouts at 90% of VO2max for 10 min each. Subsequently, the participants performed an endurance test (running at 90% of the anaerobic threshold until exhaustion after the ingestion of 77 mg.kg-1 of BCAA or placebo, in a double blind crossover design. Both trials, BCAA and placebo, were a week apart. No differences were observed between placebo and BCAA experimental conditions regarding time to exhaustion (50.1±8.9 vs 52.4±4.5 min, respectively and total distance performed (8.8±1.3 vs 9.1±0.6 km, respectively in endurance capacity test. Furthermore, no difference was observed in glucose, lactate or ammonia plasma concentration between both experimental conditions. In conclusion, BCAA supplementation did not affect endurance exercise performance.

  19. Mixed maximal and explosive strength training in recreational endurance runners.

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    Taipale, Ritva S; Mikkola, Jussi; Salo, Tiina; Hokka, Laura; Vesterinen, Ville; Kraemer, William J; Nummela, Ari; Häkkinen, Keijo

    2014-03-01

    Supervised periodized mixed maximal and explosive strength training added to endurance training in recreational endurance runners was examined during an 8-week intervention preceded by an 8-week preparatory strength training period. Thirty-four subjects (21-45 years) were divided into experimental groups: men (M, n = 9), women (W, n = 9), and control groups: men (MC, n = 7), women (WC, n = 9). The experimental groups performed mixed maximal and explosive exercises, whereas control subjects performed circuit training with body weight. Endurance training included running at an intensity below lactate threshold. Strength, power, endurance performance characteristics, and hormones were monitored throughout the study. Significance was set at p ≤ 0.05. Increases were observed in both experimental groups that were more systematic than in the control groups in explosive strength (12 and 13% in men and women, respectively), muscle activation, maximal strength (6 and 13%), and peak running speed (14.9 ± 1.2 to 15.6 ± 1.2 and 12.9 ± 0.9 to 13.5 ± 0.8 km Ł h). The control groups showed significant improvements in maximal and explosive strength, but Speak increased only in MC. Submaximal running characteristics (blood lactate and heart rate) improved in all groups. Serum hormones fluctuated significantly in men (testosterone) and in women (thyroid stimulating hormone) but returned to baseline by the end of the study. Mixed strength training combined with endurance training may be more effective than circuit training in recreational endurance runners to benefit overall fitness that may be important for other adaptive processes and larger training loads associated with, e.g., marathon training.

  20. How does high-intensity intermittent training affect recreational endurance runners? Acute and chronic adaptations: A systematic review

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    Felipe García-Pinillos

    2017-03-01

    Conclusion: HIIT-based running plans (2 to 3 HIIT sessions per week, combining HIIT and CR runs show athletic performance improvements in endurance runners by improving maximal oxygen uptake and running economy along with muscular and metabolic adaptations. To maximize the adaptations to training, both HIIT and CR must be part of training programs for endurance runners.

  1. Running Technique is an Important Component of Running Economy and Performance

    Science.gov (United States)

    FOLLAND, JONATHAN P.; ALLEN, SAM J.; BLACK, MATTHEW I.; HANDSAKER, JOSEPH C.; FORRESTER, STEPHANIE E.

    2017-01-01

    ABSTRACT Despite an intuitive relationship between technique and both running economy (RE) and performance, and the diverse techniques used by runners to achieve forward locomotion, the objective importance of overall technique and the key components therein remain to be elucidated. Purpose This study aimed to determine the relationship between individual and combined kinematic measures of technique with both RE and performance. Methods Ninety-seven endurance runners (47 females) of diverse competitive standards performed a discontinuous protocol of incremental treadmill running (4-min stages, 1-km·h−1 increments). Measurements included three-dimensional full-body kinematics, respiratory gases to determine energy cost, and velocity of lactate turn point. Five categories of kinematic measures (vertical oscillation, braking, posture, stride parameters, and lower limb angles) and locomotory energy cost (LEc) were averaged across 10–12 km·h−1 (the highest common velocity < velocity of lactate turn point). Performance was measured as season's best (SB) time converted to a sex-specific z-score. Results Numerous kinematic variables were correlated with RE and performance (LEc, 19 variables; SB time, 11 variables). Regression analysis found three variables (pelvis vertical oscillation during ground contact normalized to height, minimum knee joint angle during ground contact, and minimum horizontal pelvis velocity) explained 39% of LEc variability. In addition, four variables (minimum horizontal pelvis velocity, shank touchdown angle, duty factor, and trunk forward lean) combined to explain 31% of the variability in performance (SB time). Conclusions This study provides novel and robust evidence that technique explains a substantial proportion of the variance in RE and performance. We recommend that runners and coaches are attentive to specific aspects of stride parameters and lower limb angles in part to optimize pelvis movement, and ultimately enhance performance

  2. Strength Training Prior to Endurance Exercise: Impact on the Neuromuscular System, Endurance Performance and Cardiorespiratory Responses

    Directory of Open Access Journals (Sweden)

    Conceição Matheus

    2014-12-01

    Full Text Available This study aimed to investigate the acute effects of two strength-training protocols on the neuromuscular and cardiorespiratory responses during endurance exercise. Thirteen young males (23.2 ± 1.6 years old participated in this study. The hypertrophic strength-training protocol was composed of 6 sets of 8 squats at 75% of maximal dynamic strength. The plyometric strength-training protocol was composed of 6 sets of 8 jumps performed with the body weight as the workload. Endurance exercise was performed on a cycle ergometer at a power corresponding to the second ventilatory threshold until exhaustion. Before and after each protocol, a maximal voluntary contraction was performed, and the rate of force development and electromyographic parameters were assessed. After the hypertrophic strengthtraining and plyometric strength-training protocol, significant decreases were observed in the maximal voluntary contraction and rate of force development, whereas no changes were observed in the electromyographic parameters. Oxygen uptake and a heart rate during endurance exercise were not significantly different among the protocols. However, the time-to-exhaustion was significantly higher during endurance exercise alone than when performed after hypertrophic strength-training or plyometric strength-training (p <0.05. These results suggest that endurance performance may be impaired when preceded by strength-training, with no oxygen uptake or heart rate changes during the exercise.

  3. Influence of stress and recovery on endurance performance indicators

    NARCIS (Netherlands)

    Otter, Ruby; Brink, Michel; Lemmink, Koen

    2016-01-01

    Endurance athletes seek for the optimal balance in stress and recovery so that they can perform at their best. However, it is still largely unknown how psychosocial stress and recovery influence performance indicators of endurance athletes. Therefore, the aim of the study was to investigate how

  4. Effect of post-exercise hydrotherapy water temperature on subsequent exhaustive running performance in normothermic conditions.

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    Dunne, Alan; Crampton, David; Egaña, Mikel

    2013-09-01

    Despite the widespread use of cold water immersion (CWI) in normothermic conditions, little data is available on its effect on subsequent endurance performance. This study examined the effect of CWI as a recovery strategy on subsequent running performance in normothermic ambient conditions (∼22°C). Nine endurance-trained men completed two submaximal exhaustive running bouts on three separate occasions. The running bouts (Ex1 and Ex2) were separated by 15min of un-immersed seated rest (CON), hip-level CWI at 8°C (CWI-8) or hip-level CWI at 15°C (CWI-15). Intestinal temperature, blood lactate and heart rate were recorded throughout and V˙O2, running economy and exercise times were recorded during the running sessions. Running time to failure (min) during Ex2 was significantly (p<0.05, ES=0.7) longer following CWI-8 (27.7±6.3) than CON (23.3±5) but not different between CWI-15 (26.3±3.4) and CON (p=0.06, ES=0.7) or CWI-8 and CWI-15 (p=0.4, ES=0.2). Qualitative analyses showed a 95% and 89% likely beneficial effect of CWI-8 and CWI-15 during Ex2 compared with CON, respectively. Time to failure during Ex2 was significantly shorter than Ex1 only during the CON condition. Intestinal temperature and HR were significantly lower for most of Ex2 during CWI-8 and CWI-15 compared with CON but they were similar at failure for the three conditions. Blood lactate, running economy and V˙O2 were not altered by CWI. These data indicate that a 15min period of cold water immersion applied between repeated exhaustive exercise bouts significantly reduces intestinal temperature and enhances post-immersion running performance in normothermic conditions. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players

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    Iaia, F. Marcello; Fiorenza, Matteo; Perri, Enrico; Alberti, Giampietro; Millet, Grégoire P.; Bangsbo, Jens

    2015-01-01

    In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6–8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6–8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (pstrategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles’ ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players. PMID:26394225

  6. Concurrent speed endurance and resistance training improves performance, running economy and muscle NHE1 in moderately trained runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Christensen, Peter Møller; Larsen, Sonni

    2014-01-01

    , content of muscle Na(+)/K(+) pump subunits and MCT4 were unaltered. No changes were observed in CON. The present study demonstrates that SET and HRT, when performed in succession, leads to improvements in both short- and long-term running performance together with improved running economy as well...

  7. Effect of thyme extract supplementation on lipid peroxidation, antioxidant capacity, PGC-1α content and endurance exercise performance in rats.

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    Khani, Mostafa; Motamedi, Pezhman; Dehkhoda, Mohammad Reza; Dabagh Nikukheslat, Saeed; Karimi, Pouran

    2017-01-01

    Athletes have a large extent of oxidant agent production. In the current study, we aimed to determine the influence of thyme extract on the endurance exercise performance, mitochondrial biogenesis, and antioxidant status in rats. Twenty male Wistar rats were randomly divided into two groups receiving either normal drinking water (non-supplemented group, n  = 10) or thyme extract, 400 mg/kg, (supplemented group, n  = 10). Rats in both groups were subjected to endurance treadmill training (27 m/min, 10% grade, 60 min, and 5 days/week for 8 weeks). Finally, to determine the endurance capacity, time to exhaustion treadmill running at 36 m/min speed was assessed. At the end of the endurance capacity test, serum and soleus muscle samples were collected and their superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as well as malondialdehyde (MDA) concentration were measured. Protein expression of PGC-1α, as a marker of mitochondrial biogenesis, was also determined in the soleus muscle tissue by immunoblotting assay. Findings revealed that the exhaustive running time in the treatment group was significantly ( p  extract supplemented group (t 18  = 8.11, p  antioxidant capacity between groups. Furthermore, thyme supplementation significantly ( p  extract supplementation increased endurance exercise tolerance in intact animals, although decrease of oxidative stress and regulation of the PGC-1α protein expression are not considered as underlying molecular mechanisms.

  8. Combined supplementation of carbohydrate, alanine, and proline is effective in maintaining blood glucose and increasing endurance performance during long-term exercise in mice.

    Science.gov (United States)

    Nogusa, Yoshihito; Mizugaki, Ami; Hirabayashi-Osada, Yuri; Furuta, Chie; Ohyama, Kana; Suzuki, Katsuya; Kobayashi, Hisamine

    2014-01-01

    Carbohydrate supplementation is extremely important during prolonged exercise because it maintains blood glucose levels during later stages of exercise. In this study, we examined whether maintaining blood glucose levels by carbohydrate supplementation could be enhanced during long-term exercise by combining this supplementation with alanine and proline, which are gluconeogenic amino acids, and whether such a combination would affect exercise endurance performance. Male C57BL/6J mice were orally administered either maltodextrin (1.25 g/kg) or maltodextrin (1.0 g/kg) with alanine (0.225 g/kg) and proline (0.025 g/kg) 15 min before running for 170 min. Combined supplementation of maltodextrin, alanine, and proline induced higher blood glucose levels than isocaloric maltodextrin alone during the late exercise phase (100-170 min). The hepatic glycogen content of mice administered maltodextrin, alanine, and proline was higher than that of mice ingesting maltodextrin alone 60 min after beginning exercise, but the glycogen content of the gastrocnemius muscle showed no difference. We conducted a treadmill running test to determine the effect of alanine and proline on endurance performance. The test showed that running time to exhaustion of mice that were supplemented with maltodextrin (2.0 g/kg) was longer than that of mice that were supplemented with water alone. Maltodextrin supplementation (1.0 g/kg) with alanine (0.9 g/kg) and proline (0.1 g/kg) further increased running time to exhaustion compared to maltodextrin alone (2.0 g/kg). These results indicate that combined supplementation of carbohydrate, alanine, and proline is effective for maintaining blood glucose and hepatic glycogen levels and increasing endurance performance during long-term exercise in mice.

  9. Endurance training enhances skeletal muscle interleukin-15 in human male subjects

    DEFF Research Database (Denmark)

    Rinnov, Anders; Yfanti, Christina; Nielsen, Søren

    2014-01-01

    Regular endurance exercise promotes metabolic and oxidative changes in skeletal muscle. Overexpression of interleukin-15 (IL-15) in mice exerts similar metabolic changes in muscle as seen with endurance exercise. Muscular IL-15 production has been shown to increase in mice after weeks of regular...... endurance running. With the present study we aimed to determine if muscular IL-15 production would increase in human male subjects following 12 weeks of endurance training. In two different studies we obtained plasma and muscle biopsies from young healthy subjects performing: (1) 12 weeks of ergometer...... weeks of regular endurance training induced a 40% increase in basal skeletal muscle IL-15 protein content (p...

  10. DIFFERENT ENDURANCE CHARACTERISTICS OF FEMALE AND MALE GERMAN SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    C. Baumgart

    2014-08-01

    Full Text Available The aims of the present study were to assess gender differences regarding lactate threshold and intermittent shuttle run performance in female and male soccer players as well as to investigate the relationships between both endurance characteristics in both genders. Fourteen female (1st division and thirteen male (4th division soccer players completed an incremental test (IT to determine running velocities at 2 and 4 mmol · l-1 blood lactate (v2 and v4 and maximum velocity (vmax as well as an interval shuttle run test (ISRT to determine running distance. Based on v2 and v4 and their percentages in relation to vmax, three intensity zones were calculated: a low lactate zone (v4. Female soccer players have a lower v4 (8.2%, vmax (11.3% and ISRT distance (31.6%. No gender difference was found in v2. In contrast to males, ISRT distance correlates with vmax as well as with v2 and v4 in female soccer players. The intensity zones v4 differ between genders. The present study revealed that gender differences increase when the running performance is intermittent including change of directions. In both genders, different relationships between lactate threshold and intermittent shuttle run performance exist. During incremental testing, the running performances of female and male players reflect different distributions of aerobic and anaerobic metabolic pathways. The revealed gender differences should be considered for soccer endurance training.

  11. Prevalence in running events and running performance of endurance runners following a vegetarian or vegan diet compared to non-vegetarian endurance runners: the NURMI Study

    OpenAIRE

    Wirnitzer, Katharina; Seyfart, Tom; Leitzmann, Claus; Keller, Markus; Wirnitzer, Gerold; Lechleitner, Christoph; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat

    2016-01-01

    BACKGROUND: Beneficial and detrimental effects of various vegetarian and vegan diets on the health status are well known. Considering the growing background numbers of vegetarians and vegans, the number of vegetarian and vegan runners is likely to rise, too. Therefore, the Nutrition and Running High Mileage (NURMI) Study was designed as a comparative study to investigate the prevalence of omnivores, vegetarians, and vegans in running events and to detect potential differences in running perfo...

  12. Master athletes are extending the limits of human endurance

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    Romuald Lepers

    2016-12-01

    Full Text Available The increased participation of master athletes (i.e. > 40 years old in endurance and ultra-endurance events (> 6h duration over the past few decades has been accompanied by an improvement in their performances at a much faster rate than their younger counterparts. Ageing does however result in a decrease in overall endurance performance. Such age-related declines in performance depend upon the modes of locomotion, event duration and gender of the participant. For example, smaller age-related declines in cycling performance than in running and swimming have been documented. The relative stability of gender differences observed across the ages suggests that the age-related declines in physiological function did not differ between males and females. Among the main physiological determinants of endurance performance, the maximal oxygen consumption (VO2max appears to be the parameter that is most altered by age. Exercise economy and the exercise intensity at which a high fraction of VO2max can be sustained (i.e. lactate threshold, seem to decline to a lesser extent with advancing age. The ability to maintain a high exercise-training stimulus with advancing age is emerging as the single most important means of limiting the rate of decline in endurance performance. By constantly extending the limits of (ultra-endurance, master athletes therefore represent an important insight into the ability of humans to maintain physical performance and physiological function with advancing age.

  13. EFFECTS OF PALM VITAMIN E SUPPLEMENTATION ON EXERCISE-INDUCED OXIDATIVE STRESS AND ENDURANCE PERFORMANCE IN THE HEAT

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    Chen Chee Keong

    2006-12-01

    Full Text Available This study investigates the effects of tocotrienol-rich palm vitamin E supplementation on exercise-induced lipid peroxidation and endurance performance in the heat. In a double blind, cross-over study, eighteen healthy, male recreational athletes completed two endurance running trials, until exhaustion, on a motorized treadmill at 70% VO2max on two separate occasions following a 6-week supplementation regimen of either tocotrienol-rich palm vitamin E (E or placebo (P. Both trials were conducted in the heat (31oC, 70% relative humidity. During the trials, rectal temperature (Trec, ratings of perceived exertion (RPE and oxygen uptake (VO2 were recorded. Blood samples were collected for the determination of plasma volume changes (PVC, malondialdehyde (MDA, creatine kinase (CK, total antioxidant status (TAS and vitamin E. After the supplementation regimen, serum alpha-tocopherol increased ~33% but serum concentrations of tocotrienols were negligible. No significant differences were evident in mean Trec, RPE, VO2 or in the time to exhaustion between the E-supplemented and the placebo- supplemented groups. Similarly, mean PVC, CK and TAS were also not different between the two groups. Resting plasma mean MDA concentration in the E-supplemented group was significantly lower than that in the placebo-supplemented group. At exhaustion, plasma mean MDA was higher than the resting values in both groups. Although tocotrienol-rich palm vitamin E supplementation decreased lipid peroxidation at rest and, to some extent, during exercise in the heat, as evident from the lower MDA levels, it however did not enhance endurance running performance or prevent exercise-induced muscle damage or influenced body core temperature or plasma volume changes during exercise in the heat

  14. Altitude training for elite endurance performance: a 2012 update.

    Science.gov (United States)

    Fudge, Barry W; Pringle, Jamie S M; Maxwell, Neil S; Turner, Gareth; Ingham, Stephen A; Jones, Andrew M

    2012-01-01

    Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of performance on return to sea level. The purpose of the current review article was to update and evaluate recent literature relevant to the practical application of altitude training for endurance athletes. Consequently, the literature can be considered in either of two categories: performance-led investigations or mechanistic advancements/insights. Each section discusses the relevant literature and proposes future directions where appropriate.

  15. Vitamins and endurance training. Food for running or faddish claims?

    Science.gov (United States)

    van der Beek, E J

    1985-01-01

    The inter-relationship of food and physical performance, food is considered as a conglomerate of nutrients and man is depicted as a kind of organic pudding. This 'machine' concept of human performance in combination with the mysticism surrounding vitamins, has led to the faddish belief that additional vitamins are necessary to improve physical performance by means of supercharging the metabolic processes in the body. Various vitamins and their dietary recommendations as well as the indicators for vitamin status are discussed. It is concluded that a marginal or subclinical deficiency state can be defined as an intermediate between optimal vitamin status and frank clinical deficiency. Marginal deficiency is characterised by biochemical values deviating from statistically derived reference limits as well as the absence of clinical signs and symptoms of vitamin deficiency. Besides the static, mostly biochemical, indicators of vitamin status, more functional indicators are considered, among them work capacity. An extensive historical review on depletion studies, epidemiological surveys and supplementation studies is presented. It is concluded that a restricted intake of some B-complex vitamins-individually and in combination-of approximately less than 35 to 45% of the recommended dietary allowance may lead to decreased endurance capacity within a few weeks. Studies on ascorbic acid (vitamin C) depletion and fat-soluble vitamin A deficiency have noted no decrease of endurance capacity. However, in a few recent epidemiological surveys, biochemical vitamin C deficiency was actually shown to decrease aerobic power. Although the general conclusion is that a reduced water-soluble vitamin intake decreases endurance capacity, it is believed that further controlled experimentation is needed with B-complex vitamins and vitamin C individually. Furthermore, usually employed reference limits for vitamins need reappraisal translating them into impairment limits. With respect to the

  16. 10 km running performance predicted by a multiple linear regression model with allometrically adjusted variables.

    Science.gov (United States)

    Abad, Cesar C C; Barros, Ronaldo V; Bertuzzi, Romulo; Gagliardi, João F L; Lima-Silva, Adriano E; Lambert, Mike I; Pires, Flavio O

    2016-06-01

    The aim of this study was to verify the power of VO 2max , peak treadmill running velocity (PTV), and running economy (RE), unadjusted or allometrically adjusted, in predicting 10 km running performance. Eighteen male endurance runners performed: 1) an incremental test to exhaustion to determine VO 2max and PTV; 2) a constant submaximal run at 12 km·h -1 on an outdoor track for RE determination; and 3) a 10 km running race. Unadjusted (VO 2max , PTV and RE) and adjusted variables (VO 2max 0.72 , PTV 0.72 and RE 0.60 ) were investigated through independent multiple regression models to predict 10 km running race time. There were no significant correlations between 10 km running time and either the adjusted or unadjusted VO 2max . Significant correlations (p 0.84 and power > 0.88. The allometrically adjusted predictive model was composed of PTV 0.72 and RE 0.60 and explained 83% of the variance in 10 km running time with a standard error of the estimate (SEE) of 1.5 min. The unadjusted model composed of a single PVT accounted for 72% of the variance in 10 km running time (SEE of 1.9 min). Both regression models provided powerful estimates of 10 km running time; however, the unadjusted PTV may provide an uncomplicated estimation.

  17. Effect of speed endurance training and reduced training volume on running economy and single muscle fiber adaptations in trained runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Christiansen, Danny; Christensen, Peter Møller

    2018-01-01

    The aim of the present study was to examine whether improved running economy with a period of speed endurance training and reduced training volume could be related to adaptations in specific muscle fibers. Twenty trained male (n = 14) and female (n = 6) runners (maximum oxygen consumption (VO2 -m.......3 ± 0.3 vs. 18.9 ± 0.3 km/h) after than before the intervention. Thus, improved running economy with intense training may be related to changes in expression of proteins linked to energy consuming processes in primarily ST muscle fibers....

  18. Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration

    NARCIS (Netherlands)

    van Baak, M.A.; Mooij, J.M.

    1994-01-01

    Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration. Van Baak MA, Mooij JM. Department of Human Biology, University of Limburg, Maastricht, The Netherlands. To investigate the effect of glucose (Glc) infusion on endurance performance after

  19. Distance running as an ideal domain for showing a sex difference in competitiveness.

    Science.gov (United States)

    Deaner, Robert O

    2013-04-01

    Men are over-represented in the arts, sciences, and sports. This has been hypothesized to reflect an evolved male predisposition for enduring competitiveness or long-term motivation to improve one's performance and "show-off." Evidence for this hypothesis is equivocal, however, because there are viable alternative explanations for men's dominance in most cultural display domains. Here, I argue that distance running is an ideal domain for addressing this issue. Distance running is ideal because it indicates enduring competitiveness, allows objective comparisons, and is accessible, acceptable, and popular for both men and women. I review recent studies and present new data showing that substantially more men than women run relatively fast in the U.S., that this sex difference in relative performance can be attributed, at least in part, to men's greater training motivation, and that this pattern has been stable for several decades. Distance running thus provides compelling evidence for an evolved male predisposition for enduring competitiveness. I conclude with suggestions regarding how variation in achievement motivation can be informed by considering how evolved predispositions interact with environmental and social conditions.

  20. Physiological demands of running during long distance runs and triathlons.

    Science.gov (United States)

    Hausswirth, C; Lehénaff, D

    2001-01-01

    The aim of this review article is to identify the main metabolic factors which have an influence on the energy cost of running (Cr) during prolonged exercise runs and triathlons. This article proposes a physiological comparison of these 2 exercises and the relationship between running economy and performance. Many terms are used as the equivalent of 'running economy' such as 'oxygen cost', 'metabolic cost', 'energy cost of running', and 'oxygen consumption'. It has been suggested that these expressions may be defined by the rate of oxygen uptake (VO2) at a steady state (i.e. between 60 to 90% of maximal VO2) at a submaximal running speed. Endurance events such as triathlon or marathon running are known to modify biological constants of athletes and should have an influence on their running efficiency. The Cr appears to contribute to the variation found in distance running performance among runners of homogeneous level. This has been shown to be important in sports performance, especially in events like long distance running. In addition, many factors are known or hypothesised to influence Cr such as environmental conditions, participant specificity, and metabolic modifications (e.g. training status, fatigue). The decrease in running economy during a triathlon and/or a marathon could be largely linked to physiological factors such as the enhancement of core temperature and a lack of fluid balance. Moreover, the increase in circulating free fatty acids and glycerol at the end of these long exercise durations bear witness to the decrease in Cr values. The combination of these factors alters the Cr during exercise and hence could modify the athlete's performance in triathlons or a prolonged run.

  1. Upregulation of circulating IL-15 by treadmill running in healthy individuals: is IL-15 an endocrine mediator of the beneficial effects of endurance exercise?

    Science.gov (United States)

    Tamura, Yoshiaki; Watanabe, Keiichi; Kantani, Tomomi; Hayashi, Junichi; Ishida, Nobuhiko; Kaneki, Masao

    2011-01-01

    The beneficial effects of endurance exercise include insulin-sensitization and reduction of fat mass. Limited knowledge is available about the mechanisms by which endurance exercise exerts the salutary effects. Myokines, cytokines secreted by skeletal muscle, have been recognized as a potential mediator. Recently, a role of skeletal muscle-derived interleukin-15 (IL-15) in improvement of fat-lean body mass composition and insulin sensitivity has been proposed. Yet, previous studies have reported that endurance training does not increase production or secretion of IL-15 in skeletal muscle. Here, we show that in opposition to previous findings, 30-min treadmill running at 70% of age-predicted maximum heart rate resulted in a significant increase in circulating IL-15 level in untrained healthy young men. These findings suggest that IL-15 might play a role in the systemic anti-obesogenic and insulin-sensitizing effects of endurance exercise, not only as a paracrine and autocrine but also as an endocrine factor.

  2. The effects of elevated pain inhibition on endurance exercise performance

    Directory of Open Access Journals (Sweden)

    Andrew Flood

    2017-03-01

    Full Text Available Background The ergogenic effects of analgesic substances suggest that pain perception is an important regulator of work-rate during fatiguing exercise. Recent research has shown that endogenous inhibitory responses, which act to attenuate nociceptive input and reduce perceived pain, can be increased following transcranial direct current stimulation of the hand motor cortex. Using high-definition transcranial direct current stimulation (HD-tDCS; 2 mA, 20 min, the current study aimed to examine the effects of elevated pain inhibitory capacity on endurance exercise performance. It was hypothesised that HD-tDCS would enhance the efficiency of the endogenous pain inhibitory response and improve endurance exercise performance. Methods Twelve healthy males between 18 and 40 years of age (M = 24.42 ± 3.85 were recruited for participation. Endogenous pain inhibitory capacity and exercise performance were assessed before and after both active and sham (placebo stimulation. The conditioned pain modulation protocol was used for the measurement of pain inhibition. Exercise performance assessment consisted of both maximal voluntary contraction (MVC and submaximal muscular endurance performance trials using isometric contractions of the non-dominant leg extensors. Results Active HD-tDCS (pre-tDCS, −.32 ± 1.33 kg; post-tDCS, −1.23 ± 1.21 kg significantly increased pain inhibitory responses relative to the effects of sham HD-tDCS (pre-tDCS, −.91 ± .92 kg; post-tDCS, −.26 ± .92 kg; p = .046. Irrespective of condition, peak MVC force and muscular endurance was reduced from pre- to post-stimulation. HD-tDCS did not significantly influence this reduction in maximal force (active: pre-tDCS, 264.89 ± 66.87 Nm; post-tDCS, 236.33 ± 66.51 Nm; sham: pre-tDCS, 249.25 ± 88.56 Nm; post-tDCS, 239.63 ± 67.53 Nm or muscular endurance (active: pre-tDCS, 104.65 ± 42.36 s; post-tDCS, 93.07 ± 33.73 s; sham: pre-tDCS, 123.42 ± 72.48 s; post

  3. Is There an Optimal Speed for Economical Running?

    Science.gov (United States)

    Black, Matthew I; Handsaker, Joseph C; Allen, Sam J; Forrester, Stephanie E; Folland, Jonathan P

    2018-01-01

    The influence of running speed and sex on running economy is unclear and may have been confounded by measurements of oxygen cost that do not account for known differences in substrate metabolism, across a limited range of speeds, and differences in performance standard. Therefore, this study assessed the energy cost of running over a wide range of speeds in high-level and recreational runners to investigate the effect of speed (in absolute and relative terms) and sex (men vs women of equivalent performance standard) on running economy. To determine the energy cost (kcal · kg -1  · km -1 ) of submaximal running, speed at lactate turn point (sLTP), and maximal rate of oxygen uptake, 92 healthy runners (high-level men, n = 14; high-level women, n = 10; recreational men, n = 35; recreational women, n = 33) completed a discontinuous incremental treadmill test. There were no sex-specific differences in the energy cost of running for the recreational or high-level runners when compared at absolute or relative running speeds (P > .05). The absolute and relative speed-energy cost relationships for the high-level runners demonstrated a curvilinear U shape with a nadir reflecting the most economical speed at 13 km/h or 70% sLTP. The high-level runners were more economical than the recreational runners at all absolute and relative running speeds (P running, there is no sex-specific difference, and high-level endurance runners exhibit better running economy than recreational endurance runners.

  4. The changes in running economy during puberty in overweight and normal weight boys

    Directory of Open Access Journals (Sweden)

    Maciejczyk Marcin

    2015-03-01

    Full Text Available Study aim: running economy (RE is important indicator of endurance performance. During puberty dynamic changes in body composition and function are observed, as such RE is also expected to change. The aim of the study was to compare the running economy (RE in overweight and normoweight boys during a running exercise performed with constant velocity, and the assessment of changes in RE during puberty.

  5. Red light and the sleep quality and endurance performance of Chinese female basketball players.

    Science.gov (United States)

    Zhao, Jiexiu; Tian, Ye; Nie, Jinlei; Xu, Jincheng; Liu, Dongsen

    2012-01-01

    Good sleep is an important recovery method for prevention and treatment of overtraining in sport practice. Whether sleep is regulated by melatonin after red-light irradiation in athletes is unknown. To determine the effect of red light on sleep quality and endurance performance of Chinese female basketball players. Cohort study. Athletic training facility of the Chinese People's Liberation Army and research laboratory of the China Institute of Sport Science. Patients or Other Participants: Twenty athletes of the Chinese People's Liberation Army team (age = 18.60 6 3.60 years) took part in the study. Participants were divided into red-light treatment (n = 10) and placebo (n = 10) groups. The red-light treatment participants received 30 minutes of irradiation from a red-light therapy instrument every night for 14 days. The placebo group did not receive light illumination. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was completed, serum melatonin was assessed, and 12-minute run was performed at preintervention (baseline) and postintervention (14 days). The 14-day whole-body irradiation with red-light treatment improved the sleep, serum melatonin level, and endurance performance of the elite female basketball players (P Sleep Quality Index and serum melatonin levels (r = -0.695, P = .006). Our study confirmed the effectiveness of body irradiation with red light in improving the quality of sleep of elite female basketball players and offered a nonpharmacologic and noninvasive therapy to prevent sleep disorders after training.

  6. Improved running performance in hot humid conditions following whole body precooling.

    Science.gov (United States)

    Booth, J; Marino, F; Ward, J J

    1997-07-01

    On two separate occasions, eight subjects controlled speed to run the greatest distance possible in 30 min in a hot, humid environment (ambient temperature 32 degrees C, relative humidity 60%). For the experimental test (precooling), exercise was preceeded by cold-water immersion. Precooling increased the distance run by 304 +/- 166 m (P body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P body sweating are not different between tests. In conclusion, water immersion precooling increased exercise endurance in hot, humid conditions with an enhanced rate of heat storage and decreased thermoregulatory strain.

  7. APPENDIX TO THE MEASURING OF ENDURANCE OF CADETS IN HANDBALL

    Directory of Open Access Journals (Sweden)

    Dr Dragan Martinović

    2009-11-01

    Full Text Available At the sample of 80 handball cadet contestants aged between 16-17, there has been done an endurance testing in the discipline of running on a track of total of 12 and 6 minutes. The endurance was estimated in meters of the distance run. The aim of this task was to determine coorelation of the results in running on 12 and 6 minutes. The outcome is a total coorelation between the two. Running of the du- ration of 6 minutes is recommended for the trainer`s practice. Testing is more rational. With the application of the regressive analyses it has been determined that there is depenndance between running time and variables: weight, height and BMI

  8. Thoraco-abdominal coordination and performance during uphill running at altitude.

    Directory of Open Access Journals (Sweden)

    Eva Bernardi

    Full Text Available Running races on mountain trails at moderate-high altitude with large elevation changes throughout has become increasingly popular. During exercise at altitude, ventilatory demands increase due to the combined effects of exercise and hypoxia.To investigate the relationships between thoraco-abdominal coordination, ventilatory pattern, oxygen saturation (SpO2, and endurance performance in runners during high-intensity uphill exercise.Fifteen participants (13 males, mean age 42±9 yrs ran a "Vertical Kilometer," i.e., an uphill run involving a climb of approximately 1000 m with a slope greater than 30%. The athletes were equipped with a portable respiratory inductive plethysmography system, a finger pulse oximeter and a global positioning unit (GPS. The ventilatory pattern (ventilation (VE, tidal volume (VT, respiratory rate (RR, and VE/VT ratio, thoraco-abdominal coordination, which is represented by the phase angle (PhA, and SpO2 were evaluated at rest and during the run. Before and after the run, we assessed respiratory function, respiratory muscle strength and the occurrence of interstitial pulmonary edema by thoracic ultrasound.Two subjects were excluded from the respiratory inductive plethysmography analysis due to motion artifacts. A quadratic relationship between the slope and the PhA was observed (r = 0.995, p = 0.036. When the slope increased above 30%, the PhA increased, indicating a reduction in thoraco-abdominal coordination. The reduced thoraco-abdominal coordination was significantly related to reduced breathing efficiency (i.e., an increased VE/VT ratio; r = 0.961, p = 0.038 and SpO2 (r = -0.697, p<0.001. Lower SpO2 values were associated with lower speeds at 20%≥slope≤40% (r = 0.335, p<0.001 for horizontal and r = 0.36, p<0.001 for vertical. The reduced thoraco-abdominal coordination and consequent reduction in SpO2 were associated with interstitial pulmonary edema.Reductions in thoraco-abdominal coordination are associated

  9. The effect of graduated compression tights, compared with running shorts, on counter movement jump performance before and after submaximal running.

    Science.gov (United States)

    Rugg, Stuart; Sternlicht, Eric

    2013-04-01

    The purpose of this study was to determine if wearing graduated compression tights, compared with loose fitting running shorts, would increase and or help sustain counter movement jump (CMJ) height after submaximal running. Fourteen competitive runners (6 women and 8 men) participated in this study. The subjects' mean (±SD) for age, height, body mass, percent body fat, resting heart rate, and maximal heart rate were 28.2 ± 14.0 years, 174.7 ± 8.6 cm, 70.2 ± 14.9 kg, 15.5 ± 8.1%, 67.2 ± 7.4 b.min, and 186.5 ± 9.5 b.min, respectively. During testing, subjects wore a Polar RS400 heart rate monitor. Each trial consisted of 15 minutes of continual treadmill running with 5 minutes performed at 50%, 70%, and 85% of the subject's heart rate reserve. Using a Vertec vertical leaper, each subject performed 3 CMJ, both pre- and postrun trials, with the mean value used to measure relative leg power. In addition to the CMJ height data, each subject rated their level of perceived exertion (RPE), and their comfort level, after the postrun trials. The mean postrun CMJ height in graduated compression tights of 60.3 ± 19.4 cm was significantly greater (at the p shorts of 57.7 ± 19.6 cm (4.5% increase). In addition, the subjects reported a significantly lower level of perceived exertion and greater comfort values while wearing the graduated compression tights. The results of the present study support the use of graduated compression tights for maintenance of lower limb muscle power after submaximal endurance running.

  10. Bone health in endurance athletes: runners, cyclists, and swimmers.

    Science.gov (United States)

    Scofield, Kirk L; Hecht, Suzanne

    2012-01-01

    Weight-bearing exercise has been recognized widely to be beneficial for long-term bone health. However inherent differences in bone-loading characteristics and energy expenditure during participation in endurance sports place many endurance athletes at a relative disadvantage with regard to bone health compared with other athletes. Adolescents and adults who participate in endurance sports, such as running, and non-weight-bearing sports, such as biking and swimming, often have lower bone mineral density (BMD) than athletes participating in ball and power sports, and sometimes their BMD is lower than their inactive peers. Low BMD increases the risk of stress and fragility fractures, both while an athlete is actively competing and later in life. This article reviews the variable effects of distance running, cycling, swimming, and triathlons on bone health; the evaluation of stress and fragility fractures; and the diagnosis, management, and prevention of low BMD in endurance athletes.

  11. Angiotensin II receptor blocker telmisartan enhances running endurance of skeletal muscle through activation of the PPAR-δ/AMPK pathway.

    Science.gov (United States)

    Feng, Xiaoli; Luo, Zhidan; Ma, Liqun; Ma, Shuangtao; Yang, Dachun; Zhao, Zhigang; Yan, Zhencheng; He, Hongbo; Cao, Tingbing; Liu, Daoyan; Zhu, Zhiming

    2011-07-01

    Clinical trials have shown that angiotensin II receptor blockers reduce the new onset of diabetes in hypertensives; however, the underlying mechanisms remain unknown. We investigated the effects of telmisartan on peroxisome proliferator activated receptor γ (PPAR-δ) and the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway in cultured myotubes, as well as on the running endurance of wild-type and PPAR-δ-deficient mice. Administration of telmisartan up-regulated levels of PPAR-δ and phospho-AMPKα in cultured myotubes. However, PPAR-δ gene deficiency completely abolished the telmisartan effect on phospho-AMPKαin vitro. Chronic administration of telmisartan remarkably prevented weight gain, enhanced running endurance and post-exercise oxygen consumption, and increased slow-twitch skeletal muscle fibres in wild-type mice, but these effects were absent in PPAR-δ-deficient mice. The mechanism is involved in PPAR-δ-mediated stimulation of the AMPK pathway. Compared to the control mice, phospho-AMPKα level in skeletal muscle was up-regulated in mice treated with telmisartan. In contrast, phospho-AMPKα expression in skeletal muscle was unchanged in PPAR-δ-deficient mice treated with telmisartan. These findings highlight the ability of telmisartan to improve skeletal muscle function, and they implicate PPAR-δ as a potential therapeutic target for the prevention of type 2 diabetes. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  12. Peculiarities of endurance development for first year students

    Directory of Open Access Journals (Sweden)

    A.G. Pochernina

    2014-06-01

    Full Text Available Purpose: to determine the dynamics of the specific endurance first-year students in the classroom of physical education. Material : the study involved 20 students. Conducted educational testing: seed of lifting in supine position, hang on bent arms, jumping from sitting up with the stop, run 30m, bending and straightening the arms in emphasis lying, tilt forward from a sitting position, shuttle run, broad jump start. Results : found that the passage of the training module volleyball observed development of specific endurance and all motor abilities. Established that the manifestation and development of motor skills are interrelated. Since force is a functional foundation for the development of other skills, flexibility - the foundation of all mechanical movements. Without the development of strength, speed, coordination abilities impossible to develop endurance. Therefore, it is inappropriate and incorrect receipt of unidirectional only specific endurance (dynamic power and static, speed-power. Conclusions: indicated the need to achieve functional specialization of the body in the direction which is necessary for high-level manifestation of certain motor skills.

  13. Voluntary Wheel Running in Mice.

    Science.gov (United States)

    Goh, Jorming; Ladiges, Warren

    2015-12-02

    Voluntary wheel running in the mouse is used to assess physical performance and endurance and to model exercise training as a way to enhance health. Wheel running is a voluntary activity in contrast to other experimental exercise models in mice, which rely on aversive stimuli to force active movement. This protocol consists of allowing mice to run freely on the open surface of a slanted, plastic saucer-shaped wheel placed inside a standard mouse cage. Rotations are electronically transmitted to a USB hub so that frequency and rate of running can be captured via a software program for data storage and analysis for variable time periods. Mice are individually housed so that accurate recordings can be made for each animal. Factors such as mouse strain, gender, age, and individual motivation, which affect running activity, must be considered in the design of experiments using voluntary wheel running. Copyright © 2015 John Wiley & Sons, Inc.

  14. Effect of additional speed endurance training on performance and muscle adaptations

    DEFF Research Database (Denmark)

    Gunnarsson, Thomas; Christensen, Peter Møller; Holse, Kris

    2012-01-01

    PURPOSE: The present study examined the effect of additional speed-endurance training during the season on muscle adaptations and performance of trained soccer players. METHODS: Eighteen sub-elite soccer players performed one session with 6-9 30-s intervals at an intensity of 90-95 % ofmaximal...... intensity (speed endurance training; SET) a week for 5 weeks (SET-intervention). Before and after the SET-intervention the players carried out the Yo-Yo intermittent recovery level 2 (Yo- Yo IR2) test, a sprint test (10- and 30-m) and an agility test. In addition, seven of the players had a resting muscle...

  15. The effect of footwear on running performance and running economy in distance runners.

    Science.gov (United States)

    Fuller, Joel T; Bellenger, Clint R; Thewlis, Dominic; Tsiros, Margarita D; Buckley, Jonathan D

    2015-03-01

    The effect of footwear on running economy has been investigated in numerous studies. However, no systematic review and meta-analysis has synthesised the available literature and the effect of footwear on running performance is not known. The aim of this systematic review and meta-analysis was to investigate the effect of footwear on running performance and running economy in distance runners, by reviewing controlled trials that compare different footwear conditions or compare footwear with barefoot. The Web of Science, Scopus, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, AMED (Allied and Complementary Medicine), CINAHL and SPORTDiscus databases were searched from inception up until April 2014. Included articles reported on controlled trials that examined the effects of footwear or footwear characteristics (including shoe mass, cushioning, motion control, longitudinal bending stiffness, midsole viscoelasticity, drop height and comfort) on running performance or running economy and were published in a peer-reviewed journal. Of the 1,044 records retrieved, 19 studies were included in the systematic review and 14 studies were included in the meta-analysis. No studies were identified that reported effects on running performance. Individual studies reported significant, but trivial, beneficial effects on running economy for comfortable and stiff-soled shoes [standardised mean difference (SMD) beneficial effect on running economy for cushioned shoes (SMD = 0.37; P beneficial effect on running economy for training in minimalist shoes (SMD = 0.79; P beneficial effects on running economy for light shoes and barefoot compared with heavy shoes (SMD running was identified (P running economy. Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.

  16. Endurance running ability at adolescence as a predictor of blood pressure levels and hypertension in men: a 25-year follow-up study.

    Science.gov (United States)

    Mikkelsson, L; Kaprio, J; Kautiainen, H; Nupponen, H; Tikkanen, M J; Kujala, U M

    2005-01-01

    The aim was to study whether aerobic fitness measured by a maximal endurance running test at adolescence predicts prevalence of hypertension or blood pressure levels in adulthood. From the 413 (197 slow runners and 216 fast runners) participating in a 2000-meter running test at adolescence in 1976 and responding to a health and fitness questionnaire in 2001, 29 subjects (15 very slow runners and 14 very fast runners) participated in a clinical follow-up study in 2001. Compared to those who were fast runners in adolescence, those who were slow runners tended to have higher age-adjusted risk of hypertension at follow-up (OR 2.7, 95 % CI 0.9 to 7.5; p=0.07). The result persisted after further adjustment for body mass index at follow-up (OR 2.9, 95 % CI 1.0 to 8.3; p=0.05). Diastolic blood pressure was higher for very slow runners at adolescence compared to very fast runners, the age-adjusted mean diastolic blood pressure being 90 mm Hg (95 % CI 86 to 93) vs. 83 mm Hg (95 % CI 80 to 87), age-adjusted p=0.013. High endurance type fitness in adolescence predicts low risk of hypertension and low resting diastolic blood pressure levels in adult men.

  17. Genome-wide association study identifies three novel genetic markers associated with elite endurance performance

    DEFF Research Database (Denmark)

    Ahmetov, Ii; Kulemin, Na; Popov, Dv

    2015-01-01

    To investigate the association between multiple single-nucleotide polymorphisms (SNPs), aerobic performance and elite endurance athlete status in Russians. By using GWAS approach, we examined the association between 1,140,419 SNPs and relative maximal oxygen consumption rate ([Formula: see text]O2......max) in 80 international-level Russian endurance athletes (46 males and 34 females). To validate obtained results, we further performed case-control studies by comparing the frequencies of the most significant SNPs (with P endurance athletes and opposite cohorts (192...... Russian controls, 1367 European controls, and 230 Russian power athletes). Initially, six 'endurance alleles' were identified showing discrete associations with [Formula: see text]O2max both in males and females. Next, case-control studies resulted in remaining three SNPs (NFIA-AS2 rs1572312, TSHR rs...

  18. Muscle injury after low-intensity downhill running reduces running economy.

    Science.gov (United States)

    Baumann, Cory W; Green, Michael S; Doyle, J Andrew; Rupp, Jeffrey C; Ingalls, Christopher P; Corona, Benjamin T

    2014-05-01

    Contraction-induced muscle injury may reduce running economy (RE) by altering motor unit recruitment, lowering contraction economy, and disturbing running mechanics, any of which may have a deleterious effect on endurance performance. The purpose of this study was to determine if RE is reduced 2 days after performing injurious, low-intensity exercise in 11 healthy active men (27.5 ± 5.7 years; 50.05 ± 1.67 VO2peak). Running economy was determined at treadmill speeds eliciting 65 and 75% of the individual's peak rate of oxygen uptake (VO2peak) 1 day before and 2 days after injury induction. Lower extremity muscle injury was induced with a 30-minute downhill treadmill run (6 × 5 minutes runs, 2 minutes rest, -12% grade, and 12.9 km·h(-1)) that elicited 55% VO2peak. Maximal quadriceps isometric torque was reduced immediately and 2 days after the downhill run by 18 and 10%, and a moderate degree of muscle soreness was present. Two days after the injury, steady-state VO2 and metabolic work (VO2 L·km(-1)) were significantly greater (4-6%) during the 65% VO2peak run. Additionally, postinjury VCO2, VE and rating of perceived exertion were greater at 65% but not at 75% VO2peak, whereas whole blood-lactate concentrations did not change pre-injury to postinjury at either intensity. In conclusion, low-intensity downhill running reduces RE at 65% but not 75% VO2peak. The results of this study and other studies indicate the magnitude to which RE is altered after downhill running is dependent on the severity of the injury and intensity of the RE test.

  19. Skin autofluorescence is associated with arterial stiffness and insulin level in endurance runners and healthy controls - Effects of aging and endurance exercise.

    Science.gov (United States)

    Couppé, Christian; Dall, Christian Have; Svensson, Rene Brüggebusch; Olsen, Rasmus Huan; Karlsen, Anders; Praet, Stephan; Prescott, Eva; Magnusson, S Peter

    2017-05-01

    Life-long regular endurance exercise yields positive effects on cardiovascular and metabolic function, disease and mortality rate. Glycation may be a major mechanism behind age-related diseases. However, it remains unknown if skin autofluorescence (SAF), which reflects glycation, is related to arterial and metabolic function in life-long endurance runners and sedentary controls. Healthy elderly men: 15 life-long endurance runners (OT) (64±4years) and 12 old untrained (OU) (66±4years), and healthy young men; ten young athletes (YT) (26±4years) matched to OT for running distance, and 12 young untrained (YU) (24±3years) were recruited. Endothelial function (reactive hyperemia index, RHI) and arterial stiffness (augmentation index, AI@75 and AI) were measured by an operator-independent PAT 2000. SAF was non-invasively determined using an autofluorescence spectrometer. For AI@75 there was an effect of age (page correction (both r 2 =0.19, paging and pathology). Surprisingly, endurance running only had modest effects on cardiovascular function compared to lean healthy controls. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Financial Performance of Health Insurers: State-Run Versus Federal-Run Exchanges.

    Science.gov (United States)

    Hall, Mark A; McCue, Michael J; Palazzolo, Jennifer R

    2018-06-01

    Many insurers incurred financial losses in individual markets for health insurance during 2014, the first year of Affordable Care Act mandated changes. This analysis looks at key financial ratios of insurers to compare profitability in 2014 and 2013, identify factors driving financial performance, and contrast the financial performance of health insurers operating in state-run exchanges versus the federal exchange. Overall, the median loss of sampled insurers was -3.9%, no greater than their loss in 2013. Reduced administrative costs offset increases in medical losses. Insurers performed better in states with state-run exchanges than insurers in states using the federal exchange in 2014. Medical loss ratios are the underlying driver more than administrative costs in the difference in performance between states with federal versus state-run exchanges. Policy makers looking to improve the financial performance of the individual market should focus on features that differentiate the markets associated with state-run versus federal exchanges.

  1. Performance evaluation and financial market runs

    NARCIS (Netherlands)

    Wagner, W.B.

    2013-01-01

    This paper develops a model in which performance evaluation causes runs by fund managers and results in asset fire sales. Performance evaluation nonetheless is efficient as it disciplines managers. Optimal performance evaluation combines absolute and relative components in order to make runs less

  2. Digital Physical Activity Data Collection and Use by Endurance Runners and Distance Cyclists

    Science.gov (United States)

    Lee, Victor R.; Drake, Joel

    2013-01-01

    The introduction of sensor technologies to sports has allowed athletes to quantify and track their performance, adding an information-based layer to athletic practices. This information layer is particularly prevalent in practices involving formal competition and high levels of physical endurance, such as biking and running. We interviewed 20…

  3. Effects of strength training on endurance capacity in top-level endurance athletes

    DEFF Research Database (Denmark)

    Aagaard, Per; Andersen, Jesper L

    2010-01-01

    The effect of concurrent strength (S) and endurance (E) training on adaptive changes in aerobic capacity, endurance performance, maximal muscle strength and muscle morphology is equivocal. Some data suggest an attenuated cardiovascular and musculoskeletal response to combined E and S training......, while other data show unimpaired or even superior adaptation compared with either training regime alone. However, the effect of concurrent S and E training only rarely has been examined in top-level endurance athletes. This review describes the effect of concurrent SE training on short-term and long......-term endurance performance in endurance-trained subjects, ranging from moderately trained individuals to elite top-level athletes. It is concluded that strength training can lead to enhanced long-term (>30 min) and short-term (...

  4. Nutritional habits among high-performance endurance athletes

    Directory of Open Access Journals (Sweden)

    Marius Baranauskas

    2015-01-01

    Conclusions: The diet of highly trained endurance athletes does not fully meet their requirements and in this situation cannot ensure maximum adaptation to very intense and/or long-duration physical loads. The diet of highly trained endurance athletes must be optimized, adjusted and individualized. Particular attention should be focused on female athletes.

  5. Energy cost of running instability evaluated with wearable trunk accelerometry.

    Science.gov (United States)

    Schütte, Kurt H; Sackey, Saint; Venter, Rachel; Vanwanseele, Benedicte

    2018-02-01

    Maintaining stability under dynamic conditions is an inherent challenge to bipedal running. This challenge may impose an energetic cost (Ec) thus hampering endurance running performance, yet the underlying mechanisms are not clear. Wireless triaxial trunk accelerometry is a simple tool that could be used to unobtrusively evaluate these mechanisms. Here, we test a cost of instability hypothesis by examining the contribution of trunk accelerometry-based measures (triaxial root mean square, step and stride regularity, and sample entropy) to interindividual variance in Ec (J/m) during treadmill running. Accelerometry and indirect calorimetry data were collected concurrently from 30 recreational runners (16 men; 14 women) running at their highest steady-state running speed (80.65 ± 5.99% V̇o 2max ). After reducing dimensionality with factor analysis, the effect of dynamic stability features on Ec was evaluated using hierarchical multiple regression analysis. Three accelerometry-based measures could explain an additional 10.4% of interindividual variance in Ec after controlling for body mass, attributed to anteroposterior stride regularity (5.2%), anteroposterior root mean square ratio (3.2%), and mediolateral sample entropy (2.0%). Our results lend support to a cost of instability hypothesis, with trunk acceleration waveform signals that are 1) more consistent between strides anteroposterioly, 2) larger in amplitude variability anteroposterioly, and 3) more complex mediolaterally and are energetically advantageous to endurance running performance. This study shows that wearable trunk accelerometry is a useful tool for understanding the Ec of running and that running stability is important for economy in recreational runners. NEW & NOTEWORTHY This study evaluates and more directly lends support to a cost of instability hypothesis between runners. Moreover, this hypothesis was tested using a minimalist setup including a single triaxial trunk mounted accelerometer

  6. Measuring Ucrit and endurance: equipment choice influences estimates of fish swimming performance.

    Science.gov (United States)

    Kern, P; Cramp, R L; Gordos, M A; Watson, J R; Franklin, C E

    2018-01-01

    This study compared the critical swimming speed (U crit ) and endurance performance of three Australian freshwater fish species in different swim-test apparatus. Estimates of U crit measured in a large recirculating flume were greater for all species compared with estimates from a smaller model of the same recirculating flume. Large differences were also observed for estimates of endurance swimming performance between these recirculating flumes and a free-surface swim tunnel. Differences in estimates of performance may be attributable to variation in flow conditions within different types of swim chambers. Variation in estimates of swimming performance between different types of flumes complicates the application of laboratory-based measures to the design of fish passage infrastructure. © 2017 The Fisheries Society of the British Isles.

  7. Physical fitness differences of students with different cardiorespiratory endurance levels

    Directory of Open Access Journals (Sweden)

    Stojanović Darko

    2016-01-01

    Full Text Available In order to determine physical fitness differences in students with different cardiorespiratory endurance levels, a study was conducted on a sample of students of the Faculty of Sport and Physical Education at the University of Nis. The sample was divided into two subsamples, where the first subsample comprised 27 female students and the other 35 male students. Physical fitness was assessed using eight tests from the Eurofit battery of tests: the single-leg balance test - for the assessment of general balance, plate tapping - for the assessment of speed of movement, sit-and-reach - for the assessment of flexibility, the standing broad jump - for the assessment of explosive strength, the handgrip test - for the assessment of static strength, sit-ups - for the assessment of repetitive trunk strength, the bent arm hang - for the assessment of muscular endurance and the 10x5 meter shuttle run - for the assessment of the speed/agility. Cardiorespiratory endurance was estimated with the aid of 20 m endurance shuttle-run test. Based on the level of cardiorespiratory endurance, the participants in each subsample, were divided into three groups using a cluster analysis: high (VKRI, average (PKRI and low level (NKRI. The physical fitness differences of students with different cardiorespiratory endurance levels were calculated using the one-way analysis of variance. The results showed that there were no differences in physical fitness of students with different cardiorespiratory endurance levels. Based on the results it can be concluded that the level of cardiorespiratory endurance does not affect the components of physical fitness among students of both sexes.

  8. A Clinician Guide to Altitude Training for Optimal Endurance Exercise Performance at Sea Level.

    Science.gov (United States)

    Constantini, Keren; Wilhite, Daniel P; Chapman, Robert F

    2017-06-01

    Constantini, Keren, Daniel P. Wilhite, and Robert F. Chapman. A clinician guide to altitude training for optimal endurance exercise performance at sea level. High Alt Med Biol. 18:93-101, 2017.-For well over 50 years, endurance athletes have been utilizing altitude training in an effort to enhance performance in sea level competition. This brief review will offer the clinician a series of evidence-based best-practice guidelines on prealtitude and altitude training considerations, which can ultimately maximize performance improvement outcomes.

  9. The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players.

    Directory of Open Access Journals (Sweden)

    F Marcello Iaia

    Full Text Available In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6 or speed endurance maintenance (SEM; n = 7 training, three times per wk. SEP training consisted of 6-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01 the total time in a repeated sprint ability test (RSAt by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01 and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01% but induced a very likely impairment in RSAt (from 83.81±2.37 to 84.65±2.27 s. The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001 and 3.8% (p<0.05 higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in

  10. Testing of badminton specific endurance

    DEFF Research Database (Denmark)

    Madsen, Christian Møller; Højlyng, Mads; Nybo, Lars

    2016-01-01

    In the present study, a novel intermittent badminton endurance test (B-ENDURANCE) was developed and tested in elite (n=17) and skilled (n=9) badminton players as well as in age-matched physically active men (non-badminton players; n=8). In addition, B-ENDURANCE test-retest reproducibility...... was evaluated in nine badminton players.B-ENDURANCE is an incremental test where each level consists of repeated sequences of badminton specific actions towards the four corners on the court. The subject starts in the center of the court in front of a computer screen and within each sequence he must...... decreases until the subjects cannot follow the dictated tempo.B-ENDURANCE performance for elite players was better (Pbadminton players. In addition, B-ENDURANCE performance correlated (r=0.8; P

  11. Effects of Low Versus Moderate Glycemic Index Diets on Aerobic Capacity in Endurance Runners: Three-Week Randomized Controlled Crossover Trial

    Directory of Open Access Journals (Sweden)

    Krzysztof Durkalec-Michalski

    2018-03-01

    Full Text Available The glycemic index (GI of ingested carbohydrates may influence substrate oxidation during exercise and athletic performance. Therefore, the aim of this study was to assess the effect of low- and moderate-GI three-week diets on aerobic capacity and endurance performance in runners. We conducted a randomized crossover feeding study of matched diets differing only in GI (low vs. moderate in 21 endurance-trained runners. Each participant consumed both, low- (LGI and moderate-GI (MGI high-carbohydrate (~60% and nutrient-balanced diets for three weeks each. At the beginning and end of each diet, participants had their aerobic capacity and body composition measured and performed a 12-min running test. After LGI, time to exhaustion during incremental cycling test (ICT and distance covered in the 12-min run were significantly increased. The MGI diet led to an increase in maximal oxygen uptake ( V ˙ O2max, but no performance benefits were found after the MGI diet. The LGI and MGI diets improved time and workload at gas exchange threshold (GET during ICT. The results indicate that a three-week high-carbohydrate LGI diet resulted in a small but significant improvement in athletic performance in endurance runners. Observed increase in V ˙ O2max on MGI diet did not affect performance.

  12. Ultra-endurance sports have no negative impact on indices of arterial stiffness.

    Science.gov (United States)

    Radtke, Thomas; Schmidt-Trucksäss, Arno; Brugger, Nicolas; Schäfer, Daniela; Saner, Hugo; Wilhelm, Matthias

    2014-01-01

    Marathon running has been linked with higher arterial stiffness. Blood pressure is a major contributor to pulse wave velocity (PWV). We examined indices of arterial stiffness with a blood pressure-independent method in marathon runners and ultra-endurance athletes. Male normotensive amateur runners were allocated to three groups according to former participation in competitions: group I (recreational athletes), group II (marathon runners) and group III (ultra-endurance athletes). Indices of arterial stiffness were measured with a non-invasive device (VaSera VS-1500N, Fukuda Denshi, Japan) to determine the cardio-ankle vascular index (CAVI, primary endpoint) and brachial-ankle PWV (baPWV). Lifetime training hours were calculated. Cumulative competitions were expressed as marathon equivalents. Linear regression analysis was performed to determine predictors for CAVI and baPWV. Measurements of arterial stiffness were performed in 51 subjects (mean age 44.6 ± 1.2 years): group I (n = 16), group II (n = 19) and group III (n = 16). No between-group differences existed in age, anthropometric characteristics and resting BP. CAVI and baPWV were comparable between all groups (P = 0.604 and P = 0.947, respectively). In linear regression analysis, age was the only independent predictor for CAVI (R(2) = 0.239, β = 0.455, P = 0.001). Systolic BP was significantly associated with baPWV (R(2) = 0.225, β = 0.403, P = 0.004). In middle-aged normotensive athletes marathon running and ultra-endurance sports had no negative impact on arterial stiffness.

  13. Índices fisiológicos associados com a "performance" aeróbia em corredores de "endurance": efeitos da duração da prova Índices fisiológicos asociados a la "performance" aerobia en competidores de "endurance": efectos de la duración de la prueba Physiological indexes associated with aerobic performance in endurance runners: effects of race duration

    Directory of Open Access Journals (Sweden)

    Benedito Sérgio Denadai

    2004-10-01

    .000m (17,9 ± 0,9 fueron significantemente diferentes. La regresión múltiple stepwise mostró que el LAn fue el único elemento de predicción de la performance de la v5.000m, explicando el 50% de la variación de esta performance. Para la v1.500m, el Tlim y la vVO2max explicaron el 88% de la variación de la performance. Con base en nuestros resultados, se puede concluir que la validez de los índices fisiológicos (VO2max, vVO2max, Tlim, EC y LAn, para la predicción de la performance aerobia de atletas de endurance depende de la distancia de la prueba (1.500 x 5.000m analizada.The aim of this study was to assess the validity of the maximal oxygen uptake (VO2max, the velocity at VO2max (vVO2max, time to exhaustion at vVO2max (Tlim, running economy (RE and anaerobic threshold (AnT to predict the aerobic performance of the endurance athletes. Fourteen well-trained long-distance runners (33.4 ± 4.4 yr.; 62.7 ± 4.3 kg; 166.1 ± 5.0 cm; VO2max = 60.4 ± 5.9 ml.kg-1.min-1 underwent the following tests: a simulated competitions in the distances of 1500 and 5000 m and; b laboratory treadmill tests to determine their VO2max, vVO2max, Tlim, EC and AnT. The velocities (km/h at vVO2max (18.7 + 0.8, LAn (17.3 + 1.1 v1500 m (19.9 + 0.8 and v5000 m (17.9 + 0.9 were significantly different. A stepwise multiple-regression analysis revealed that AnT alone was the best single predictor of v-5000 m and explained 50% of the variability in 5000 m running velocity. For v1.500 m, Tlim and vVO2max explained 88 % of the variability of the performance. We conclude that, in a group of well-trained long-distance runners, the validity of the physiological indexes (VO2max, vVO2max, Tlim, EC e LAn to predict the aerobic performance is dependent of the distance (1500 x 5000 m analyzed.

  14. The effect of recreational soccer training and running on postural balance in untrained men

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Krustrup, Peter

    2011-01-01

    The aim of this study was to examine the effect of intense intermittent exercise performed as soccer training or interval running in comparison with continuous endurance running exercise on postural balance in young healthy untrained males. Young sedentary men were randomized to soccer training...... strength and countermovement jump velocity. Postural control was improved in response to 12 weeks of soccer training and high-intensity interval running, respectively, while less-marked changes were observed following continuous running. Notably, the reduced variability in CoP acceleration after soccer...

  15. Non-conscious visual cues related to affect and action alter perception of effort and endurance performance

    Directory of Open Access Journals (Sweden)

    Anthony William Blanchfield

    2014-12-01

    Full Text Available The psychobiological model of endurance performance proposes that endurance performance is determined by a decision-making process based on perception of effort and potential motivation. Recent research has reported that effort-based decision-making during cognitive tasks can be altered by non-conscious visual cues relating to affect and action. The effect of these non-conscious visual cues on effort and performance during physical tasks is however unknown. We report two experiments investigating the effect of subliminal priming with visual cues related to affect and action on perception of effort and endurance performance. In Experiment 1 thirteen individuals were subliminally primed with happy or sad faces as they cycled to exhaustion in a counterbalanced and randomized crossover design. A paired t-test (happy vs. sad faces revealed that individuals cycled for significantly longer (178 s, p = .04 when subliminally primed with happy faces. A 2 x 5 (condition x iso-time ANOVA also revealed a significant main effect of condition on rating of perceived exertion (RPE during the time to exhaustion (TTE test with lower RPE when subjects were subliminally primed with happy faces (p = .04. In Experiment 2, a single-subject randomization tests design found that subliminal priming with action words facilitated a significantly longer (399 s, p = .04 TTE in comparison to inaction words (p = .04. Like Experiment 1, this greater TTE was accompanied by a significantly lower RPE (p = .03. These experiments are the first to show that subliminal visual cues relating to affect and action can alter perception of effort and endurance performance. Non-conscious visual cues may therefore influence the effort-based decision-making process that is proposed to determine endurance performance. Accordingly, the findings raise notable implications for individuals who may encounter such visual cues during endurance competitions, training, or health related exercise.

  16. Endurance performance and energy metabolism during exercise in mice with a muscle-specific defect in the control of branched-chain amino acid catabolism.

    Science.gov (United States)

    Xu, Minjun; Kitaura, Yasuyuki; Ishikawa, Takuya; Kadota, Yoshihiro; Terai, Chihaya; Shindo, Daichi; Morioka, Takashi; Ota, Miki; Morishita, Yukako; Ishihara, Kengo; Shimomura, Yoshiharu

    2017-01-01

    It is known that the catabolism of branched-chain amino acids (BCAAs) in skeletal muscle is suppressed under normal and sedentary conditions but is promoted by exercise. BCAA catabolism in muscle tissues is regulated by the branched-chain α-keto acid (BCKA) dehydrogenase complex, which is inactivated by phosphorylation by BCKA dehydrogenase kinase (BDK). In the present study, we used muscle-specific BDK deficient mice (BDK-mKO mice) to examine the effect of uncontrolled BCAA catabolism on endurance exercise performance and skeletal muscle energy metabolism. Untrained control and BDK-mKO mice showed the same performance; however, the endurance performance enhanced by 2 weeks of running training was somewhat, but significantly less in BDK-mKO mice than in control mice. Skeletal muscle of BDK-mKO mice had low levels of glycogen. Metabolome analysis showed that BCAA catabolism was greatly enhanced in the muscle of BDK-mKO mice and produced branched-chain acyl-carnitine, which induced perturbation of energy metabolism in the muscle. These results suggest that the tight regulation of BCAA catabolism in muscles is important for homeostasis of muscle energy metabolism and, at least in part, for adaptation to exercise training.

  17. Endurance performance and energy metabolism during exercise in mice with a muscle-specific defect in the control of branched-chain amino acid catabolism.

    Directory of Open Access Journals (Sweden)

    Minjun Xu

    Full Text Available It is known that the catabolism of branched-chain amino acids (BCAAs in skeletal muscle is suppressed under normal and sedentary conditions but is promoted by exercise. BCAA catabolism in muscle tissues is regulated by the branched-chain α-keto acid (BCKA dehydrogenase complex, which is inactivated by phosphorylation by BCKA dehydrogenase kinase (BDK. In the present study, we used muscle-specific BDK deficient mice (BDK-mKO mice to examine the effect of uncontrolled BCAA catabolism on endurance exercise performance and skeletal muscle energy metabolism. Untrained control and BDK-mKO mice showed the same performance; however, the endurance performance enhanced by 2 weeks of running training was somewhat, but significantly less in BDK-mKO mice than in control mice. Skeletal muscle of BDK-mKO mice had low levels of glycogen. Metabolome analysis showed that BCAA catabolism was greatly enhanced in the muscle of BDK-mKO mice and produced branched-chain acyl-carnitine, which induced perturbation of energy metabolism in the muscle. These results suggest that the tight regulation of BCAA catabolism in muscles is important for homeostasis of muscle energy metabolism and, at least in part, for adaptation to exercise training.

  18. 'The engine just started coughing!' - Limits of physical performance, aging and career continuity in elite endurance sports.

    Science.gov (United States)

    Ronkainen, Noora J; Ryba, Tatiana V; Nesti, Mark S

    2013-12-01

    This research examines male endurance athletes' experience of aging and/or reaching the perceived limits of physical performance. More specifically, the current study aimed to explore how existential meanings attached to these experiences are connected with athletes' decision-making concerning career continuity and retirement. Life story interviews were conducted with 10 Finnish runners and/or orienteers aged between 25 and 62 and the data was analyzed with an existential-narrative framework. Four major storylines related to aging were identified: The end of an era, putting things in perspective, the attitude has to change and winning was never the only motive. Our results suggest that endurance athletes possess diverse ways of bringing meaning to the experience of aging, both confirming and resisting the dominant cultural narrative of decline. While three athletes' stories confirmed the normativity of retirement when unable to improve their results anymore, other athletes demonstrated career continuity and positive aspects in the late career years, such as lack of competitive anxiety, finding perspective and increased enjoyment in running. We suggest that through awareness of alternative narratives, sport psychology consultants may be able to help their clients to explore new meanings in the potentially challenging and beneficial experiences of aging and athletic retirement. © 2013.

  19. Anticipatory Guidance for Long-Distance Running in Young Athletes.

    Science.gov (United States)

    Blankson, Kwabena L; Brenner, Joel S

    2016-03-01

    More young children are participating in endurance running events such as full and half marathons, and the safety of these events for children has been heavily debated. There is a paucity of evidence on either side of the debate. However, overuse injuries, stress fractures, as well as the potential for psychologic burnout are legitimate concerns. Parents who are seeking advice from pediatricians about child participation in these endurance events should be made aware of these risks. Young children may participate in endurance running events under close supervision from health professionals, coaches, and parents, with full medical evaluation before initiation of training, throughout training, as well as 6 to 12 months post-race. Special attention should be made to the psychologic well-being of the child, with the participation in running being child-driven, not parent- or coach-driven, and emphasis on enjoyment and fitness, not competition. Copyright 2016, SLACK Incorporated.

  20. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    The ATLAS Muon Trigger Performance: Run 1 and Initial Run 2 Performance

Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns i...

  1. Endurance Exercise Mobilizes Developmentally Early Stem Cells into Peripheral Blood and Increases Their Number in Bone Marrow: Implications for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2016-01-01

    Full Text Available Endurance exercise has been reported to increase the number of circulating hematopoietic stem/progenitor cells (HSPCs in peripheral blood (PB as well as in bone marrow (BM. We therefore became interested in whether endurance exercise has the same effect on very small embryonic-like stem cells (VSELs, which have been described as a population of developmentally early stem cells residing in BM. Mice were run daily for 1 hour on a treadmill for periods of 5 days or 5 weeks. Human volunteers had trained in long-distance running for one year, six times per week. FACS-based analyses and RT-PCR of murine and human VSELs and HSPCs from collected bone marrow and peripheral blood were performed. We observed that endurance exercise increased the number of VSELs circulating in PB and residing in BM. In parallel, we observed an increase in the number of HSPCs. These observations were subsequently confirmed in young athletes, who showed an increase in circulating VSELs and HSPCs after intensive running exercise. We provide for the first time evidence that endurance exercise may have beneficial effects on the expansion of developmentally early stem cells. We hypothesize that these circulating stem cells are involved in repairing minor exercise-related tissue and organ injuries.

  2. Influence of ABO blood group on sports performance.

    Science.gov (United States)

    Lippi, Giuseppe; Gandini, Giorgio; Salvagno, Gian Luca; Skafidas, Spyros; Festa, Luca; Danese, Elisa; Montagnana, Martina; Sanchis-Gomar, Fabian; Tarperi, Cantor; Schena, Federico

    2017-06-01

    Despite being a recessive trait, the O blood group is the most frequent worldwide among the ABO blood types. Since running performance has been recognized as a major driver of evolutionary advantage in humans, we planned a study to investigate whether the ABO blood group may have an influence on endurance running performance in middle-aged recreational athletes. The study population consisted of 52 recreational, middle-aged, Caucasian athletes (mean age: 49±13 years, body mass index, 23.4±2.3 kg/m 2 ), regularly engaged in endurance activity. The athletes participated to a scientific event called "Run for Science" (R4S), entailing the completion of a 21.1 km (half-marathon) run under competing conditions. The ABO blood type status of the participants was provided by the local Service of Transfusion Medicine. In univariate analysis, running performance was significantly associated with age and weekly training, but not with body mass index. In multiple linear regression analysis, age and weekly training remained significantly associated with running performance. The ABO blood group status was also found to be independently associated with running time, with O blood type athletes performing better than those with non-O blood groups. Overall, age, weekly training and O blood group type explained 62.2% of the total variance of running performance (age, 41.6%; training regimen, 10.5%; ABO blood group, 10.1%). The results of our study show that recreational athletes with O blood group have better endurance performance compared to those with non-O blood group types. This finding may provide additional support to the putative evolutionary advantages of carrying the O blood group.

  3. Effect of sodium bicarbonate on prolonged running performance: A randomized, double-blind, cross-over study.

    Directory of Open Access Journals (Sweden)

    Tanja Freis

    Full Text Available The ability to sustain intense exercise seems to be partially limited by the body's capability to counteract decreases in both intra- and extracellular pH. While the influence of an enhanced buffering capacity via sodium bicarbonate (BICA on short-term, high-intensity exercise performance has been repeatedly investigated, studies on prolonged endurance performances are comparatively rare, especially for running. The aim of the following study was to assess the ergogenic effects of an oral BICA substitution upon exhaustive intensive endurance running performance.In a double-blind randomized cross-over study, 18 trained runners (VO2peak: 61.2 ± 6.4 ml•min-1•kg-1 performed two exhaustive graded exercise tests and two constant load tests (30 main at 95% individual anaerobic threshold (IAT followed by 110% IAT until exhaustion after ingestion of either sodium bicarbonate (BICA (0.3 g/kg or placebo (4 g NaCl diluted in 700 ml of water. Time to exhaustion (TTE in the constant load test was defined as the main outcome measure. Throughout each test respiratory gas exchange measurements were conducted as well as determinations of heart rate, blood gases and blood lactate concentration.TTE in the constant load test did not differ significantly between BICA and placebo conditions (BICA: 39.6 ± 5.6 min, placebo: 39.3 ± 5.6 min; p = 0.78. While pH in the placebo test dropped to a slightly acidotic value two minutes after cessation of exercise (7.34 ± 0.05 the value in the BICA trial remained within the normal range (7.41 ± 0.06 (p < 0.001. In contrast, maximum running speed (Vmax in the exhaustive graded exercise test was significantly higher with BICA (17.4 ± 1.0 km/h compared to placebo (17.1 ± 1.0 km/h (p = 0.009. The numerical difference in maximum oxygen consumption (VO2peak failed to reach statistical significance (BICA: 61.2 ± 6.4 ml•min-1•kg-1, placebo: 59.8 ± 6.4 ml•min-1•kg-1; p = 0.31. Maximum blood lactate was significantly

  4. Effect of sodium bicarbonate on prolonged running performance: A randomized, double-blind, cross-over study.

    Science.gov (United States)

    Freis, Tanja; Hecksteden, Anne; Such, Ulf; Meyer, Tim

    2017-01-01

    The ability to sustain intense exercise seems to be partially limited by the body's capability to counteract decreases in both intra- and extracellular pH. While the influence of an enhanced buffering capacity via sodium bicarbonate (BICA) on short-term, high-intensity exercise performance has been repeatedly investigated, studies on prolonged endurance performances are comparatively rare, especially for running. The aim of the following study was to assess the ergogenic effects of an oral BICA substitution upon exhaustive intensive endurance running performance. In a double-blind randomized cross-over study, 18 trained runners (VO2peak: 61.2 ± 6.4 ml•min-1•kg-1) performed two exhaustive graded exercise tests and two constant load tests (30 main at 95% individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion) after ingestion of either sodium bicarbonate (BICA) (0.3 g/kg) or placebo (4 g NaCl) diluted in 700 ml of water. Time to exhaustion (TTE) in the constant load test was defined as the main outcome measure. Throughout each test respiratory gas exchange measurements were conducted as well as determinations of heart rate, blood gases and blood lactate concentration. TTE in the constant load test did not differ significantly between BICA and placebo conditions (BICA: 39.6 ± 5.6 min, placebo: 39.3 ± 5.6 min; p = 0.78). While pH in the placebo test dropped to a slightly acidotic value two minutes after cessation of exercise (7.34 ± 0.05) the value in the BICA trial remained within the normal range (7.41 ± 0.06) (p < 0.001). In contrast, maximum running speed (Vmax) in the exhaustive graded exercise test was significantly higher with BICA (17.4 ± 1.0 km/h) compared to placebo (17.1 ± 1.0 km/h) (p = 0.009). The numerical difference in maximum oxygen consumption (VO2peak) failed to reach statistical significance (BICA: 61.2 ± 6.4 ml•min-1•kg-1, placebo: 59.8 ± 6.4 ml•min-1•kg-1; p = 0.31). Maximum blood lactate was significantly

  5. Effects of caloric restriction and overnight fasting on cycling endurance performance.

    Science.gov (United States)

    Ferguson, Lisa M; Rossi, Kelly A; Ward, Emily; Jadwin, Emily; Miller, Todd A; Miller, Wayne C

    2009-03-01

    In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

  6. Metabolic clues regarding the enhanced performance of elite endurance athletes from orchiectomy-induced hormonal changes.

    Science.gov (United States)

    Atwood, Craig S; Bowen, Richard L

    2007-01-01

    This article examines the metabolic performance of an elite cyclist, Lance Armstrong, before and after his diagnosis with testicular cancer. Although a champion cyclist in 1-day events prior to his diagnosis of testicular cancer at age 25, he was not a contender in multi-day endurance cycle races such as the 3-week Tour de France. His genetic makeup and physiology (high VO2max, long femur, strong heavy build) coupled with his ambition and motivation enabled him at an early age to become one of the best 1-day cyclists in the world. Following his cancer diagnosis, he underwent a unilateral orchiectomy, brain surgery and four cycles of chemotherapy. After recovering, he returned to cycling and surprisingly excelled in the Tour de France, winning this hardest of endurance events 7 years running. This dramatic transformation from a 1-day to a 3-week endurance champion has led many to query how this is possible, and under the current climate, has led to suggestions of doping as to the answer to this metamorphosis. Physiological tests following his recovery indicated that physiological parameters such as VO2max were not affected by the unilateral orchiectomy and chemotherapy. We propose that his dramatic improvement in recovery between stages, the most important factor in winning multi-day stage races, is due to his unilateral orchiectomy, a procedure that results in permanent changes in serum hormones. These hormonal changes, specifically an increase in gonadotropins (and prolactin) required to maintain serum testosterone levels, alter fuel metabolism; increasing hormone sensitive lipase expression and activity, promoting increased free fatty acid (FFA) mobilization to, and utilization by, muscles, thereby decreasing the requirement to expend limiting glycogen stores before, during and after exercise. Such hormonal changes also have been associated with ketone body production, improvements in muscle repair and haematocrit levels and may facilitate the loss of body weight

  7. Endurance Capacity Is Not Correlated with Endothelial Function in Male University Students

    Science.gov (United States)

    Wu, Fang; Su, Chen; Fan, Zhen-guo; Zhu, Zhu; Tao, Jun; Huang, Yi-jun

    2014-01-01

    Background Endurance capacity, assessed by 1000-meter (1000 m) run of male university students, is an indicator of cardiovascular fitness in Chinese students physical fitness surveillance. Although cardiovascular fitness is related to endothelial function closely in patients with cardiovascular diseases, it remains unclear whether endurance capacity correlates with endothelial function, especially with circulating endothelial microparticles (EMPs), a new sensitive marker of endothelial dysfunction in young students. The present study aimed to investigate the relationship between endurance capacity and endothelial function in male university students. Methods Forty-seven healthy male university students (mean age, 20.1±0.6 years; mean height, 172.4±6.3 cm; and mean weight, 60.0±8.2 kg) were recruited in this study. The measurement procedure of 1000 m run time was followed to Chinese national students Constitutional Health Criterion. Endothelium function was assessed by flow-mediated vasodilation (FMD) in the brachial artery measured by ultrasonic imaging, and the level of circulating EMPs was measured by flow cytometry. Cardiovascular fitness indicator - maximal oxygen uptake (VO2 max) - was also measured on a cycle ergometer using a portable gas analyzer. Results 1000 m run time was correlated with VO2max (r = −0.399, p0.05). Conclusion The correlations between endurance capacity or cardiovascular fitness and endothelial function were not found in healthy Chinese male university students. These results suggest that endurance capacity may not reflect endothelial function in healthy young adults with well preserved FMD and low level of circulating CD31+/CD42-EMPs. PMID:25101975

  8. Effects of Physical Training and Fitness on Running Injuries in Physically Active Young Men.

    Science.gov (United States)

    Grier, Tyson L; Canham-Chervak, Michelle; Anderson, Morgan K; Bushman, Timothy T; Jones, Bruce H

    2017-01-01

    Grier, TL, Canham-Chervak, M, Anderson, MK, Bushman, TT, and Jones, BH. Effects of physical training and fitness on running injuries in physically active young men. J Strength Cond Res 31(1): 207-216, 2017-The purpose of this investigation was to determine the effects of physical training (PT) and fitness on risks for running-related injuries (RRIs) in physically active young men. Personal characteristics, PT, Army Physical Fitness Test scores, and injury data were obtained by survey. Army Physical Fitness Test variables (push-ups, sit-ups, and 2-mile run) were converted into quartiles (Q), where Q1 = lowest performance and Q4 = highest performance. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using multivariate logistic regression. Over 4,000 (n = 4,236) soldiers were surveyed. Running injury incidence was 14%. A greater risk of an RRI was associated with older age (OR31+/run per week during personal PT (OR5.1-10/1-5 miles = 0.70, 95% CI, 0.53-0.91, OR10.1-16 +/1-5 miles = 0.58, 95% CI, 0.35-0.97, OR16.1+/1-5 miles = 0.54, 95% CI, 0.30-0.98), higher aerobic endurance as measured by 2-mile run performance (ORQ4/Q1 = 0.50, 95% CI, 0.35-0.72), and unit resistance training ≥3 times a week (OR≥3 times per week/none = 0.46, 95% CI, 0.29-0.73). Greater personal PT running mileage decreased injuries in this population suggesting that the increased protective effect of higher aerobic fitness outweighed the injurious effect of running more miles during personal PT. Countermeasures to prevent RRIs could entail enhancing aerobic endurance, providing opportunities for personal aerobic training, monitoring for excessive unit PT running mileage and encouraging unit resistance training ≥3 times per week.

  9. [Osteoarthritis from long-distance running?].

    Science.gov (United States)

    Hohmann, E; Wörtler, K; Imhoff, A

    2005-06-01

    Long distance running has become a fashionable recreational activity. This study investigated the effects of external impact loading on bone and cartilage introduced by performing a marathon race. Seven beginners were compared to six experienced recreational long distance runners and two professional athletes. All participants underwent magnetic resonance imaging of the hip and knee before and after a marathon run. Coronal T1 weighted and STIR sequences were used. The pre MRI served as a baseline investigation and monitored the training effect. All athletes demonstrated normal findings in the pre run scan. All but one athlete in the beginner group demonstrated joint effusions after the race. The experienced and professional runners failed to demonstrate pathology in the post run scans. Recreational and professional long distance runners tolerate high impact forces well. Beginners demonstrate significant changes on the post run scans. Whether those findings are a result of inadequate training (miles and duration) warrant further studies. We conclude that adequate endurance training results in adaptation mechanisms that allow the athlete to compensate for the stresses introduced by long distance running and do not predispose to the onset of osteoarthritis. Significant malalignment of the lower extremity may cause increased focal loading of joint and cartilage.

  10. Seasonal Variation of Agility, Speed and Endurance Performance in Young Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Michal Dragijsky

    2017-02-01

    Full Text Available The aim of this study was to investigate changes in the linear running speed (LRS for 30 m, change of direction speed (CODS, and endurance in young elite Czech soccer players. The following tests were conducted to assess CODS and endurance: Agility 505 turning toward the dominant (A505DL and non-dominant lower limb (A505NL; Illinois Agility Test (IAT; and intermittent test (Yo-Yo IRT1. During the soccer season, we investigated performance at the following time periods: the start (t1 and the end of the pre-season period (t2; during (t3 and at the end of the competitive period (t4. Repeated measurement analysis of variance revealed a significant effect of time period on selected fitness parameters (p < 0.05. Post hoc analysis for test A505DL revealed significant improvements of performance at t3 (2.71 ± 0.08 s and t4 (2.72 ± 0.06 s compared to t1 (2.81 ± 0.09 s. A505NL was significantly different between t1 (2.83 ± 0.09 s and t2 (2.76 ± 0.09 s, t3 (2.7 ± 0.07 s and t4 (2.71 ± 0.09 s. Performance of CODS at t1 for the IAT (18.82 ± 0.56 s was significantly lower (p < 0.05 than any other time period (t2 = 18.52 ± 0.63 s, t3 = 17.94 ± 0.51 s, t4 = 17.89 ± 0.66 s. The power of LRS was significantly different at t3 (4.99 ± 0.15 s, and t4 (4.98 ± 0.17 s compared to t1 (5.15 ± 0.21 s, and t2 (5.07 ± 0.14 s. For the Yo-Yo IRT1 test, we observed a significant increase in performance between t1 (625.26 ± 170.34 m, t2 (858.95 ± 210.55 m, and t3 (953.68 ± 229.88 m. These results show the impact of soccer season time period on young soccer player performance and may further serve as a basis for comparison with similar research conducted by peers. These results may aid sports practice for clinicians, conditioning coaches, soccer coaches and physiotherapeutic coaches.

  11. Barefoot running: does it prevent injuries?

    Science.gov (United States)

    Murphy, Kelly; Curry, Emily J; Matzkin, Elizabeth G

    2013-11-01

    Endurance running has evolved over the course of millions of years and it is now one of the most popular sports today. However, the risk of stress injury in distance runners is high because of the repetitive ground impact forces exerted. These injuries are not only detrimental to the runner, but also place a burden on the medical community. Preventative measures are essential to decrease the risk of injury within the sport. Common running injuries include patellofemoral pain syndrome, tibial stress fractures, plantar fasciitis, and Achilles tendonitis. Barefoot running, as opposed to shod running (with shoes), has recently received significant attention in both the media and the market place for the potential to promote the healing process, increase performance, and decrease injury rates. However, there is controversy over the use of barefoot running to decrease the overall risk of injury secondary to individual differences in lower extremity alignment, gait patterns, and running biomechanics. While barefoot running may benefit certain types of individuals, differences in running stance and individual biomechanics may actually increase injury risk when transitioning to barefoot running. The purpose of this article is to review the currently available clinical evidence on barefoot running and its effectiveness for preventing injury in the runner. Based on a review of current literature, barefoot running is not a substantiated preventative running measure to reduce injury rates in runners. However, barefoot running utility should be assessed on an athlete-specific basis to determine whether barefoot running will be beneficial.

  12. Effects of Mental Fatigue on Physical Endurance Performance and Muscle Activation Are Attenuated by Monetary Incentives.

    Science.gov (United States)

    Brown, Denver M Y; Bray, Steven R

    2017-12-01

    Physical performance is impaired following cognitive control exertion. Incentives can ameliorate adverse carryover effects of cognitive control exertion but have not been investigated for physical endurance. This study examined the effect of monetary incentives on physical performance and muscle activation following exposure to a mentally fatiguing, cognitive control task. Participants (N = 82) performed two isometric endurance handgrip trials separated by a 12-min cognitive control manipulation using a 2 (high cognitive control [HCC]/low cognitive control [LCC]) × 2 (incentive/no incentive) design. Mental fatigue was significantly higher in the HCC conditions. Performance decreased in the HCC/no incentive condition but was unaffected in the HCC/incentive condition, which did not differ from the low cognitive control conditions. Electromyography data revealed increased muscle activation in the HCC/no incentive condition, which was also attenuated in the HCC/incentive condition. Findings show that incentives counteract the negative effects of HCC on physical endurance and alter central drive to motor units.

  13. Training modalities: impact on endurance capacity.

    Science.gov (United States)

    Flueck, Martin; Eilers, Wouter

    2010-03-01

    Endurance athletes demonstrate an exceptional resistance to fatigue when exercising at high intensity. Much research has been devoted to the contribution of aerobic capacity for the economy of endurance performance. Important aspects of the fine-tuning of metabolic processes and power output in the endurance athlete have been overlooked. This review addresses how training paradigms exploit bioenergetic pathways in recruited muscle groups to promote the endurance phenotype. A special focus is laid on the genome-mediated mechanisms that underlie the conditioning of fatigue resistance and aerobic performance by training macrocycles and complements. The available data on work-induced muscle plasticity implies that different biologic strategies are exploited in athletic and untrained populations to boost endurance capacity. Olympic champions are probably endowed with a unique constitution that renders the conditioning of endurance capacity for competition particularly efficient. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

    Science.gov (United States)

    van der Zwaard, Stephan; van der Laarse, Willem J; Weide, Guido; Bloemers, Frank W; Hofmijster, Mathijs J; Levels, Koen; Noordhof, Dionne A; de Koning, Jos J; de Ruiter, Cornelis J; Jaspers, Richard T

    2018-04-01

    Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15-km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass 2/3 to eliminate the influence of body size. Performance determinants were obtained from whole-body oxygen consumption, blood sampling, knee-extensor maximal force, muscle oxygenation, whole-muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast-type fibers and muscle volume ( R 2 = 0.65; P body.

  15. Effect of Glycemic Index of a Pre-exercise Meal on Endurance Exercise Performance

    NARCIS (Netherlands)

    Burdon, Catriona A.; Spronk, Inge; Cheng, Hoi Lun; O’Connor, Helen T.

    2017-01-01

    Background: Low glycemic index (GI) pre-exercise meals may enhance endurance performance by maintaining euglycemia and altering fuel utilization. However, evidence for performance benefits is equivocal. Objective: To evaluate the effect of a low GI (LGI) versus a high GI (HGI) pre-exercise meal on

  16. Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial.

    Science.gov (United States)

    Paulsen, Gøran; Cumming, Kristoffer T; Holden, Geir; Hallén, Jostein; Rønnestad, Bent Ronny; Sveen, Ole; Skaug, Arne; Paur, Ingvild; Bastani, Nasser E; Østgaard, Hege Nymo; Buer, Charlotte; Midttun, Magnus; Freuchen, Fredrik; Wiig, Havard; Ulseth, Elisabeth Tallaksen; Garthe, Ina; Blomhoff, Rune; Benestad, Haakon B; Raastad, Truls

    2014-04-15

    In this double-blind, randomised, controlled trial, we investigated the effects of vitamin C and E supplementation on endurance training adaptations in humans. Fifty-four young men and women were randomly allocated to receive either 1000 mg of vitamin C and 235 mg of vitamin E or a placebo daily for 11 weeks. During supplementation, the participants completed an endurance training programme consisting of three to four sessions per week (primarily of running), divided into high-intensity interval sessions [4-6 × 4-6 min; >90% of maximal heart rate (HRmax)] and steady state continuous sessions (30-60 min; 70-90% of HRmax). Maximal oxygen uptake (VO2 max ), submaximal running and a 20 m shuttle run test were assessed and blood samples and muscle biopsies were collected, before and after the intervention. Participants in the vitamin C and E group increased their VO2 max (mean ± s.d.: 8 ± 5%) and performance in the 20 m shuttle test (10 ± 11%) to the same degree as those in the placebo group (mean ± s.d.: 8 ± 5% and 14 ± 17%, respectively). However, the mitochondrial marker cytochrome c oxidase subunit IV (COX4) and cytosolic peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1α) increased in the m. vastus lateralis in the placebo group by 59 ± 97% and 19 ± 51%, respectively, but not in the vitamin C and E group (COX4: -13 ± 54%; PGC-1α: -13 ± 29%; P ≤ 0.03, between groups). Furthermore, mRNA levels of CDC42 and mitogen-activated protein kinase 1 (MAPK1) in the trained muscle were lower in the vitamin C and E group than in the placebo group (P ≤ 0.05). Daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training. However, no clear interactions were detected for improvements in VO2 max and running performance. Consequently, vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to the performance tests

  17. Enzymatic and hormonal responses following a 24 h endurance run and a 10 h triathlon race.

    Science.gov (United States)

    Fellmann, N; Sagnol, M; Bedu, M; Falgairette, G; Van Praagh, E; Gaillard, G; Jouanel, P; Coudert, J

    1988-01-01

    Muscle cell leakage and hormonal changes were compared immediately after and during the 3 days following a 24 h endurance run (R24h) in 8 subjects, and a 10 h triathlon non-competitive race (T10h) in 6 subjects. The study showed three main differences: 1) plasma enzyme increases were considerably more significant in R24h than in T10h: compared with resting levels, creatine kinase increased x 120 after R24h but only x 2 after T10h; lactic dehydrogenase x 4, as opposed to x 1.5; and transaminases only showed an increase after R24h. The plasma myoglobin increase after R24h was double that found after T10h; 2) for the same magnitude of plasma aldosterone and cortisol after R24h and T10h (3 times the resting levels), a highly significant decrease in urinary Na+ (p less than 0.001) and an increase in urinary K+ (p less than 0.01) were found only after R24h; and 3) the plasma free noradrenaline level increased significantly after R24h (x 2.6) whereas it was unchanged after T10h. In contrast, the plasma level of conjugated dopamine increased only after T10h (x 3.7, p less than 0.05). These results suggest that long-distance running causes more muscular lesions than the triathlon, and that important factors other than aldosterone are probably involved in the regulation of urinary electrolyte excretions during T10h.

  18. Altering Pace Control and Pace Regulation: Attentional Focus Effects during Running.

    Science.gov (United States)

    Brick, Noel E; Campbell, Mark J; Metcalfe, Richard S; Mair, Jacqueline L; Macintyre, Tadhg E

    2016-05-01

    To date, there are no published studies directly comparing self-controlled (SC) and externally controlled (EC) pace endurance tasks. However, previous research suggests pace control may impact on cognitive strategy use and effort perceptions. The primary aim of this study was to investigate the effects of manipulating perception of pace control on attentional focus, physiological, and psychological outcomes during running. The secondary aim was to determine the reproducibility of self-paced running performance when regulated by effort perceptions. Twenty experienced endurance runners completed four 3-km time trials on a treadmill. Subjects completed two SC pace trials, one perceived exertion clamped (PE) trial, and one EC pace time trial. PE and EC were completed in a counterbalanced order. Pacing strategy for EC and perceived exertion instructions for PE replicated the subjects' fastest SC time trial. Subjects reported a greater focus on cognitive strategies such as relaxing and optimizing running action during EC than during SC. The mean HR was 2% lower during EC than that during SC despite an identical pacing strategy. Perceived exertion did not differ between the three conditions. However, increased internal sensory monitoring coincided with elevated effort perceptions in some subjects during EC and a 10% slower completion time for PE (13.0 ± 1.6 min) than that for SC (11.8 ± 1.2 min). Altering pace control and pace regulation impacted on attentional focus. External control over pacing may facilitate performance, particularly when runners engage attentional strategies conducive to improved running efficiency. However, regulating pace based on effort perceptions alone may result in excessive monitoring of bodily sensations and a slower running speed. Accordingly, attentional focus interventions may prove beneficial for some athletes to adopt task-appropriate attentional strategies to optimize performance.

  19. Effects of respiratory muscle endurance training on wheelchair racing performance in athletes with paraplegia: a pilot study.

    NARCIS (Netherlands)

    Muller, G.; Perret, C.; Hopman, M.T.E.

    2008-01-01

    OBJECTIVE: Respiratory muscle endurance training (RMET) has been shown to improve both respiratory muscle and cycling exercise endurance in able-bodied subjects. Since effects of RMET on upper extremity exercise performance have not yet been investigated, we evaluated the effects of RMET on 10-km

  20. Carbohydrate gel ingestion significantly improves the intermittent endurance capacity, but not sprint performance, of adolescent team games players during a simulated team games protocol.

    Science.gov (United States)

    Phillips, Shaun M; Turner, Anthony P; Sanderson, Mark F; Sproule, John

    2012-03-01

    The aim of this study was to investigate the influence of ingesting a carbohydrate (CHO) gel on the intermittent endurance capacity and sprint performance of adolescent team games players. Eleven participants [mean age 13.5 ± 0.7 years, height 1.72 ± 0.08 m, body mass (BM) 62.1 ± 9.4 kg] performed two trials separated by 3-7 days. In each trial, they completed four 15 min periods of part A of the Loughborough Intermittent Shuttle Test (LIST), followed by an intermittent run to exhaustion (part B). In the 5 min pre-exercise, participants consumed 0.818 mL kg(-1) BM of a CHO or a non-CHO placebo gel, and a further 0.327 mL kg(-1) BM every 15 min during part A of the LIST (38.0 ± 5.5 g CHO h(-1) in the CHO trial). Intermittent endurance capacity was increased by 21.1% during part B when the CHO gel was ingested (4.6 ± 2.0 vs. 3.8 ± 2.4 min, P games players during a simulated team games protocol.

  1. Cooling During Exercise: An Overlooked Strategy for Enhancing Endurance Performance in the Heat.

    Science.gov (United States)

    Stevens, Christopher J; Taylor, Lee; Dascombe, Ben J

    2017-05-01

    It is well established that endurance performance is negatively affected by environmental heat stress due to a complex interaction of physical, physiological and psychological alterations. Numerous scientific investigations have attempted to improve performance in the heat with pre-cooling (cooling prior to an exercise test), and as such this has become a well-established ergogenic practice for endurance athletes. However, the use of mid-cooling (cooling during an exercise test) has received considerably less research attention in comparison, despite recent evidence to suggest that the advantage gained from mid-cooling may outweigh that of pre-cooling. A range of mid-cooling strategies are beneficial for endurance performance in the heat, including the ingestion of cold fluids and ice slurry, both with and without menthol, as well as cooling of the neck and face region via a cooling collar or water poured on the head and face. The combination of pre-cooling and mid-cooling has also been effective, but few comparisons exist between the timing and type of such interventions. Therefore, athletes should experiment with a range of suitable mid-cooling strategies for their event during mock competition scenarios, with the aim to determine their individual tolerable limits and performance benefits. Based on current evidence, the effect of mid-cooling on core temperature appears largely irrelevant to any subsequent performance improvements, while cardiovascular, skin temperature, central nervous system function and psychophysiological factors are likely involved. Research is lacking on elite athletes, and as such it is currently unclear how this population may benefit from mid-cooling.

  2. Moderate running and plyometric training during off-season did not show a significant difference on soccer-related high-intensity performances compared with no-training controls.

    Science.gov (United States)

    Nakamura, Daisuke; Suzuki, Tomohiro; Yasumatsu, Mikinobu; Akimoto, Takayuki

    2012-12-01

    Several investigators have reported the effects of reduced training and interrupted training on athletic performance, but few reports are available for soccer players. The purpose of this study was to examine, using the Yo-Yo intermittent recovery level 2 (YoYoIR2) test and sprint performance, the effects on soccer players of a reduced training program consisting of either moderate running training, plyometric training. After the completion of a competitive season, 29 male soccer players were divided into 3 groups: the running group (n = 13), the plyometric group (n = 11), and the control group (n = 5). Both training groups completed either running or plyometric training sessions 2 d·wk(-1) for 3 weeks, whereas the control group was not allowed to perform any training. The subjects performed YoYoIR2 and 20-m sprint tests before (pre) and after (post) the experimental period. Neither training group showed any significant training effects on the YoYoIR2 performance or 20-m sprint times compared with the control group. This study suggests that neither endurance running nor plyometric training 2 d·wk(-1) for 3 weeks has a significant effect on high-intensity performance compared with a nontraining regimen. However, our results do not support complete inactivity. These results may have important implications for the management of training cessation for a few weeks.

  3. Variation in foot strike patterns during running among habitually barefoot populations.

    Science.gov (United States)

    Hatala, Kevin G; Dingwall, Heather L; Wunderlich, Roshna E; Richmond, Brian G

    2013-01-01

    Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns.

  4. Variation in foot strike patterns during running among habitually barefoot populations.

    Directory of Open Access Journals (Sweden)

    Kevin G Hatala

    Full Text Available Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns.

  5. Nutritional Supplements for Endurance Athletes

    Science.gov (United States)

    Rasmussen, Christopher J.

    Athletes engaged in heavy endurance training often seek additional nutritional strategies to help maximize performance. Specific nutritional supplements exist to combat certain factors that limit performance beginning with a sound everyday diet. Research has further demonstrated that safe, effective, legal supplements are in fact available for today's endurance athletes. Several of these supplements are marketed not only to aid performance but also to combat the immunosuppressive effects of intense endurance training. It is imperative for each athlete to research the legality of certain supplements for their specific sport or event. Once the legality has been established, it is often up to each individual athlete to decipher the ethics involved with ingesting nutritional supplements with the sole intent of improving performance.

  6. Testing of Badminton-Specific Endurance.

    Science.gov (United States)

    Madsen, Christian M; Højlyng, Mads; Nybo, Lars

    2016-09-01

    Madsen, CM, Højlyng, M, and Nybo, L. Testing of badminton-specific endurance. J Strength Cond Res 30(9): 2582-2590, 2016-In the present study, a novel intermittent badminton endurance (B-ENDURANCE) test was developed and tested in elite (n = 17) and skilled (n = 9) badminton players and in age-matched physically active men (nonbadminton players; n = 8). In addition, B-ENDURANCE test-retest reproducibility was evaluated in 9 badminton players. The B-ENDURANCE test is an incremental test where each level consists of repeated sequences of badminton-specific actions toward the 4 corners of the court. The subject starts in the center of the court in front of a computer screen and within each sequence, he must, in a randomized order, complete 8 actions as dictated by the computer, providing the audiovisual input and verifying that the appropriate sensor is activated within the allocated time. Recovery time between each sequence is 10 seconds throughout the test, but the time to complete each sequence is gradually decreased until the subjects cannot follow the dictated tempo. The B-ENDURANCE test performance for elite players was better (p ≤ 0.05) compared with the skilled players and nonbadminton players. In addition, the B-ENDURANCE test performance correlated (r = 0.8 and p badminton-specific endurance but at least 1 familiarization trial is recommended if the test is used for evaluation of longitudinal changes, e.g., tracking training effects.

  7. Physiological characteristics of the best Eritrean runners-exceptional running economy.

    Science.gov (United States)

    Lucia, Alejandro; Esteve-Lanao, Jonathan; Oliván, Jesús; Gómez-Gallego, Félix; San Juan, Alejandro F; Santiago, Catalina; Pérez, Margarita; Chamorro-Viña, Carolina; Foster, Carl

    2006-10-01

    Despite their young age, limited training history, and lack of running tradition compared with other East African endurance athletes (e.g., Kenyans and Ethiopians), male endurance runners from Eritrea have recently attained important running successes. The purposes of our study were (i) to document the main physical and physiological characteristics of elite black Eritrean distance runners (n = 7; age: 22 +/- 3 years) and (ii) to compare them with those of their elite white Spanish counterparts. For this second purpose we selected a control group of elite Spanish runners (n = 9; 24 +/- 2 years), owing to the traditionally high success of Spanish athletes in long-distance running compared with other white runners, especially in cross-country competitions. The subjects' main anthropometric characteristics were determined, together with their maximum oxygen uptake (VO2 max) and VO2 (mL.kg(-1).min(-1)), blood lactate, and ammonia concentrations while running at 17, 19, or 21 km.h(-1). The body mass index (18.9 +/- 1.5 kg.m(-2)) and maximal calf circumference (30.9 +/- 1.5 cm) was lower in Eritreans than in Spaniards (20.5 +/- 1.7 kg.m(-2) and 33.9 +/- 2.0 cm, respectively) (p economy of Eritreans is associated, at least partly, with anthropometric variables. Comparison of their submaximal running cost with other published data suggests that superior running economy, rather than enhanced aerobic capacity, may be the common denominator in the success of black endurance runners of East African origin.

  8. ATLAS detector performance in Run1: Calorimeters

    CERN Document Server

    Burghgrave, B; The ATLAS collaboration

    2014-01-01

    ATLAS operated with an excellent efficiency during the Run 1 data taking period, recording respectively in 2011 and 2012 an integrated luminosity of 5.3 fb-1 at √s = 7 TeV and 21.6 fb-1 at √s = 8TeV. The Liquid Argon and Tile Calorimeter contributed to this effort by operating with a good data quality efficiency, improving over the whole Run 1. This poster presents the Run 1 overall status and performance, LS1 works and Preparations for Run 2.

  9. The effect of different dosages of caffeine on endurance performance time

    NARCIS (Netherlands)

    Pasman, W.J.; Baak, M.A. van; Jeukendrup, A.E.; Haan, A. de

    1995-01-01

    The effect of different dosages of caffeine (0 - 5 - 9 - 13 mg · kg body weight-1) on endurance performance was examined. Nine well-trained cyclists participated in this study (VO2max 65.1 + 2.6 ml · kg-1 · min-1). Caffeine capsules were administered in random order and double-blind. One hour after

  10. ALICE HLT Run 2 performance overview.

    Science.gov (United States)

    Krzewicki, Mikolaj; Lindenstruth, Volker; ALICE Collaboration

    2017-10-01

    For the LHC Run 2 the ALICE HLT architecture was consolidated to comply with the upgraded ALICE detector readout technology. The software framework was optimized and extended to cope with the increased data load. Online calibration of the TPC using online tracking capabilities of the ALICE HLT was deployed. Offline calibration code was adapted to run both online and offline and the HLT framework was extended to support that. The performance of this schema is important for Run 3 related developments. An additional data transport approach was developed using the ZeroMQ library, forming at the same time a test bed for the new data flow model of the O2 system, where further development of this concept is ongoing. This messaging technology was used to implement the calibration feedback loop augmenting the existing, graph oriented HLT transport framework. Utilising the online reconstruction of many detectors, a new asynchronous monitoring scheme was developed to allow real-time monitoring of the physics performance of the ALICE detector, on top of the new messaging scheme for both internal and external communication. Spare computing resources comprising the production and development clusters are run as a tier-2 GRID site using an OpenStack-based setup. The development cluster is running continuously, the production cluster contributes resources opportunistically during periods of LHC inactivity.

  11. Run-2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Winklmeier, Frank; The ATLAS collaboration

    2016-01-01

    The 2nd LHC run has started in June 2015 with a pp centre-of-mass collision energy of 13 TeV, and ATLAS has taken first data at this new energy. In this talk the improvements made to the ATLAS experiment during the 2-year shutdown 2013/2014 will be discussed, and first detector and trigger performance results from the Run-2 will be shown. In general, reconstruction algorithms of tracks, e/gamma, muons, taus, jets and flavour tag- ging have been improved for Run-2. The new reconstruction algorithms and their performance measured using the data taken in 2015 at sqrt(s)=13 TeV will be discussed. Reconstruction efficiency, isolation performance, transverse momentum resolution and momentum scales are measured in various regions of the detector and in momentum intervals enlarged with respect to those measured in the Run-1. This presentation will also give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown in order to deal with the increased trigger rates (fact...

  12. Metabolic characteristics of keto-adapted ultra-endurance runners.

    Science.gov (United States)

    Volek, Jeff S; Freidenreich, Daniel J; Saenz, Catherine; Kunces, Laura J; Creighton, Brent C; Bartley, Jenna M; Davitt, Patrick M; Munoz, Colleen X; Anderson, Jeffrey M; Maresh, Carl M; Lee, Elaine C; Schuenke, Mark D; Aerni, Giselle; Kraemer, William J; Phinney, Stephen D

    2016-03-01

    Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO2max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n=10, %carbohydrate:protein:fat=59:14:25) diet, and the other a low-carbohydrate (LC; n=10, 10:19:70) diet for an average of 20 months (range 9 to 36 months). Peak fat oxidation was 2.3-fold higher in the LC group (1.54±0.18 vs 0.67±0.14 g/min; P=0.000) and it occurred at a higher percentage of VO2max (70.3±6.3 vs 54.9±7.8%; P=0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21±0.02 vs 0.76±0.11 g/min; P=0.000) corresponding to a greater relative contribution of fat (88±2 vs 56±8%; P=0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (-64% from pre-exercise) and 120 min of recovery (-36% from pre-exercise). Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. The role of fluid temperature and form on endurance performance in the heat.

    Science.gov (United States)

    Tan, P M S; Lee, J K W

    2015-06-01

    Exercising in the heat often results in an excessive increase in body core temperature, which can be detrimental to health and endurance performance. Research in recent years has shifted toward the optimum temperature at which drinks should be ingested. The ingestion of cold drinks can reduce body core temperature before exercise but less so during exercise. Temperature of drinks does not seem to have an effect on the rate of gastric emptying and intestinal absorption. Manipulating the specific heat capacity of a solution can further induce a greater heat sink. Ingestion of ice slurry exploits the additional energy required to convert the solution from ice to water (enthalpy of fusion). Body core temperature is occasionally observed to be higher at the point of exhaustion with the ingestion of ice slurry. There is growing evidence to suggest that ingesting ice slurry is an effective and practical strategy to prevent excessive rise of body core temperature and improve endurance performance. This information is especially important when only a fixed amount of fluid is allowed to be carried, often seen in some ultra-endurance events and military operations. Future studies should evaluate the efficacy of ice slurry in various exercise and environmental conditions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Run 2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2018-01-01

    The 2nd LHC run has started in June 2015 with a proton-proton centre-of-mass collision energy of 13 TeV. During the years 2016 and 2017, LHC delivered an unprecedented amount of luminosity under the ever-increasing challenging conditions in terms of peak luminosity, pile-up and trigger rates. In this talk, the LHC running conditions and the improvements made to the ATLAS experiment in the course of Run 2 will be discussed, and the latest ATLAS detector and ATLAS trigger performance results from the Run 2 will be presented.

  15. Neuromuscular adaptations to training, injury and passive interventions: implications for running economy.

    Science.gov (United States)

    Bonacci, Jason; Chapman, Andrew; Blanch, Peter; Vicenzino, Bill

    2009-01-01

    Performance in endurance sports such as running, cycling and triathlon has long been investigated from a physiological perspective. A strong relationship between running economy and distance running performance is well established in the literature. From this established base, improvements in running economy have traditionally been achieved through endurance training. More recently, research has demonstrated short-term resistance and plyometric training has resulted in enhanced running economy. This improvement in running economy has been hypothesized to be a result of enhanced neuromuscular characteristics such as improved muscle power development and more efficient use of stored elastic energy during running. Changes in indirect measures of neuromuscular control (i.e. stance phase contact times, maximal forward jumps) have been used to support this hypothesis. These results suggest that neuromuscular adaptations in response to training (i.e. neuromuscular learning effects) are an important contributor to enhancements in running economy. However, there is no direct evidence to suggest that these adaptations translate into more efficient muscle recruitment patterns during running. Optimization of training and run performance may be facilitated through direct investigation of muscle recruitment patterns before and after training interventions. There is emerging evidence that demonstrates neuromuscular adaptations during running and cycling vary with training status. Highly trained runners and cyclists display more refined patterns of muscle recruitment than their novice counterparts. In contrast, interference with motor learning and neuromuscular adaptation may occur as a result of ongoing multidiscipline training (e.g. triathlon). In the sport of triathlon, impairments in running economy are frequently observed after cycling. This impairment is related mainly to physiological stress, but an alteration in lower limb muscle coordination during running after cycling

  16. The ATLAS Muon Trigger Performance in Run I and Initial Run II Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00437899; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run I, the instantaneous luminosity of the LHC reached 7.7x1033 cm-2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. The performance of muon triggers during the LHC Run 1 data-taking campaigns is presented, together with an overview and preliminary results of the new muon str...

  17. The ATLAS Muon Trigger Performance in Run I and Initial Run II Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00437899; The ATLAS collaboration

    2016-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider. An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run I, the instantaneous luminosity reached $7.7\\times10^{33}$ cm$^{-2}$s$^{-1}$ and the average number of interactions that occur in the same bunch crossing was 25. The ATLAS muon trigger has successfully adapted to this challenging environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of the Higgs boson in 2012 and for many searches for new physics. The performance of muon triggers during the Large Hadron Collider Run I data-taking campaigns is presented, together with an overview and pre...

  18. ‘The engine just started coughing!’ — Limits of physical performance, aging and career continuity in elite endurance sports

    DEFF Research Database (Denmark)

    Ronkainen, Noora; Ryba, Tatiana; Nesti, Mark

    2013-01-01

    This research examines male endurance athletes' experience of aging and/or reaching the perceived limits of physical performance. More specifically, the current study aimed to explore how existential meanings attached to these experiences are connected with athletes' decision-making concerning...... career continuity and retirement. Life story interviews were conducted with 10 Finnish runners and/or orienteers aged between 25 and 62 and the data was analyzed with an existential-narrative framework. Four major storylines related to aging were identified: The end of an era, putting things...... the normativity of retirement when unable to improve their results anymore, other athletes demonstrated career continuity and positive aspects in the late career years, such as lack of competitive anxiety, finding perspective and increased enjoyment in running. We suggest that through awareness of alternative...

  19. [Endurance capabilities of triathlon competitors with type 1 diabetes mellitus].

    Science.gov (United States)

    Boehncke, S; Poettgen, K; Maser-Gluth, C; Reusch, J; Boehncke, W-H; Badenhoop, K

    2009-04-01

    Treatment of type 1 diabetes mellitus (DM) aims to prevent complications by strictly optimizing blood glucose levels. Although physical exercise is an important part of metabolic control, endurance sports are considered hazardous for patients with type 1 diabetes because of the extreme physiological stress they represent. To further elucidate the metabolic challenge this form of exercise presented we investigated the performance of triathlon competitors with type 1 diabetes. Ten patients (32-61 years) with type 1 diabetes (disease duration 2-35 years) were followed for three years, during which each year they participated in one triathlon long-distance competitions (2.4 miles swimming, 26.2 miles running and 112 miles cycling; Ironman Germany 2005-2007). Glucose, cortisol, aldosterone, renin, thyroid hormones, testosterone, growth hormone and catecholamines were measured in blood and saliva. Five non-diabetic competitors served as controls. The performance equalled those of age-matched healthy athletes. Several participants experienced hyperglycemia early in the bike leg, whereas all of them developed low blood glucose levels during the marathon leg. Basal insulin supply was reduced up to 50 % on race day. Hormone levels in athletes with type 1 DM and healthy controls were similar. Patients with type 1 DM can successfully sustain extreme endurance challenges. Physiological alterations of the metabolic state complicated by type 1 DM can readily be compensated by adapting intensified insulin therapy and nutritional modifications. Thus 1 DM should not be regarded a contraindication to participating in high endurance sports.

  20. An empirical study of race times in recreational endurance runners.

    Science.gov (United States)

    Vickers, Andrew J; Vertosick, Emily A

    2016-01-01

    Studies of endurance running have typically involved elite athletes, small sample sizes and measures that require special expertise or equipment. We examined factors associated with race performance and explored methods for race time prediction using information routinely available to a recreational runner. An Internet survey was used to collect data from recreational endurance runners (N = 2303). The cohort was split 2:1 into a training set and validation set to create models to predict race time. Sex, age, BMI and race training were associated with mean race velocity for all race distances. The difference in velocity between males and females decreased with increasing distance. Tempo runs were more strongly associated with velocity for shorter distances, while typical weekly training mileage and interval training had similar associations with velocity for all race distances. The commonly used Riegel formula for race time prediction was well-calibrated for races up to a half-marathon, but dramatically underestimated marathon time, giving times at least 10 min too fast for half of runners. We built two models to predict marathon time. The mean squared error for Riegel was 381 compared to 228 (model based on one prior race) and 208 (model based on two prior races). Our findings can be used to inform race training and to provide more accurate race time predictions for better pacing.

  1. Endurance Exercise Ability in the Horse: A Trait with Complex Polygenic Determinism.

    Science.gov (United States)

    Ricard, Anne; Robert, Céline; Blouin, Christine; Baste, Fanny; Torquet, Gwendoline; Morgenthaler, Caroline; Rivière, Julie; Mach, Nuria; Mata, Xavier; Schibler, Laurent; Barrey, Eric

    2017-01-01

    Endurance horses are able to run at more than 20 km/h for 160 km (in bouts of 30-40 km). This level of performance is based on intense aerobic metabolism, effective body heat dissipation and the ability to endure painful exercise. The known heritabilities of endurance performance and exercise-related physiological traits in Arabian horses suggest that adaptation to extreme endurance exercise is influenced by genetic factors. The objective of the present genome-wide association study (GWAS) was to identify single nucleotide polymorphisms (SNPs) related to endurance racing performance in 597 Arabian horses. The performance traits studied were the total race distance, average race speed and finishing status (qualified, eliminated or retired). We used three mixed models that included a fixed allele or genotype effect and a random, polygenic effect. Quantile-quantile plots were acceptable, and the regression coefficients for actual vs. expected log 10 p -values ranged from 0.865 to 1.055. The GWAS revealed five significant quantitative trait loci (QTL) corresponding to 6 SNPs on chromosomes 6, 1, 7, 16, and 29 (two SNPs) with corrected p -values from 1.7 × 10 -6 to 1.8 × 10 -5 . Annotation of these 5 QTL revealed two genes: sortilin-related VPS10-domain-containing receptor 3 ( SORCS3 ) on chromosome 1 is involved in protein trafficking, and solute carrier family 39 member 12 ( SLC39A12 ) on chromosome 29 is active in zinc transport and cell homeostasis. These two coding genes could be involved in neuronal tissues (CNS). The other QTL on chromosomes 6, 7, and 16 may be involved in the regulation of the gene expression through non-coding RNAs, CpG islands and transcription factor binding sites. On chromosome 6, a new candidate equine long non-coding RNA ( KCNQ1OT1 ortholog: opposite antisense transcript 1 of potassium voltage-gated channel subfamily Q member 1 gene) was predicted in silico and validated by RT-qPCR in primary cultures of equine myoblasts and fibroblasts

  2. Endurance Exercise Ability in the Horse: A Trait with Complex Polygenic Determinism

    Directory of Open Access Journals (Sweden)

    Anne Ricard

    2017-06-01

    Full Text Available Endurance horses are able to run at more than 20 km/h for 160 km (in bouts of 30–40 km. This level of performance is based on intense aerobic metabolism, effective body heat dissipation and the ability to endure painful exercise. The known heritabilities of endurance performance and exercise-related physiological traits in Arabian horses suggest that adaptation to extreme endurance exercise is influenced by genetic factors. The objective of the present genome-wide association study (GWAS was to identify single nucleotide polymorphisms (SNPs related to endurance racing performance in 597 Arabian horses. The performance traits studied were the total race distance, average race speed and finishing status (qualified, eliminated or retired. We used three mixed models that included a fixed allele or genotype effect and a random, polygenic effect. Quantile-quantile plots were acceptable, and the regression coefficients for actual vs. expected log10p-values ranged from 0.865 to 1.055. The GWAS revealed five significant quantitative trait loci (QTL corresponding to 6 SNPs on chromosomes 6, 1, 7, 16, and 29 (two SNPs with corrected p-values from 1.7 × 10−6 to 1.8 × 10−5. Annotation of these 5 QTL revealed two genes: sortilin-related VPS10-domain-containing receptor 3 (SORCS3 on chromosome 1 is involved in protein trafficking, and solute carrier family 39 member 12 (SLC39A12 on chromosome 29 is active in zinc transport and cell homeostasis. These two coding genes could be involved in neuronal tissues (CNS. The other QTL on chromosomes 6, 7, and 16 may be involved in the regulation of the gene expression through non-coding RNAs, CpG islands and transcription factor binding sites. On chromosome 6, a new candidate equine long non-coding RNA (KCNQ1OT1 ortholog: opposite antisense transcript 1 of potassium voltage-gated channel subfamily Q member 1 gene was predicted in silico and validated by RT-qPCR in primary cultures of equine myoblasts and

  3. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  4. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables......, and endurance time at W90 with FCPR-25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. W90 was 325 (47) W. FCPR at W90 was 78 (11) rpm, resulting in FCPR-25 being 59 (8) rpm and FCPR+25...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables...

  5. Estimating Stair Running Performance Using Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Lauro V. Ojeda

    2017-11-01

    Full Text Available Stair running, both ascending and descending, is a challenging aerobic exercise that many athletes, recreational runners, and soldiers perform during training. Studying biomechanics of stair running over multiple steps has been limited by the practical challenges presented while using optical-based motion tracking systems. We propose using foot-mounted inertial measurement units (IMUs as a solution as they enable unrestricted motion capture in any environment and without need for external references. In particular, this paper presents methods for estimating foot velocity and trajectory during stair running using foot-mounted IMUs. Computational methods leverage the stationary periods occurring during the stance phase and known stair geometry to estimate foot orientation and trajectory, ultimately used to calculate stride metrics. These calculations, applied to human participant stair running data, reveal performance trends through timing, trajectory, energy, and force stride metrics. We present the results of our analysis of experimental data collected on eleven subjects. Overall, we determine that for either ascending or descending, the stance time is the strongest predictor of speed as shown by its high correlation with stride time.

  6. Altitude training for elite endurance athletes: A review for the travel medicine practitioner.

    Science.gov (United States)

    Flaherty, Gerard; O'Connor, Rory; Johnston, Niall

    2016-01-01

    High altitude training is regarded as an integral component of modern athletic preparation, especially for endurance sports such as middle and long distance running. It has rapidly achieved popularity among elite endurance athletes and their coaches. Increased hypoxic stress at altitude facilitates key physiological adaptations within the athlete, which in turn may lead to improvements in sea-level athletic performance. Despite much research in this area to date, the exact mechanisms which underlie such improvements remain to be fully elucidated. This review describes the current understanding of physiological adaptation to high altitude training and its implications for athletic performance. It also discusses the rationale and main effects of different training models currently employed to maximise performance. Athletes who travel to altitude for training purposes are at risk of suffering the detrimental effects of altitude. Altitude illness, weight loss, immune suppression and sleep disturbance may serve to limit athletic performance. This review provides an overview of potential problems which an athlete may experience at altitude, and offers specific training recommendations so that these detrimental effects are minimised. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The ATLAS Tau Trigger Performance during LHC Run 1 and Prospects for Run 2

    CERN Document Server

    Mitani, T; The ATLAS collaboration

    2016-01-01

    The ATLAS tau trigger is designed to select hadronic decays of the tau leptons. Tau lepton plays an important role in Standard Model (SM) physics, such as in Higgs boson decays. Tau lepton is also important in beyond the SM (BSM) scenarios, such as supersymmetry and exotic particles, as they are often produced preferentially in these models. During the 2010-2012 LHC run (Run1), the tau trigger was accomplished successfully, which leads several rewarding results such as evidence for $H\\rightarrow \\tau\\tau$. From the 2015 LHC run (Run2), LHC will be upgraded and overlapping interactions per bunch crossing (pile-up) are expected to increase by a factor two. It will be challenging to control trigger rates while keeping interesting physics events. This paper summarized the tau trigger performance in Run1 and its prospects for Run2.

  8. Compliance in doing Senam Kesegaran Jasmani 1988 exercise improves cardiorespiratory endurance of attention deficit/hyperactivity disorder children

    Directory of Open Access Journals (Sweden)

    Listya T. Mirtha

    2018-05-01

    Full Text Available Background: Physical exercise was hypothesized to be able to improve the behavior of children with attention deficit/hyperactivity disorder (ADHD by improving attention and concentration. Several studies mentioned that physical exercise could make ADHD children calmer, not only as a supportive therapy, but also as a therapeutic therapy. The aim of this study was to evaluate the effects of physical exercise to the behavior of ADHD patients and to analyze the effects of Senam Kesegaran Jasmani 1988 (SKJ 88 exercise compliance to the cardiorespiratory endurance in ADHD children.Methods: This study was an experimental study with 40 subjects from a special needs school in Tangerang, Indonesia. Subjects were given SKJ 88 exercise for 8 weeks, and the level of cardiorespiratory endurance was assessed with 600 m run before and after intervention.Results: 21 subjects (52.5% were compliant, and the rest were very compliant. Although statistical analysis showed that there was no significant difference in cardiorespiratory endurance before and after intervention, the mean results of cardiorespiratory endurance test before intervention was higher than after. Mean time spent in the 600-m run before intervention was 497.9 seconds (SD 73.53, and after intervention was 313.7 seconds (SD 43.28.Conclusion: Based on the statistical test, we concluded that there was significant decrease of time spent for cardiorespiratory endurance test (p<0.001. The reduction of time taken to run 600 m by 184.3 seconds (SD 73.33 showed the improvement of cardiorespiratory endurance after the treatment.

  9. Age, sex and (the) race: gender and geriatrics in the ultra-endurance age.

    Science.gov (United States)

    Whyte, Greg

    2014-01-01

    Ultra-endurance challenges were once the stuff of legend isolated to the daring few who were driven to take on some of the greatest physical endurance challenges on the planet. With a growing fascination for major physical challenges during the nineteenth century, the end of the Victorian era witnessed probably the greatest ultra-endurance race of all time; Scott and Amundsen's ill-fated race to the South Pole. Ultra-endurance races continued through the twentieth century; however, these events were isolated to the elite few. In the twenty-first century, mass participation ultra-endurance races have grown in popularity. Endurance races once believed to be at the limit of human durability, i.e. marathon running, are now viewed as middle-distance races with the accolade of true endurance going to those willing to travel significantly further in a single effort or over multiple days. The recent series of papers in Extreme Physiology & Medicine highlights the burgeoning research data from mass participation ultra-endurance events. In support of a true 'mass participation' ethos Knetchtle et al. reported age-related changes in Triple and Deca Iron-ultra-triathlon with an upper age of 69 years! Unlike their shorter siblings, the ultra-endurance races appear to present larger gender differences in the region of 20% to 30% across distance and modality. It would appear that these gender differences remain for multi-day events including the 'Marathon des Sables'; however, this gap may be narrower in some events, particularly those that require less load bearing (i.e. swimming and cycling), as evidenced from the 'Ultraman Hawaii' and 'Swiss Cycling Marathon', and shorter (a term I used advisedly!) distances including the Ironman Triathlon where differences are similar to those of sprint and endurance distances i.e. c. 10%. The theme running through this series of papers is a continual rise in participation to the point where major events now require selection races to remain

  10. Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle.

    Science.gov (United States)

    Bjarnegård, N; Länne, T; Cinthio, M; Ekstrand, J; Hedman, K; Nylander, E; Henriksson, J

    2018-06-01

    To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women. Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform. Carotid-radial PWV was lower in WBA than in RUN (P sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk. © 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  11. Can persistence hunting signal male quality? A test considering digit ratio in endurance athletes.

    Directory of Open Access Journals (Sweden)

    Daniel Longman

    Full Text Available Various theories have been posed to explain the fitness payoffs of hunting success among hunter-gatherers. 'Having' theories refer to the acquisition of resources, and include the direct provisioning hypothesis. In contrast, 'getting' theories concern the signalling of male resourcefulness and other desirable traits, such as athleticism and intelligence, via hunting prowess. We investigated the association between androgenisation and endurance running ability as a potential signalling mechanism, whereby running prowess, vital for persistence hunting, might be used as a reliable signal of male reproductive fitness by females. Digit ratio (2D:4D was used as a proxy for prenatal androgenisation in 439 males and 103 females, while a half marathon race (21km, representing a distance/duration comparable with that of persistence hunting, was used to assess running ability. Digit ratio was significantly and positively correlated with half-marathon time in males (right hand: r = 0.45, p<0.001; left hand: r = 0.42, p<0.001 and females (right hand: r = 0.26, p<0.01; left hand: r = 0.23, p = 0.02. Sex-interaction analysis showed that this correlation was significantly stronger in males than females, suggesting that androgenisation may have experienced stronger selective pressure from endurance running in males. As digit ratio has previously been shown to predict reproductive success, our results are consistent with the hypothesis that endurance running ability may signal reproductive potential in males, through its association with prenatal androgen exposure. However, further work is required to establish whether and how females respond to this signalling for fitness.

  12. LHCb detector and trigger performance in Run II

    Science.gov (United States)

    Francesca, Dordei

    2017-12-01

    The LHCb detector is a forward spectrometer at the LHC, designed to perform high precision studies of b- and c- hadrons. In Run II of the LHC, a new scheme for the software trigger at LHCb allows splitting the triggering of events into two stages, giving room to perform the alignment and calibration in real time. In the novel detector alignment and calibration strategy for Run II, data collected at the start of the fill are processed in a few minutes and used to update the alignment, while the calibration constants are evaluated for each run. This allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger. The larger timing budget, available in the trigger, allows to perform the same track reconstruction online and offline. This enables LHCb to achieve the best reconstruction performance already in the trigger, and allows physics analyses to be performed directly on the data produced by the trigger reconstruction. The novel real-time processing strategy at LHCb is discussed from both the technical and operational point of view. The overall performance of the LHCb detector on the data of Run II is presented as well.

  13. Increasing the electrical discharge endurance of acid anhydride cured DGEBA epoxy resin by dispersion of nanoparticle silica. High Perform. Polym. 11 (1999) pp 281-296 by IOP Publishing Ltd

    DEFF Research Database (Denmark)

    Henk, Peter O; Kortsen, T.W.; Kvarts, T.

    1999-01-01

    combinations were used: (a) fumed nanoparticle silicon dioxide referred to as Aerosil, (b) equal volumes of Aerosil and nanoparticle anatase, and (c) Aerosil plus anatase in combination with coarse-particle filler grade calcium-magnesium carbonate dolomite. A test for endurance using the CIGRE method II...... electrode arrangement was applied, the test comprising the establishment of partial discharges running perpendicularly onto one face of a plate specimen for a period measured until breakdown.Our results show that the endurance of the pure polymer is low. Increased loading with Aerosil increases...... the endurance by a factor of up to 20 as the Aerosil content goes from zero to 5.4 vol%. Aerosil mixed with anatase has a similar effect. The high level of endurance is maintained with an additional high-volume (35 vol.%) filling of coarse-particle dolomite to an epoxy system already containing Aerosil...

  14. Mechanical and morphological properties of different muscle-tendon units in the lower extremity and running mechanics: effect of aging and physical activity.

    Science.gov (United States)

    Karamanidis, Kiros; Arampatzis, Adamantios

    2005-10-01

    The objectives of this work were (i) to investigate whether chronic endurance running is a sufficient stimulus to counteract the age-related changes in the mechanical and morphological properties of human triceps surae (TS) and quadriceps femoris (QF) muscle-tendon units (MTUs) by comparing runners and non-active subjects at different ages (young and old), (ii) to identify adaptational phenomena in running mechanics due to age-related changes in the mechanical and morphological properties of the TS and QF MTUs, and finally (iii) to examine whether chronic endurance-running exercise is associated with adaptational effects on running characteristics in old and young adults. The investigation was conducted on 30 old and 19 young adult males divided into two subgroups according to their running activity: endurance-runners vs non-active. To analyse the properties of the MTUs, all subjects performed isometric maximal voluntary (MVC) ankle plantarflexion and knee extension contractions at 11 different MTU lengths on a dynamometer. The activation of the TS and QF during MVC was estimated by surface electromyography. The gastrocnemius medialis and the vastus lateralis and their distal aponeuroses were visualized by ultrasonography at rest and during MVC, respectively. Ground reaction forces and kinematic data were recorded during running trials at 2.7 m s(-1). The TS and QF MTU capacities were reduced with aging (lower muscle strength and lower tendon stiffness). Runners and non-active subjects had similar MTU properties, suggesting that chronic endurance-running exercise does not counteract the age-related degeneration of the MTUs. Runners showed a higher mechanical advantage for the QF MTU while running (lower gear ratio) compared to non-active subjects, indicating a task-specific adaptation even at old age. Older adults reacted to the reduced capacities of their MTUs by increasing running safety (higher duty factor, lower flight time) and benefitting from a mechanical

  15. Individual Endurance Training Prescription with Heart Rate Variability.

    Science.gov (United States)

    Vesterinen, Ville; Nummela, Ari; Heikura, Ida; Laine, Tanja; Hynynen, Esa; Botella, Javier; Häkkinen, Keijo

    2016-07-01

    Measures of HR variability (HRV) have shown potential to be of use in training prescription. The aim of this study was to investigate the effectiveness of using HRV in endurance training prescription. Forty recreational endurance runners were divided into the HRV-guided experimental training group (EXP) and traditional predefined training group (TRAD). After a 4-wk preparation training period, TRAD trained according to a predefined training program including two to three moderate- (MOD) and high-intensity training (HIT) sessions per week during an 8-wk intensive training period. The timing of MOD and HIT sessions in EXP was based on HRV, measured every morning. The MOD/HIT session was programmed if HRV was within an individually determined smallest worthwhile change. Otherwise, low-intensity training was performed. Maximal oxygen consumption (V˙O2max) and 3000-m running performance (RS3000m) were measured before and after both training periods. The number of MOD and HIT sessions was significantly lower (P = 0.021, effect size = 0.98) in EXP (13.2 ± 6.0 sessions) compared with TRAD (17.7 ± 2.5 sessions). No other differences in training were found between the groups. RS3000m improved in EXP (2.1% ± 2.0%, P = 0.004) but not in TRAD (1.1% ± 2.7%, P = 0.118) during the intensive training period. A small between-group difference (effect size = 0.42) was found in the change in RS3000m. V˙O2max improved in both groups (EXP: 3.7% ± 4.6%, P = 0.027; TRAD: 5.0% ± 5.2%, P = 0.002). The results of the present study suggest the potential of resting HRV to prescribe endurance training by individualizing the timing of vigorous training sessions.

  16. Positional Match Running Performance in Elite Gaelic Football.

    Science.gov (United States)

    Malone, Shane; Solan, Barry; Collins, Kieran D; Doran, Dominic A

    2016-08-01

    Malone, S, Solan, B, Collins, KD, and Doran, DA. Positional match running performance in elite Gaelic football. J Strength Cond Res 30(8): 2292-2298, 2016-There is currently limited information available on match running performance in Gaelic football. The objective of the current study was to report on the match running profile of elite male Gaelic football and assess positional running performance. In this observational study, 50 elite male Gaelic football players wore 4-Hz global positioning systems units (VX Sports) across 30 competitive games with a total of 215 full game data sets collected. Activity was classed according to total distance, high-speed distance (≥17 km·h), sprint distance (≥22 km·h), mean velocity (km·h), peak velocity (km·h), and number of accelerations. The average match distance was 8,160 ± 1,482 m, reflective of a relative distance of 116 ± 21 m·min, with 1,731 ± 659 m covered at high speed, which is reflective of a relative high-speed distance of 25 ± 9 m·min. The observed sprint distance was 445 ± 169 m distributed across 44 sprint actions. The peak velocity was 30.3 ± 1.8 km·h with a mean velocity of 6.5 ± 1.2 km·h. Players completed 184 ± 40 accelerations, which represent 2.6 ± 0.5 accelerations per minute. There were significant differences between positional groups for both total running distance, high-speed running distance, and sprint distance, with midfielders covering more total and high-speed running distance, compared with other positions (p football match play.

  17. Effect of pre-cooling, with and without thigh cooling, on strain and endurance exercise performance in the heat.

    Science.gov (United States)

    Cotter, J D; Sleivert, G G; Roberts, W S; Febbraio, M A

    2001-04-01

    Body cooling before exercise (i.e. pre-cooling) reduces physiological strain in humans during endurance exercise in temperate and warm environments, usually improving performance. This study examined the effectiveness of pre-cooling humans by ice-vest and cold (3 degrees C) air, with (LC) and without (LW) leg cooling, in reducing heat strain and improving endurance performance in the heat (35 degrees C, 60% RH). Nine habitually-active males completed three trials, involving pre-cooling (LC and LW) or no pre-cooling (CON: 34 degrees C air) before 35-min cycle exercise: 20 min at approximately 65% VO2peak then a 15-min work-performance trial. At exercise onset, mean core (Tc, from oesophagus and rectum) and skin temperatures, forearm blood flow (FBF), heart rate (HR), and ratings of exertion, body temperature and thermal discomfort were lower in LW and LC than CON (Pcooling by ice-vest and cold air effectively reduced physiological and psychophysical strain and improved endurance performance in the heat, irrespective of whether thighs were warmed or cooled.

  18. Fitness Assessment Comparison Between the "Jackie Chan Action Run" Videogame, 1-Mile Run/Walk, and the PACER.

    Science.gov (United States)

    Haddock, Bryan; Siegel, Shannon; Costa, Pablo; Jarvis, Sarah; Klug, Nicholas; Medina, Ernie; Wilkin, Linda

    2012-06-01

    The purpose of this study was to examine whether a correlation existed among the scores of the "Jackie Chan Studio Fitness(™) Action Run" active videogame (XaviX(®), SSD Company, Ltd., Kusatsu, Japan), the 1-mile run/walk, and Progressive Aerobic Cardiovascular Endurance Run (PACER) aerobic fitness tests of the FITNESSGRAM(®) (The Cooper Institute, Dallas, TX) in order to provide a potential alternative testing method for days that are not environmentally desirable for outdoor testing. Participants were a convenience sample from physical education classes of students between the ages of 10 and 15 years. Participants (n=108) were randomly assigned to one of three groups with the only difference being the order of testing. The tests included the "Jackie Chan Action Run" active videogame, the 1-mile run/walk, and the PACER. Testing occurred on three different days during the physical education class. Rating of perceived exertion (RPE) was reported. Significant correlations (r=-0.598 to 0.312) were found among the three aerobic fitness tests administered (P<0.05). The RPE for the "Jackie Chan Action Run" was lower than the RPE for the 1-mile run/walk and the PACER (3.81±1.89, 5.93±1.77, and 5.71±2.14, respectively). The results suggest that the "Jackie Chan Action Run" test could be an alternative to the 1-mile run/walk and PACER, allowing physical education teachers to perform aerobic fitness testing in an indoor setting that requires less space. Also, children may be more willing to participate in the "Jackie Chan Action Run" based on the lower RPE.

  19. Does respiratory muscle training increase physical performance?

    Science.gov (United States)

    Sperlich, Billy; Fricke, Hannes; de Marées, Markus; Linville, John W; Mester, Joachim

    2009-09-01

    Special force units and military personnel undergo demanding physical exercise and might benefit from high-intensity respiratory muscle training (RMT) by increasing their endurance performance. This study examined the effects of a 6-week high-intensity RMT on running performance and oxygen uptake (VO2max) in a group of German Special Force Squad members. 17 participants were randomly assigned to a training or control group. Baseline and post-testing included a ramp test, as well as an incremental test on a treadmill, performed to physical exhaustion. VO2, respiratory exchange ratio, and heart rate were measured breath by breath. Furthermore, maximum running speed (V(max)), 4 mmol x 1(-1) lactate threshold (V4) and perception of respiratory effort were determined. During pulmonary testing, sustained maximum inspiratory and expiratory pressure (PI(max) and PE(max)) were obtained. RMT was performed daily at approximately 90% PI(max) for 6 weeks with 2 x 30 breath cycles using an Ultrabreathe lung trainer. No statistical differences were detected between the groups for any parameter after RMT. High-intensity RMT did not show any benefits on VO2max and endurance performance and are unlikely to be of benefit to military or paramilitary training programs for an increase in endurance performance.

  20. Determinants of time trial performance and maximal incremental exercise in highly trained endurance athletes

    DEFF Research Database (Denmark)

    Jacobs, Robert Acton; Rasmussen, Peter; Siebenmann, Christoph

    2011-01-01

    Human endurance performance can be predicted from maximal oxygen consumption (VO(2max)), lactate threshold, and exercise efficiency. These physiologic parameters, however, are not wholly exclusive from one another and their interplay is complex. Accordingly, we sought to identify more specific me...

  1. Endurance training-induced changes in the GH-IGF-I axis influence maximal muscle strength in previously untrained men.

    Science.gov (United States)

    Grandys, Marcin; Majerczak, Joanna; Kuczek, Piotr; Sztefko, Krystyna; Duda, Krzysztof; Zoladz, Jerzy A

    2017-02-01

    In this study we have determined the effects of 20weeks of endurance running training on the GH-IGF-I axis changes in the context of the skeletal muscle performance and physical capacity level. Before and after the endurance training program a maximal incremental exercise tests, a 1500m race and a muscle strength measurements were performed and the blood samples were taken to determine both resting as well as end-exercise serum growth hormone (GH), insulin-like growth hormone-I (IGF-I), insulin-like growth hormone binding protein-3 (IGFBP-3) and plasma interleukin-6 (IL-6) concentrations. 20weeks of endurance running training improved power output generated at the end of the maximal incremental test by 24% (P<0.012), 1500m running time by 13% (P<0.012) and maximal muscle strength by 9% (P<0.02). End-exercise IGF-I/IGFBP-3 ratio was decreased by 22% after the training (P<0.04) and the magnitude of IGF-I/IGFBP-3 ratio decrease (ΔIGF-I/IGFBP-3 ex ) was 2.3 times higher after the training (P<0.04). The magnitude of the exercise-induced changes in IGFBP-3 concentration was also significantly higher (P<0.04) and there was a trend toward lower end-exercise IGF-I concentration (P=0.08) after the training. These changes were accompanied by a significantly higher (30%) end-exercise IL-6 concentration (P<0.01) as well as by a 3.4 times higher magnitude of IL-6 increase (P<0.02) after the training. Moreover, there were strong positive correlations between changes in resting serum IGF-I concentration (ΔIGF-I res ) and IGF-I/IGFBP-3 ratio (ΔIGF-I/IGFBP-3 res ) and changes in muscle strength (ΔMVC) (r=0.95, P=0.0003 and r=0.90, P=0.002, respectively). The training-induced changes in the components of the GH-IGF-I axis may have additive effects on skeletal muscle performance and physical capacity improvement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

    Science.gov (United States)

    Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

    2007-05-01

    Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

  3. Physiological and Biomechanical Mechanisms of Distance Specific Human Running Performance.

    Science.gov (United States)

    Thompson, M A

    2017-08-01

    Running events range from 60-m sprints to ultra-marathons covering 100 miles or more, which presents an interesting diversity in terms of the parameters for successful performance. Here, we review the physiological and biomechanical variations underlying elite human running performance in sprint to ultramarathon distances. Maximal running speeds observed in sprint disciplines are achieved by high vertical ground reaction forces applied over short contact times. To create this high force output, sprint events rely heavily on anaerobic metabolism, as well as a high number and large cross-sectional area of type II fibers in the leg muscles. Middle distance running performance is characterized by intermediates of biomechanical and physiological parameters, with the possibility of unique combinations of each leading to high-level performance. The relatively fast velocities in mid-distance events require a high mechanical power output, though ground reaction forces are less than in sprinting. Elite mid-distance runners exhibit local muscle adaptations that, along with a large anaerobic capacity, provide the ability to generate a high power output. Aerobic capacity starts to become an important aspect of performance in middle distance events, especially as distance increases. In distance running events, V˙O2max is an important determinant of performance, but is relatively homogeneous in elite runners. V˙O2 and velocity at lactate threshold have been shown to be superior predictors of elite distance running performance. Ultramarathons are relatively new running events, as such, less is known about physiological and biomechanical parameters that underlie ultra-marathon performance. However, it is clear that performance in these events is related to aerobic capacity, fuel utilization, and fatigue resistance. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in

  4. Comparison of an Intermittent Hypoxic Exposure Acclimatization Program to Staging at Moderate Altitude on Endurance Performance at 4300 m

    Science.gov (United States)

    2009-10-01

    Endurance Performance at 4300 m 7 - 6 RTO-MP-HFM-181 breakfast volunteers were provided with two commercially available energy bars and fruit juice ...food composition = 510 kcal, 14 gm fat, 65 gm carbohydrate, 32 gm protein) at 1 to 2 hrs prior to the beginning of each of the cycle endurance test...JE, Robinson SR, Skrinar GS, Lewis SF and Sawka MN. Intermittent altitude exposures improve muscular performance at 4,300 m. J Appl Physiol 95

  5. Mucosal immunity and upper respiratory tract symptoms in recreational endurance runners.

    Science.gov (United States)

    Ihalainen, Johanna K; Schumann, Moritz; Häkkinen, Keijo; Mero, Antti A

    2016-01-01

    The present study investigated the effects of a 12-week endurance-training intervention on salivary proteins and upper respiratory tract symptoms (URS) in 25 young men. Saliva samples of 25 recreational male endurance runners (age 34.6 years, body mass index = 23.8 kg·m(-2), peak aerobic capacity = 47.2 mL·kg(-1)·min(-1)) were collected before (PRE) and after (POST) the training intervention, in a fasting state, as well as both before and after a maximal incremental treadmill run. The training consisted of both continuous and interval training sessions, 4-6 times per week based on the polarized training approach. Participants filled in Wisconsin Upper Respiratory Symptom Survey-21 and were retrospectively divided into 2 groups according to whether they reported URS (URS group, n = 13) or not (HEALTHY group, n = 12). Basal salivary immunoglobulin A (sa-sIgA) levels were significantly higher (+70%, p < 0.05) in the HEALTHY group both at PRE and POST whereas no significant differences were observed in salivary immunoglobulin M, salivary immunoglobulin G, lysozyme, or salivary α-amylase activity (sAA). Sa-sIgA concentration at PRE significantly correlated with the number of sick-days (R = -0.755, p < 0.001) in all subjects. The incremental treadmill run acutely increased sAA significantly (p < 0.05) at PRE (200%) and POST (166%) in the HEALTHY group but not in the URS group. This study demonstrated that subjects, who experienced URS during the 12 weeks of progressive endurance training intervention, had significantly lower basal sa-sIgA levels both before and after the experimental endurance training period. In addition to sa-sIgA, acute sAA response to exercise might be a possible determinant of susceptibility to URS in endurance runners.

  6. Effects of high intensity training and continuous endurance training on aerobic capacity and body composition in recreationally active runners.

    Science.gov (United States)

    Hottenrott, Kuno; Ludyga, Sebastian; Schulze, Stephan

    2012-01-01

    The aim of the study was to examine the effects of two different training programs (high-intensity-training vs. continuous endurance training) on aerobic power and body composition in recreationally active men and women and to test whether or not participants were able to complete a half marathon after the intervention period. Thirty-four recreational endurance runners were randomly assigned either to a Weekend-Group (WE, n = 17) or an After-Work- Group (AW, n = 17) for a 12 week-intervention period. WE weekly completed 2 h 30 min of continuous endurance running composed of 2 sessions on the weekend. In contrast, AW performed 4 30 min sessions of high intensity training and an additional 30 min endurance run weekly, always after work. During an exhaustive treadmill test aerobic power was measured and heart rate was continuously recorded. Body composition was assessed using bio-impedance. Following the intervention period all subjects took part in a half-marathon. AW significantly improved peak oxygen uptake (VO2 peak) from 36.8 ± 4.5 to 43.6 ± 6.5 [mL.min(-1).kg(-1)], velocity at lactate threshold (VLT) from 9.7 ± 2.2 to 11.7 ± 1.8 [km.h(-1)] and visceral fat from 5.6 ± 2.2 to 4.7 ± 1.9 In WE VO2 peak signifi-cantly increased from 38.8 ± 5.0 to 41.5 ± 6.0 [mL.min(-1).kg(-1)], VLT from 9.9 ± 1.3 to 11.2 ± 1.7 [km.h(-1)] and visceral fat was reduced from 5.7 ± 2.1 to 5.4 ± 1.9 (p marathon with no significant differences in performance (p = 0.63). Short, intensive endurance training sessions of about 30 min are effective in improving aerobic fitness in recreationally active runners. Key pointsContinuous endurance training and high intensity training lead to significant improvements of aerobic capacity and body compositionBoth training methods enable recreationally active runners to finish a half-marathonHigh intensity training is favorable to improve VO2 peak.

  7. Age-related decrements in cycling and running performance ...

    African Journals Online (AJOL)

    South African Journal of Sports Medicine ... This study examined age-related decrements in athletic performance during running and cycling activities. ... These findings establish a trend that there is 'accelerated' aging during running which can perhaps be attributed to the increased weight-bearing stress on the muscles ...

  8. Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise.

    Science.gov (United States)

    Zheng, Xinyan; Hasegawa, Hiroshi

    2016-10-01

    Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.

  9. Effects of Endurance and Endurance Strength Training on Body Composition and Physical Capacity in Women with Abdominal Obesity

    Science.gov (United States)

    Skrypnik, Damian; Bogdański, Paweł; Mądry, Edyta; Karolkiewicz, Joanna; Ratajczak, Marzena; Kryściak, Jakub; Pupek-Musialik, Danuta; Walkowiak, Jarosław

    2015-01-01

    Aims To compare the effects of endurance training with endurance strength training on the anthropometric, body composition, physical capacity, and circulatory parameters in obese women. Methods 44 women with abdominal obesity were randomized into groups A and B, and asked to perform endurance (A) and endurance strength training (B) for 3 months, 3 times/week, for 60 min. Dual-energy X-ray absorptiometry and Graded Exercise Test were performed before and after training. Results Significant decreases in body mass, BMI, total body fat, total body fat mass, and waist and hip circumference were observed after both types of intervention. Marked increases in total body lean and total body fat-free mass were documented in group B. In both groups, significant increases in peak oxygen uptake, time to exhaustion, maximal work rate, and work rate at ventilatory threshold were accompanied by noticeably decreased resting heart rate, resting systolic blood pressure, and resting and exercise diastolic blood pressure. No significant differences were noticed between groups for the investigated parameters. Conclusion Our findings demonstrate evidence for a favorable and comparable effect of 3-month endurance and endurance strength training on anthropometric parameters, body composition, physical capacity, and circulatory system function in women with abdominal obesity. PMID:25968470

  10. The effect of almond consumption on elements of endurance exercise performance in trained athletes

    Science.gov (United States)

    Almonds are a healthy tree nut food with high nutrient density. Their consumption has been shown to ameliorate oxidative stress, inflammation, etc. The objective of the study was to examine the effect of almonds on elements of endurance exercise performance in trained athletes. A 10-week crossover, ...

  11. Run For Fun : Intrinsic Motivation and Physical Performance

    NARCIS (Netherlands)

    Filippin, A.; van Ours, J.C.

    2012-01-01

    Abstract: We use data from the 24-hours Belluno run which has the unique characteristic that participants are affiliated with teams and run for an hour. This allows us not only to study the individual relationship between age and performance but also to study group dynamics in terms of accessions to

  12. Impact of Short-Term Training Camp on Aortic Blood Pressure in Collegiate Endurance Runners

    Directory of Open Access Journals (Sweden)

    Tsubasa Tomoto

    2018-03-01

    Full Text Available To investigate the influence of short-term vigorous endurance training on aortic blood pressure (BP, pulse wave analysis was performed in 36 highly trained elite collegiate endurance runners before and after a 7-day intense training camp. Subjects participated three training sessions per day, which mainly consisted of long distance running and sprint training to reach the daily target distance of 26 km. After the camp, they were divided into two groups based on whether the target training was achieved. Aortic systolic BP, pulse pressure, and tension-time index (TTI, a surrogate index of the myocardial oxygen demand were significantly elevated after the camp in the accomplished group but not in the unaccomplished group, whereas the brachial BP remained unchanged in both groups. The average daily training distance was significantly correlated with the changes in aortic systolic BP (r = 0.608, p = 0.0002, pulse pressure (r = 0.415, p = 0.016, and TTI (r = 0.438, p = 0.011. These results suggest that aortic BP is affected by a short-term vigorous training camp even in highly trained elite endurance athletes presumably due to a greater training volume compared to usual.

  13. Ingestion of carbohydrate or carbohydrate plus protein does not enhance performance during endurance exercise: a randomized cross-over placebo-controlled clinical trial.

    Science.gov (United States)

    Finger, Débora; Lanferdini, Fábio Juner; Farinha, Juliano Boufleur; Brusco, Clarissa Müller; Helal, Lucas; Boeno, Francesco Pinto; Cadore, Eduardo Lusa; Pinto, Ronei Silveira

    2018-03-15

    Protein (PRO) combined with a carbohydrate (CHO) beverage may have an ergogenic effect on endurance performance. However, evidence regarding its efficacy on similar conditions to athletes' race day is still lacking. To compare the effect of three different nutritional supplementation strategies on performance and muscle recovery in a duathlon protocol. , 13 male athletes (29.7 ± 7.7 years) participated in three simulated Olympic-distance duathlons under three different, randomly assigned, supplementation regimens: carbohydrate drink (CHO, 75 g); isocaloric CHO plus protein drink (CHO+PRO, 60.5 g CHO + 14.5 g PRO); and, placebo drink (PLA), offered during the cycling bout. Blood samples were collected before, immediately after and 24 h after each test for creatine kinase (CK) analysis. Isometric peak torque (PT) was measured before and 24 h after each condition. The primary outcome was the time to complete the last 5km running section (t5km) in a self-selected pace. Statistical differences were considered when p<0.05. There was no difference in t5km between CHO (1270.3 ± 130.5 s) vs. CHO+PRO (1267.2 ± 138.9 s) vs. PLA (1275.4 ± 120 s); p = 0.87; ES ≤ 0.1. Pre-post changes for PT and CK values did not show differences in any of three conditions (p = 0.24, ES ≤ 0.4, p = 0.32, 0.3-1.04). For endurance sports lasting up to 2 h, with a pre-meal containing 1.5 g/kg of CHO, CHO or CHO+PRO supplementation does not offer additional benefits when compared to a PLA in performance and muscle recovery.

  14. The Supplementation of Branched-Chain Amino Acids, Arginine, and Citrulline Improves Endurance Exercise Performance in Two Consecutive Days

    Directory of Open Access Journals (Sweden)

    I-Shiung Cheng, Yi-Wen Wang, I-Fan Chen, Gi-Sheng Hsu, Chun-Fang Hsueh, Chen-Kang Chang

    2016-09-01

    Full Text Available The central nervous system plays a crucial role in fatigue during endurance exercise. Branched-chain amino acids (BCAA could reduce cerebral serotonin synthesis by competing with its precursor tryptophan for crossing the blood brain barrier. Arginine and citrulline could prevent excess hyperammonemia accompanied by BCAA supplementation. This study investigated the combination of BCAA, arginine, and citrulline on endurance performance in two consecutive days. Seven male and three female endurance runners ingested 0.17 g·kg-1 BCAA, 0.05 g·kg-1 arginine and 0.05 g·kg-1 citrulline (AA trial or placebo (PL trial in a randomized cross-over design. Each trial contained a 5000 m time trial on the first day, and a 10000 m time trial on the second day. The AA trial had significantly better performance in 5000 m (AA: 1065.7 ± 33.9 s; PL: 1100.5 ± 40.4 s and 10000 m (AA: 2292.0 ± 211.3 s; PL: 2375.6 ± 244.2 s. The two trials reported similar ratings of perceived exertion. After exercise, the AA trial had significantly lower tryptophan/BCAA ratio, similar NH3, and significantly higher urea concentrations. In conclusion, the supplementation could enhance time-trial performance in two consecutive days in endurance runners, possibly through the inhibition of cerebral serotonin synthesis by BCAA and the prevention of excess hyperammonemia by increased urea genesis.

  15. The human endurance athlete: heterogeneity and adaptability of ...

    African Journals Online (AJOL)

    In human subjects, large variations between individuals (up to 3-fold) exist in the capacity for endurance exercise performance. In a heterogeneous population, endurance performance is strongly related to whole body maximal oxygen uptake (VO2 max). This is in part genotype dependent (~25%) but is adaptable with ...

  16. Keto-adaptation enhances exercise performance and body composition responses to training in endurance athletes.

    Science.gov (United States)

    McSwiney, Fionn T; Wardrop, Bruce; Hyde, Parker N; Lafountain, Richard A; Volek, Jeff S; Doyle, Lorna

    2018-04-01

    Low-carbohydrate diets have recently grown in popularity among endurance athletes, yet little is known about the long-term (>4wk) performance implications of consuming a low-carbohydrate high fat ketogenic diet (LCKD) in well-trained athletes. Twenty male endurance-trained athletes (age 33±11y, body mass 80±11kg; BMI 24.7±3.1kg/m 2 ) who habitually consumed a carbohydrate-based diet, self-selected into a high-carbohydrate (HC) group (n=11, %carbohydrate:protein:fat=65:14:20), or a LCKD group (n=9, 6:17:77). Both groups performed the same training intervention (endurance, strength and high intensity interval training (HIIT)). Prior to and following successful completion of 12-weeks of diet and training, participants had their body composition assessed, and completed a 100km time trial (TT), six second (SS) sprint, and a critical power test (CPT). During post-intervention testing the HC group consumed 30-60g/h carbohydrate, whereas the LCKD group consumed water, and electrolytes. The LCKD group experienced a significantly greater decrease in body mass (HC -0.8kg, LCKD -5.9kg; P=0.006, effect size (ES): 0.338) and percentage body fat percentage (HC -0.7%, LCKD -5.2%; P=0.008, ES: 0.346). Fasting serum beta-hydroxybutyrate (βHB) significantly increased from 0.1 at baseline to 0.5mmol/L in the LCKD group (P=0.011, ES: 0.403) in week 12. There was no significant change in performance of the 100km TT between groups (HC -1.13min·s, LCKD -4.07min·s, P=0.057, ES: 0.196). SS sprint peak power increased by 0.8 watts per kilogram bodyweight (w/kg) in the LCKD group, versus a -0.1w/kg reduction in the HC group (P=0.025, ES: 0.263). CPT peak power decreased by -0.7w/kg in the HC group, and increased by 1.4w/kg in the LCKD group (P=0.047, ES: 0.212). Fat oxidation in the LCKD group was significantly greater throughout the 100km TT. Compared to a HC comparison group, a 12-week period of keto-adaptation and exercise training, enhanced body composition, fat oxidation during

  17. Investigation of Cardiovascular Endurance Levels of Sedentary High School Students

    Science.gov (United States)

    Akyol, Betül; Sögüt, Kayhan

    2018-01-01

    The aim of our study is to examine the cardiovascular endurance systems of sedentary high school students. The 112 sedentary individual was taken to the 1600 meter walking test run, and the 120 sedentary individual Harward step test. While both individuals were participating in the same test, weight, height, oxygen saturation, and heart rate of…

  18. Effects of moderate and heavy endurance exercise on nocturnal HRV.

    Science.gov (United States)

    Hynynen, E; Vesterinen, V; Rusko, H; Nummela, A

    2010-06-01

    This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effects on autonomic modulation after exercises, which may give useful information on the extent of exercise-induced nocturnal autonomic modulation and disturbance to the homeostasis.

  19. Biomechanical factors associated with running economy and performance of elite Kenyan distance runners: A systematic review.

    Science.gov (United States)

    Tawa, Nassib; Louw, Quinette

    2018-01-01

    Running economy (RE) is a determinant of performance in endurance sports and is a complex multi-factorial measure which reflects the combined functioning of bio-mechanical, neuro-muscular, metabolic and cardio-respiratory factors some of which are hereditary or adapt to coaching. Kenyan distance runners have dominated major global events with their unmatched performance for decades and this phenomenon has prompted several investigations aimed at establishing possible factors associated with their performance. This systematic review was aimed at establishing up-to date quantitative synthesis of evidence on biomechanical factors associated with running economy and performance of elite Kenyan distance runners and to provide an algorithm for future research and coaching strategies. A comprehensive electronic search was conducted through June 2017. Quality appraisal was independently done by both reviewers using the STROBE checklist. Descriptive summaries and tables were used to illustrate biomechanical outcomes, mean differences and confidence intervals. Evidence from reviewed studies was graded according to the Australian National Health and Medical Research Council (NHMRC) hierarchy for aetiological factors and meta-analysis was performed where applicable. Eight cross-sectional studies were included. The overall methodological score was moderate (58%). Elite Kenyan distance runners have significant longer gastroc-Achilles tendons compared to their counterparts while their shank length is not significantly longer. There is no certainty of evidence regarding the association between their characteristic unique profile of tall and slender bodies, low BMI and low body mass, short ground contact and flight times, greater forward lean torso and faster and greater forward leg swing with RE and performance. Our findings presents evidence on biomechanical factors associated with RE and performance of elite Kenyan distance runners. Despite these findings, there are a number of

  20. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns is presented, together with an overview and preliminary results of the new muo...

  1. Effects of music interventions on emotional States and running performance.

    Science.gov (United States)

    Lane, Andrew M; Davis, Paul A; Devonport, Tracey J

    2011-01-01

    The present study compared the effects of two different music interventions on changes in emotional states before and during running, and also explored effects of music interventions upon performance outcome. Volunteer participants (n = 65) who regularly listened to music when running registered online to participate in a three-stage study. Participants attempted to attain a personally important running goal to establish baseline performance. Thereafter, participants were randomly assigned to either a self-selected music group or an Audiofuel music group. Audiofuel produce pieces of music designed to assist synchronous running. The self-selected music group followed guidelines for selecting motivating playlists. In both experimental groups, participants used the Brunel Music Rating Inventory-2 (BMRI-2) to facilitate selection of motivational music. Participants again completed the BMRI-2 post- intervention to assess the motivational qualities of Audiofuel music or the music they selected for use during the study. Results revealed no significant differences between self-selected music and Audiofuel music on all variables analyzed. Participants in both music groups reported increased pleasant emotions and decreased unpleasant emotions following intervention. Significant performance improvements were demonstrated post-intervention with participants reporting a belief that emotional states related to performance. Further analysis indicated that enhanced performance was significantly greater among participants reporting music to be motivational as indicated by high scores on the BMRI-2. Findings suggest that both individual athletes and practitioners should consider using the BMRI-2 when selecting music for running. Key pointsListening to music with a high motivational quotient as indicated by scores on the BMRI-2 was associated with enhanced running performance and meta-emotional beliefs that emotions experienced during running helped performance.Beliefs on the

  2. Effects of endurance training and competition on exercise tests in relatively untrained people.

    Science.gov (United States)

    Verstappen, F T; Janssen, G M; Does, R J

    1989-10-01

    One hundred fourteen subjects (34 +/- 8 years) without any competition background took part in an endurance training study to be completed after 1.5 years with running a marathon. Ultimately, 60 males and 18 females achieved that goal. The training program, carefully supervised, was divided into three phases with a maximum of 45, 70, and 110 km/week training volume and concluded with a performance race of 15, 25, and 42.195 km, respectively. Three days before and 3 and 5 days after each race, 35 subjects were selected to perform a progressive treadmill test and the remaining subjects participated in performing field tests of running 400 and 1000 m. The maximal velocity achieved in the treadmill test was 4.75 +/- 0.36 m.s-1 for males and 4.18 +/- 0.28 m.s-1 for females; it remained constant throughout the study. However, the running velocity at 4 mmol.1(-1) plasma lactate concentration increased about 10% from phase 1 to 3. In the females this rise already appeared to be completed in phase 2. Heart rate showed a tendency to increase at both submaximal and maximal exercise from training phase 1 to 2 and 3, whereas plasma lactate concentration showed a decreasing tendency. Three days after the 25 km and the marathon race the maximal running velocity in the exercise test was 2%-4% lower compared with the pre-race test (P less than 0.05). Five days after the race this difference again faded away. This small decline in running performance was not reflected in changes of physiologic responses such as heart rate or plasma lactate concentration.

  3. Waiting Endurance Time Estimation of Electric Two-Wheelers at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Mei Huan

    2014-01-01

    Full Text Available The paper proposed a model for estimating waiting endurance times of electric two-wheelers at signalized intersections using survival analysis method. Waiting duration times were collected by video cameras and they were assigned as censored and uncensored data to distinguish between normal crossing and red-light running behavior. A Cox proportional hazard model was introduced, and variables revealing personal characteristics and traffic conditions were defined as covariates to describe the effects of internal and external factors. Empirical results show that riders do not want to wait too long to cross intersections. As signal waiting time increases, electric two-wheelers get impatient and violate the traffic signal. There are 12.8% of electric two-wheelers with negligible wait time. 25.0% of electric two-wheelers are generally nonrisk takers who can obey the traffic rules after waiting for 100 seconds. Half of electric two-wheelers cannot endure 49.0 seconds or longer at red-light phase. Red phase time, motor vehicle volume, and conformity behavior have important effects on riders’ waiting times. Waiting endurance times would decrease with the longer red-phase time, the lower traffic volume, or the bigger number of other riders who run against the red light. The proposed model may be applicable in the design, management and control of signalized intersections in other developing cities.

  4. Waiting endurance time estimation of electric two-wheelers at signalized intersections.

    Science.gov (United States)

    Huan, Mei; Yang, Xiao-bao

    2014-01-01

    The paper proposed a model for estimating waiting endurance times of electric two-wheelers at signalized intersections using survival analysis method. Waiting duration times were collected by video cameras and they were assigned as censored and uncensored data to distinguish between normal crossing and red-light running behavior. A Cox proportional hazard model was introduced, and variables revealing personal characteristics and traffic conditions were defined as covariates to describe the effects of internal and external factors. Empirical results show that riders do not want to wait too long to cross intersections. As signal waiting time increases, electric two-wheelers get impatient and violate the traffic signal. There are 12.8% of electric two-wheelers with negligible wait time. 25.0% of electric two-wheelers are generally nonrisk takers who can obey the traffic rules after waiting for 100 seconds. Half of electric two-wheelers cannot endure 49.0 seconds or longer at red-light phase. Red phase time, motor vehicle volume, and conformity behavior have important effects on riders' waiting times. Waiting endurance times would decrease with the longer red-phase time, the lower traffic volume, or the bigger number of other riders who run against the red light. The proposed model may be applicable in the design, management and control of signalized intersections in other developing cities.

  5. Meta-Analyses of the Effects of Habitual Running on Indices of Health in Physically Inactive Adults

    NARCIS (Netherlands)

    Hespanhol, L.C.; Pillay, J.; van Mechelen, W.; Verhagen, E.A.L.M.

    2015-01-01

    Background: In order to implement running to promote physical activity, it is essential to quantify the extent to which running improves health. Objective: The aim was to summarise the literature on the effects of endurance running on biomedical indices of health in physically inactive adults. Data

  6. Tests for predicting endurance kayak performance | Olivier | South ...

    African Journals Online (AJOL)

    Methods : The following variables were measured on 23 competitive endurance kayakers, who provided written informed consent : Arm crank VO2 peak; 1 minute dips; armspan; modified sit-and-reach; grip strength; body mass; height. These were selected on the basis of their being identified as possibly contributing to ...

  7. Performance of the ATLAS Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Burghgrave, Blake; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range |η|<4.9. The calibration and performance of the calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb−1 of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb−1 of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the calorimeter operation, monitoring and data quality, as well as their performance will be presented, including the calibration and stability of the electromagnetic scale, response uniformit...

  8. Performance of the ATLAS Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00354209; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range $|\\eta|<4.9$. The calibration and performance of the calorimetry system was established through beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~\\ifb of proton-proton collision data were collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~\\ifb of data at a center-of-mass energy of 13~TeV recorded in the first year. We present a summary of the calorimeter operation, monitoring and data quality, as well as their performance, including the calibration and stability of the electromagnetic scale...

  9. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults.

    Science.gov (United States)

    Choudhary, Bakhtiar; Shetty, A; Langade, Deepak G

    2015-01-01

    Ashwagandha (Withania somnifera [L.] Dunal) has been traditionally used for various actions ranging from vitalizer, improve endurance and stamina, promote longevity, improve immunity, and male and female fertility. However, clinical studies are needed to prove the clinical efficacy of this herb, especially in cardiovascular endurance and physical performance. This prospective, double-blind, randomized, and placebo-controlled study evaluated the efficacy of Ashwagandha roots extract in enhancing cardiorespiratory endurance and improving the quality of life (QOL) in 50 healthy male/female athletic adults. Cardiorespiratory endurance was assessed by measuring the oxygen consumption at peak physical exertion (VO2 max) levels during a 20 m shuttle run test. The World Health Organization self-reported QOL questionnaire (physical health, psychological health, social relationships, and environmental factors) was used to assess the QOL. Student's t-test was used to compare the differences in a mean and change from baseline VO2 max levels, whereas Wilcoxon signed-rank test was used to assess changes in QOL scores from baseline in the two groups. There was a greater increase from baseline (P < 0.0001) in the mean VO2 max with KSM-66 Ashwagandha (n = 24) compared to placebo (n = 25) at 8 weeks (4.91 and 1.42, respectively) and at 12 weeks (5.67 and 1.86 respectively). The QOL scores for all subdomains significantly improved to a greater extent in the Ashwagandha group at 12 weeks compared to placebo (P < 0.05). The findings suggest that Ashwagandha root extract enhances the cardiorespiratory endurance and improves QOL in healthy athletic adults.

  10. Hypoxic training methods for improving endurance exercise performance

    Directory of Open Access Journals (Sweden)

    Jacob A. Sinex

    2015-12-01

    Full Text Available Endurance athletic performance is highly related to a number of factors that can be altered through altitude and hypoxic training including increases in erythrocyte volume, maximal aerobic exercise capacity, capillary density, and economy. Physiological adaptations in response to acute and chronic exposure to hypoxic environments are well documented and range from short-term detrimental effects to longer-term adaptations that can improve performance at altitude and in sea-level competitions. Many altitude and hypoxic training protocols have been developed, employing various combinations of living and training at sea-level, low, moderate, and high altitudes and utilizing natural and artificial altitudes, with varying degrees of effectiveness. Several factors have been identified that are associated with individual responses to hypoxic training, and techniques for identifying those athletes most likely to benefit from hypoxic training continue to be investigated. Exposure to sufficiently high altitude (2000–3000 m for more than 12 h/day, while training at lower altitudes, for a minimum of 21 days is recommended. Timing of altitude training related to competition remains under debate, although general recommendations can be considered.

  11. Effect of Vertical, Horizontal, and Combined Plyometric Training on Explosive, Balance, and Endurance Performance of Young Soccer Players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Gallardo, Francisco; Henriquez-Olguín, Carlos; Meylan, Cesar M P; Martínez, Cristian; Álvarez, Cristian; Caniuqueo, Alexis; Cadore, Eduardo L; Izquierdo, Mikel

    2015-07-01

    The aim of this study was to compare the effects of 6 weeks of vertical, horizontal, or combined vertical and horizontal plyometric training on muscle explosive, endurance, and balance performance. Forty young soccer players aged between 10 and 14 years were randomly divided into control (CG; n = 10), vertical plyometric group (VG; n = 10), horizontal plyometric group (HG; n = 10), and combined vertical and horizontal plyometric group (VHG; n = 10). Players performance in the vertical and horizontal countermovement jump with arms, 5 multiple bounds test (MB5), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), sprint, change of direction speed (CODS), Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1), and balance was measured. No significant or meaningful changes in the CG, apart from small change in the Yo-Yo IR1, were observed while all training programs resulted in meaningful changes in explosive, endurance, and balance performance. However, only VHG showed a statistically significant (p ≤ 0.05) increase in all performance test and most meaningful training effect difference with the CG across tests. Although no significant differences in performance changes were observed between experimental groups, the VHG program was more effective compared with VG (i.e., jumps, MKV, sprint, CODS, and balance performance) and HG (i.e., sprint, CODS, and balance performance) to small effect. The study demonstrated that vertical, horizontal, and combined vertical and horizontal jumps induced meaningful improvement in explosive actions, balance, and intermittent endurance capacity. However, combining vertical and horizontal drills seems more advantageous to induce greater performance improvements.

  12. Carbohydrate Dependence During Prolonged, Intense Endurance Exercise.

    Science.gov (United States)

    Hawley, John A; Leckey, Jill J

    2015-11-01

    A major goal of training to improve the performance of prolonged, continuous, endurance events lasting up to 3 h is to promote a range of physiological and metabolic adaptations that permit an athlete to work at both higher absolute and relative power outputs/speeds and delay the onset of fatigue (i.e., a decline in exercise intensity). To meet these goals, competitive endurance athletes undertake a prodigious volume of training, with a large proportion performed at intensities that are close to or faster than race pace and highly dependent on carbohydrate (CHO)-based fuels to sustain rates of muscle energy production [i.e., match rates of adenosine triphosphate (ATP) hydrolysis with rates of resynthesis]. Consequently, to sustain muscle energy reserves and meet the daily demands of training sessions, competitive athletes freely select CHO-rich diets. Despite renewed interest in high-fat, low-CHO diets for endurance sport, fat-rich diets do not improve training capacity or performance, but directly impair rates of muscle glycogenolysis and energy flux, limiting high-intensity ATP production. When highly trained athletes compete in endurance events lasting up to 3 h, CHO-, not fat-based fuels are the predominant fuel for the working muscles and CHO, not fat, availability becomes rate limiting for performance.

  13. The design and performance of the ATLAS Inner Detector trigger for Run 2

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the early LHC Run 2 data are discussed. The redesign of the ID trigger, which took place during the 2013-15 long shutdown, in order to satisfy the demands of the higher energy LHC Run 2 operation is described. The ID trigger HLT algorithms are essential for nearly all trigger signatures within the ATLAS trigger. The detailed performance of the tracking algorithms with the early Run 2 data for the different trigger signatures is presented, including the detailed timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy are made and demonstrate the superior performance of the strategy adopted for Run 2.

  14. EFFECTS OF HIGH INTENSITY TRAINING AND CONTINUOUS ENDURANCE TRAINING ON AEROBIC CAPACITY AND BODY COMPOSITION IN RECREATIONALLY ACTIVE RUNNERS

    Directory of Open Access Journals (Sweden)

    Kuno Hottenrott

    2012-09-01

    Full Text Available The aim of the study was to examine the effects of two different training programs (high-intensity-training vs. continuous endurance training on aerobic power and body composition in recreationally active men and women and to test whether or not participants were able to complete a half marathon after the intervention period. Thirty-four recreational endurance runners were randomly assigned either to a Weekend-Group (WE, n = 17 or an After-Work- Group (AW, n = 17 for a 12 week-intervention period. WE weekly completed 2 h 30 min of continuous endurance running composed of 2 sessions on the weekend. In contrast, AW performed 4 30 min sessions of high intensity training and an additional 30 min endurance run weekly, always after work. During an exhaustive treadmill test aerobic power was measured and heart rate was continuously recorded. Body composition was assessed using bio-impedance. Following the intervention period all subjects took part in a half-marathon. AW significantly improved peak oxygen uptake (VO2 peak from 36.8 ± 4.5 to 43.6 ± 6.5 [mL.min-1.kg-1], velocity at lactate threshold (VLT from 9.7 ± 2.2 to 11.7 ± 1.8 [km.h-1] and visceral fat from 5.6 ± 2.2 to 4.7 ± 1.9 In WE VO2 peak signifi-cantly increased from 38.8 ± 5.0 to 41.5 ± 6.0 [mL.min-1.kg-1], VLT from 9.9 ± 1.3 to 11.2 ± 1.7 [km.h-1] and visceral fat was reduced from 5.7 ± 2.1 to 5.4 ± 1.9 (p < 0.01. Only the improvements of VO2 peak were significantly greater in AW compared with WE (pre/post group interaction: F=15.4, p = 0.01, η2 = 0.36. Both groups completed a half marathon with no significant differences in performance (p = 0.63. Short, intensive endurance training sessions of about 30 min are effective in improving aerobic fitness in recreationally active runners

  15. The ATLAS Trigger algorithms upgrade and performance in Run 2

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    Title: The ATLAS Trigger algorithms upgrade and performance in Run 2 (TDAQ) The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a center-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken impr...

  16. Tapering strategies in elite British endurance runners.

    Science.gov (United States)

    Spilsbury, Kate L; Fudge, Barry W; Ingham, Stephen A; Faulkner, Steve H; Nimmo, Myra A

    2015-01-01

    The aim of the study was to explore pre-competition training practices of elite endurance runners. Training details from elite British middle distance (MD; 800 m and 1500 m), long distance (LD; 3000 m steeplechase to 10,000 m) and marathon (MAR) runners were collected by survey for 7 days in a regular training (RT) phase and throughout a pre-competition taper. Taper duration was [median (interquartile range)] 6 (3) days in MD, 6 (1) days in LD and 14 (8) days in MAR runners. Continuous running volume was reduced to 70 (16)%, 71 (24)% and 53 (12)% of regular levels in MD, LD and MAR runners, respectively (P training (MD; 53 (45)%, LD; 67 (23)%, MAR; 64 (34)%, P training intensity was above race speed in LD and MAR runners (112 (27)% and 114 (3)%, respectively, P training undertaken prior to the taper in elite endurance runners is predictive of the tapering strategy implemented before competition.

  17. Match running performance and fitness in youth soccer.

    Science.gov (United States)

    Buchheit, M; Mendez-Villanueva, A; Simpson, B M; Bourdon, P C

    2010-11-01

    The activity profiles of highly trained young soccer players were examined in relation to age, playing position and physical capacity. Time-motion analyses (global positioning system) were performed on 77 (U13-U18; fullbacks [FB], centre-backs [CB], midfielders [MD], wide midfielders [W], second strikers [2 (nd)S] and strikers [S]) during 42 international club games. Total distance covered (TD) and very high-intensity activities (VHIA; >16.1 km·h (-1)) were computed during 186 entire player-matches. Physical capacity was assessed via field test measures (e. g., peak running speed during an incremental field test, VVam-eval). Match running performance showed an increasing trend with age ( Pperformance was position-dependent ( Pperformance and physical capacities were position-dependent, with poor or non-significant correlations within FB, CB, MD and W (e. g., VHIA vs. VVam-eval: R=0.06 in FB) but large associations within 2 (nd)S and S positions (e. g., VHIA vs. VVam-eval: R=0.70 in 2 (nd)S). In highly trained young soccer players, the importance of fitness level as a determinant of match running performance should be regarded as a function of playing position.

  18. Meta-Analyses of the Effects of Habitual Running on Indices of Health in Physically Inactive Adults.

    Science.gov (United States)

    Hespanhol Junior, Luiz Carlos; Pillay, Julian David; van Mechelen, Willem; Verhagen, Evert

    2015-10-01

    In order to implement running to promote physical activity, it is essential to quantify the extent to which running improves health. The aim was to summarise the literature on the effects of endurance running on biomedical indices of health in physically inactive adults. Electronic searches were conducted in October 2014 on PubMed, Embase, CINAHL, SPORTDiscus, PEDro, the Cochrane Library and LILACS, with no limits of date and language of publication. Randomised controlled trials (with a minimum of 8 weeks of running training) that included physically inactive but healthy adults (18-65 years) were selected. The studies needed to compare intervention (i.e. endurance running) and control (i.e., no intervention) groups. Two authors evaluated study eligibility, extracted data, and assessed risk of bias; a third author resolved any uncertainties. Random-effects meta-analyses were performed to summarise the estimates for length of training and sex. A dose-response analysis was performed with random-effects meta-regression in order to investigate the relationship between running characteristics and effect sizes. After screening 22,380 records, 49 articles were included, of which 35 were used to combine data on ten biomedical indices of health. On average the running programs were composed of 3.7 ± 0.9 sessions/week, 2.3 ± 1.0 h/week, 14.4 ± 5.4 km/week, at 60-90% of the maximum heart rate, and lasted 21.5 ± 16.8 weeks. After 1 year of training, running was effective in reducing body mass by 3.3 kg [95% confidence interval (CI) 4.1-2.5], body fat by 2.7% (95% CI 5.1-0.2), resting heart rate by 6.7 min(-1) (95% CI 10.3-3.0) and triglycerides by 16.9 mg dl(-1) (95% CI 28.1-5.6). Also, running significantly increased maximal oxygen uptake (VO2max) by 7.1 ml min(-1) kg(-1) (95% CI 5.0-9.1) and high-density lipoprotein (HDL) cholesterol by 3.3 mg dl(-1) (95% CI 1.2-5.4). No significant effect was found for lean body mass, body mass index, total cholesterol and low

  19. Endurance training at altitude.

    Science.gov (United States)

    Saunders, Philo U; Pyne, David B; Gore, Christopher J

    2009-01-01

    Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological responses occur that can comprise performance at altitude; these include increased ventilation, increased heart rate, decreased stroke volume, reduced plasma volume, and lower maximal aerobic power ((.)Vo(2max)) by approximately 15% to 20%. Over a period of several weeks, one primary acclimatization response is an increase in the volume of red blood cells and consequently of (.)Vo(2max). Altitudes > approximately 2000 m for >3 weeks and adequate iron stores are required to elicit these responses. However, the primacy of more red blood cells for superior sea-level performance is not clear-cut since the best endurance athletes in the world, from Ethiopia (approximately 2000 to 3000 m), have only marginally elevated hemoglobin concentrations. The substantial reduction in (.)Vo(2max) of athletes at moderate altitude implies that their training should include adequate short-duration (approximately 1 to 2 min), high-intensity efforts with long recoveries to avoid a reduction in race-specific fitness. At the elite level, athlete performance is not dependent solely on (.)Vo(2max), and the "smallest worthwhile change" in performance for improving race results is as little as 0.5%. Consequently, contemporary statistical approaches that utilize the concept of the smallest worthwhile change are likely to be more appropriate than conventional statistical methods when attempting to understand the potential benefits and mechanisms of altitude training.

  20. Spontaneous Entrainment of Running Cadence to Music Tempo.

    Science.gov (United States)

    Van Dyck, Edith; Moens, Bart; Buhmann, Jeska; Demey, Michiel; Coorevits, Esther; Dalla Bella, Simone; Leman, Marc

    Since accumulating evidence suggests that step rate is strongly associated with running-related injuries, it is important for runners to exercise at an appropriate running cadence. As music tempo has been shown to be capable of impacting exercise performance of repetitive endurance activities, it might also serve as a means to (re)shape running cadence. The aim of this study was to validate the impact of music tempo on running cadence. Sixteen recreational runners ran four laps of 200 m (i.e. 800 m in total); this task was repeated 11 times with a short break in between each four-lap sequence. During the first lap of a sequence, participants ran at a self-paced tempo without musical accompaniment. Running cadence of the first lap was registered, and during the second lap, music with a tempo matching the assessed cadence was played. In the final two laps, the music tempo was either increased/decreased by 3.00, 2.50, 2.00, 1.50, or 1.00 % or was kept stable. This range was chosen since the aim of this study was to test spontaneous entrainment (an average person can distinguish tempo variations of about 4 %). Each participant performed all conditions. Imperceptible shifts in musical tempi in proportion to the runner's self-paced running tempo significantly influenced running cadence ( p  tempo conditions and adaptation in running cadence ( p  effect of condition on the level of entrainment was revealed ( p  effects of music tempo on running cadence can only be obtained up to a certain level of tempo modification. Finally, significantly higher levels of tempo entrainment were found for female participants compared to their male counterparts ( p  music tempo could serve as an unprompted means to impact running cadence. As increases in step rate may prove beneficial in the prevention and treatment of common running-related injuries, this finding could be especially relevant for treatment purposes, such as exercise prescription and gait retraining. Music tempo

  1. EFFECTS OF MUSIC INTERVENTIONS ON EMOTIONAL STATES AND RUNNING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Andrew M. Lane

    2011-06-01

    Full Text Available The present study compared the effects of two different music interventions on changes in emotional states before and during running, and also explored effects of music interventions upon performance outcome. Volunteer participants (n = 65 who regularly listened to music when running registered online to participate in a three-stage study. Participants attempted to attain a personally important running goal to establish baseline performance. Thereafter, participants were randomly assigned to either a self-selected music group or an Audiofuel music group. Audiofuel produce pieces of music designed to assist synchronous running. The self-selected music group followed guidelines for selecting motivating playlists. In both experimental groups, participants used the Brunel Music Rating Inventory-2 (BMRI-2 to facilitate selection of motivational music. Participants again completed the BMRI-2 post- intervention to assess the motivational qualities of Audiofuel music or the music they selected for use during the study. Results revealed no significant differences between self-selected music and Audiofuel music on all variables analyzed. Participants in both music groups reported increased pleasant emotions and decreased unpleasant emotions following intervention. Significant performance improvements were demonstrated post-intervention with participants reporting a belief that emotional states related to performance. Further analysis indicated that enhanced performance was significantly greater among participants reporting music to be motivational as indicated by high scores on the BMRI-2. Findings suggest that both individual athletes and practitioners should consider using the BMRI-2 when selecting music for running

  2. Effects of caffeine ingestion on endurance performance in mentally fatigued individuals.

    Science.gov (United States)

    Azevedo, Rafael; Silva-Cavalcante, Marcos David; Gualano, Bruno; Lima-Silva, Adriano E; Bertuzzi, Romulo

    2016-12-01

    To examine the effects of caffeine ingestion on physiological and perceptual responses in mentally fatigued individuals. Eight male physically active subjects completed four cycling constant-workload tests in four experimental conditions at 80 % of maximal power output: control (C), mental fatigue (MF), mental fatigue plus caffeine ingestion (5 mg/kg) (MF-CAF), and mental fatigue plus placebo (MF-PLA). The mental fatigue was induced by a continuous performance task A-X version (AX-CPT). Before and after the AX-CPT, the profile of mood state (POMS) and blood samples for lactate measurement were collected. Oxygen consumption ([Formula: see text]), rating of perceived exertion (RPE), and electromyography (EMG) activity were measured during the cycling test. The time to exhaustion in C, MF, MF-PLA, and MF-CAF were 251 ± 30, 222 ± 23, 248 ± 28, and 285 ± 42 s, respectively. Delta values (corrected by C condition) were higher in MF-CAF than MF (P = 0.031). MF-CAF reported higher Vigor scores when compared with C (P = 0.046) and MF (P = 0.020). RPE at the first minute was significantly higher in MF-PLA than in C (P = 0.050); at the second minute, RPE was higher in MF-PLA than in C (P = 0.049) and MF-CAF (P = 0.048). EMG activity was not different between the conditions. Caffeine ingestion increased approximately 14 % endurance performance after the induction of mental fatigue. This effect was accompanied by a tendency to improvement in mood state (i.e., vigor). Therefore, caffeine ingestion can promote a beneficial effect on endurance performance in mentally fatigued individuals.

  3. Shoulder muscle endurance: the development of a standardized and reliable protocol

    Directory of Open Access Journals (Sweden)

    Roy Jean-Sébastien

    2011-01-01

    Full Text Available Abstract Background Shoulder muscle fatigue has been proposed as a possible link to explain the association between repetitive arm use and the development of rotator cuff disorders. To our knowledge, no standardized clinical endurance protocol has been developed to evaluate the effects of muscle fatigue on shoulder function. Such a test could improve clinical examination of individuals with shoulder disorders. Therefore, the purpose of this study was to establish a reliable protocol for objective assessment of shoulder muscle endurance. Methods An endurance protocol was developed on a stationary dynamometer (Biodex System 3. The endurance protocol was performed in isotonic mode with the resistance set at 50% of each subject's peak torque as measured for shoulder external (ER and internal rotation (IR. Each subject performed 60 continuous repetitions of IR/ER rotation. The endurance protocol was performed by 36 healthy individuals on two separate occasions at least two days apart. Maximal isometric shoulder strength tests were performed before and after the fatigue protocol to evaluate the effects of the endurance protocol and its reliability. Paired t-tests were used to evaluate the reduction in shoulder strength due to the protocol, while intraclass correlation coefficients (ICC and minimal detectable change (MDC were used to evaluate its reliability. Results Maximal isometric strength was significantly decreased after the endurance protocol (P 0.84. Conclusions Changes in muscular performance observed during and after the muscular endurance protocol suggests that the protocol did result in muscular fatigue. Furthermore, this study established that the resultant effects of fatigue of the proposed isotonic protocol were reproducible over time. The protocol was performed without difficulty by all volunteers and took less than 10 minutes to perform, suggesting that it might be feasible for clinical practice. This protocol could be used to induce

  4. EFFECTIVENESS OF LAND BASED ENDURANCE TRAINING VERSUS AQUATIC BASED ENDURANCE TRAINING ON IMPROVING ENDURANCE IN NORMAL INDIVIDUALS

    Directory of Open Access Journals (Sweden)

    Sabitha Eunice Regima

    2015-06-01

    Full Text Available Background: Recently the exercises and fitness professionals have adopted water as an alternative medium for delivering programs to improve fitness and health. When exercise on dry land our skeletal muscular, cardiovascular, respiratory and other body systems are greatly affected by the forces of gravity. When exercise in water, the effects created by the gravitational pull on the body are attenuated. Therefore the aim of this study was to determine the effectiveness of land based endurance training and aquatic based endurance training for enhancing endurance in normal individuals. Methods: An experimental study design with 30 subjects healthy individuals between 20-30 years of both sexes currently were divided equally into 2 groups. Group A underwent land based exercises while Group B underwent aquatic based exercises. The outcome measures consist of RPP (rate pressure product, REC HR (recovery heart rate, RHR (resting heart rate and 6MWD (6 minute walking distance was measured before (pre-training and after four weeks of endurance training. Results: In this study, the mean improvement between the 2 groups of land and aquatic based endurance exercises were tested for significance using a dependent t test. The calculated t value were 43.550, 4.583, 16, 5.870 for RPP, REC HR, RHR, 6MWD for group A respectively. For group B 25.922, 12.762, 27.495,19.236 for RPP, REC HR, RHR, 6MWD for group A respectively with p<0.05. This clearly indicated that both land based exercises and aquatic based exercises will improve cardiovascular endurance significantly and there is no significant difference between land based exercises and aquatic based exercises for enhancing endurance in normal individuals. Conclusion: It is concluded that both land based and aquatic based endurance exercises methods produce equivalent, if not same effect on the enhancement of aerobic endurance. There was no significant difference between these two exercising mediums. Nonetheless

  5. Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Carlos Burgos

    2016-01-01

    Full Text Available The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2 training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6±1.6 years were randomized into hyperbaric-hyperoxic (HH training (n=6 and normobaric normoxic (NN training (n=6 groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid, plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX], arterial blood gases, acid-base balance, bases excess (BE, and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max and peak power output (PPO were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players.

  6. V02 'overshoot' during moderate-intensity exercise in endurance-trained athletes: the influence of exercise modality.

    Science.gov (United States)

    Kilding, Andrew E; Jones, Andrew M

    2008-02-01

    The purpose of this study was to investigate the influence of exercise modality on the 'overshoot' in V(O2) that has been reported following the onset of moderate-intensity (below the gas exchange threshold, GET) exercise in endurance athletes. Seven trained endurance cyclists and seven trained endurance runners completed six square-wave transitions to a work-rate or running speed requiring 80% of mode-specific GET during both cycle and treadmill running exercise. The kinetics of V(O2) was assessed using non-linear regression and any overshoot in V(O2) was quantified as the integrated volume (IV) of O(2) consumed above the steady-state requirement. During cycling, an overshoot in V(O2) was evident in all seven cyclists (IV = 136 +/- 41 ml) and in four runners (IV = 81 +/- 94 ml). During running, an overshoot in V(O2) was evident in four runners (IV = 72 +/- 61 ml) but no cyclists. These data challenge the notion that V(O2) always rises towards a steady-state with near-exponential kinetics in this exercise intensity domain. The greater incidence of the V(O2) overshoot during cycling (11/14 subjects) compared to running (4/14 subjects) indicates that the overshoot phenomenon is related to an interaction between high levels of aerobic fitness and exercise modality. We speculate that a transient loss in muscle efficiency as a consequence of a non-constant ATP requirement following the onset of constant-work-rate exercise or an initially excessive recruitment of motor units (relative to the work-rate) might contribute to the overshoot phenomenon.

  7. Effects of protein in combination with carbohydrate supplements on acute or repeat endurance exercise performance: a systematic review.

    Science.gov (United States)

    McLellan, Tom M; Pasiakos, Stefan M; Lieberman, Harris R

    2014-04-01

    Protein supplements are consumed frequently by athletes and recreationally active adults for various reasons, including improved exercise performance and recovery after exercise. Yet, far too often, the decision to purchase and consume protein supplements is based on marketing claims rather than available evidence-based research. The purpose of this review was to provide a systematic and comprehensive analysis of the literature that tested the hypothesis that protein supplements, when combined with carbohydrate, directly enhance endurance performance by sparing muscle glycogen during exercise and increasing the rate of glycogen restoration during recovery. The analysis was used to create evidence statements based on an accepted strength of recommendation taxonomy. English language articles were searched with PubMed and Google Scholar using protein and supplements together with performance, exercise, competition, and muscle, alone or in combination as keywords. Additional articles were retrieved from reference lists found in these papers. Inclusion criteria specified recruiting healthy active adults less than 50 years of age and evaluating the effects of protein supplements in combination with carbohydrate on endurance performance metrics such as time-to-exhaustion, time-trial, or total power output during sprint intervals. The literature search identified 28 articles, of which 26 incorporated test metrics that permitted exclusive categorization into one of the following sections: ingestion during an acute bout of exercise (n = 11) and ingestion during and after exercise to affect subsequent endurance performance (n = 15). The remaining two articles contained performance metrics that spanned both categories. All papers were read in detail and searched for experimental design confounders such as energy content of the supplements, dietary control, use of trained or untrained participants, number of subjects recruited, direct measures of muscle glycogen utilization and

  8. Effect of Progressive Volume-Based Overload During Plyometric Training on Explosive and Endurance Performance in Young Soccer Players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Henríquez-Olguín, Carlos; Burgos, Carlos; Andrade, David C; Zapata, Daniel; Martínez, Cristian; Álvarez, Cristian; Baez, Eduardo I; Castro-Sepúlveda, Mauricio; Peñailillo, Luis; Izquierdo, Mikel

    2015-07-01

    The purpose of the study was to compare the effects of progressive volume-based overload with constant volume-based overload on muscle explosive and endurance performance adaptations during a biweekly short-term (i.e., 6 weeks) plyometric training intervention in young soccer players. Three groups of young soccer players (age 13.0 ± 2.3 years) were divided into: control (CG; n = 8) and plyometric training with (PPT; n = 8) and without (NPPT; n = 8) a progressive increase in volume (i.e., 16 jumps per leg per week, with an initial volume of 80 jumps per leg each session). Bilateral and unilateral horizontal and vertical countermovement jump with arms (CMJA), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), 10-m sprint, change of direction speed (CODS), and Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) were measured. Although both experimental groups significantly increased CMJA, RSI20, CODS, and endurance performance, only PPT showed a significant improvement in MKV and 10-m sprint time. In addition, only PPT showed a significantly higher performance improvement in jumping, MKV, and Yo-Yo IR1 compared with CG. Also, PPT showed higher meaningful improvement compared with NPPT in all (except 1) jump performance measures. Furthermore, although PPT involved a higher total volume compared with NPPT, training efficiency (i.e., percentage change in performance/total jump volume) was similar between groups. Our results show that PPT and NPPT ensured significant improvement in muscle explosive and endurance performance measures. However, a progressive increase in plyometric training volume seems more advantageous to induce soccer-specific performance improvements.

  9. Metabolic factors limiting performance in marathon runners.

    Science.gov (United States)

    Rapoport, Benjamin I

    2010-10-21

    Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers), more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as 'hitting the wall'), and thousands drop out before reaching the finish lines (approximately 1-2% of those who start). Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making 'hitting the wall' seem inevitable), or implied that maximal glycogen loading is required in order to complete a marathon without 'hitting the wall.' The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity) of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding 'the wall.' The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.

  10. Metabolic factors limiting performance in marathon runners.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    2010-10-01

    Full Text Available Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers, more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as 'hitting the wall', and thousands drop out before reaching the finish lines (approximately 1-2% of those who start. Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making 'hitting the wall' seem inevitable, or implied that maximal glycogen loading is required in order to complete a marathon without 'hitting the wall.' The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding 'the wall.' The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.

  11. Effect of Jump Interval Training on Kinematics of the Lower Limbs and Running Economy.

    Science.gov (United States)

    Ache-Dias, Jonathan; Pupo, Juliano Dal; Dellagrana, Rodolfo A; Teixeira, Anderson S; Mochizuki, Luis; Moro, Antônio R P

    2018-02-01

    Ache-Dias, J, Pupo, JD, Dellagrana, RA, Teixeira, AS, Mochizuki, L, and Moro, ARP. Effect of jump interval training on kinematics of the lower limbs and running economy. J Strength Cond Res 32(2): 416-422, 2017-This study analyzed the effects of the addition of jump interval training (JIT) to continuous endurance training (40-minute running at 70% of peak aerobic velocity, 3 times per week for 4 weeks) on kinematic variables and running economy (RE) during submaximal constant-load running. Eighteen recreational runners, randomized into control group (CG) or experimental group (EG) performed the endurance training. In addition, the EG performed the JIT twice per week, which consisted of 4-6 bouts of continuous vertical jumping (30 seconds) with 5-minute intervals. The oxygen consumption (V[Combining Dot Above]O2) during the submaximal test (performed at 9 km·h) was similar before (EG: 38.48 ± 2.75 ml·kg·min; CG: 36.45 ± 2.70 ml·kg·min) and after training (EG: 37.42 ± 2.54 ml·kg·min; CG: 35.81 ± 3.10 ml·kg·min). No effect of training, group, or interaction (p > 0.05) was found for RE. There was no interaction or group effect for the kinematic variables (p > 0.05). Most of the kinematic variables had a training effect for both groups (support time [p ≤ 0.05]; step rate [SR; p ≤ 0.05]; and step length [SL; p ≤ 0.05]). In addition, according to the practical significance analysis (percentage chances of a better/trivial/worse effect), important effects in leg stiffness (73/25/2), vertical stiffness (73/25/2), SR (71/27/2), and SL (64/33/3) were found for the EG. No significant relationship between RE and stiffness were found for EG and CG. In conclusion, the results suggest that JIT induces important changes in the kinematics of the lower limbs of recreational runners, but the changes do not affect RE.

  12. Effects of Cognitive Demand on Situational Interest and Running Task Performances

    Science.gov (United States)

    Zhu, Xihe; Chen, Senlin

    2017-01-01

    This study examined the effect of cognitive demand on situational interest and performance using running tasks in physical education. Adolescents (N = 179) participated in a field study involving three different levels of cognitive demand. Running performances and situational interest were measured four times with a testing interval of seven days.…

  13. Long-term endurance sport is a risk factor for development of lone atrial flutter.

    Science.gov (United States)

    Claessen, Guido; Colyn, Erwin; La Gerche, André; Koopman, Pieter; Alzand, Becker; Garweg, Christophe; Willems, Rik; Nuyens, Dieter; Heidbuchel, Hein

    2011-06-01

    To evaluate whether in a population of patients with 'lone atrial flutter', the proportion of those engaged in long-term endurance sports is higher than that observed in the general population. An age and sex-matched retrospective case-control study. A database with 638 consecutive patients who underwent ablation for atrial flutter at the University of Leuven. Sixty-one patients (55 men, 90%) fitted the inclusion criteria of 'lone atrial flutter', ie, aged 65 years or less, without documented atrial fibrillation and without identifiable underlying disease (including hypertension). Sex, age and inclusion criteria-matched controls, two for each flutter patient, were selected in a general practice in the same geographical region. Sports activity was evaluated by detailed questionnaires, which were available in 58 flutter patients (95%). A transthoracic echocardiogram was performed in all lone flutter patients. Types of sports, number of years of participation and average number of hours per week. The proportion of regular sportsmen (≥3 h of sports practice per week) among patients with lone atrial flutter was significantly higher than that observed in the general population (50% vs 17%; pendurance sports (participation in cycling, running or swimming for ≥3 h/week) was also significantly higher in lone flutter patients than in controls (31% vs 8%; p=0.0003). Those flutter patients performing endurance sports had a larger left atrium than non-sportsmen (p=0.04, by one-way analysis of variance). A history of endurance sports and subsequent left atrial remodelling may be a risk factor for the development of atrial flutter.

  14. LONG-RUN OPERATING PERFORMANCE OF PREFERRED STOCK ISSUERS

    OpenAIRE

    Devrim Yaman

    2011-01-01

    In this paper, we study the long-run operating performance of preferred stock issuers. We use three different measures of operating performance; pre-tax cash flows, profit margin and return on assets. We study the performance of industrial firms, financial firms, and utilities separately, as well as the performance of the whole sample. Our results indicate that the operating performance of preferred stock issuers as a whole declines in the three-years before the issue. We find that profitabil...

  15. Study on Endurance and Performance of Impregnated Ruthenium Catalyst for Thruster System.

    Science.gov (United States)

    Kim, Jincheol; Kim, Taegyu

    2018-02-01

    Performance and endurance of the Ru catalyst were studied for nitrous oxide monopropellant thruster system. The thermal decomposition of N2O requires a considerably high temperature, which make it difficult to be utilized as a thruster propellant, while the propellant decomposition temperature can be reduced by using the catalyst through the decomposition reaction with the propellant. However, the catalyst used for the thruster was frequently exposed to high temperature and high-pressure environment. Therefore, the state change of the catalyst according to the thruster operation was analyzed. Characterization of catalyst used in the operation condition of the thruster was performed using FE-SEM and EDS. As a result, performance degradation was occurred due to the volatilization of Ru catalyst and reduction of the specific surface area according to the phase change of Al2O3.

  16. Static and Dynamic Handgrip Strength Endurance: Test-Retest Reproducibility.

    Science.gov (United States)

    Gerodimos, Vassilis; Karatrantou, Konstantina; Psychou, Dimitra; Vasilopoulou, Theodora; Zafeiridis, Andreas

    2017-03-01

    This study investigated the reliability of static and dynamic handgrip strength endurance using different protocols and indicators for the assessment of strength endurance. Forty young, healthy men and women (age, 18-22 years) performed 2 handgrip strength endurance protocols: a static protocol (sustained submaximal contraction at 50% of maximal voluntary contraction) and a dynamic one (8, 10, and 12 maximal repetitions). The participants executed each protocol twice to assess the test-retest reproducibility. Total work and total time were used as indicators of strength endurance in the static protocol; the strength recorded at each maximal repetition, the percentage change, and fatigue index were used as indicators of strength endurance in the dynamic protocol. The static protocol showed high reliability irrespective of sex and hand for total time and work. The 12-repetition dynamic protocol exhibited moderate-high reliability for repeated maximal repetitions and percentage change; the 8- and 10-repetition protocols demonstrated lower reliability irrespective of sex and hand. The fatigue index was not a reliable indicator for the assessment of dynamic handgrip endurance. Static handgrip endurance can be measured reliably using the total time and total work as indicators of strength endurance. For the evaluation of dynamic handgrip endurance, the 12-repetition protocol is recommended, using the repeated maximal repetitions and percentage change as indicators of strength endurance. Practitioners should consider the static (50% maximal voluntary contraction) and dynamic (12 repeated maximal repetitions) protocols as reliable for the assessment of handgrip strength endurance. The evaluation of static endurance in conjunction with dynamic endurance would provide more complete information about hand function. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. Comparison of Brain-Derived Neurotrophic Factor (BDNF and Insulin-like Growth Factor 1 (IGF-1 Responses to Different Endurance Training Intensities in Runner Men

    Directory of Open Access Journals (Sweden)

    M. Habibian

    2017-04-01

    Full Text Available Aims: Blood neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF and Insulin-like Growth Factor 1 (IGF-1, mediate exercise- induced health benefits in humans. The purpose of this study was to compare the response of BDNF and IGF-1 to different endurance training intensities in runner men. Materials & Methods: In this semi-experimental study with pre-test-posttest design in 2015, 10 people of male runners from Gorgan were selected through purposeful and accessible sampling. The endurance training protocol was 6 km running with moderate (70-75% of heart rate reserve or severe (80-85% of heart rate reserve intensity, which was performed within a week's interval. Fasting blood samples were collected before and immediately after both acute training sessions and serum levels of BDNF and IGF-1 were measured by ELISA and radioimmunoassay enzyme. Data were analyzed by SPSS 20 software using independent t-test and paired t-test. Findings: Both acute endurance training significantly increased serum levels of BDNF and IGF-1 in runners, but high intensity endurance exercises increased BDNF levels in comparison with moderate intensity (p0.05. Conclusion: Serum BDNF response in endurance athletes is affected by the intensity of exercise, so that the effect of high intensity endurance training on BDNF levels is greater than moderate intensity exercise, but the response of IGF-1 to acute endurance training is independent of the intensity of exercise.

  18. Comparison between two types of anaerobic speed endurance training in competitive soccer players

    DEFF Research Database (Denmark)

    Mohr, Magni; Krustrup, Peter

    2016-01-01

    The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional...... during training were higher (psoccer players with superior...... speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and postintervention. Yo-Yo IR2 performance...

  19. Comparison of running and cycling economy in runners, cyclists, and triathletes.

    Science.gov (United States)

    Swinnen, Wannes; Kipp, Shalaya; Kram, Rodger

    2018-07-01

    Exercise economy is one of the main physiological factors determining performance in endurance sports. Running economy (RE) can be improved with running-specific training, while the improvement of cycling economy (CE) with cycling-specific training is controversial. We investigated whether exercise economy reflects sport-specific skills/adaptations or is determined by overall physiological factors. We compared RE and CE in 10 runners, 9 cyclists and 9 triathletes for running at 12 km/h and cycling at 200 W. Gross rates of oxygen consumption and carbon dioxide production were collected and used to calculate gross metabolic rate in watts for both running and cycling. Runners had better RE than cyclists (917 ± 107 W vs. 1111 ± 159 W) (p < 0.01). Triathletes had intermediate RE values (1004 ± 98 W) not different from runners or cyclists. CE was not different (p = 0.20) between the three groups (runners: 945 ± 60 W; cyclists: 982 ± 44 W; triathletes: 979 ± 54 W). RE can be enhanced with running-specific training, but CE is independent of cycling-specific training.

  20. Effect of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in the heat.

    Science.gov (United States)

    Beaumont, Ross E; James, Lewis J

    2017-11-01

    This study investigated the influence of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in high ambient temperature. Double-blind cross-over study. Eight healthy, recreationally active males (mean±SD; age: 22±1 years; body mass: 71.1±8.5kg; VO 2peak : 55.9±5.8mLkg -1 min -1 ; W max : 318±37W) completed one VO 2peak test, one familiarisation trial and two experimental trials. After an overnight fast, participants ingested a placebo or a 6mgkg -1 caffeine dose 60min before exercise. The exercise protocol consisted of 60min of cycle exercise at 55% W max , followed by a 30min performance task (total kJ produced) in 30°C and 50% RH. Performance was enhanced (Cohen's d effect size=0.22) in the caffeine trial (363.8±47.6kJ) compared with placebo (353.0±49.0kJ; p=0.004). Caffeine did not influence core (p=0.188) or skin temperature (p=0.577) during exercise. Circulating prolactin (p=0.572), cortisol (p=0.842) and the estimated rates of fat (p=0.722) and carbohydrate oxidation (p=0.454) were also similar between trial conditions. Caffeine attenuated perceived exertion during the initial 60min of exercise (p=0.033), with no difference in thermal stress across trials (p=0.911). Supplementation with 6mgkg -1 caffeine improved endurance cycle performance in a warm environment, without differentially influencing thermoregulation during prolonged exercise at a fixed work-rate versus placebo. Therefore, moderate caffeine doses which typically enhance performance in temperate environmental conditions also appear to benefit endurance performance in the heat. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Combined speed endurance and endurance exercise amplify the exercise-induced PGC-1α and PDK4 mRNA response in trained human muscle

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Brandt, Nina; Pilegaard, Henriette

    2016-01-01

    The aim of this study was to investigate the mRNA response related to mitochondrial biogenesis, metabolism, angiogenesis, and myogenesis in trained human skeletal muscle to speed endurance exercise (S), endurance exercise (E), and speed endurance followed by endurance exercise (S + E). Seventeen...... trained male subjects (maximum oxygen uptake (VO2-max): 57.2 ± 3.7 (mean ± SD) mL·min(-1)·kg(-1)) performed S (6 × 30 sec all-out), E (60 min ~60% VO2-max), and S + E on a cycle ergometer on separate occasions. Muscle biopsies were obtained at rest and 1, 2, and 3 h after the speed endurance exercise (S...... and S + E) and at rest, 0, 1, and 2 h after exercise in E In S and S + E, muscle peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1α) and pyruvate dehydrogenase kinase-4 (PDK4) mRNA were higher (P endurance exercise than at rest. Muscle PGC-1α and PDK4 m...

  2. The metabolic and performance effects of caffeine compared to coffee during endurance exercise.

    Science.gov (United States)

    Hodgson, Adrian B; Randell, Rebecca K; Jeukendrup, Asker E

    2013-01-01

    There is consistent evidence supporting the ergogenic effects of caffeine for endurance based exercise. However, whether caffeine ingested through coffee has the same effects is still subject to debate. The primary aim of the study was to investigate the performance enhancing effects of caffeine and coffee using a time trial performance test, while also investigating the metabolic effects of caffeine and coffee. In a single-blind, crossover, randomised counter-balanced study design, eight trained male cyclists/triathletes (Mean ± SD: Age 41 ± 7 y, Height 1.80 ± 0.04 m, Weight 78.9 ± 4.1 kg, VO2 max 58 ± 3 ml • kg(-1) • min(-1)) completed 30 min of steady-state (SS) cycling at approximately 55% VO2max followed by a 45 min energy based target time trial (TT). One hour prior to exercise each athlete consumed drinks consisting of caffeine (5 mg CAF/kg BW), instant coffee (5 mg CAF/kg BW), instant decaffeinated coffee or placebo. The set workloads produced similar relative exercise intensities during the SS for all drinks, with no observed difference in carbohydrate or fat oxidation. Performance times during the TT were significantly faster (~5.0%) for both caffeine and coffee when compared to placebo and decaf (38.35 ± 1.53, 38.27 ± 1.80, 40.23 ± 1.98, 40.31 ± 1.22 min respectively, pperformance times were similar for both caffeine and coffee. Average power for caffeine and coffee during the TT was significantly greater when compared to placebo and decaf (294 ± 21 W, 291 ± 22 W, 277 ± 14 W, 276 ± 23 W respectively, pcaffeine (5 mg/kg/BW) and coffee (5 mg/kg/BW) consumed 1 h prior to exercise can improve endurance exercise performance.

  3. Carbohydrate Electrolyte Solutions Enhance Endurance Capacity in Active Females

    Directory of Open Access Journals (Sweden)

    Feng-Hua Sun

    2015-05-01

    Full Text Available The purpose of the present study was to investigate the effects of supplementation with a carbohydrate-electrolyte solution (CES in active females during a prolonged session of submaximal running to exhaustion. Eight healthy active females volunteered to perform a session of open-ended running to exhaustion at 70% of their maximal oxygen consumption on a treadmill during the follicular phase of their menstrual cycle on two occasions. During each run, the subjects consumed either 3mL·kg−1 body mass of a 6% CES or a placebo drink (PL every 20 min during exercise. The trials were administered in a randomized double-blind, cross-over design. During the run, the subjects ingested similar volumes of fluid in two trials (CES: 644 ± 75 mL vs. PL: 593 ± 66 mL, p > 0.05. The time to exhaustion was 16% longer during the CES trial (106.2 ± 9.4 min than during the PL trial (91.6 ± 5.9 min (p < 0.05. At 45 min during exercise, the plasma glucose concentration in the CES trial was higher than that in PL trial. No differences were observed in the plasma lactate level, respiratory exchange ratio, heart rate, perceived rate of exertion, sensation of thirst, or abdominal discomfort between the two trials (p > 0.05. The results of the present study confirm that CES supplementation improves the moderate intensity endurance capacity of active females during the follicular phases of the menstrual cycle. However, the exogenous oxidation of carbohydrate does not seem to explain the improved capacity after CES supplementation.

  4. The ATLAS Trigger system upgrade and performance in Run 2

    CERN Document Server

    Shaw, Savanna Marie; The ATLAS collaboration

    2017-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the LHC Run-2 in 2015/16 at a centre-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. In order to prepare for the anticipated further luminosity increase of the LHC in 2017/18, improving the trigger performance remain...

  5. Endurance training and GH administration in elderly women

    DEFF Research Database (Denmark)

    Lange, K H; Lorentsen, J; Isaksson, F

    2001-01-01

    and after completion of the training program. Similarly, no effect on subcutaneous abdominal adipose tissue lipolysis was observed when combining endurance training with rhGH administration. However, in both the placebo and the GH groups, fat oxidation was significantly increased during exercise performed......In the present study, the effect of endurance training alone and endurance training combined with recombinant human growth hormone (rhGH) administration on subcutaneous abdominal adipose tissue lipolysis was investigated. Sixteen healthy women [age 75 +/- 2 yr (mean +/- SE)] underwent a 12-wk...... endurance training program on a cycle ergometer. rhGH was administered in a randomized, double-blinded, placebo-controlled design in addition to the training program. Subcutaneous abdominal adipose tissue lipolysis was estimated by means of microdialysis combined with measurements of subcutaneous abdominal...

  6. No Effect of Exercise Intensity on Appetite in Highly-Trained Endurance Women

    Science.gov (United States)

    Howe, Stephanie M.; Hand, Taryn M.; Larson-Meyer, D. Enette; Austin, Kathleen J.; Alexander, Brenda M.; Manore, Melinda M.

    2016-01-01

    In endurance-trained men, an acute bout of exercise is shown to suppress post-exercise appetite, yet limited research has examined this response in women. The purpose of this study was to investigate the effect of exercise intensity on appetite and gut hormone responses in endurance-trained women. Highly-trained women (n = 15, 18–40 years, 58.4 ± 6.4 kg, VO2MAX = 55.2 ± 4.3 mL/kg/min) completed isocaloric bouts (500 kcals or 2093 kJ) of moderate-intensity (MIE, 60% VO2MAX) and high-intensity (HIE, 85% VO2MAX) treadmill running at the same time of day, following a similar 48-h diet/exercise period, and at least 1-week apart. Blood was drawn pre-exercise (baseline), immediately post-exercise and every 20-min for the next 60-min. Plasma concentrations of acylated ghrelin, PYY3–36, GLP-1 and subjective appetite ratings via visual analog scale (VAS) were assessed at each time point. Acylated ghrelin decreased (p = 0.014) and PYY3–36 and GLP-1 increased (p = 0.036, p appetite suppression. VAS ratings of hunger and desire to eat decreased immediately post-exercise (p = 0.0012, p = 0.0031, respectively), also indicating appetite suppression. There were no differences between exercise intensities for appetite hormones or VAS. Similar to males, post-exercise appetite regulatory hormones were altered toward suppression in highly-trained women and independent of energy cost of exercise. Results are important for female athletes striving to optimize nutrition for endurance performance. PMID:27096869

  7. No Effect of Exercise Intensity on Appetite in Highly-Trained Endurance Women.

    Science.gov (United States)

    Howe, Stephanie M; Hand, Taryn M; Larson-Meyer, D Enette; Austin, Kathleen J; Alexander, Brenda M; Manore, Melinda M

    2016-04-18

    In endurance-trained men, an acute bout of exercise is shown to suppress post-exercise appetite, yet limited research has examined this response in women. The purpose of this study was to investigate the effect of exercise intensity on appetite and gut hormone responses in endurance-trained women. Highly-trained women (n = 15, 18-40 years, 58.4 ± 6.4 kg, VO2MAX = 55.2 ± 4.3 mL/kg/min) completed isocaloric bouts (500 kcals or 2093 kJ) of moderate-intensity (MIE, 60% VO2MAX) and high-intensity (HIE, 85% VO2MAX) treadmill running at the same time of day, following a similar 48-h diet/exercise period, and at least 1-week apart. Blood was drawn pre-exercise (baseline), immediately post-exercise and every 20-min for the next 60-min. Plasma concentrations of acylated ghrelin, PYY3-36, GLP-1 and subjective appetite ratings via visual analog scale (VAS) were assessed at each time point. Acylated ghrelin decreased (p = 0.014) and PYY3-36 and GLP-1 increased (p = 0.036, p exercise, indicating appetite suppression. VAS ratings of hunger and desire to eat decreased immediately post-exercise (p = 0.0012, p = 0.0031, respectively), also indicating appetite suppression. There were no differences between exercise intensities for appetite hormones or VAS. Similar to males, post-exercise appetite regulatory hormones were altered toward suppression in highly-trained women and independent of energy cost of exercise. Results are important for female athletes striving to optimize nutrition for endurance performance.

  8. Branched-Chain Amino Acids Are the Primary Limiting Amino Acids in the Diets of Endurance-Trained Men after a Bout of Prolonged Exercise.

    Science.gov (United States)

    Kato, Hiroyuki; Suzuki, Katsuya; Bannai, Makoto; Moore, Daniel R

    2018-05-09

    The indicator amino acid oxidation (IAAO) method estimates the protein intake required to maximize whole-body protein synthesis and identify the daily protein requirement in a variety of populations. However, it is unclear whether the greater requirements for endurance athletes previously determined by the IAAO reflect an increased demand for all or only some amino acids. The aim of this study was to determine the primary rate-limiting amino acids in endurance-trained athletes after prolonged exercise, by measuring the oxidation of ingested [1-13C]phenylalanine in response to variable amino acid intake. Five endurance-trained men (means ± SDs: age, 26 ± 7 y; body weight, 66.9 ± 9.5 kg; maximal oxygen consumption, 63.3 ± 4.3 mL · kg-1 · min-1) performed 5 trials that involved 2 d of controlled diet (1.4 g protein · kg-1 · d-1) and running (10 km on day 1 and 5 km on day 2) prior to performing an acute bout of endurance exercise (20-km treadmill run) on day 3. During recovery on day 3, participants consumed test diets as 8 isocaloric hourly meals providing sufficient energy and carbohydrate but a variable amino acid intake. The test diets, consumed in random order, were deficient (BASE: 0.8 g · kg-1 · d-1) and sufficient (SUF; 1.75 g · kg-1 · d-1) amino acid diets modeled after egg protein, and BASE supplemented with branched-chain amino acids (BCAA diet; 1.03 g · kg-1 · d-1), essential amino acids (EAA diet; 1.23 g · kg-1 · d-1), or nonessential amino acids (NEAA diet; 1.75 g · kg-1 · d-1). Whole-body phenylalanine flux (Q), 13CO2 excretion (F13CO2), and phenylalanine oxidation (OX) were determined according to standard IAAO methodology. There was no effect of amino acid intake on Q (P = 0.43). F13CO2 was significantly (all P amino acids in the greater daily protein requirement of endurance trained men. This trial was registered at clinicaltrial.gov as NCT02628249.

  9. Strength, Endurance, Throwing Velocity and in-Water Jump Performance of Elite German Water Polo Players

    Directory of Open Access Journals (Sweden)

    Zinner Christoph

    2015-03-01

    Full Text Available The purpose of this study was threefold: 1 to assess the eggbeater kick and throwing performance using a number of water polo specific tests, 2 to explore the relation between the eggbeater kick and throwing performance, and 3 to investigate the relation between the eggbeater kick in the water and strength tests performed in a controlled laboratory setting in elite water polo players. Fifteen male water polo players of the German National Team completed dynamic and isometric strength tests for muscle groups (adductor, abductor, abdominal, pectoralis frequently used during water polo. After these laboratory strength tests, six water polo specific in-water tests were conducted. The eggbeater kick assessed leg endurance and agility, maximal throwing velocity and jump height. A 400 m test and a sprint test examined aerobic and anaerobic performance. The strongest correlation was found between jump height and arm length (p < 0.001, r = 0.89. The laboratory diagnostics of important muscles showed positive correlations with the results of the in-water tests (p < 0.05, r = 0.52-0.70. Muscular strength of the adductor, abdominal and pectoralis muscles was positively related to in-water endurance agility as assessed by the eggbeater kick (p < 0.05; r = 0.53-0.66. Findings from the current study emphasize the need to assess indices of water polo performance both in and out of the water as well as the relation among these parameters to best assess the complex profile of water polo players.

  10. Attenuated Increase in Maximal Force of Rat Medial Gastrocnemius Muscle after Concurrent Peak Power and Endurance Training

    Directory of Open Access Journals (Sweden)

    Regula Furrer

    2013-01-01

    Full Text Available Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control, peak power training (PT, or both peak power and endurance training (PET, which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training.

  11. Factors affecting running performance in 6-12-year-olds: The Health Oriented Pedagogical Project (HOPP).

    Science.gov (United States)

    Fredriksen, Per Morten; Mamen, Asgeir; Gammelsrud, Heidi; Lindberg, Morten; Hjelle, Ole Petter

    2018-05-01

    The purpose of this study was to examine factors affecting running performance in children. A cross-sectional study exploring the relationships between height, weight, waist circumference, muscle mass, body fat percentage, relevant biomarkers, and the Andersen intermittent running test in 2272 children aged 6 to 12 years. Parental education level was used as a non-physiological explanatory variable. Mean values (SD) and percentiles are presented as reference values. Height (β = 6.4, p running test. In addition, high parental education level showed a positive association with the running test. Boys display better running performance than girls at all age ages, except 7 years old, probably because of additional muscle mass and less fatty tissue. Height and increased level of haemoglobin positively affected running performance. Lower body fat percentage and high parental education level correlated with better running performance.

  12. Nutrition for endurance sports: marathon, triathlon, and road cycling.

    Science.gov (United States)

    Jeukendrup, Asker E

    2011-01-01

    Endurance sports are increasing in popularity and athletes at all levels are looking for ways to optimize their performance by training and nutrition. For endurance exercise lasting 30 min or more, the most likely contributors to fatigue are dehydration and carbohydrate depletion, whereas gastrointestinal problems, hyperthermia, and hyponatraemia can reduce endurance exercise performance and are potentially health threatening, especially in longer events (>4 h). Although high muscle glycogen concentrations at the start may be beneficial for endurance exercise, this does not necessarily have to be achieved by the traditional supercompensation protocol. An individualized nutritional strategy can be developed that aims to deliver carbohydrate to the working muscle at a rate that is dependent on the absolute exercise intensity as well as the duration of the event. Endurance athletes should attempt to minimize dehydration and limit body mass losses through sweating to 2-3% of body mass. Gastrointestinal problems occur frequently, especially in long-distance races. Problems seem to be highly individual and perhaps genetically determined but may also be related to the intake of highly concentrated carbohydrate solutions, hyperosmotic drinks, as well as the intake of fibre, fat, and protein. Hyponatraemia has occasionally been reported, especially among slower competitors with very high intakes of water or other low sodium drinks. Here I provide a comprehensive overview of recent research findings and suggest several new guidelines for the endurance athlete on the basis of this. These guidelines are more detailed and allow a more individualized approach.

  13. Protective Effect of Curcumin Supplementation and Light Resistance Exercises on Superoxide Dismutase Enzyme Activity and Malondialdehyde Levels in a Severe Endurance Training Period in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    A Gorzi

    2017-07-01

    Background and aim: Extreme endurance exercises lead to oxidative stress in athletes. Therefore, the purpose of this study was to investigate the effect of curcumin supplement supplementation and light resistance training on the activity of SOD and MDA levels of male Wistar rats during a 8-week endurance training. Methods: In the present experimental study, 36 male Wistar rats were randomly assigned into one of six control groups, curcumin, endurance training, exercise, after one week of information (age 9 weeks and weight 255.62 ± 19.69 grams. Endurance + resistance, endurance training + curcumin and endurance training + curcumin + resistance. Incremental endurance training (8 weeks, 5 sessions per week was performed on a special treadmill. Speed ​​and running time in the last week reached 35 m / min and 70 minutes. Resistance training (8 weeks, 2 sessions per week was performed on vertical ladder by closing the rat's weight to the tail. Rats received supplemental curcumin by intraperitoneal injection (8 weeks, 3 sessions per week, 30 mg / kg body weight. SOD activity of the muscle was measured using ELISA kits and serum MDA levels using Tobartic acid (TBARS method. Data were analyzed using one-way ANOVA (ANOVA.   Results: The antioxidant enzyme activity of SOD in the endometrial muscle of endurance group (1.08 ± 0.222 μg / ml was significantly lower than control group (22.2 ± 0.481 kg (P = 0.043, and SOD activity in the endurance + resistance group (1.87 ± 0.172, p = 0.44, endurance + curcumin (2.24 ± 0.222; P = 0.039, and endurance + curcumin + resistance (0.202 ± 0.15, p = 0.029 was significantly higher than endurance group. The levels of malondialdehyde in the endurance group (4.27 ± 0.438 nmol / ml protein were significantly higher in comparison with the control group (3.42 ± 0.350 (0.331 and Also, serum MDA levels in endurance + resistance groups (± 3.03 ± 0.342, p = 0.003, endurance + curcumin (p = 0.001, p <0.001, and endurance + curcumin

  14. Combined strength and endurance training in competitive swimmers.

    Science.gov (United States)

    Aspenes, Stian; Kjendlie, Per-Ludvik; Hoff, Jan; Helgerud, Jan

    2009-01-01

    A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11) or a control group (n = 9) from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers. Key pointsTwo weekly sessions of dry land strength training improves the

  15. Leg strength declines with advancing age despite habitual endurance exercise in active older adults.

    Science.gov (United States)

    Marcell, Taylor J; Hawkins, Steven A; Wiswell, Robert A

    2014-02-01

    Age-associated loss of muscle mass (sarcopenia) and strength (dynapenia) is associated with a loss of independence that contributes to falls, fractures, and nursing home admissions, whereas regular physical activity has been suggested to offset these losses. The purpose of this study was to evaluate the effect of habitual endurance exercise on muscle mass and strength in active older adults. A longitudinal analysis of muscle strength (≈4.8 years apart) was performed on 59 men (age at start of study: 58.6 ± 7.3 years) and 35 women (56.9 ± 8.2 years) who used endurance running as their primary mode of exercise. There were no changes in fat-free mass although body fat increased minimally (1.0-1.5%). Training volume (km·wk, d·wk) decreased in both the men and women. There was a significant loss of both isometric knee extension (≈5% per year) and knee flexion (≈3.6% per year) strength in both the men and women. However, there was no significant change in either isokinetic concentric or eccentric torque of the knee extensors. Our data demonstrated a significant decline in isometric knee extensor and knee flexor strength although there were no changes in body mass in this group of very active older men and women. Our data support newer exercise guidelines for older Americans suggesting resistance training be an integral component of a fitness program and that running alone was not sufficient to prevent the loss in muscle strength (dynapenia) with aging.

  16. Body composition and hydration status changes in male and female open-water swimmers during an ultra-endurance event.

    Science.gov (United States)

    Weitkunat, Tim; Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas

    2012-01-01

    Body mass changes during ultra-endurance performances have been described for running, cycling and for swimming in a heated pool. The present field study of 20 male and 11 female open-water swimmers investigated the changes in body composition and hydration status during an ultra-endurance event. Body mass, both estimated fat mass and skeletal muscle mass, haematocrit, plasma sodium concentration ([Na+]) and urine specific gravity were determined. Energy intake, energy expenditure and fluid intake were estimated. Males experienced significant reductions in body mass (-0.5 %) and skeletal muscle mass (-1.1 %) (P 0.05). Changes in percent body fat, fat mass, and fat-free mass were heterogeneous and did not reach statistical significance (P > 0.05) between gender groups. Fluid intake relative to plasma volume was higher in females than in males during the ultra-endurance event. Compared to males, females' average increase in haematocrit was 3.3 percentage points (pp) higher, urine specific gravity decrease 0.1 pp smaller, and plasma [Na+] 1.3 pp higher. The observed patterns of fluid intake, changes in plasma volume, urine specific gravity, and plasma [Na+] suggest that, particularly in females, a combination of fluid shift from blood vessels to interstitial tissue, facilitated by skeletal muscle damage, as well as exercise-associated hyponatremia had occurred. To summarise, changes in body composition and hydration status are different in male compared to female open-water ultra-endurance swimmers.

  17. Achieving the optimal performance of the CMS ECAL in Run II

    CERN Document Server

    Sun, Menglei

    2016-01-01

    Many physics analyses using the Compact Muon Solenoid (CMS) detector at the LHC require accurate, high resolution electron and photon energy measurements. Particularly important are decays of the Higgs boson resulting in electromagnetic particles in the final state. Di-photon events in CMS are also a very important channel in the search for Higgs boson production in association with other particles or in the search for possible new resonances of higher mass. The requirement for high performance electromagnetic calorimetry therefore remains high during LHC Run II. Following the excellent performance achieved in Run~I at a center of mass energy of 7 and 8 TeV, the CMS electromagnetic calorimeter (ECAL) started operating at the LHC in Spring 2015 with proton-proton collisions at 13 TeV center-of-mass energy. The instantaneous luminosity delivered by the LHC during Run~II is expected to exceed the levels achieved in Run I, using 25 ns bunch spacing. The average number of concurrent proton-proton collisions per bu...

  18. Effects of cognitive stimulation with a self-modeling video on time to exhaustion while running at maximal aerobic velocity: a pilot study.

    Science.gov (United States)

    Hagin, Vincent; Gonzales, Benoît R; Groslambert, Alain

    2015-04-01

    This study assessed whether video self-modeling improves running performance and influences the rate of perceived exertion and heart rate response. Twelve men (M age=26.8 yr., SD=6; M body mass index=22.1 kg.m(-2), SD=1) performed a time to exhaustion running test at 100 percent maximal aerobic velocity while focusing on a video self-modeling loop to synchronize their stride. Compared to the control condition, there was a significant increase of time to exhaustion. Perceived exertion was lower also, but there was no significant change in mean heart rate. In conclusion, the video self-modeling used as a pacer apparently increased endurance by decreasing perceived exertion without affecting the heart rate.

  19. Performance data from the ZEPLIN-III second science run

    International Nuclear Information System (INIS)

    Majewski, P; Edwards, B; Kalmus, G E; Lindote, A; Solovov, V N; Chepel, V; DeViveiros, L; Lopes, M I; Akimov, D Yu; Belov, V A; Burenkov, A A; Kobyakin, A S; Kovalenko, A G; Araújo, H M; Currie, A; Horn, M; Lebedenko, V N; Barnes, E J; Ghag, C; Hollingsworth, A

    2012-01-01

    ZEPLIN-III is a two-phase xenon direct dark matter experiment located at the Boulby Mine (U.K.). After its first science run in 2008 it was upgraded with: an array of low background photomultipliers, a new anti-coincidence detector system with plastic scintillator and an improved calibration system. After 319 days of data taking the second science run ended in May 2011. In this paper we describe the instrument performance with emphasis on the position and energy reconstruction algorithm and summarise the final science results.

  20. A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors.

    Directory of Open Access Journals (Sweden)

    P W H Kwong

    Full Text Available To use structural equation modelling (SEM to determine (1 the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2 the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors.In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS and the 6-minute walk test (6MWT were used to evaluate balance performance and walking endurance, respectively.SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (β = 0.41, p <0.001. An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (β = 0.18, p = 0.044 and the BBS score (β = 0.21, p = 0.021 had direct associations with the SIPSO score.The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration.

  1. CAFFEINE INTAKE ENHANCES ENDURANCE PERFORMANCE IN SUB-ELITE BUT NOT IN ELITE ATHLETES

    Directory of Open Access Journals (Sweden)

    Ondřej Smolka

    2015-01-01

    Full Text Available The aim of our contribution is to evaluate the influence of caffeine (CAF ingestion on maximal power output (MPO during endurance performance. Two groups of men – 10 sub-elite cyclists and 8 elite cyclists completed a randomized, crossover, double-blind study. Over the course of three days participants completed three identical experimental tests (60min cycling time trial on 70 % VO2max followed by test to exhaustion. Three experimental meals - a combination of 500ml water, a gel supplement and a specific dose of CAF: a placebo (PLA, no caffeine, CAF2 (2 mg / kg body weight (BW and CAF7 (7 mg / kg BW were administered 45min prior to the start of the experimental tests. Subjective RPE values were determined using the Borg 20-category scale. The results show significant differences between MPOPLA and MPOCAF7 and between MPOCAF2 and MPOCAF7 with p = 0.018 and p = 0.019, respectively, in the sub-elite cyclists group only. The mean MPO during experimental test in sub-elite cyclists, but not in elite cyclists, was significantly enhanced following caffeine ingestion (p = 0.05. These findings indicate that caffeine intake at recommended levels is not associated with improved performance in a professional level cyclist. The results of the comparison of the experimental situations using the Borg scale are not persuasive. We found a significant difference (0.008356 between the PLA and CAF2 experimental measurements (p < 0.05. The level of substantive significance was assessed using Cohen’s coefficient effect and only a small “size of effect” (0.19 was found. It is therefore not possible to determine whether the Borg scale might be used to define the effects of caffeine ingestion on endurance performance, due to the multifactorial effects of caffeine.

  2. Effect of increased and maintained frequency of speed endurance training on performance and muscle adaptations in runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Bangsbo, Jens

    2017-01-01

    The aim of the study was, in runners accustomed to speed endurance training (SET), to examine the effect of increased and maintained frequency of SET on performance and muscular adaptations. After familiarization (FAM) to SET, eighteen male (n=14) and female (n=4) runners (VO2-max: 57.3±3.4 ml·mi...

  3. Tolerance of Lower Body Negative Pressure (LBNP) in endurance runners, weightlifters, swimmers and nonathletes

    Science.gov (United States)

    1980-01-01

    Thirteen endurance runners (R), 12 weightlifters (WL), 12 swimmers (SW) and 10 nonathletes (NA) were tested for their tolerance of lower body negative pressure (LBNP) in consecutive 5 minute stages at -20, -30, -40, -50 and -60 torr. Each subject also performed an exercise test on a bicycle ergometer with progressive workloads to exhaustion to determined aerobic capacity. The R had a much higher aerobic capacity than any of the other groups, but a significantly lower LBNP tolerance. While responses in heart rate and pulse pressure were quite similar in all 4 groups, the rate of increase in leg volume relative to LBNP stress (leg compliance, LC) was considerably greater in R than in the other athletes and NA. The greater LC in R could be attributed not only to a more rapid shift of blood to the lower extremities but also to a greater tendency for edema formation, both contributing to a more rapid loss in effective central blood volume for a given LBNP stress. These results substantiate earlier observations which led to the conclusion that endurance running is not advisable as a training regimen for astronauts.

  4. Effects of Ramadan intermittent fasting on middle-distance running performance in well-trained runners.

    Science.gov (United States)

    Brisswalter, Jeanick; Bouhlel, Ezzedine; Falola, Jean Marie; Abbiss, Christopher R; Vallier, Jean Marc; Hausswirth, Christophe; Hauswirth, Christophe

    2011-09-01

    To assess whether Ramadan intermittent fasting (RIF) affects 5000-m running performance and physiological parameters classically associated with middle-distance performance. Two experimental groups (Ramadan fasting, n = 9, vs control, n = 9) participated in 2 experimental sessions, one before RIF and the other at the last week of fasting. For each session, subjects completed 4 tests in the same order: a maximal running test, a maximal voluntary contraction (MVC) of knee extensor, 2 rectangular submaximal exercises on treadmill for 6 minutes at an intensity corresponding to the first ventilatory threshold (VT1), and a running performance test (5000 m). Eighteen, well-trained, middle-distance runners. Maximal oxygen consumption, MVC, running performance, running efficiency, submaximal VO(2) kinetics parameters (VO(2), VO(2)b, time constant τ, and amplitude A1) and anthropometric parameters were recorded or calculated. At the end of Ramadan fasting, a decrease in MVC was observed (-3.2%; P < 0.00001; η, 0.80), associated with an increase in the time constant of oxygen kinetics (+51%; P < 0.00007; η, 0.72) and a decrease in performance (-5%; P < 0.0007; η, 0.51). No effect was observed on running efficiency or maximal aerobic power. These results suggest that Ramadan changes in muscular performance and oxygen kinetics could affect performance during middle-distance events and need to be considered to choose training protocols during RIF.

  5. CEPRAM: Compression for Endurance in PCM RAM

    OpenAIRE

    González Alberquilla, Rodrigo; Castro Rodríguez, Fernando; Piñuel Moreno, Luis; Tirado Fernández, Francisco

    2017-01-01

    We deal with the endurance problem of Phase Change Memories (PCM) by proposing Compression for Endurance in PCM RAM (CEPRAM), a technique to elongate the lifespan of PCM-based main memory through compression. We introduce a total of three compression schemes based on already existent schemes, but targeting compression for PCM-based systems. We do a two-level evaluation. First, we quantify the performance of the compression, in terms of compressed size, bit-flips and how they are affected by e...

  6. The Robust Running Ape: Unraveling the Deep Underpinnings of Coordinated Human Running Proficiency

    Directory of Open Access Journals (Sweden)

    John Kiely

    2017-06-01

    Full Text Available In comparison to other mammals, humans are not especially strong, swift or supple. Nevertheless, despite these apparent physical limitations, we are among Natures most superbly well-adapted endurance runners. Paradoxically, however, notwithstanding this evolutionary-bestowed proficiency, running-related injuries, and Overuse syndromes in particular, are widely pervasive. The term ‘coordination’ is similarly ubiquitous within contemporary coaching, conditioning, and rehabilitation cultures. Various theoretical models of coordination exist within the academic literature. However, the specific neural and biological underpinnings of ‘running coordination,’ and the nature of their integration, remain poorly elaborated. Conventionally running is considered a mundane, readily mastered coordination skill. This illusion of coordinative simplicity, however, is founded upon a platform of immense neural and biological complexities. This extensive complexity presents extreme organizational difficulties yet, simultaneously, provides a multiplicity of viable pathways through which the computational and mechanical burden of running can be proficiently dispersed amongst expanded networks of conditioned neural and peripheral tissue collaborators. Learning to adequately harness this available complexity, however, is a painstakingly slowly emerging, practice-driven process, greatly facilitated by innate evolutionary organizing principles serving to constrain otherwise overwhelming complexity to manageable proportions. As we accumulate running experiences persistent plastic remodeling customizes networked neural connectivity and biological tissue properties to best fit our unique neural and architectural idiosyncrasies, and personal histories: thus neural and peripheral tissue plasticity embeds coordination habits. When, however, coordinative processes are compromised—under the integrated influence of fatigue and/or accumulative cycles of injury, overuse

  7. Running Performance of a Pinning-Type Superconducting Magnetic Levitation Guide

    International Nuclear Information System (INIS)

    Okano, M; Iwamoto, T; Furuse, M; Fuchino, S; Ishii, I

    2006-01-01

    A pinning-type superconducting magnetic levitation guide with bulk high-Tc superconductors was studied for use as a goods transportation system, an energy storage system, etc. A superconducting magnetic levitation running test apparatus with a circular track of ca. 38 m length, 12 m diameter, which comprises the magnetic rail constituted by Nd-B-Fe rare-earth permanent magnets and steel plates, was manufactured to examine loss and high-speed performance of the magnetic levitation guide. Running tests were conducted in air. These tests clarify that a vehicle supported by a superconducting magnetic levitation guide runs stably at speeds greater than 42 km/h above the circular track

  8. Running Performance of a Pinning-Type Superconducting Magnetic Levitation Guide

    Science.gov (United States)

    Okano, M.; Iwamoto, T.; Furuse, M.; Fuchino, S.; Ishii, I.

    2006-06-01

    A pinning-type superconducting magnetic levitation guide with bulk high-Tc superconductors was studied for use as a goods transportation system, an energy storage system, etc. A superconducting magnetic levitation running test apparatus with a circular track of ca. 38 m length, 12 m diameter, which comprises the magnetic rail constituted by Nd-B-Fe rare-earth permanent magnets and steel plates, was manufactured to examine loss and high-speed performance of the magnetic levitation guide. Running tests were conducted in air. These tests clarify that a vehicle supported by a superconducting magnetic levitation guide runs stably at speeds greater than 42 km/h above the circular track.

  9. Acute Impact of Inhaled Short Acting B-Agonists on 5 Km Running Performance

    Directory of Open Access Journals (Sweden)

    John Dickinson

    2014-06-01

    Full Text Available Whilst there appears to be no ergogenic effect from inhaled salbutamol no study has investigated the impact of the acute inhalation of 1600 µg, the World Anti-Doping Agency (WADA daily upper limit, on endurance running performance. To investigate the ergogenic effect of an acute inhalation of short acting β2-agonists at doses up to 1600 µg on 5 km time trial performance and resultant urine concentration. Seven male non-asthmatic runners (mean ± SD; age 22.4 ± 4.3 years; height 1.80 ± 0.07 m; body mass 76.6 ± 8.6 kg provided written informed consent. Participants completed six 5 km time-trials on separate days (three at 18 °C and three at 30 °C. Fifteen minutes prior to the initiation of each 5 km time-trial participants inhaled: placebo (PLA, 800 µg salbutamol (SAL800 or 1600 µg salbutamol (SAL1600. During each 5 km time-trial HR, VO2, VCO2, VE, RPE and blood lactate were measured. Urine samples (90 ml were collected between 30-180 minutes post 5 km time-trial and analysed for salbutamol concentration. There was no significant difference in total 5 km time between treatments (PLA 1714.7 ± 186.2 s; SAL800 1683.3 ± 179.7 s; SAL1600 1683.6 ± 190.7 s. Post 5 km time-trial salbutamol urine concentration between SAL800 (122.96 ± 69.22 ug·ml-1 and SAL1600 (574.06 ± 448.17 ug·ml-1 were not significantly different. There was no improvement in 5 km time-trial performance following the inhalation of up to 1600 µg of salbutamol in non-asthmatic athletes. This would suggest that the current WADA guidelines, which allow athletes to inhale up to 1600 µg per day, is sufficient to avoid pharmaceutical induced performance enhancement.

  10. Performance and endurance of a PEMFC operated with synthetic reformate fuel feed

    Energy Technology Data Exchange (ETDEWEB)

    Sishtla, C; Koncar, G; Platon, R [Institute of Gas Technology, Des Plaines, IL (United States); Gamburzev, S; Appleby, A J [Texas Engineering Experimental Station, Texas A and M Univ. System, College Station, TX (United States). Center for Electrochemical Systems and Hydrogen Research; Velev, O A [AeroVironment, Inc., Monrovia, CA (United States)

    1998-03-15

    Widespread implementation of polymer electrolyte membrane fuel cell (PEMFC) powerplants for stationary and vehicular applications will be dependent in the near future on using readily available hydrocarbon fuels as the source of the hydrogen fuel. Methane and propane are ideal fuels for stationary applications, while methanol, gasoline, and diesel fuel are better suited for vehicular applications. Various means of fuel processing are possible to produce a gaseous fuel containing H{sub 2}, CO{sub 2} and CO. CO is a known electrocatalyst poison and must be reduced to low (10`s) ppm levels and CO{sub 2} is said to cause additional polarization effects. Even with no CO in the feed gas a H{sub 2}/CO{sub 2}/H{sub 2}O gas mixture will form some CO. Therefore, as a first step of developing a PEMFC that can operate for thousands of hours using a reformed fuel, we used an anode gas feed of 80% H{sub 2} and 20% CO{sub 2} to simulate the reforming of CH{sub 4}. To investigate the effect of reformate on cell performance and endurance, a single cell with an active area of 58 cm{sup 2} was assembled with a membrane electrode assembly (MEA) furnished by Texas A and M University using IGT`s internally manifolded heat exchange (IMHEX{sup TM}) design configuration. The MEA consisted of a Nafion 112 membrane with anode and cathode Pt catalyst loadings of 0.26 and 1.46 mg/cm{sup 2}, respectively. The cell was set to operate on a synthetic reformate - air at 60 C and 1 atm and demonstrated over 5000 h of endurance with a decay rate of less than 1%/1000 h of operation. The cell also underwent four successful thermal cycles with no appreciable loss in performance. The stable performance is attributed to a combination of the IGT IMHEX plate design with its inherent uniform gas flow distribution across the entire active area and MEA quality. The effects of temperature, gas composition, fuel utilization (stoics) and thermal cycle on cell performance are described. (orig.)

  11. Caffeine withdrawal and high-intensity endurance cycling performance.

    Science.gov (United States)

    Irwin, Christopher; Desbrow, Ben; Ellis, Aleisha; O'Keeffe, Brooke; Grant, Gary; Leveritt, Michael

    2011-03-01

    In this study, we investigated the impact of a controlled 4-day caffeine withdrawal period on the effect of an acute caffeine dose on endurance exercise performance. Twelve well-trained and familiarized male cyclists, who were caffeine consumers (from coffee and a range of other sources), were recruited for the study. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials. Participants abstained from dietary caffeine sources for 4 days before the trials and ingested capsules (one in the morning and one in the afternoon) containing either placebo or caffeine (1.5 mg · kg(-1) body weight · day(-1)). On day 5, capsules containing placebo or caffeine (3 mg · kg(-1) body weight) were ingested 90 min before completing a time trial, equivalent to one hour of cycling at 75% peak sustainable power output. Hence the study was designed to incorporate placebo-placebo, placebo-caffeine, caffeine-placebo, and caffeine-caffeine conditions. Performance time was significantly improved after acute caffeine ingestion by 1:49 ± 1:41 min (3.0%, P = 0.021) following a withdrawal period (placebo-placebo vs. placebo-caffeine), and by 2:07 ± 1:28 min (3.6%, P = 0.002) following the non-withdrawal period (caffeine-placebo vs. caffeine-caffeine). No significant difference was detected between the two acute caffeine trials (placebo-caffeine vs. caffeine-caffeine). Average heart rate throughout exercise was significantly higher following acute caffeine administration compared with placebo. No differences were observed in ratings of perceived exertion between trials. A 3 mg · kg(-1) dose of caffeine significantly improves exercise performance irrespective of whether a 4-day withdrawal period is imposed on habitual caffeine users.

  12. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  13. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Morgenstern, Stefanie; The ATLAS collaboration

    2018-01-01

    Liquid-argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region $\\eta<3.2$, and for hadronic and forward calorimetry in the region from $\\eta=1.5$ to $\\eta=4.9$. In the first LHC run a total luminosity of $27\\,\\mathrm{fb}^{-1}$ has been collected at centre-of-mass energies of $7-8\\,\\mathrm{TeV}$. After detector consolidation during a long shutdown, Run-2 started in 2015 and $86.4\\,\\mathrm{fb}^{-1}$ of data at a centre-of-mass energy of $13\\,\\mathrm{TeV}$ have been recorded. In order to realize the level-1 acceptance rate of $100\\,\\mathrm{kHz}$ in Run-2 data taking, the number of readout samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibrated and highly granular LAr calorimeter reached its design values both in energy measurement as well as in direction resolution. This contribution will give an overview of the detector operation, hardware...

  14. Trunk muscle activation during moderate- and high-intensity running.

    Science.gov (United States)

    Behm, David G; Cappa, Dario; Power, Geoffrey A

    2009-12-01

    Time constraints are cited as a barrier to regular exercise. If particular exercises can achieve multiple training functions, the number of exercises and the time needed to achieve a training goal may be decreased. It was the objective of this study to compare the extent of trunk muscle electromyographic (EMG) activity during running and callisthenic activities. EMG activity of the external obliques, lower abdominals (LA), upper lumbar erector spinae (ULES), and lumbosacral erector spinae (LSES) was monitored while triathletes and active nonrunners ran on a treadmill for 30 min at 60% and 80% of their maximum heart rate (HR) reserve, as well as during 30 repetitions of a partial curl-up and 3 min of a modified Biering-Sørensen back extension exercise. The mean root mean square (RMS) amplitude of the EMG signal was monitored over 10-s periods with measures normalized to a maximum voluntary contraction rotating curl-up (external obliques), hollowing exercise (LA), or back extension (ULES and LSES). A main effect for group was that triathletes had greater overall activation of the external obliques (p runs, respectively, than with the curl-ups (p = 0.001). The back extension exercise provided less ULES (p = 0.009) and LSES (p = 0.0001) EMG activity than the 60% and 80% runs, respectively. In conclusion, triathletes had greater trunk activation than nonrunners did while running, which could have contributed to their better performance. Back-stabilizing muscles can be activated more effectively with running than with a prolonged back extension activity. Running can be considered as an efficient, multifunctional exercise combining cardiovascular and trunk endurance benefits.

  15. The Relationship between Field Tests of Anaerobic Power and 10-km Run Performance.

    Science.gov (United States)

    Sinnett, Aaron M.; Berg, Kris; Latin, Richard W.; Noble, John M.

    2001-01-01

    Investigated the relationship between several field tests of anaerobic power (e.g., +various sprints, vertical jumps, and a plyometric leap) and distance running performance in trained adult male and female runners. Results indicate that anaerobic power is significantly related to distance running performance and may explain a meaningful…

  16. The ATLAS Trigger Algorithms Upgrade and Performance in Run-2

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a center-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken improvements resulted in more pile-up robust selection efficiencies and event ra...

  17. The ATLAS Trigger system upgrade and performance in Run 2

    CERN Document Server

    Shaw, Savanna Marie; The ATLAS collaboration

    2018-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a centre-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken improvements resulted in more pile-up robust selection efficiencies and event ra...

  18. Comparison between two types of anaerobic speed endurance training in competitive soccer players

    Directory of Open Access Journals (Sweden)

    Mohr Magni

    2016-06-01

    Full Text Available The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional speed endurance production (SEP or speed endurance maintenance (SEM training (two additional sessions/wk for 4 weeks during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2 and a repeated sprint test (RST pre- and post-intervention. Yo-Yo IR2 performance increased (p<0.001 by 50 ± 8% and 26 ± 5% in SEP and SEM, respectively, with greater (p=0.03 improvement in SEP. RST performance improved by 2.1 ± 0.3% and 1.3 ± 0.4% in SEP and SEM, respectively, while the RST fatigue index decreased (4.4 ± 0.8 to 3.4 ± 0.5%; p<0.04 in SEP only. Peak and average speed during training were higher (p<0.001 in SEP than in SEM (24.5 ± 0.3 vs 19.2 ± 0.3 and 15.5 ± 0.1 km·h-1 vs 9.4 ± 0.1 km·h-1. Additional in-season anaerobic speed endurance production and maintenance training improves high-intensity exercise performance in competitive soccer players with superior effects of speed endurance production training.

  19. The repeated bout effect of traditional resistance exercises on running performance across 3 bouts.

    Science.gov (United States)

    Doma, Kenji; Schumann, Moritz; Leicht, Anthony Scott; Heilbronn, Brian Edward; Damas, Felipe; Burt, Dean

    2017-09-01

    This study investigated the repeated bout effect of 3 typical lower body resistance-training sessions on maximal and submaximal effort running performance. Twelve resistance-untrained men (age, 24 ± 4 years; height, 1.81 ± 0.10 m; body mass, 79.3 ± 10.9 kg; peak oxygen uptake, 48.2 ± 6.5 mL·kg -1 ·min -1 ; 6-repetition maximum squat, 71.7 ± 12.2 kg) undertook 3 bouts of resistance-training sessions at 6-repetitions maximum. Countermovement jump (CMJ), lower-body range of motion (ROM), muscle soreness, and creatine kinase (CK) were examined prior to and immediately, 24 h (T24), and 48 h (T48) after each resistance-training bout. Submaximal (i.e., below anaerobic threshold (AT)) and maximal (i.e., above AT) running performances were also conducted at T24 and T48. Most indirect muscle damage markers (i.e., CMJ, ROM, and muscle soreness) and submaximal running performance were significantly improved (P running performance was also improved following the third bout (P 0.05). In conclusion, the initial bout induced the greatest change in CK; however, at least 2 bouts were required to produce protective effects on other indirect muscle damage markers and submaximal running performance measures. This suggests that submaximal running sessions should be avoided for at least 48 h after resistance training until the third bout, although a greater recovery period may be required for maximal running sessions.

  20. Effects of body-mapping-designed clothing on heat stress and running performance in a hot environment.

    Science.gov (United States)

    Jiao, Jiao; Li, Yi; Yao, Lei; Chen, Yajun; Guo, Yueping; Wong, Stephen H S; Ng, Frency S F; Hu, Junyan

    2017-10-01

    To investigate clothing-induced differences in human thermal response and running performance, eight male athletes participated in a repeated-measure study by wearing three sets of clothing (CloA, CloB, and CloC). CloA and CloB were body-mapping-designed with 11% and 7% increased capacity of heat dissipation respectively than CloC, the commonly used running clothing. The experiments were conducted by using steady-state running followed by an all-out performance running in a controlled hot environment. Participants' thermal responses such as core temperature (T c ), mean skin temperature ([Formula: see text]), heat storage (S), and the performance running time were measured. CloA resulted in shorter performance time than CloC (323.1 ± 10.4 s vs. 353.6 ± 13.2 s, p = 0.01), and induced the lowest [Formula: see text], smallest ΔT c , and smallest S in the resting and running phases. This study indicated that clothing made with different heat dissipation capacities affects athlete thermal responses and running performance in a hot environment. Practitioner Summary: A protocol that simulated the real situation in running competitions was used to investigate the effects of body-mapping-designed clothing on athletes' thermal responses and running performance. The findings confirmed the effects of optimised clothing with body-mapping design and advanced fabrics, and ensured the practical advantage of developed clothing on exercise performance.

  1. Individual responses to combined endurance and strength training in older adults.

    Science.gov (United States)

    Karavirta, Laura; Häkkinen, Keijo; Kauhanen, Antti; Arija-Blázquez, Alfredo; Sillanpää, Elina; Rinkinen, Niina; Häkkinen, Arja

    2011-03-01

    A combination of endurance and strength training is generally used to seek further health benefits or enhanced physical performance in older adults compared with either of the training modes alone. The mean change within a training group, however, may conceal a wide range of individual differences in the responses. The purpose, therefore, was to examine the individual trainability of aerobic capacity and maximal strength, when endurance and strength training are performed separately or concurrently. For this study, 175 previously untrained volunteers, 89 men and 86 women between the ages of 40 and 67 yr, completed a 21-wk period of either strength training (S) twice a week, endurance training (E) twice a week, combined training (ES) four times per week, or served as controls. Training adaptations were quantified as peak oxygen uptake (VO2peak) in a bicycle ergometer test to exhaustion and maximal isometric bilateral leg extension force (MVC) in a dynamometer. A large range in training responses, similar to endurance or strength training alone, was also observed with combined endurance and strength training in both ΔVO2peak (from -8% to 42%) and ΔMVC (from -12% to 87%). There were no significant correlations between the training responses in VO2peak and MVC in the E, S, or especially in the ES group, suggesting that the same subjects did not systematically increase both aerobic capacity and maximal strength. The goal of combined endurance and strength training--increasing both aerobic capacity and maximal strength simultaneously--was only achieved by some of the older subjects. New means are needed to personalize endurance, strength, and especially combined endurance and strength training programs for optimal individual adaptations.

  2. The baseline serum value of α-amylase is a significant predictor of distance running performance.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Tarperi, Cantor; La Torre, Antonio; Guidi, Gian Cesare; Schena, Federico

    2015-02-01

    This study was planned to investigate whether serum α-amylase concentration may be associated with running performance, physiological characteristics and other clinical chemistry analytes in a large sample of recreational athletes undergoing distance running. Forty-three amateur runners successfully concluded a 21.1 km half-marathon at 75%-85% of their maximal oxygen uptake (VO2max). Blood was drawn during warm up and 15 min after conclusion of the run. After correction for body weight change, significant post-run increases were observed for serum values of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bilirubin, creatine kinase (CK), iron, lactate dehydrogenase (LDH), triglycerides, urea and uric acid, whereas the values of body weight, glomerular filtration rate, total and low density lipoprotein-cholesterol were significantly decreased. The concentration of serum α-amylase was unchanged. In univariate analysis, significant associations with running performance were found for gender, VO2max, training regimen and pre-run serum values of α-amylase, CK, glucose, high density lipoprotein-cholesterol, LDH, urea and uric acid. In multivariate analysis, only VO2max (p=0.042) and baseline α-amylase (p=0.021) remained significant predictors of running performance. The combination of these two variables predicted 71% of variance in running performance. The baseline concentration of serum α-amylase was positively correlated with variation of serum glucose during the trial (r=0.345; p=0.025) and negatively with capillary blood lactate at the end of the run (r=-0.352; p=0.021). We showed that the baseline serum α-amylase concentration significantly and independently predicts distance running performance in recreational runners.

  3. The design of the run Clever randomized trial: running volume, -intensity and running-related injuries.

    Science.gov (United States)

    Ramskov, Daniel; Nielsen, Rasmus Oestergaard; Sørensen, Henrik; Parner, Erik; Lind, Martin; Rasmussen, Sten

    2016-04-23

    Injury incidence and prevalence in running populations have been investigated and documented in several studies. However, knowledge about injury etiology and prevention is needed. Training errors in running are modifiable risk factors and people engaged in recreational running need evidence-based running schedules to minimize the risk of injury. The existing literature on running volume and running intensity and the development of injuries show conflicting results. This may be related to previously applied study designs, methods used to quantify the performed running and the statistical analysis of the collected data. The aim of the Run Clever trial is to investigate if a focus on running intensity compared with a focus on running volume in a running schedule influences the overall injury risk differently. The Run Clever trial is a randomized trial with a 24-week follow-up. Healthy recreational runners between 18 and 65 years and with an average of 1-3 running sessions per week the past 6 months are included. Participants are randomized into two intervention groups: Running schedule-I and Schedule-V. Schedule-I emphasizes a progression in running intensity by increasing the weekly volume of running at a hard pace, while Schedule-V emphasizes a progression in running volume, by increasing the weekly overall volume. Data on the running performed is collected by GPS. Participants who sustain running-related injuries are diagnosed by a diagnostic team of physiotherapists using standardized diagnostic criteria. The members of the diagnostic team are blinded. The study design, procedures and informed consent were approved by the Ethics Committee Northern Denmark Region (N-20140069). The Run Clever trial will provide insight into possible differences in injury risk between running schedules emphasizing either running intensity or running volume. The risk of sustaining volume- and intensity-related injuries will be compared in the two intervention groups using a competing

  4. Physiological and bodily changes associated with endurance athletic activities and challenges during peri-operative period

    Directory of Open Access Journals (Sweden)

    Umesh K Dash

    2016-01-01

    Full Text Available Endurance athletic activities, which requires top level cardio respiratory system fitness are recently becoming popular in the various parts of the country. Armed Forces are forefront in participation of those sporting activities, like marathon running, prolonged swimming or cycling. It has been found to have various long term beneficial effect in body function as a result of prolonged endurance activities, but it has also found that there are various bodily changes which may affect in anaesthetising the individual during emergency and elective surgeries. Literature review of various journals related to endurance sporting activities has described those bodily changes and effects of anaesthesia and pain on those changes. Based upon the available literature a guideline has been formulated for perioperative management of those patients. Most of those available literatures are from countries other than our country. The time has come for venturing in for carrying out further studies in our scenario, especially in Armed Forces in this new horizon of anaesthesia and critical care

  5. Western diet increases wheel running in mice selectively bred for high voluntary wheel running.

    Science.gov (United States)

    Meek, T H; Eisenmann, J C; Garland, T

    2010-06-01

    Mice from a long-term selective breeding experiment for high voluntary wheel running offer a unique model to examine the contributions of genetic and environmental factors in determining the aspects of behavior and metabolism relevant to body-weight regulation and obesity. Starting with generation 16 and continuing through to generation 52, mice from the four replicate high runner (HR) lines have run 2.5-3-fold more revolutions per day as compared with four non-selected control (C) lines, but the nature of this apparent selection limit is not understood. We hypothesized that it might involve the availability of dietary lipids. Wheel running, food consumption (Teklad Rodent Diet (W) 8604, 14% kJ from fat; or Harlan Teklad TD.88137 Western Diet (WD), 42% kJ from fat) and body mass were measured over 1-2-week intervals in 100 males for 2 months starting 3 days after weaning. WD was obesogenic for both HR and C, significantly increasing both body mass and retroperitoneal fat pad mass, the latter even when controlling statistically for wheel-running distance and caloric intake. The HR mice had significantly less fat than C mice, explainable statistically by their greater running distance. On adjusting for body mass, HR mice showed higher caloric intake than C mice, also explainable by their higher running. Accounting for body mass and running, WD initially caused increased caloric intake in both HR and C, but this effect was reversed during the last four weeks of the study. Western diet had little or no effect on wheel running in C mice, but increased revolutions per day by as much as 75% in HR mice, mainly through increased time spent running. The remarkable stimulation of wheel running by WD in HR mice may involve fuel usage during prolonged endurance exercise and/or direct behavioral effects on motivation. Their unique behavioral responses to WD may render HR mice an important model for understanding the control of voluntary activity levels.

  6. Effects of Acute Endurance Exercise Performed in the Morning and Evening on Inflammatory Cytokine and Metabolic Hormone Responses.

    Directory of Open Access Journals (Sweden)

    Hyeon-Ki Kim

    Full Text Available To compare the effects of endurance exercise performed in the morning and evening on inflammatory cytokine responses in young men.Fourteen healthy male participants aged 24.3 ± 0.8 years (mean ± standard error performed endurance exercise in the morning (0900-1000 h on one day and then in the evening (1700-1800 h on another day with an interval of at least 1 week between each trial. In both the morning and evening trials, the participants walked for 60 minutes at approximately 60% of the maximal oxygen uptake (VO2max on a treadmill. Blood samples were collected to determine hormones and inflammatory cytokines at pre-exercise, immediately post exercise, and 2 h post exercise.Plasma interleukin (IL-6 and adrenaline concentrations were significantly higher immediately after exercise in the evening trial than in the morning trial (P < 0.01, both. Serum free fatty acids concentrations were significantly higher in the evening trial than in the morning trial at 2 h after exercise (P < 0.05. Furthermore, a significant correlation was observed between the levels of IL-6 immediately post-exercise and free fatty acids 2 h post-exercise in the evening (r = 0.68, P < 0.01.These findings suggest that the effect of acute endurance exercise in the evening enhances the plasma IL-6 and adrenaline concentrations compared to that in the morning. In addition, IL-6 was involved in increasing free fatty acids, suggesting that the evening is more effective for exercise-induced lipolysis compared with the morning.

  7. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Yatsenko, Elena; The ATLAS collaboration

    2017-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm−2 s−1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. In the first LHC run a total luminosity of 27 fb−1 has been collected at center-of-mass energies of 7-8 TeV between year of 2010 to 2012. Following a period of detector consolidation during a long shutdown, Run-2 started with approximately 3.9 fb-1 and 35.6 fb-1 of data at a center-of-mass energy of 13 TeV recorded in 2015 and 2016, respectively. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, number of read-out samples for the energy and the time measurement has been modified from five to four with keeping the expected performance. The well calibrated and highly granular Liquid Ar...

  8. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Morgenstern, Stefanie; The ATLAS collaboration

    2018-01-01

    Liquid argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region eta<3.2, and for hadronic and forward calorimetry in the region from eta=1.5 to eta=4.9. In the first LHC run a total luminosity of 27 fb-1 has been collected at c.o.m energies of 7-8 TeV. After detector consolidation during a long shutdown, Run-2 started in 2015 and 86.4fb-1 of data at a c.o.m energy of 13 TeV have been recorded. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, the number of read-out samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibrated and highly granular LAr Calorimeter reached its design values both in energy measurement as well as in direction resolution. This contribution will give an overview of the detector operation, hardware improvements, changes in the monitoring and data quality procedures, to cope with increased ...

  9. Performance environment and nested task constraints influence long jump approach run: a preliminary study.

    Science.gov (United States)

    Panteli, Flora; Smirniotou, Athanasia; Theodorou, Apostolos

    2016-01-01

    The purpose of the study was to investigate possible changes at step pattern and technical performance of the long jump approach run in seven young long jumpers by modifying the performance environment (long jump runway versus track lane) and the nested actions (run-through with take-off versus complete long jump). Our findings suggest that the step pattern and technical aspects of the approach run are affected by environmental context and nested task constraints. In terms of environmental context, it appears that practising the training routine of run-through followed by take-off on the long jump runway allows athletes to simulate competition conditions in terms of step regulation and technical efficacy. The task of run-through followed by take-off on the track lane failed to initiate visual perception, step regulation and technical efficiency at the steps preceding the instant of take-off. In terms of nested task constraints, when run-ups were followed by jump for distance instead of only a take-off, a higher level of consistency was achieved and step regulation was based on perception-action coupling. Practising long jump run-up accuracy at a setting not containing the informational elements of the performance environment fails to develop the key elements of the skill.

  10. Mouth rinsing improves cycling endurance performance during Ramadan fasting in a hot humid environment.

    Science.gov (United States)

    Che Muhamed, Ahmad Munir; Mohamed, Nazirah Gulam; Ismail, Norjana; Aziz, Abdul Rashid; Singh, Rabindarjeet

    2014-04-01

    This study examined the effect of mouth rinsing during endurance cycling in a hot humid environment (32 °C and 75% relative humidity) on athletes in the Ramadan fasted state. Nine trained adolescent male cyclists completed 3 trials that consisted of a carbohydrate mouth-rinse (CMR), a placebo mouth-rinse (PMR), and a no-rinse (NOR) trial during the last 2 weeks of Ramadan. Each trial consisted of a preloading cycle at 65% peak rate of oxygen consumption for 30 min followed by a 10-km time trial (TT10 km) under hot humid condition. During the CMR and PMR trials, each cyclist rinsed his mouth with 25 mL of the solution for 5 s before expectorating the solution pre-exercise, after 5, 15, and 25 min of the preloading cycle, and 15 s prior to the start of TT10 km. Time to complete the TT10 km was significantly faster in the CMR and PMR trials compared with the NOR trial (12.9 ± 1.7 and 12.6 ± 1.7 vs. 16.8 ± 1.6 min, respectively; p benefits compared with a no-rinse condition on TT10 km performance in acute Ramadan fasted subjects during endurance cycling in a heat stress environment.

  11. The relationship between customer satisfaction, social responsibility, and long-run financial performance

    Directory of Open Access Journals (Sweden)

    Yi-Chen Wang

    2012-12-01

    Full Text Available This paper investigates the link between long-run corporate financial performance, corporate social responsibility, and customer satisfaction. Using annual financial data, customer satisfaction index, and the Dow Jones Sustainability Index, the paper seeks to establish whether it pays organizations to use ethical methods in striving to be sustainable. Data used for this research cover the period 2001 to 2008. We used dynamic panel data linear regression models to analyze the effect of customer satisfaction and social responsibility on short-run and long-run financial performance. It was found that it may benefit organizations to use ethical methods in pursuing sustainability. since organizations who invest time, money, and effort in corporate social responsibility activities, their good reputations and satisfied customers yield long-term cash flow growth. Keywords: corporate customer satisfaction, Corporate Social Responsibility, corporate financial performance DisciplinesL business studies, international studies, ethics, finance studies

  12. Exercise training reveals trade-offs between endurance performance and immune function, but does not influence growth, in juvenile lizards.

    Science.gov (United States)

    Husak, Jerry F; Roy, Jordan C; Lovern, Matthew B

    2017-04-15

    Acquired energetic resources allocated to a particular trait cannot then be re-allocated to a different trait. This often results in a trade-off between survival and reproduction for the adults of many species, but such a trade-off may be manifested differently in juveniles not yet capable of reproduction. Whereas adults may allocate resources to current and/or future reproduction, juveniles can only allocate to future reproduction. Thus, juveniles should allocate resources toward traits that increase survival and their chances of future reproductive success. We manipulated allocation of resources to performance, via endurance exercise training, to examine trade-offs among endurance capacity, immune function and growth in juvenile green anole lizards. We trained male and female captive anoles on a treadmill for 8 weeks, with increasing intensity, and compared traits with those of untrained individuals. Our results show that training enhanced endurance capacity equally in both sexes, but immune function was suppressed only in females. Training had no effect on growth, but males had higher growth rates than females. Previous work showed that trained adults have enhanced growth, so juvenile growth is either insensitive to stimulation with exercise, or they are already growing at maximal rates. Our results add to a growing body of literature indicating that locomotor performance is an important part of life-history trade-offs that are sex and age specific. © 2017. Published by The Company of Biologists Ltd.

  13. No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes

    Science.gov (United States)

    Wolfarth, Bernd; Wang, Guan; Sarzynski, Mark A.; Alexeev, Dmitry G.; Ahmetov, Ildus I.; Boulay, Marcel R.; Cieszczyk, Pawel; Eynon, Nir; Filipenko, Maxim L.; Garton, Fleur C.; Generozov, Edward V.; Govorun, Vadim M.; Houweling, Peter J.; Kawahara, Takashi; Kostryukova, Elena S.; Kulemin, Nickolay A.; Larin, Andrey K.; Maciejewska-Karłowska, Agnieszka; Miyachi, Motohiko; Muniesa, Carlos A.; Murakami, Haruka; Ospanova, Elena A.; Padmanabhan, Sandosh; Pavlenko, Alexander V.; Pyankova, Olga N.; Santiago, Catalina; Sawczuk, Marek; Scott, Robert A.; Uyba, Vladimir V.; Yvert, Thomas; Perusse, Louis; Ghosh, Sujoy; Rauramaa, Rainer; North, Kathryn N.; Lucia, Alejandro; Pitsiladis, Yannis; Bouchard, Claude

    2016-01-01

    There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES) was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners), from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games) and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002), even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0), all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance performance but

  14. No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes.

    Directory of Open Access Journals (Sweden)

    Tuomo Rankinen

    Full Text Available There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners, from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002, even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0, all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance

  15. Muscle morphology of the vastus lateralis is strongly related to ergometer performance, sprint capacity and endurance capacity in Olympic rowers

    NARCIS (Netherlands)

    van der Zwaard, Stephan; Weide, Guido; Levels, Koen; Eikelboom, Michelle R.I.; Noordhof, Dionne A.; Hofmijster, Mathijs J.; van der Laarse, Willem J.; de Koning, Jos J.; de Ruiter, Cornelis J.; Jaspers, Richard T.

    2018-01-01

    Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates

  16. Endurance Training - Science and Practice

    African Journals Online (AJOL)

    I have always had an interest in endurance sports and have been fortunate enough to work with endurance athletes while completing my PhD. Professor Mujika is a well-respected scientist who, apart from his research work, consults with many elite endurance athletes. I was surprised at how excited I was to review.

  17. Factores que afectan al rendimiento en carreras de fondo. [Factors affecting long-distance running performance].

    Directory of Open Access Journals (Sweden)

    Ana Ogueta-Alday

    2016-07-01

    and runners are interested on learning about the factors that affect long-distance running performance. Facing this new reality, scientific literature has been concerned about the aforementioned factors, and the amount of studies has considerably grown. Therefore, the purpose of this review is to analyse factors affecting long-distance running performance from different points of view. Literature review was performed through 3 different databases (Medline, SportDiscus and Google Scholar and the factors were classified into 5 main groups, subdivided into different sections: 1- environmental (air/wind, temperature, humidity, altitude and slope of the ground, 2- training-related (endurance, resistance, training in hot environments and in altitude, 3- physiological (VO2max, thersholds, running economy, age, gender, muscle fibre type, fatigue and race, 4- biomechanical (anthropometry, leg-stiffness, flexibility, foot strike pattern, footwear, foot orthoses and spatio-temporal parameters and 5- psychological (intervention strategies, direction of attention and music. Even though the influence of some of these factors on running performance in quite well-known, the influence of some psychological (direction of attention and music and biomechanical factors (foot strike pattern and spatio-temporal parameters is still unclear. There are few studies or the results cannot be generalized. Future studies and the progress of new technologies and measurement tools will provide a better understanding.

  18. Exercise training effects on hypoxic and hypercapnic ventilatory responses in mice selected for increased voluntary wheel running.

    Science.gov (United States)

    Kelly, Scott A; Rezende, Enrico L; Chappell, Mark A; Gomes, Fernando R; Kolb, Erik M; Malisch, Jessica L; Rhodes, Justin S; Mitchell, Gordon S; Garland, Theodore

    2014-02-01

    , did not systematically alter ventilation across all gas concentrations. As with most human studies, our findings support the idea that endurance training (access to wheel running) attenuates resting ventilation. However, little evidence was found for a correlation at the level of the individual variation between ventilatory chemoreflexes and performance (amount of individual voluntary wheel running). We tentatively conclude that exercise 'training' alters respiratory behaviours, but these changes may not be necessary to achieve high levels of wheel running.

  19. Glucose ingestion during endurance training does not alter adaptation

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Fischer, Christian P; Plomgaard, Peter

    2009-01-01

    , 2) lower citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activity and glycogen content in skeletal muscle, and 3) attenuated endurance performance enhancement in the trained state. To investigate this we studied nine male subjects who performed 10 wk of one-legged knee...... extensor training. They trained one leg while ingesting a 6% glucose solution (Glc) and ingested a sweetened placebo while training the other leg (Plc). The subjects trained their respective legs 2 h at a time on alternate days 5 days a week. Endurance training increased peak power (P(max)) and time...

  20. Allometric scaling of body mass in running economy data: An important consideration in modeling marathon performance

    OpenAIRE

    Lundstrom, Christopher John; Biltz, George R.; Snyder, Eric M.; Ingraham, Stacy Jean

    2017-01-01

    The purpose of this study was to compare metabolic variables during submaximal running as predictors of marathon performance. Running economy (RE) and respiratory exchange ratio (RER) data were gathered during a 30 min incremental treadmill run completed within 2 weeks prior to running a 42.2-km marathon. Paces during the treadmill run progressed every 5 min from 75-100% of 10-km race velocity. Variables at each stage were analyzed as predictors of relative marathon performance (RMP) in compe...

  1. Overspeed HIIT in Lower-Body Positive Pressure Treadmill Improves Running Performance.

    Science.gov (United States)

    Gojanovic, Boris; Shultz, Rebecca; Feihl, Francois; Matheson, Gordon

    2015-12-01

    Optimal high-intensity interval training (HIIT) regimens for running performance are unknown, although most protocols result in some benefit to key performance factors (running economy (RE), anaerobic threshold (AT), or maximal oxygen uptake (VO2max)). Lower-body positive pressure (LBPP) treadmills offer the unique possibility to partially unload runners and reach supramaximal speeds. We studied the use of LBPP to test an overspeed HIIT protocol in trained runners. Eleven trained runners (35 ± 8 yr, VO2max, 55.7 ± 6.4 mL·kg⁻¹·min⁻¹) were randomized to an LBPP (n = 6) or a regular treadmill (CON, n = 5), eight sessions over 4 wk of HIIT program. Four to five intervals were run at 100% of velocity at VO2max (vVO2max) during 60% of time to exhaustion at vVO2max (Tlim) with a 1:1 work:recovery ratio. Performance outcomes were 2-mile track time trial, VO2max, vVO2max, vAT, Tlim, and RE. LBPP sessions were carried out at 90% body weight. Group-time effects were present for vVO2max (CON, 17.5 vs. 18.3, P = 0.03; LBPP, 19.7 vs. 22.3 km·h⁻¹; P HIIT protocol at 100% vVO2max improves field performance, vVO2max, VO2max and submaximal HR in trained runners. Improvements are similar if intervals are run on a regular treadmill or at higher speeds on a LPBB treadmill with 10% body weight reduction. LBPP could provide an alternative for taxing HIIT sessions.

  2. Endurance time method for Seismic analysis and design of structures

    International Nuclear Information System (INIS)

    Estekanchi, H.E.; Vafai, A.; Sadeghazar, M.

    2004-01-01

    In this paper, a new method for performance based earthquake analysis and design has been introduced. In this method, the structure is subjected to accelerograms that impose increasing dynamic demand on the structure with time. Specified damage indexes are monitored up to the collapse level or other performance limit that defines the endurance limit point for the structure. Also, a method for generating standard intensifying accelerograms has been described. Three accelerograms have been generated using this method. Furthermore, the concept of Endurance Time has been described by applying these accelerograms to single and multi degree of freedom linear systems. The application of this method for analysis of complex nonlinear systems has been explained. Endurance Time method provides a uniform approach to seismic analysis and design of complex structures that can be applied in numerical and experimental investigations

  3. Cardiac output and performance during a marathon race in middle-aged recreational runners.

    Science.gov (United States)

    Billat, Véronique L; Petot, Hélène; Landrain, Morgan; Meilland, Renaud; Koralsztein, Jean Pierre; Mille-Hamard, Laurence

    2012-01-01

    Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min). Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m(-1)) (r = -0.65, P marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners.

  4. LHCb Particle Identification Strategy and Performance in Run 2

    CERN Multimedia

    Tilley, Matthew James

    2018-01-01

    For Run 2 of LHCb data taking, the selection of PID calibration samples is implemented in the high level trigger. A further processing is needed to provide calibration samples used for the determination the PID performance, which is achieved through a centralised production that makes highly efficient use of LHCb computing resources. This poster presents the major steps of the production procedure and the charged particle PID performance measured using these calibration samples.

  5. ATLAS LAr Calorimeters Performance in LHC Run-2

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2018-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities above 1034 cm−2 s−1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic and forward calorimetry in the region from |η| = 1.5 to |η| = 4.9. In the first LHC run a total luminosity of 27 fb−1 has been collected at center-of-mass energies of 7-8 TeV between year of 2010 to 2012. After a period of detector consolidation during a long shutdown, Run-2 started in 2015 and 3.9 fb-1, 35.6 fb-1 and 46.9 fb-1 of data at a center-of-mass energy of 13 TeV have been recorded up to now per year. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, the number of read-out samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibra...

  6. Effect of Conjugated Linoleic Acid Intake on Endurance Exercise Performance and Anti-fatigue in Student Athletes.

    Science.gov (United States)

    Terasawa, Naoko; Okamoto, Ken; Nakada, Kenta; Masuda, Kazumi

    2017-07-01

    Conjugated linoleic acids (CLA) intake has been reported to reduce body fat mass or increase lean body mass and to improve exercise outcome by modulating testosterone in humans. These reports have studied mostly overweight subjects; few were athletes. Therefore, in this study, the effect of CLA intake on endurance performance and anti-fatigue in student athletes was investigated. A double-blind, crossover study was conducted with 10 male student athletes. Each subject was administered with either CLA (net 0.9 g/day) or a placebo for 14 days. They were subjected to an exercise tolerance test (steady loading) using a cycle ergometer on days 0 and 14. Peak VO 2 was determined for each subject using a graded loading test. The steady loading test was performed with a pedaling exercise load of 50% peak VO 2 for 40 min and then with a load of 70% peak VO 2 until exhaustion. Blood sampling and measurement of critical flicker frequency (CFF) were performed before and after exercise. The rate of perceived exertion (RPE) was measured serially during exercise. In the results, amount of body weight variation significantly increased and amount of body fat percentage variation tended to decrease by CLA intake, it might have an effect by increase in muscle mass. In addition, amount of exercise time variation significantly increased, amount of variation of CFF before and after exercise tended to increase, that of RPE during exercise tended to decrease, and that of creatine phosphokinase before and after exercise tended to decrease in the CLA group. These results suggested that CLA intake for 14 days might have an effect on endurance performance and anti-fatigue in student athletes.

  7. CMS detector tracking performance in Run-II

    CERN Document Server

    Brondolin, Erica

    2017-01-01

    Since the start of Run-II in June 2015, LHC has delivered pp collisions at a center of mass energy of 13TeV and with a bunch time separation of 25 ns. On avarage, more than 25 inelastic collisions are superimposed on the event of interest. Under these new conditions, the CMS collaboration has re-calibrated and verified the performance of the whole detector. In particular, the CMS tracking performance has been measured both directly and indirectly. Direct measurements are, among others, the beam spot determination, the vertex resolution and the muon reconstruction efficiency with the tag and probe technique. An indirect assessment can be given by the pion reconstruction efficiency and the low-mass resonance parameters as a function of different single track kinematics.

  8. Iron Supplementation during Three Consecutive Days of Endurance Training Augmented Hepcidin Levels

    Directory of Open Access Journals (Sweden)

    Aya Ishibashi

    2017-07-01

    Full Text Available Iron supplementation contributes an effort to improving iron status among athletes, but it does not always prevent iron deficiency. In the present study, we explored the effect of three consecutive days of endurance training (twice daily on the hepcidin-25 (hepcidin level. The effect of iron supplementation during this period was also determined. Fourteen male endurance athletes were enrolled and randomly assigned to either an iron-treated condition (Fe condition, n = 7 or a placebo condition (Control condition; CON, n = 7. They engaged in two 75-min sessions of treadmill running at 75% of maximal oxygen uptake on three consecutive days (days 1–3. The Fe condition took 12 mg of iron twice daily (24 mg/day, and the CON condition did not. On day 1, both conditions exhibited significant increases in serum hepcidin and plasma interleukin-6 levels after exercise (p < 0.05. In the CON condition, the hepcidin level did not change significantly throughout the training period. However, in the Fe condition, the serum hepcidin level on day 4 was significantly higher than that of the CON condition (p < 0.05. In conclusion, the hepcidin level was significantly elevated following three consecutive days of endurance training when moderate doses of iron were taken.

  9. Iron Supplementation during Three Consecutive Days of Endurance Training Augmented Hepcidin Levels.

    Science.gov (United States)

    Ishibashi, Aya; Maeda, Naho; Kamei, Akiko; Goto, Kazushige

    2017-07-30

    Iron supplementation contributes an effort to improving iron status among athletes, but it does not always prevent iron deficiency. In the present study, we explored the effect of three consecutive days of endurance training (twice daily) on the hepcidin-25 (hepcidin) level. The effect of iron supplementation during this period was also determined. Fourteen male endurance athletes were enrolled and randomly assigned to either an iron-treated condition (Fe condition, n = 7) or a placebo condition (Control condition; CON, n = 7). They engaged in two 75-min sessions of treadmill running at 75% of maximal oxygen uptake on three consecutive days (days 1-3). The Fe condition took 12 mg of iron twice daily (24 mg/day), and the CON condition did not. On day 1, both conditions exhibited significant increases in serum hepcidin and plasma interleukin-6 levels after exercise ( p < 0.05). In the CON condition, the hepcidin level did not change significantly throughout the training period. However, in the Fe condition, the serum hepcidin level on day 4 was significantly higher than that of the CON condition ( p < 0.05). In conclusion, the hepcidin level was significantly elevated following three consecutive days of endurance training when moderate doses of iron were taken.

  10. Update in the understanding of altitude-induced limitations to performance in team-sport athletes.

    Science.gov (United States)

    Billaut, François; Aughey, Robert J

    2013-12-01

    The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200-2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform consecutive accelerations (CAC) or sprint endurance and thereby change the outcome of a match. The higher the altitude, the more severe the hypoxaemia, and thus, the larger the expected decline in aerobic endurance, CAC and match running performance. Therefore, it is critical for athletes and coaches to understand how arterial hypoxaemia affects aerobic endurance and CAC and the magnitude of decline they may face at altitude for optimal preparation and increased chances of success. This mini review summarises the effects of acute altitude/hypoxia exposure on aerobic endurance, CAC and activity profiles of TS athletes performing in the laboratory and during matches at natural altitude, and analyses the latest findings about the consequences of arterial hypoxaemia on the relationship between peripheral perturbations, neural adjustments and performance during repeated sprints or CAC. Finally, we briefly discuss how altitude training can potentially help athletes prepare for competition at altitude.

  11. Effects of order and sequence of resistance and endurance training on body fat in elementary school-aged girls

    Directory of Open Access Journals (Sweden)

    Ana R. Alves

    2017-12-01

    Full Text Available The purpose of this study was to analyse the effects of order and sequence of concurrent resistance and endurance training on body fat percentage (BFP in a large sample of elementary school-aged girls. One hundred and twenty-six healthy girls, aged 10-11 years (10.95 ± 0.48 years, were randomly assigned to six groups to perform different training protocols per week for 8 weeks: Resistance-only (R, Endurance-only (E, Concurrent Distinct Endurance-Resistance (CDER, Concurrent Parallel Endurance-Resistance (CPER, Concurrent Parallel Resistance-Endurance (CPRE, and a Control group (C. In R and E, the subjects performed single sessions of resistance or endurance exercises, respectively (two days per week. In CDER, resistance-endurance training was performed on different days each week (four days per week. CPER and CPRE performed single-session combined endurance-resistance training or combined resistance-endurance training, respectively, each week (two days per week. After an 8-week training period, BFP decreased in all experimental groups (CPER: 13.3%, p0.05; and CDER: 5.6%, p>0.05. However, a significant difference was found in CPER and CPRE when compared to CDER, E, and R, indicating that training sequence may influence BFP. All programmes were effective, but CPER and CPRE obtained better results for BFP than CDER, E, or R. The effects of concurrent resistance and endurance training on body fat percentage can be mediated by order and sequence of exercise. These results provide insight into optimization of school-based fat loss exercise programmes in childhood.

  12. Accounting for Laminar Run & Trip Drag in Supersonic Cruise Performance Testing

    Science.gov (United States)

    Goodsell, Aga M.; Kennelly, Robert A.

    1999-01-01

    An improved laminar run and trip drag correction methodology for supersonic cruise performance testing was derived. This method required more careful analysis of the flow visualization images which revealed delayed transition particularly on the inboard upper surface, even for the largest trip disks. In addition, a new code was developed to estimate the laminar run correction. Once the data were corrected for laminar run, the correct approach to the analysis of the trip drag became evident. Although the data originally appeared confusing, the corrected data are consistent with previous results. Furthermore, the modified approach, which was described in this presentation, extends prior historical work by taking into account the delayed transition caused by the blunt leading edges.

  13. Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes.

    Science.gov (United States)

    Cox, Pete J; Kirk, Tom; Ashmore, Tom; Willerton, Kristof; Evans, Rhys; Smith, Alan; Murray, Andrew J; Stubbs, Brianna; West, James; McLure, Stewart W; King, M Todd; Dodd, Michael S; Holloway, Cameron; Neubauer, Stefan; Drawer, Scott; Veech, Richard L; Griffin, Julian L; Clarke, Kieran

    2016-08-09

    Ketosis, the metabolic response to energy crisis, is a mechanism to sustain life by altering oxidative fuel selection. Often overlooked for its metabolic potential, ketosis is poorly understood outside of starvation or diabetic crisis. Thus, we studied the biochemical advantages of ketosis in humans using a ketone ester-based form of nutrition without the unwanted milieu of endogenous ketone body production by caloric or carbohydrate restriction. In five separate studies of 39 high-performance athletes, we show how this unique metabolic state improves physical endurance by altering fuel competition for oxidative respiration. Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Energy costs and performance of transfemoral amputees and non-amputees during walking and running: A pilot study.

    Science.gov (United States)

    Mengelkoch, Larry J; Kahle, Jason T; Highsmith, M Jason

    2017-10-01

    Limited information is available concerning the effects of prosthetic foot components on energy costs and ambulatory performance for transfemoral amputees. Compare energy costs (VO 2 ; gait economy) and ambulatory performance (self-selected walking speeds, self-selected running speeds, peak running speeds) differences during walking and running for transfemoral amputees and matched, non-amputee runners. Repeated measures. Transfemoral amputees were accommodated and tested with three prosthetic feet: conventional foot, solid-ankle cushioned heel (SACH); energy storing and return foot, Renegade; and running-specific energy storing and return foot, Nitro. During walking, VO 2 was similar between transfemoral amputees but was increased compared to controls. Self-selected walking speeds were slower for SACH compared to Renegade and Nitro. For transfemoral amputees, gait economy was decreased and self-selected walking speeds were slower compared to controls. During fixed running speeds, transfemoral amputees ran using Nitro, and VO 2 was greater compared to controls. Transfemoral amputees ran at self-selected running speeds using Renegade and Nitro. Self-selected running speeds were slower for Renegade compared to Nitro. For transfemoral amputees, gait economy was decreased and self-selected running speeds were slower compared to controls. VO 2 peak was similar between transfemoral amputees and controls, but controls achieved greater peak running speeds and % grade. Energy costs were greater and ambulatory performance was lower for transfemoral amputees compared to matched, non-amputee controls for all prosthetic foot conditions. Clinical relevance Both types of energy storing and return feet may improve walking performance for transfemoral amputees by providing faster self-selected walking speeds. For transfemoral amputees interested in performing vigorous running (exercise and running competition), clinicians should recommend a running-specific energy storing and

  15. Endurance training increases the efficiency of rat skeletal muscle mitochondria.

    Science.gov (United States)

    Zoladz, Jerzy A; Koziel, Agnieszka; Woyda-Ploszczyca, Andrzej; Celichowski, Jan; Jarmuszkiewicz, Wieslawa

    2016-10-01

    Endurance training enhances mitochondrial oxidative capacity, but its effect on mitochondria functioning is poorly understood. In the present study, the influence of an 8-week endurance training on the bioenergetic functioning of rat skeletal muscle mitochondria under different assay temperatures (25, 35, and 42 °C) was investigated. The study was performed on 24 adult 4-month-old male Wistar rats, which were randomly assigned to either a treadmill training group (n = 12) or a sedentary control group (n = 12). In skeletal muscles, endurance training stimulated mitochondrial biogenesis and oxidative capacity. In isolated mitochondria, endurance training increased the phosphorylation rate and elevated levels of coenzyme Q. Moreover, a decrease in mitochondrial uncoupling, including uncoupling protein-mediated proton leak, was observed after training, which could explain the increased reactive oxygen species production (in nonphosphorylating mitochondria) and enhanced oxidative phosphorylation efficiency. At all studied temperatures, endurance training significantly augmented H2O2 production (and coenzyme Q reduction level) in nonphosphorylating mitochondria and decreased H2O2 production (and coenzyme Q reduction level) in phosphorylating mitochondria. Endurance training magnified the hyperthermia-induced increase in oxidative capacity and attenuated the hyperthermia-induced decline in oxidative phosphorylation efficiency and reactive oxygen species formation of nonphosphorylating mitochondria via proton leak enhancement. Thus, endurance training induces both quantitative and qualitative changes in muscle mitochondria that are important for cell signaling as well as for maintaining muscle energy homeostasis, especially at high temperatures.

  16. Long-Run Nexus between Tax Revenue on Economic Performance: Empirical Evidence from Malaysia

    OpenAIRE

    Roshaiza Taha; Nanthakumar Loganathan

    2014-01-01

    Taxation is main source of government income and has direct linkages with economic performance for most of countries. This study attempts to investigate the long-run nexus between economic performance and tax revenue for Malaysia as a developing nation with dynamic economic progress for the last 2 decades. To determine the long-run nexus, we used the structural breaks effects with the conjunction of ARDL cointegration analysis along with causality analysis. The empirical finding successfully ...

  17. Exercise economy in skiing and running

    Directory of Open Access Journals (Sweden)

    Thomas eLosnegard

    2014-01-01

    Full Text Available Substantial inter-individual variations in exercise economy exist even in highly trained endurance athletes. The variation is believed to be determined partly by intrinsic factors. Therefore, in the present study, we compared exercise economy in V2-skating, double poling and uphill running. Ten highly trained male cross-country skiers (23 ± 3 years, 180 ± 6 cm, 75 ± 8 kg, VO2peak running: 76.3 ± 5.6 mL•kg-1•min-1 participated in the study. Exercise economy and VO2peak during treadmill running, ski skating (V2 technique and double poling were compared based on correlation analysis with subsequent criteria for interpreting the magnitude of correlation (r. There was a very large correlation in exercise economy between V2-skating and double poling (r = 0.81 and a large correlation between V2-skating and running (r = 0.53 and double poling and running (r = 0.58. There were trivial to moderate correlations between exercise economy and VO2peak (r = 0.00-0.23, cycle rate (r = 0.03-0.46, body mass (r = -0.09-0.46 and body height (r = 0.11-0.36. In conclusion, the inter-individual variation in exercise economy could only moderately be explained by differences in VO2peak, body mass and body height and therefore we suggest that other intrinsic factors contribute to the variation in exercise economy between highly trained subjects.

  18. Sensing Athletes: Sensory Dimensions of Recreational Endurance Sports

    Directory of Open Access Journals (Sweden)

    Stefan Groth

    2017-12-01

    Full Text Available Sport has become increasingly popular with recreational athletes over the last couple of decades. This has only gained minimal attention so far from scholars interested in the relations between recreational sports and everyday culture. With this paper, we seek to contribute to this field by scrutinising the sensory dimensions of recreational sport. Rather than probing into or highlighting isolated senses, we look at sensory dimensions understood as a combination of different, non-separable sensory experiences featured in recreational endurance sports. We are interested in how senses play a role for recreational endurance athletes in running, triathlon and cycling both in training and competition. We start by examining how cultural and social dimensions are inextricably linked to doing sports. Secondly, we show how different configurations of the senses and their communicative mediation are contingent on sport disciplines, specific settings, technology, development and change as sensory careers over time. Thirdly, we discuss the kinaesthetic dimensions of doing sports in relation to the senses and the role of atmospheres. We conclude by arguing that highlighting specific senses by athletes is a cultural practice that calls for a holistic analysis of senses in sport, and outline some methodological implications for research on the senses.

  19. Venous hemogasometry of equines finalists in 90 km endurance races

    Directory of Open Access Journals (Sweden)

    Cinthia B.S. Dumont

    2014-06-01

    Full Text Available Front of exercise, the organic systems may suffer water-electrolyte and acid-base imbalances, particularly in the case of blood gases, demonstrating variations from different causes, whether respiratory and/or metabolic. Understanding the physiological adaptations to exercise is essential in the search for the optimum performance. In this way, this study measured the venous blood gases (pO2, pCO2, as well as the oxygen saturation (SatO2 in healthy equines, Arabian horses finalists in 90km endurance races. A total of fourteen Arabian horses were evaluated, nine males and five females, between six and 12 years old, finalists in 90km endurance races. There was a significant reduction in pO2, pCO2 and SatO2 after the exercise, however, the values remained within the normality range, and did not change the athletic performance of the animals, indicating a temporary alteration, assuming thus a character of physiological response to the exercise performed. The equines, finalists in 90 Km endurance races, demonstrated efficient ventilatory process, without any alterations in the athletic performance, being adapted to the type of exercise imposed.

  20. Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review

    Directory of Open Access Journals (Sweden)

    Raúl Domínguez

    2017-01-01

    Full Text Available Athletes use nutritional supplementation to enhance the effects of training and achieve improvements in their athletic performance. Beetroot juice increases levels of nitric oxide (NO, which serves multiple functions related to increased blood flow, gas exchange, mitochondrial biogenesis and efficiency, and strengthening of muscle contraction. These biomarker improvements indicate that supplementation with beetroot juice could have ergogenic effects on cardiorespiratory endurance that would benefit athletic performance. The aim of this literature review was to determine the effects of beetroot juice supplementation and the combination of beetroot juice with other supplements on cardiorespiratory endurance in athletes. A keyword search of DialNet, MedLine, PubMed, Scopus and Web of Science databases covered publications from 2010 to 2016. After excluding reviews/meta-analyses, animal studies, inaccessible full-text, and studies that did not supplement with beetroot juice and adequately assess cardiorespiratory endurance, 23 articles were selected for analysis. The available results suggest that supplementation with beetroot juice can improve cardiorespiratory endurance in athletes by increasing efficiency, which improves performance at various distances, increases time to exhaustion at submaximal intensities, and may improve the cardiorespiratory performance at anaerobic threshold intensities and maximum oxygen uptake (VO2max. Although the literature shows contradictory data, the findings of other studies lead us to hypothesize that supplementing with beetroot juice could mitigate the ergolytic effects of hypoxia on cardiorespiratory endurance in athletes. It cannot be stated that the combination of beetroot juice with other supplements has a positive or negative effect on cardiorespiratory endurance, but it is possible that the effects of supplementation with beetroot juice can be undermined by interaction with other supplements such as caffeine.

  1. Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle

    Science.gov (United States)

    Allen, Michael J.

    2005-01-01

    A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cross-country speed. This report presents a quantitative analysis of a small electric-powered uninhabited air vehicle using updrafts to extend its endurance over a target location. A three-degree-of-freedom simulation of the uninhabited air vehicle was used to determine the yearly effect of updrafts on performance. Surface radiation and rawinsonde balloon measurements taken at Desert Rock, Nevada, were used to determine updraft size, strength, spacing, shape, and maximum height for the simulation. A fixed-width spiral path was used to search for updrafts at the same time as maintaining line-of-sight to the surface target position. Power was used only when the aircraft was flying at the lower-altitude limit in search of updrafts. Results show that an uninhabited air vehicle with a nominal endurance of 2 hours can fly a maximum of 14 hours using updrafts during the summer and a maximum of 8 hours during the winter. The performance benefit and the chance of finding updrafts both depend on what time of day the uninhabited air vehicle is launched. Good endurance and probability of finding updrafts during the year was obtained when the uninhabited air vehicle was launched 30 percent into the daylight hours after sunrise each day. Yearly average endurance was found to be 8.6 hours with these launch times.

  2. RELATIONSHIPS BETWEEN MUSCLE FATIGUE CHARACTERISTICS AND MARKERS OF ENDURANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Martyn G. Morris

    2008-12-01

    Full Text Available The aim of this study was to examine the relationship of a range of in-vivo whole muscle characteristics to determinants of endurance performance. Eleven healthy males completed a cycle ergometer step test to exhaustion for the determination of the lactate threshold, gross mechanical efficiency, peak power and VO2max. On two separate occasions, contractile and fatigue characteristics of the quadriceps femoris were collected using a specially designed isometric strength-testing chair. Muscle fatigue was then assessed by stimulating the muscle for 3 minutes. Force, rate of force development and rates of relaxation were calculated at the beginning and end of the 3 minute protocol and examined for reliability and in relation to lactate threshold, VO2max, gross mechanical efficiency and peak power. Muscle characteristics, rate of force development and relaxation rate were demonstrated to be reliable measures. Force drop off over the 3 minutes (fatigue index was related to lactate threshold (r = -0.72 p < 0.01 but not to VO2max. The rate of force development related to the peak power at the end of the cycle ergometer test (r = -0.75 p < 0.01. Rates of relaxation did not relate to any of the performance markers. We found in-vivo whole muscle characteristics, such as the fatigue index and rate of force development, relate to specific markers of peripheral, but not to central, fitness components. Our investigation suggests that muscle characteristics assessed in this way is reliable and could be feasibly utilised to further our understanding of the peripheral factors underpinning performance

  3. Effects of a 4-week high-intensity interval training on pacing during 5-km running trial

    Directory of Open Access Journals (Sweden)

    R. Silva

    2017-10-01

    Full Text Available This study analyzed the influence of a 4-week high-intensity interval training on the pacing strategy adopted by runners during a 5-km running trial. Sixteen male recreational long-distance runners were randomly assigned to a control group (CON, n=8 or a high-intensity interval training group (HIIT, n=8. The HIIT group performed high-intensity interval-training twice per week, while the CON group maintained their regular training program. Before and after the training period, the runners performed an incremental exercise test to exhaustion to measure the onset of blood lactate accumulation, maximal oxygen uptake (VO2max, and peak treadmill speed (PTS. A submaximal constant-speed test to measure the running economy (RE and a 5-km running trial on an outdoor track to establish pacing strategy and performance were also done. During the 5-km running trial, the rating of perceived exertion (RPE and time to cover the 5-km trial (T5 were registered. After the training period, there were significant improvements in the HIIT group of ∼7 and 5% for RE (P=0.012 and PTS (P=0.019, respectively. There was no significant difference between the groups for VO2max (P=0.495 or onset of blood lactate accumulation (P=0.101. No difference was found in the parameters measured during the 5-km trial before the training period between HIIT and CON (P>0.05. These findings suggest that 4 weeks of HIIT can improve some traditional physiological variables related to endurance performance (RE and PTS, but it does not alter the perception of effort, pacing strategy, or overall performance during a 5-km running trial.

  4. Effect of ultra-endurance exercise on left ventricular performance and plasma cytokines in healthy trained men

    Directory of Open Access Journals (Sweden)

    K Krzemiński

    2016-01-01

    Full Text Available The purpose of this study was to investigate the effect of ultra-endurance exercise on left ventricular (LV performance and plasma concentration of interleukin (IL-6, IL-10, IL-18 and tumour necrosis factoralpha (TNF-IX as well as to examine the relationships between exercise-induced changes in plasma cytokines and those in echocardiographic indices of LV function in ultra-marathon runners. Nine healthy trained men (mean age 3011.0 years participated in a 100-km ultra-marathon. Heart rate, blood pressure, ejection fraction (EF, fractional shortening (FS, ratio of early (E to late (A mitral inflow peak velocities (E/A, ratio of early (E' to late (A' diastolic mitral annulus peak velocities (E‘/A’ and E-wave deceleration time (DT were obtained by echocardiography before, immediately after and in the 90th minute of the recovery period. Blood samples were taken before each echocardiographic evaluation. The ultra-endurance exercise caused significant increases in plasma IL-6, IL-10, IL-18 and TNF-α. Echocardiography revealed significant decreases in both E and the E/A ratio immediately after exercise, without any significant changes in EF, FS, DT or the E/E’ ratio. At the 90th minute of the recovery period, plasma TNF-or and the E/A ratio did not differ significantly from the pre-exercise values, whereas FS was significantly lower than before and immediately after exercise. The increases in plasma TNF-or correlated with changes in FS (r=0.73 and DT (r=-0.73. It is concluded that ultra-endurance exercise causes alterations in LV diastolic function. The present data suggest that TNF-or might be involved in this effect.

  5. Muscular strength and endurance and cardio-metabolic health in disadvantaged Hispanic children from the U.S.

    Directory of Open Access Journals (Sweden)

    Ryan D. Burns

    2017-03-01

    Full Text Available The predictive relationship between muscular strength and endurance and cardio-metabolic health, independent from aerobic fitness, is not clear in disadvantaged Hispanic children. The purpose of this study was to examine the predictive relationship between muscular strength and endurance and clustered cardio-metabolic risk, controlling for aerobic fitness, in Hispanic children from low-income schools. Participants were 320 Hispanic children (Mean age = 10.1 ± 1.1 years; 164 girls, 156 boys recruited during the 2014–2015 and 2015–2016 academic years from five low-income schools from the state of Utah in the U.S. Muscular strength and endurance was assessed using the push-up and curl-up tests and estimated VO2 Peak was calculated from the Progressive Aerobic Cardiovascular Endurance Run. A clustered metabolic syndrome composite score (MetS was calculated from cardio-metabolic health measurements consisting of HDL cholesterol, triglycerides, waist circumference, blood glucose, and mean arterial pressure (MAP. Multi-level general linear mixed effects models were used to examine the predictive relationship between muscular strength and endurance and MetS, controlling for the effect of aerobic fitness and the clustering of children within classrooms and schools. Children who were in the middle and upper tertiles for muscular strength and endurance associated with a lower (more favorable MetS score (middle tertile: β = −2.59, 95% C.I. [−4.23, −0.95], p < 0.05; upper tertile: β = −1.57, 95% C.I. [−3.20, −0.16], p < 0.05. The results suggest that higher levels of muscular strength and endurance relate to lower cardio-metabolic risk, independent of aerobic fitness, in Hispanic children from low-income schools.

  6. RAPPORT: running scientific high-performance computing applications on the cloud.

    Science.gov (United States)

    Cohen, Jeremy; Filippis, Ioannis; Woodbridge, Mark; Bauer, Daniela; Hong, Neil Chue; Jackson, Mike; Butcher, Sarah; Colling, David; Darlington, John; Fuchs, Brian; Harvey, Matt

    2013-01-28

    Cloud computing infrastructure is now widely used in many domains, but one area where there has been more limited adoption is research computing, in particular for running scientific high-performance computing (HPC) software. The Robust Application Porting for HPC in the Cloud (RAPPORT) project took advantage of existing links between computing researchers and application scientists in the fields of bioinformatics, high-energy physics (HEP) and digital humanities, to investigate running a set of scientific HPC applications from these domains on cloud infrastructure. In this paper, we focus on the bioinformatics and HEP domains, describing the applications and target cloud platforms. We conclude that, while there are many factors that need consideration, there is no fundamental impediment to the use of cloud infrastructure for running many types of HPC applications and, in some cases, there is potential for researchers to benefit significantly from the flexibility offered by cloud platforms.

  7. Analysis of Running and Technical Performance in Substitute Players in International Male Rugby Union Competition.

    Science.gov (United States)

    Lacome, Mathieu; Piscione, Julien; Hager, Jean-Philippe; Carling, Christopher

    2016-09-01

    To investigate the patterns and performance of substitutions in 18 international 15-a-side men's rugby union matches. A semiautomatic computerized time-motion system compiled 750 performance observations for 375 players (422 forwards, 328 backs). Running and technical-performance measures included total distance run, high-intensity running (>18.0 km/h), number of individual ball possessions and passes, percentage of passes completed, and number of attempted and percentage of successful tackles. A total of 184 substitutions (85.2%) were attributed to tactical and 32 (14.8%) to injury purposes respectively. The mean period for non-injury-purpose substitutions in backs (17.7%) occurred between 70 and 75 min, while forward substitutions peaked equally between 50-55 and 60-65 min (16.4%). Substitutes generally demonstrated improved running performance compared with both starter players who completed games and players whom they replaced (small differences, ES -0.2 to 0.5) in both forwards and backs over their entire time played. There was also a trend for better running performance in forward and back substitutes over their first 10 min of play compared with the final 10 min for replaced players (small to moderate differences, ES 0.3-0.6). Finally, running performance in both forward and back substitutes was generally lower (ES -0.1 to 0.3, unclear or small differences) over their entire 2nd-half time played compared with their first 10 min of play. The impact of substitutes on technical performance was generally considered unclear. This information provides practitioners with practical data relating to the physical and technical contributions of substitutions that subsequently could enable optimization of their impact on match play.

  8. Status and performance of the CMS muon system in Run2

    CERN Document Server

    Cabrera Mora, Andres Leonardo

    2016-01-01

    The CMS muon system has played a key role for many physics results obtained from the LHC Run1 and Run2 data. During the Long Shutdown (2013-2014), as well as during the last year-end technical stop (2015-2016), significant consolidation and upgrades have been carried out on the muon detectors and on the Level-1 (L1) muon trigger. The algorithms for muon reconstruction and identification have also been improved for both the High-Level Trigger (HLT) and the offline reconstruction. Results of the performance of muon detectors, reconstruction and trigger, obtained using data collected at 13 TeV center-of-mass energy during the 2015 and 2016 LHC runs, are presented. Comparison of simulation with experimental data is also discussed where relevant. The system's state of the art is also shown, as well the improvements foreseen to achieve excellent overall quality of muon reconstruction in the high-luminosity conditions expected during Run2.

  9. Performance of the ATLAS Liquid Argon Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Benitez, Jose; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{-2}$ s${^-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|<3.2$, and for hadronic calorimetry in the region from $|\\eta|=1.5$ to $|\\eta|=4.9$. The calibration and performance of the LAr calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb$^{-1}$ of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the LAr calorimeter operation, monitoring and data quality, as we...

  10. Polarized training has greater impact on key endurance variables than threshold, high intensity or high volume training

    Directory of Open Access Journals (Sweden)

    Thomas eStöggl

    2014-02-01

    Full Text Available Endurance athletes integrate four conditioning concepts in their training programs: high-volume training (HVT, ‘threshold-training’ (THR, high-intensity interval training (HIIT and a combination of these aforementioned concepts known as polarized training (POL. The purpose of this study was to explore which of these four training concepts provides the greatest response on key components of endurance performance in well-trained endurance athletes. Methods: Forty eight runners, cyclists, triathletes and cross-country skiers (peak oxygen uptake: (VO2peak: 62.6±7.1 mL∙min-1∙kg-1 were randomly assigned to one of four groups performing over nine weeks. An incremental test, work economy and a VO2peak tests were performed. Training intensity was heart rate controlled. Results: POL demonstrated the greatest increase in VO2peak (+6.8 ml∙min∙kg-1 or 11.7%, P0.05. Conclusion: POL resulted in the greatest improvements in most key variables of endurance performance in well-trained endurance athletes. THR or HVT did not lead to further improvements in performance related variables.

  11. Cardiac Output and Performance during a Marathon Race in Middle-Aged Recreational Runners

    OpenAIRE

    Billat, Véronique L.; Petot, Hélène; Landrain, Morgan; Meilland, Renaud; Koralsztein, Jean Pierre; Mille-Hamard, Laurence

    2012-01-01

    Purpose. Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). Methods. We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maxima...

  12. Mental toughness latent profiles in endurance athletes.

    Science.gov (United States)

    Zeiger, Joanna S; Zeiger, Robert S

    2018-01-01

    Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female). Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ), Psychological Performance Inventory-Alternative (PPI-A), and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE). A three-class solution emerged, designated as high mental toughness (High MT), moderate mental toughness (Moderate MT) and low mental toughness (Low MT). ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; Pathletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; Pathletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  13. Single muscle fiber gene expression with run taper.

    Directory of Open Access Journals (Sweden)

    Kevin Murach

    Full Text Available This study evaluated gene expression changes in gastrocnemius slow-twitch myosin heavy chain I (MHC I and fast-twitch (MHC IIa muscle fibers of collegiate cross-country runners (n = 6, 20±1 y, VO₂max = 70±1 ml•kg-1•min-1 during two distinct training phases. In a controlled environment, runners performed identical 8 kilometer runs (30:18±0:30 min:s, 89±1% HRmax while in heavy training (∼72 km/wk and following a 3 wk taper. Training volume during the taper leading into peak competition was reduced ∼50% which resulted in improved race times and greater cross-section and improved function of MHC IIa fibers. Single muscle fibers were isolated from pre and 4 hour post run biopsies in heavily trained and tapered states to examine the dynamic acute exercise response of the growth-related genes Fibroblast growth factor-inducible 14 (FN14, Myostatin (MSTN, Heat shock protein 72 (HSP72, Muscle ring-finger protein-1 (MURF1, Myogenic factor 6 (MRF4, and Insulin-like growth factor 1 (IGF1 via qPCR. FN14 increased 4.3-fold in MHC IIa fibers with exercise in the tapered state (P<0.05. MSTN was suppressed with exercise in both fiber types and training states (P<0.05 while MURF1 and HSP72 responded to running in MHC IIa and I fibers, respectively, regardless of training state (P<0.05. Robust induction of FN14 (previously shown to strongly correlate with hypertrophy and greater overall transcriptional flexibility with exercise in the tapered state provides an initial molecular basis for fast-twitch muscle fiber performance gains previously observed after taper in competitive endurance athletes.

  14. Mental toughness latent profiles in endurance athletes.

    Directory of Open Access Journals (Sweden)

    Joanna S Zeiger

    Full Text Available Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female. Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ, Psychological Performance Inventory-Alternative (PPI-A, and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE. A three-class solution emerged, designated as high mental toughness (High MT, moderate mental toughness (Moderate MT and low mental toughness (Low MT. ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; P<0.001, athletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; P<0.01, high sports satisfaction (OR = 8.17; 95% CI, 5.63, 11.87; P<0.001, and high division placement (OR = 2.18; 95% CI, 1.46,3.26; P<0.001. The data showed that mental toughness latent profiles exist in endurance athletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  15. Running on Empty: Leptin Signaling in VTA Regulates Reward from Physical Activity.

    Science.gov (United States)

    Chen, Zuxin; Kenny, Paul J

    2015-10-06

    Hunger increases physical activity and stamina to support food-directed foraging behaviors, but underlying mechanisms are unclear. In this issue, Fernandes et al. (2015) show that disruption of leptin-regulated STAT3 signaling in midbrain dopamine neurons increases the rewarding effects of running in mice, which could explain the "high" experienced by endurance runners. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. ATLAS LAr calorimeter performance and LHC Run-2 commissioning

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00366625; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was built to study proton-proton collisions produced by the Large Hadron Collider (LHC) at a center of mass energy of up to 14 TeV. The Liquid Argon (LAr) calorimeters are used for all electromagnetic calorimetry as well as the hadronic calorimetry in the endcap and forward regions. They have shown excellent performance during the first LHC data taking campaign, from 2010 to 2012, so-called Run 1, at a peak luminosity of $8 \\times 10^{33} \\text{cm}^{-2}\\text{s}^{-1}$. During the next run, peak luminosities of $1.5 \\times 10^{34} \\text{cm}^{-2}\\text{s}^{-1}$ and even higher are expected at a 25ns bunch spacing. Such a high collision rate may have an impact on the quality of the energy reconstruction which is attempted to be maintained at a high level using a calibration procedure described in this contribution. It also poses major challenges to the first level of the trigger system which is constrained to a maximal rate of 100 kHz. For Run-3, scheduled to start in 2019, instantaneous luminos...

  17. Energy Monitoring and Control Systems--Performance Verification and Endurance Test Procedures.

    Science.gov (United States)

    1982-12-01

    EM-; tK2 s) trave h.en loadted in qvstem sit ~rp sm:l , o,1 ti-’.~ -1 rouiitthe factoz’, lest. E.VEF.NT Comnmwid the system to display the status of...contractor correction of all outstanding deficiencies . 163 TEST NO: END-i Page I of 1 OBJECTIVE: To demonstrate EMCS normal mode operation 24 TITLE: Endurance

  18. 14 CFR 33.49 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 33.49 Section 33.49... STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.49 Endurance test. (a) General. Each engine must be subjected to an endurance test that includes a total of 150 hours of operation...

  19. Concurrent Development of Endurance Capacity and Explosiveness: Training Characteristics of World-Class Nordic-Combined Athletes.

    Science.gov (United States)

    Tønnessen, Espen; Rasdal, Vegard; Svendsen, Ida S; Haugen, Thomas A; Hem, Erlend; Sandbakk, Øyvind

    2016-07-01

    Performing at an elite level in Nordic combined (NC) requires both the explosiveness required for ski jumping performance and the endurance capacity required for cross-country skiing. To describe the characteristics of world-class NC athletes' training and determine how endurance and non-endurance (ie, strength, power, and ski jumping) training is periodized. Annual training characteristics and the periodization of endurance and non-endurance training were determined by analyzing the training diaries of 6 world-class NC athletes. Of 846 ± 72 annual training hours, 540 ± 37 h were endurance training, with 88.6% being low-, 5.9% moderate-, and 5.5% high-intensity training. While training frequency remained relatively constant, the total training volume was reduced from the general preparatory to the competition phase, primarily due to less low- and moderate-intensity training (P ski-jump-specific training (908 ± 165 ski jumps and ski-jump imitations). The proportion of non-endurance training increased significantly toward the competition phase (P ski-jump training. These data provide novel insight on how successful athletes execute their training and may facilitate more-precise coaching of future athletes in this sport. In addition, this information is of high relevance for the training organization of other sports that require optimization of 2 fundamentally different physical capacities.

  20. Reduced satellite cell numbers and myogenic capacity in aging can be alleviated by endurance exercise.

    Directory of Open Access Journals (Sweden)

    Gabi Shefer

    2010-10-01

    Full Text Available Muscle regeneration depends on satellite cells, myogenic stem cells that reside on the myofiber surface. Reduced numbers and/or decreased myogenic aptitude of these cells may impede proper maintenance and contribute to the age-associated decline in muscle mass and repair capacity. Endurance exercise was shown to improve muscle performance; however, the direct impact on satellite cells in aging was not yet thoroughly determined. Here, we focused on characterizing the effect of moderate-intensity endurance exercise on satellite cell, as possible means to attenuate adverse effects of aging. Young and old rats of both genders underwent 13 weeks of treadmill-running or remained sedentary.Gastrocnemius muscles were assessed for the effect of age, gender and exercise on satellite-cell numbers and myogenic capacity. Satellite cells were identified in freshly isolated myofibers based on Pax7 immunostaining (i.e., ex-vivo. The capacity of individual myofiber-associated cells to produce myogenic progeny was determined in clonal assays (in-vitro. We show an age-associated decrease in satellite-cell numbers and in the percent of myogenic clones in old sedentary rats. Upon exercise, there was an increase in myofibers that contain higher numbers of satellite cells in both young and old rats, and an increase in the percent of myogenic clones derived from old rats. Changes at the satellite cell level in old rats were accompanied with positive effects on the lean-to-fat Gast muscle composition and on spontaneous locomotion levels. The significance of these data is that they suggest that the endurance exercise-mediated boost in both satellite numbers and myogenic properties may improve myofiber maintenance in aging.

  1. 14 CFR 33.87 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 33.87 Section 33.87... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.87 Endurance test. (a) General. Each engine must be subjected to an endurance test that includes a total of at least 150 hours of operation...

  2. Personal best marathon time and longest training run, not anthropometry, predict performance in recreational 24-hour ultrarunners.

    Science.gov (United States)

    Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas; Lepers, Romuald

    2011-08-01

    In recent studies, a relationship between both low body fat and low thicknesses of selected skinfolds has been demonstrated for running performance of distances from 100 m to the marathon but not in ultramarathon. We investigated the association of anthropometric and training characteristics with race performance in 63 male recreational ultrarunners in a 24-hour run using bi and multivariate analysis. The athletes achieved an average distance of 146.1 (43.1) km. In the bivariate analysis, body mass (r = -0.25), the sum of 9 skinfolds (r = -0.32), the sum of upper body skinfolds (r = -0.34), body fat percentage (r = -0.32), weekly kilometers ran (r = 0.31), longest training session before the 24-hour run (r = 0.56), and personal best marathon time (r = -0.58) were related to race performance. Stepwise multiple regression showed that both the longest training session before the 24-hour run (p = 0.0013) and the personal best marathon time (p = 0.0015) had the best correlation with race performance. Performance in these 24-hour runners may be predicted (r2 = 0.46) by the following equation: Performance in a 24-hour run, km) = 234.7 + 0.481 (longest training session before the 24-hour run, km) - 0.594 (personal best marathon time, minutes). For practical applications, training variables such as volume and intensity were associated with performance but not anthropometric variables. To achieve maximum kilometers in a 24-hour run, recreational ultrarunners should have a personal best marathon time of ∼3 hours 20 minutes and complete a long training run of ∼60 km before the race, whereas anthropometric characteristics such as low body fat or low skinfold thicknesses showed no association with performance.

  3. Shoulder Girdle Muscles Endurance in Subjects with and without Impingement Syndrome

    Directory of Open Access Journals (Sweden)

    Afsoun Nodehi-Moghadam

    2011-07-01

    Full Text Available Objective: Any minimal alteration in performance and coordination of scapular and glenohumeral muscles has the potential to lead to shoulder joint dysfunction. The impingement syndrome has been reported as is the most common diagnosis of shoulder pain. The purpose of this study was to determine whether endurance deficits could be detected in patients with shoulder impingement. Materials & Methods: By convenient sampling 15 patients with impingement syndrome at average of 45.3 years of age and 15 healthy persons (age 45.8 years through a case–control design participated in the study. Endurance of glenohumeral and scapulothoracic muscles were tested with a hand held dynamometer. Independent t–test was used to statistically analyze different groups. Results: Compared to non–impaired subjects, those with impingement syndrome demonstrated a significantly lower endurance of external rotation, scaption and scapular abduction and upward rotation movements (P<0.05. In impingement syndrome patients, the external–to–internal rotator muscles endurance ratio was significantly lower than the control group (P<0.05. Conclusion: The result of the study suggests that endurance deficit of rotator cuff and scapular upward rotator muscles may be an important aspect of the impingement syndrome. Shoulder girdle muscles endurance should be considered in evaluation and physical therapy of impingement syndrome patients.

  4. 14 CFR 35.39 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 35.39 Section 35.39... STANDARDS: PROPELLERS Tests and Inspections § 35.39 Endurance test. Endurance tests on the propeller system... propellers must be subjected to one of the following tests: (1) A 50-hour flight test in level flight or in...

  5. Relationships between triathlon performance and pacing strategy during the run in an international competition.

    Science.gov (United States)

    Le Meur, Yann; Bernard, Thierry; Dorel, Sylvain; Abbiss, Chris R; Honnorat, Gérard; Brisswalter, Jeanick; Hausswirth, Christophe

    2011-06-01

    The purpose of the present study was to examine relationships between athlete's pacing strategies and running performance during an international triathlon competition. Running split times for each of the 107 finishers of the 2009 European Triathlon Championships (42 females and 65 males) were determined with the use of a digital synchronized video analysis system. Five cameras were placed at various positions of the running circuit (4 laps of 2.42 km). Running speed and an index of running speed variability (IRSVrace) were subsequently calculated over each section or running split. Mean running speed over the first 1272 m of lap 1 was 0.76 km·h-1 (+4.4%) and 1.00 km·h-1 (+5.6%) faster than the mean running speed over the same section during the three last laps, for females and males, respectively (P international competitions, even if high levels of motivation and direct opponents lead them to adopt an aggressive strategy.

  6. Effects of age, maturity and body dimensions on match running performance in highly trained under-15 soccer players.

    Science.gov (United States)

    Buchheit, Martin; Mendez-Villanueva, Alberto

    2014-01-01

    The aim of the present study was to compare, in 36 highly trained under-15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n = 115 player-files). Total distance and distance covered >16 km h(-1) (D > 16 km h(-1)) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen's d for MSS: 0.5-1.0, likely to almost certain) and match running performances (D > 16 km h(-1): 0.2-0.5, possibly to likely) than their younger, less mature and/or smaller teammates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures versus match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players' maturity status when assessing their on-field playing performance.

  7. High-intensity endurance training increases nocturnal heart rate variability in sedentary participants

    Directory of Open Access Journals (Sweden)

    A Nummela

    2016-01-01

    Full Text Available The effects of endurance training on endurance performance characteristics and cardiac autonomic modulation during night sleep were investigated during two 4-week training periods. After the first 4-week training period (3 x 40 min per week, at 75% of HRR the subjects were divided into HIGH group (n = 7, who performed three high-intensity endurance training sessions per week; and CONTROL group (n = 8 who did not change their training. An incremental treadmill test was performed before and after the two 4-weektraining periods. Furthermore, nocturnal RR-intervals were recorded after each training day. In the second 4-weektraining period HIGH group increased their V0Zmax (P = 0.005 more than CONTROL group. At the same time, nocturnal HR decreased (P = 0.039 and high-frequency power (HFP increased (P = 0.003 in HIGH group while no changes were observed in CONTROL group. Furthermore, a correlation was observed between the changes in nocturnal HFP and changes in V0Zmax during the second 4-week training period (r = 0.90, P < 0.001. The present study showed that the increased HFP is related to improved VO2max in sedentary subjects suggesting that nocturnal HFP can provide a useful method in monitoring individual responses to endurance training.

  8. Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

    DEFF Research Database (Denmark)

    Aagaard, P; Andersen, J L; Bennekou, M

    2011-01-01

    Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO(2max) ), cycling economy (CE) and long....../short-term endurance capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

  9. Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

    DEFF Research Database (Denmark)

    Aagaard, P; Andersen, J L; Bennekou, M

    2011-01-01

    Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO2max), cycling economy (CE) and long/short-term endurance...... capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

  10. Warm-Up Exercises May Not Be So Important for Enhancing Submaximal Running Performance.

    Science.gov (United States)

    Takizawa, Kazuki; Yamaguchi, Taichi; Shibata, Keisuke

    2018-05-01

    Takizawa, K, Yamaguchi, T, and Shibata, K. Warm-up exercises may not be so important for enhancing submaximal running performance. J Strength Cond Res 32(5): 1383-1390, 2018-The purpose of this study was to determine an appropriate warm-up intensity for enhancing performance in submaximal running at 90% vV[Combining Dot Above]O2max (it assumes 3,000-5,000 m in track events). Seven trained male university athletes took part in this study (age: 21.3 ± 2.1 years, height: 169.3 ± 4.7 cm, body mass: 58.4 ± 5.6 kg, V[Combining Dot Above]O2max: 73.33 ± 5.46 ml·kg·min). Each subject ran on a treadmill at 90% vV[Combining Dot Above]O2max until exhaustion after 1 of 4 warm-up treatments. The 4 warm-up treatments were no warm-up, 15 minutes running at 60% vV[Combining Dot Above]O2max, at 70% vV[Combining Dot Above]O2max, and at 80% vV[Combining Dot Above]O2max. The running performance was evaluated by time to exhaustion (TTE). V[Combining Dot Above]O2, and vastus lateralis muscle temperature were also measured. There were no significant differences in TTE among the warm-up exercises (p > 0.05). V[Combining Dot Above]O2 in no warm-up showed slower reaction than the other warm-up exercises. Regarding, the vastus lateralis muscle temperature immediately after warm-up, no warm-up was significantly (p warm-up exercises. Our results suggested that submaximal running performance was not affected by the presence or absence of a warm-up or by warm-up intensity, although physiological changes occurred.

  11. Critical evaluation of a badminton-specific endurance test.

    Science.gov (United States)

    Fuchs, Michael; Faude, Oliver; Wegmann, Melissa; Meyer, Tim

    2014-03-01

    To overcome the limitations of traditional 1-dimensional fitness tests in analyzing physiological properties of badminton players, a badminton-specific endurance test (BST) was created. This study aimed at analyzing the influence of various fitness dimensions on BST performance. 18 internationally competing male German badminton players (22.4 ± 3.2 y, 79.2 ± 7.7 kg, 1.84 ± 0.06 m, world-ranking position [WRP] 21-501) completed a straight-sprint test, a change-of-direction speed test, various jump tests (countermovement jump, drop jump, standing long jump), a multistage running test (MST), and the BST. During this on-court field test players have to respond to a computerized sign indicating direction and speed of badminton-specific movements by moving into the corresponding corners. Significant correlations were found between performance in MST and BST (individual anaerobic threshold [IAT], r = .63, P = .005; maximum velocity [Vmax], r = .60, P = .009). A negative correlation (r = -.59, P = .014) was observed between IAT in BST and drop-jump contact time. No further associations between performance indices could be detected. Apart from a small portion explained by MST results (IAT, R2 = .40; Vmax, R2 = .36), the majority of BST performance cannot be explained by the determined physiological correlates. Moreover, it was impossible to predict the WRP of a player on the basis of BST results (r = -.15, P = .55). Neither discipline-specific performance nor basic physiological properties were appropriately reflected by a BST in elite badminton players. This does not substantiate its validity for regular use as a testing tool. However, it may be useful for monitoring on-court training sessions.

  12. Thermal endurance tests on silicone rubber specimens

    International Nuclear Information System (INIS)

    Warburton, C.

    1977-07-01

    Thermal endurance tests have been performed on a range of silicone rubber specimens at temperature above 300 0 C. It is suggested that the rubber mix A2426, the compound from which Wylfa sealing rings are manufactured, will fail at temperatures above 300 0 C within weeks. Hardness measurements show that this particular rubber performs in a similar manner to Walker's S.I.L./60. (author)

  13. The road to gold: training and peaking characteristics in the year prior to a gold medal endurance performance.

    Science.gov (United States)

    Tønnessen, Espen; Sylta, Øystein; Haugen, Thomas A; Hem, Erlend; Svendsen, Ida S; Seiler, Stephen

    2014-01-01

    To describe training variations across the annual cycle in Olympic and World Champion endurance athletes, and determine whether these athletes used tapering strategies in line with recommendations in the literature. Eleven elite XC skiers and biathletes (4 male; 28±1 yr, 85±5 mL x min(-1) x kg(-1) VO2max, 7 female, 25±4 yr, 73±3 mL x min(-1) x kg(-1) VO2max) reported one year of day-to-day training leading up to the most successful competition of their career. Training data were divided into periodization and peaking phases and distributed into training forms, intensity zones and endurance activity forms. Athletes trained ∼800 h/500 sessions x year(-1), including ∼500 h x year(-1) of sport-specific training. Ninety-four percent of all training was executed as aerobic endurance training. Of this, ∼90% was low intensity training (LIT, below the first lactate threshold) and 10% high intensity training (HIT, above the first lactate threshold) by time. Categorically, 23% of training sessions were characterized as HIT with primary portions executed at or above the first lactate turn point. Training volume and specificity distribution conformed to a traditional periodization model, but absolute volume of HIT remained stable across phases. However, HIT training patterns tended to become more polarized in the competition phase. Training volume, frequency and intensity remained unchanged from pre-peaking to peaking period, but there was a 32±15% (Pphase. The annual training data for these Olympic and World champion XC skiers and biathletes conforms to previously reported training patterns of elite endurance athletes. During the competition phase, training became more sport-specific, with 92% performed as XC skiing. However, they did not follow suggested tapering practice derived from short-term experimental studies. Only three out of 11 athletes took a rest day during the final 5 days prior to their most successful competition.

  14. The road to gold: training and peaking characteristics in the year prior to a gold medal endurance performance.

    Directory of Open Access Journals (Sweden)

    Espen Tønnessen

    Full Text Available To describe training variations across the annual cycle in Olympic and World Champion endurance athletes, and determine whether these athletes used tapering strategies in line with recommendations in the literature.Eleven elite XC skiers and biathletes (4 male; 28±1 yr, 85±5 mL x min(-1 x kg(-1 VO2max, 7 female, 25±4 yr, 73±3 mL x min(-1 x kg(-1 VO2max reported one year of day-to-day training leading up to the most successful competition of their career. Training data were divided into periodization and peaking phases and distributed into training forms, intensity zones and endurance activity forms.Athletes trained ∼800 h/500 sessions x year(-1, including ∼500 h x year(-1 of sport-specific training. Ninety-four percent of all training was executed as aerobic endurance training. Of this, ∼90% was low intensity training (LIT, below the first lactate threshold and 10% high intensity training (HIT, above the first lactate threshold by time. Categorically, 23% of training sessions were characterized as HIT with primary portions executed at or above the first lactate turn point. Training volume and specificity distribution conformed to a traditional periodization model, but absolute volume of HIT remained stable across phases. However, HIT training patterns tended to become more polarized in the competition phase. Training volume, frequency and intensity remained unchanged from pre-peaking to peaking period, but there was a 32±15% (P<.01 volume reduction from the preparation period to peaking phase.The annual training data for these Olympic and World champion XC skiers and biathletes conforms to previously reported training patterns of elite endurance athletes. During the competition phase, training became more sport-specific, with 92% performed as XC skiing. However, they did not follow suggested tapering practice derived from short-term experimental studies. Only three out of 11 athletes took a rest day during the final 5 days prior to

  15. The influence of hypoxic training on preparedness of sportsmen who are specialized in types of endurance

    Directory of Open Access Journals (Sweden)

    Lyudmyla Shesterova

    2014-08-01

    Full Text Available Purpose: to study the problem of the influence of training in conditions of middle mountains and highlands on a functional state and preparedness of sportsmen who are specialized in types of endurance on the basis of the analysis of references. Materials and methods: analysis and synthesis of references. Results: the processing of information allowed to define the extent of influence of training in mountain conditions and in the conditions of an artificial hypoxia on a functional state and sports result of the highly skilled sportsmen who are specialized in types of endurance. Conclusions: it is defined that the correct organization of the training process in middle mountains and highlands allows not only to expand the functionality of organism of runners, but also to improve the technique of run.

  16. Calf Compression Sleeves Change Biomechanics but Not Performance and Physiological Responses in Trail Running

    Directory of Open Access Journals (Sweden)

    Hugo A. Kerhervé

    2017-04-01

    Full Text Available Introduction: The aim of this study was to determine whether calf compression sleeves (CS affects physiological and biomechanical parameters, exercise performance, and perceived sensations of muscle fatigue, pain and soreness during prolonged (~2 h 30 min outdoor trail running.Methods: Fourteen healthy trained males took part in a randomized, cross-over study consisting in two identical 24-km trail running sessions (each including one bout of running at constant rate on moderately flat terrain, and one period of all-out running on hilly terrain wearing either degressive CS (23 ± 2 mmHg or control sleeves (CON, <4 mmHg. Running time, heart rate and muscle oxygenation of the medial gastrocnemius muscle (measured using portable near-infrared spectroscopy were monitored continuously. Muscle functional capabilities (power, stiffness were determined using 20 s of maximal hopping before and after both sessions. Running biomechanics (kinematics, vertical and leg stiffness were determined at 12 km·h−1 at the beginning, during, and at the end of both sessions. Exercise-induced Achilles tendon pain and delayed onset calf muscles soreness (DOMS were assessed using visual analog scales.Results: Muscle oxygenation increased significantly in CS compared to CON at baseline and immediately after exercise (p < 0.05, without any difference in deoxygenation kinetics during the run, and without any significant change in run times. Wearing CS was associated with (i higher aerial time and leg stiffness in running at constant rate, (ii with lower ground contact time, higher leg stiffness, and higher vertical stiffness in all-out running, and (iii with lower ground contact time in hopping. Significant DOMS were induced in both CS and CON (>6 on a 10-cm scale with no difference between conditions. However, Achilles tendon pain was significantly lower after the trial in CS than CON (p < 0.05.Discussion: Calf compression did not modify muscle oxygenation during ~2 h 30

  17. Vibration test and endurance test for HANARO 36-element fuel assembly

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Kim, Heon ll; Chung, Heung June

    1998-06-01

    Vibration test and endurance test for HANARO DU (depleted uranium) 36-element fuel assembly which was fabricated by KAERI were carried out based on the HANARO operation conditions. The endurance test of 22 days was added to the previous 18 days test. The vibration test was performed at various flow rates. Vibration frequency for the 36-element fuel assembly is between 11 to 14.5 Hz. And the maximum vibration displacement is less than 100 μm. From the endurance test result, it can be concluded that the appreciable fretting wear for the 36-element fuel assembly and the hexagonal flow tube was not observed. (author). 4 refs., 5 tabs., 29 figs

  18. SUPER-CAPACITOR APPLICATION IN ELECTRICAL POWER CABLE TESTING FACILITIES IN THERMAL ENDURANCE AND MECHANICAL BRACING TESTS

    Directory of Open Access Journals (Sweden)

    I. V. Oleksyuk

    2015-01-01

    Full Text Available The current-carrying cores of the electrical power cables should be resistant to effects of short-circuit currents whose values depend on the material of the core, its cross-sectional area, cable insulation properties, environment temperature, and the duration of the short-circuit current flow (1 and 3–4 sec. when tested for thermal endurance and mechanical bracing. The facilities for testing the 10 kV aluminum core cables with short-circuit current shall provide mechanical-bracing current 56,82 kA and thermal endurance current 11,16 kA. Although capacitors provide such values of the testing currents to the best advantage, utilizing conventional capacitor-units will involve large expenditures for erecting and  running a separate building. It is expedient to apply super-capacitors qua the electric power supply for testing facilities, as they are capacitors with double-electrical layer and involve the current values of tens of kilo-amperes.The insulation voltage during short-circuit current testing being not-standardized, it is not banned to apply voltages less than 10 kV when performing short-circuit thermal endurance and mechanical bracing tests for electrical power cables of 10 kV. The super-capacitor voltage variation-in-time graph consists of two regions: capacitive and resistive. The capacitive part corresponds to the voltage change consequent on the energy change in the super-capacitors. The resistive part shows the voltage variation due to the active resistance presence in the super-capacitor.The author offers the algorithm determining the number of super capacitors requisite for testing 10 kV-electrical power cables with short-circuit currents for thermal endurance and mechanical bracing. The paper shows that installation of super-capacitors in the facilities testing the cables with short-circuit currents reduces the area needed for the super-capacitors in comparison with conventional capacitors more than by one order of magnitude.

  19. Performance of the ATLAS Muon Trigger in Run 2

    CERN Document Server

    Morgenstern, Marcus; The ATLAS collaboration

    2018-01-01

    Events containing muons in the final state are an important signature for many analyses being carried out at the Large Hadron Collider (LHC), including both standard model measurements and searches for new physics. To be able to study such events, it is required to have an efficient and well-understood muon trigger. The ATLAS muon trigger consists of a hardware based system (Level 1), as well as a software based reconstruction (High Level Trigger). Due to high luminosity and pile up conditions in Run 2, several improvements have been implemented to keep the trigger rate low while still maintaining a high efficiency. Some examples of recent improvements include requiring coincidence hits between different layers of the muon spectrometer, improvements for handling overlapping muons, and optimised muon isolation. We will present an overview of how we trigger on muons, recent improvements, and the performance of the muon trigger in Run 2 data.

  20. Improving co-running program’s performance on CMP

    Directory of Open Access Journals (Sweden)

    Tian Dawei

    2017-01-01

    Full Text Available Chip multi-processor (CMP has become the most common processor in the current cluster and desktop computer, and it is also the current development direction. On CMP, programs usually co-running with each other. However, programs commonly interfere with each other. Some time the interference takes big effect, which cause serious drop down of performance. In order to avoid the serious performance interference, programs should be scheduled reasonably to different socket to improve the program’s performance and system’s utilization. In this paper we propose a new scheduling method to realize a more reasonable scheduling. We do not only consider the LLC miss rate, but also consider the LLC reference of the programs. By the information of LLC reference and LLC miss rate, we schedule programs to different sockets, which realize a reasonable scheduling. The experiment result show that making use of the scheduling method proposed by our paper, program’s performance can improve 4%, because the performance improve is realized by on-chip resource, which is a big contribution.

  1. Metabolic responses to prolonged work during treadmill and water immersion running.

    Science.gov (United States)

    Frangolias, D D; Rhodes, E C; Taunton, J E; Belcastro, A N; Coutts, K D

    2000-12-01

    The primary aim of this study was to compare the physiological responses to prolonged treadmill (TM) and water immersion to the neck (WI) running at threshold intensity. Ten endurance runners performed TM and WI running VO2max tests. Subjects completed submaximal performance tests at ventilatory threshold (Tvent) intensities under TM and WI conditions and responses at 15 and 42 minutes examined. VO2 was lower in WI (p<0.05) at maximal effort and Tvent. The Tvent VO2 intensities interpolated from the TM and WI VO2max tests were performed in both TM (i.e., TM@TM(tvent),TM@WI(tvent), corresponding to 77.6 and 71.3% respectively of TM VO2max) and WI conditions (i.e., WI@TM(tvent), WI@WI(tvent), corresponding to 85.5% and 78.2% respectively of WI VO2max). Each of the dependent variables was analyzed using a 3-way repeated measures ANOVA (2 conditions X 2 exercise intensities X 7 time points during exercise). VO2max values were significantly lower in the WI (52.4(5.1) ml.kg(-1) min(-1)) versus TM (59.7(6.5) ml.kg(-1) min(-1)) condition. VO2 during submaximal tests were similar during the TM and WI conditions. HR and [BLa] responses to exercise at and above WI(tvent) were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition. There were no statistical differences in VE responses in the 2 conditions, however as with HR and [BLa] an upward trend was noted with TM exercise over the 42 minute duration of the tests. RPE at WI(tvent) was similar for TM and WI exercise sessions, however, RPE at TM(tvent) was higher during WI compared to TM running. Cardiovascular drift was observed during prolonged TM but not WI running. Results suggest differences in metabolic responses to prolonged submaximal exercise in WI, however it can be used effectively for cross training.

  2. Telomere length and long-term endurance exercise: does exercise training affect biological age? A pilot study.

    Directory of Open Access Journals (Sweden)

    Ida Beate Ø Østhus

    Full Text Available BACKGROUND: Telomeres are potential markers of mitotic cellular age and are associated with physical ageing process. Long-term endurance training and higher aerobic exercise capacity (VO(2max are associated with improved survival, and dynamic effects of exercise are evident with ageing. However, the association of telomere length with exercise training and VO(2max has so far been inconsistent. Our aim was to assess whether muscle telomere length is associated with endurance exercise training and VO(2max in younger and older people. METHODS: Twenty men; 10 young (22-27 years and 10 old (66-77 years, were studied in this cross-sectional study. Five out of 10 young adults and 5 out of 10 older were endurance athletes, while other halves were exercising at a medium level of activity. Mean telomere length was measured as telomere/single copy gene-ratio (T/S-ratio using quantitative real time polymerase chain reaction. VO(2max was measured directly running on a treadmill. RESULTS: Older endurance trained athletes had longer telomere length compared with older people with medium activity levels (T/S ratio 1.12±0.1 vs. 0.92±0.2, p = 0.04. Telomere length of young endurance trained athletes was not different than young non-athletes (1.47±0.2 vs. 1.33±0.1, p = 0.12. Overall, there was a positive association between T/S ratio and VO(2max (r = 0.70, p = 0.001. Among endurance trained athletes, we found a strong correlation between VO(2max and T/S ratio (r = 0.78, p = 0.02. However, corresponding association among non-athlete participants was relatively weak (r = 0.58, p = 0.09. CONCLUSION: Our data suggest that VO(2max is positively associated with telomere length, and we found that long-term endurance exercise training may provide a protective effect on muscle telomere length in older people.

  3. The Growth Story: Canada's Long-run Economic Performance and Prospects

    OpenAIRE

    Peter J. Nicholson

    2003-01-01

    In this lead article, Peter Nicholson, who until recently served as advisor to the Secretary General at the OECD and is currently serving as policy advisor to the Prime Minister, Paul Martin, discusses the long-run economic performance, prospects in Canada, and policy priorities based on the framework and insights that emerged from the recent study of economic growth released by the OECD. He argues that Canada has performed remarkably well since the mid-1990s, and that by the pro-growth polic...

  4. Changes in Running Economy, Respiratory Exchange Ratio and VO2max in Runners following a 10-day Altitude Training Camp.

    Science.gov (United States)

    Diebel, Sebastian R; Newhouse, Ian; Thompson, David S; Johnson, Vineet B K

    2017-01-01

    Running economy (RE) and VO 2 max are important predictors of endurance performance for elite and semi-elite endurance athletes, with RE being an appropriate predictor in a homogenous running population. Altitude training has been observed to change RE (mL.kg -1 .min -1 ), and VO 2 max due to alterations resulting from acclimatization. This study tracked changes in RE and VO 2 max before and after a 10-day altitude training camp at 1828 meters. VO 2 max, RE expressed calorically, and respiratory exchange ratio (RER), were measured below anaerobic threshold (AT) to observe differences between pre-and post-altitude training. Eight varsity cross-country runners between the ages of 18 and 22 years performed an incremental treadmill test, pre- and post-10-day altitude training. Paired samples t-tests were used to statistically analyze the data. Average RE (VO 2 mL.kg -1 .min -1 ) improved following altitude intervention ( M = 56.44 ± 4.28) compared to pre-altitude training (61.30 ± 7.56). These differences were statistically significant t ( 7 )= 2.71, p =.014. RE expressed as kcals.kg -1 .km -1 improved following altitude training (16.73 ± 2.96) compared to (18.44 ± 4.04) pre-altitude training and was statistically significant t( 7 ) =3.08, p = .008. RER taken during the last minute of steady-state was higher (0.97, ± .019) post-altitude training, compared to (0.90 ± .043) pre-altitude. These differences were statistically significant t ( 7 ) -3.62, p =.008. VO 2 max (mL.kg -1 .min -1 ) was lower in 6 out of 8 participants (63.91, ± 8.65) post-altitude compared to (69.90, ± 10.80) pre-altitude and was statistically significant t( 7 ) = 2.33, p =.026. The observed improvements in RE may be beneficial for endurance athletes competing and/or training at moderate altitudes near 1828 meters.

  5. Increasing Endurance by Building Fluency: Precision Teaching Attention Span.

    Science.gov (United States)

    Binder, Carl; And Others

    1990-01-01

    Precision teaching techniques can be used to chart students' attention span or endurance. Individual differences in attention span can then be better understood and dealt with effectively. The effects of performance duration on performance level, on error rates, and on learning rates are discussed. Implications for classroom practice are noted.…

  6. Effects of Marathon Running on Aerobic Fitness and Performance in Recreational Runners One Week after a Race

    OpenAIRE

    Takayama, Fuminori; Aoyagi, Atsushi; Shimazu, Wataru; Nabekura, Yoshiharu

    2017-01-01

    It is not clear whether or not recreational runners can recover aerobic fitness and performance within one week after marathon running. This study aimed to investigate the effects of running a marathon race on aerobic fitness and performance one week later. Eleven recreational runners (six men, five women) completed the race in 3 h 36 min 20 s ± 41 min 34 s (mean ± standard deviation). Before and 7 days after the race, they performed a treadmill running test. Perceived muscle soreness was ass...

  7. Run don't walk: locomotor performance of geckos on wet substrates.

    Science.gov (United States)

    Stark, Alyssa Y; Ohlemacher, Jocelyn; Knight, Ashley; Niewiarowski, Peter H

    2015-08-01

    The gecko adhesive system has been under particular scrutiny for over a decade, as the field has recently attracted attention for its application to bio-inspired design. However, little is known about how the adhesive system behaves in ecologically relevant conditions. Geckos inhabit a variety of environments, many of which are characterized by high temperature, humidity and rain. The van der Waals-based gecko adhesive system should be particularly challenged by wet substrates because water can disrupt the intimate contact necessary for adhesion. While a few previous studies have focused on the clinging ability of geckos on wet substrates, we tested a dynamic performance characteristic, sprint velocity. To better understand how substrate wettability and running orientation affect locomotor performance of multiple species on wet substrates, we measured average sprint velocity of five species of gecko on substrates that were either hydrophilic or intermediately wetting and oriented either vertically or horizontally. Surprisingly, we found no indication that wet substrates impact average sprint velocity over 1 m, and rather, in some species, sprint velocity was increased on wet substrates rather than reduced. When investigating physical characteristics and behavior that may be associated with running on wet substrates, such as total number of stops, slips and wet toes at the completion of a race, we found that there may be habitat-related differences between some species. Our results show that in general, unlike clinging and walking, geckos running along wet substrates suffer no significant loss in locomotor performance over short distances. © 2015. Published by The Company of Biologists Ltd.

  8. Mental Strategies Predict Performance and Satisfaction with Performance among Soccer Players.

    Science.gov (United States)

    Kruk, Magdalena; Blecharz, Jan; Boberska, Monika; Zarychta, Karolina; Luszczynska, Aleksandra

    2017-10-01

    This study investigated the changes in mental strategies across the season and their effects on performance and satisfaction with individual performance. Data were collected three times: at the pre-season at Time 1 (T1; baseline), in the mid-season at Time 2 (T2; two-month follow-up), and at the end-of-season at Time 3 (T3; nine-month follow-up) among male soccer players (N = 97) aged 16-27. Athletes completed the questionnaires assessing the use of nine psychological strategies in competition and the level of satisfaction with individual performance. Endurance performance was measured objectively with a 300 m run. A high level of relaxation (T1) explained better 300 m run performance (T3) and a high level of self-talk explained a higher satisfaction with individual performance (T3). A rare use of distractibility and emotional control (T1) predicted a higher level of satisfaction with individual performance (T3). No predictive role of other psychological strategies was found. The use of emotional control, relaxation, and distractibility increased over the season, whereas the use of imagery and negative thinking declined. Besides the roles of self-talk, imagery, relaxation and goal-setting, the effects of distractibility and emotional control should be taken into account when considering athletes' mental training programs.

  9. Improved performance of the LHCb Outer Tracker in LHC Run 2

    Science.gov (United States)

    d'Argent, P.; Dufour, L.; Grillo, L.; de Vries, J. A.; Ukleja, A.; Aaij, R.; Archilli, F.; Bachmann, S.; Berninghoff, D.; Birnkraut, A.; Blouw, J.; De Cian, M.; Ciezarek, G.; Färber, C.; Demmer, M.; Dettori, F.; Gersabeck, E.; Grabowski, J.; Hulsbergen, W. D.; Khanji, B.; Kolpin, M.; Kucharczyk, M.; Malecki, B. P.; Merk, M.; Mulder, M.; Müller, J.; Mueller, V.; Pellegrino, A.; Pikies, M.; Rachwal, B.; Schmelzer, T.; Spaan, B.; Szczekowski, M.; van Tilburg, J.; Tolk, S.; Tuning, N.; Uwer, U.; Wishahi, J.; Witek, M.

    2017-11-01

    The LHCb Outer Tracker is a gaseous detector covering an area of 5 × 6 m2 with 12 double layers of straw tubes. The performance of the detector is presented based on data of the LHC Run 2 running period from 2015 and 2016. Occupancies and operational experience for data collected in pp, pPb and PbPb collisions are described. An updated study of the ageing effects is presented showing no signs of gain deterioration or other radiation damage effects. In addition several improvements with respect to LHC Run 1 data taking are introduced. A novel real-time calibration of the time-alignment of the detector and the alignment of the single monolayers composing detector modules are presented, improving the drift-time and position resolution of the detector by 20%. Finally, a potential use of the improved resolution for the timing of charged tracks is described, showing the possibility to identify low-momentum hadrons with their time-of-flight.

  10. Effect of the SPARK Program on Physical Activity, Cardiorespiratory Endurance, and Motivation in Middle-School Students.

    Science.gov (United States)

    Fu, You; Gao, Zan; Hannon, James C; Burns, Ryan D; Brusseau, Timothy A

    2016-05-01

    This study aimed to examine the effect of a 9-week SPARK program on physical activity (PA), cardiorespiratory endurance (Progressive Aerobic Cardiovascular Endurance Run; PACER), and motivation in middle-school students. 174 students attended baseline and posttests and change scores computed for each outcome. A MANOVA was employed to examine change score differences using follow-up ANOVA and Bonferroni post hoc tests. MANOVA yielded a significant interaction for Grade × Gender × Group (Wilks's Λ = 0.89, P interactions with perceived competence differences between SPARK grades 6 and 8 (Mean Δ = 0.38, P < .05), Enjoyment differences between SPARK grades 6 and 7 (Mean Δ = 0.67, P < .001), and SPARK grades 6 and 8 (Mean Δ = 0.81, P < .001). Following the intervention, SPARK displayed greater increases on PA and motivation measures in younger students compared with the Traditional program.

  11. Protein Requirements Are Elevated in Endurance Athletes after Exercise as Determined by the Indicator Amino Acid Oxidation Method.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Kato

    Full Text Available A higher protein intake has been recommended for endurance athletes compared with healthy non-exercising individuals based primarily on nitrogen balance methodology. The aim of this study was to determine the estimated average protein requirement and recommended protein intake in endurance athletes during an acute 3-d controlled training period using the indicator amino acid oxidation method. After 2-d of controlled diet (1.4 g protein/kg/d and training (10 and 5km/d, respectively, six male endurance-trained adults (28±4 y of age; Body weight, 64.5±10.0 kg; VO2peak, 60.3±6.7 ml·kg-1·min-1; means±SD performed an acute bout of endurance exercise (20 km treadmill run prior to consuming test diets providing variable amounts of protein (0.2-2.8 g·kg-1·d-1 and sufficient energy. Protein was provided as a crystalline amino acid mixture based on the composition of egg protein with [1-13C]phenylalanine provided to determine whole body phenylalanine flux, 13CO2 excretion, and phenylalanine oxidation. The estimated average protein requirement was determined as the breakpoint after biphasic linear regression analysis with a recommended protein intake defined as the upper 95% confidence interval. Phenylalanine flux (68.8±8.5 μmol·kg-1·h-1 was not affected by protein intake. 13CO2 excretion displayed a robust bi-phase linear relationship (R2 = 0.86 that resulted in an estimated average requirement and a recommended protein intake of 1.65 and 1.83 g protein·kg-1·d-1, respectively, which was similar to values based on phenylalanine oxidation (1.53 and 1.70 g·kg-1·d-1, respectively. We report a recommended protein intake that is greater than the RDA (0.8 g·kg-1·d-1 and current recommendations for endurance athletes (1.2-1.4 g·kg-1·d-1. Our results suggest that the metabolic demand for protein in endurance-trained adults on a higher volume training day is greater than their sedentary peers and current recommendations for athletes based

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

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-01-01

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

  13. Effect of contrast water therapy duration on recovery of running performance.

    Science.gov (United States)

    Versey, Nathan G; Halson, Shona L; Dawson, Brian T

    2012-06-01

    To investigate whether contrast water therapy (CWT) assists acute recovery from high-intensity running and whether a dose-response relationship exists. Ten trained male runners completed 4 trials, each commencing with a 3000-m time trial, followed by 8 × 400-m intervals with 1 min of recovery. Ten minutes postexercise, participants performed 1 of 4 recovery protocols: CWT, by alternating 1 min hot (38°C) and 1 min cold (15°C) for 6 (CWT6), 12 (CWT12), or 18 min (CWT18), or a seated rest control trial. The 3000-m time trial was repeated 2 h later. 3000-m performance slowed from 632 ± 4 to 647 ± 4 s in control, 631 ± 4 to 642 ± 4 s in CWT6, 633 ± 4 to 648 ± 4 s in CWT12, and 631 ± 4 to 647 ± 4 s in CWT18. Following CWT6, performance (smallest worthwhile change of 0.3%) was substantially faster than control (87% probability, 0.8 ± 0.8% mean ± 90% confidence limit), however, there was no effect for CWT12 (34%, 0.0 ± 1.0%) or CWT18 (34%, -0.1 ± 0.8%). There were no substantial differences between conditions in exercise heart rates, or postexercise calf and thigh girths. Algometer thigh pain threshold during CWT12 was higher at all time points compared with control. Subjective measures of thermal sensation and muscle soreness were lower in all CWT conditions at some post-water-immersion time points compared with control; however, there were no consistent differences in whole body fatigue following CWT. Contrast water therapy for 6 min assisted acute recovery from high-intensity running; however, CWT duration did not have a dose-response effect on recovery of running performance.

  14. EFFECTS OF RUN-UP VELOCITY ON PERFORMANCE, KINEMATICS, AND ENERGY EXCHANGES IN THE POLE VAULT

    Directory of Open Access Journals (Sweden)

    Nicholas P. Linthorne

    2012-06-01

    Full Text Available This study examined the effect of run-up velocity on the peak height achieved by the athlete in the pole vault and on the corresponding changes in the athlete's kinematics and energy exchanges. Seventeen jumps by an experienced male pole vaulter were video recorded in the sagittal plane and a wide range of run-up velocities (4.5-8.5 m/s was obtained by setting the length of the athlete's run-up (2-16 steps. A selection of performance variables, kinematic variables, energy variables, and pole variables were calculated from the digitized video data. We found that the athlete's peak height increased linearly at a rate of 0.54 m per 1 m/s increase in run-up velocity and this increase was achieved through a combination of a greater grip height and a greater push height. At the athlete's competition run-up velocity (8.4 m/s about one third of the rate of increase in peak height arose from an increase in grip height and about two thirds arose from an increase in push height. Across the range of run-up velocities examined here the athlete always performed the basic actions of running, planting, jumping, and inverting on the pole. However, he made minor systematic changes to his jumping kinematics, vaulting kinematics, and selection of pole characteristics as the run-up velocity increased. The increase in run-up velocity and changes in the athlete's vaulting kinematics resulted in substantial changes to the magnitudes of the energy exchanges during the vault. A faster run-up produced a greater loss of energy during the take-off, but this loss was not sufficient to negate the increase in run-up velocity and the increase in work done by the athlete during the pole support phase. The athlete therefore always had a net energy gain during the vault. However, the magnitude of this gain decreased slightly as run-up velocity increased

  15. Free-piston Stirling engine/linear alternator 1000-hour endurance test

    Science.gov (United States)

    Rauch, J.; Dochat, G.

    1985-01-01

    The Free Piston Stirling Engine (FPSE) has the potential to be a long lived, highly reliable, power conversion device attractive for many product applications such as space, residential or remote site power. The purpose of endurance testing the FPSE was to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearances. The engine performed well throughout the program, completing more than 1100 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long life FPSE applications.

  16. Effects of Participation in Sports Programs on Walking Ability and Endurance Over Time in Children With Cerebral Palsy.

    Science.gov (United States)

    Ross, Sandy A; Yount, Morgan; Ankarstad, Sara; Bock, Samantha; Orso, Britta; Perry, Kimberly; Miros, Jennifer; Brunstrom-Hernandez, Janice E

    2017-12-01

    Children with cerebral palsy may benefit from maintaining a high level of physical fitness similar to typically developing children especially in terms of long-term physical performance, although in practice this is often difficult. The purpose of this study was to determine the effect of participation in sports programs on walking ability and endurance over time. A retrospective cohort study included participants with cerebral palsy, aged 6 to 20 yrs, who attended a summer sports program from 2004 to 2012. There were 256 participant sessions with pre/post data recorded. The participants consisted of a total of 97 children (mean age [SD] = 11.4 [3.1] yrs), many of whom attended multiple programs throughout the years. Programs were held 6 hrs/d, 5 d/wk for up to 4 wks. Outcome measures included the Timed Up and Go, modified 6-min walk, and 25-ft walk/run. The results showed significant improvements in the Timed Up and Go, modified 6-min walk distance and 25-ft walk/run over time. Children in Gross Motor Classification System level III made the largest gains. Walking ability and endurance seem to improve after participation in an intensive summer sports programs. Higher frequency of program attendance resulted in significant improvements in the Timed Up and Go. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Discuss the importance of physical activity at the participation level (sports programs) for children with cerebral palsy; (2) Contrast the changes in walking ability and endurance for children in Gross Motor Function Classification System level I, II, and III after sports programs; and (3) Identify the impact of higher frequency of sports program attendance over time on walking ability. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to

  17. Endurance testing with Li/Na electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Ong, E.T.; Remick, R.J.; Sishtla, C.I. [Institute of Gas Technology, Des Plaines, IL (United States)

    1996-12-31

    The Institute of Gas Technology (IGT), under subcontract to M-C Power Corporation under DOE funding, has been operating bench-scale fuel cells to investigate the performance and endurance issues of the Li/Na electrolyte because it offers higher ionic conductivity, higher exchange current densities, lower vapor pressures, and lower cathode dissolution rates than the Li/K electrolyte. These cells have continued to show higher performance and lower decay rates than the Li/K cells since the publication of our two previous papers in 1994. In this paper, test results of two long-term 100-cm{sup 2} bench scale cells are discussed. One cell operated continuously at 160 mA/cm{sup 2} for 17,000 hours with reference gases (60H{sub 2}/20CO{sub 2}/20H{sub 2}O fuel at 75% utilization and 30CO{sub 2}/70 air oxidant humidified at room temperature at 50% utilization). The other cell operated at 160 mA/cm{sup 2} for 6900 hours at 3 atm with system gases (64H{sub 2}/16CO{sub 2}/20H{sub 2}O at 75% utilization and an M-C Power system-defined oxidant at 40% utilization). Both cells have shown the highest performance and longest endurance among IGT cells operated to date.

  18. Differences in muscle mechanical properties between elite power and endurance athletes: a comparative study.

    Science.gov (United States)

    Loturco, Irineu; Gil, Saulo; Laurino, Cristiano Frota de Souza; Roschel, Hamilton; Kobal, Ronaldo; Cal Abad, Cesar C; Nakamura, Fabio Y

    2015-06-01

    The aim of this study was to compare muscle mechanical properties (using tensiomyography-TMG) and jumping performance of endurance and power athletes and to quantify the associations between TMG parameters and jumping performance indices. Forty-one high-level track and field athletes from power (n = 22; mean ± SD age, height, and weight were 27.2 ± 3.6 years; 180.2 ± 5.4 cm; and 79.4 ± 8.6 kg, respectively) and endurance (endurance runners and triathletes; n = 19; mean ± SD age, height, and weight were 27.1 ± 6.9 years; 169.6 ± 9.8 cm; 62.2 ± 13.1 kg, respectively) specialties had the mechanical properties of their rectus femoris (RF) and biceps femoris (BF) assessed by TMG. Muscle displacement (Dm), contraction time (Tc), and delay time (Td) were retained for analyses. Furthermore, they performed squat jumps (SJs), countermovement jumps (CMJs), and drop jumps to assess reactive strength index (RSI), using a contact platform. Comparisons between groups were performed using differences based on magnitudes, and associations were quantified by the Spearman's ρ correlation. Power athletes showed almost certain higher performance in all jumping performance indices when compared with endurance athletes (SJ = 44.9 ± 4.1 vs. 30.7 ± 6.8 cm; CMJ = 48.9 ± 4.5 vs. 33.6 ± 7.2 cm; RSI = 2.19 ± 0.58 vs. 0.84 ± 0.39, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05), along with better contractile indices reflected by lower Dm, Tc, and Td (Tc BF = 14.3 ± 2.3 vs. 19.4 ± 3.3 milliseconds; Dm BF = 1.67 ± 1.05 vs. 4.23 ± 1.75 mm; Td BF = 16.8 ± 1.6 vs. 19.6 ± 1.3 milliseconds; Tc RF = 18.3 ± 2.8 vs. 22.9 ± 4.0 milliseconds; Dm RF = 4.98 ± 3.71 vs. 8.88 ± 3.45 mm; Td RF = 17.5 ± 1.0 vs. 20.9 ± 1.6 milliseconds, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05). Moderate correlations (Spearman's ρ between -0.61 and -0.72) were found between TMG and jumping

  19. COMBINED STRENGTH AND ENDURANCE TRAINING IN COMPETITIVE SWIMMERS

    Directory of Open Access Journals (Sweden)

    Stian Aspenes

    2009-09-01

    Full Text Available A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11 or a control group (n = 9 from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers

  20. Plasma Growth Hormone and Prolactin Levels in Healthy Sedentary Young Men after Short-Term Endurance Training under Hot Environment

    Directory of Open Access Journals (Sweden)

    İbrahim Cicioglu

    2013-09-01

    Full Text Available Pituitary hormones play an important role energy expenditure and body temperature regulation during exercise. The aim of the stu¬dy was to investigate the effect of two different endurance training in ambient temperature (30.76 ± 1.71oC and 57.92 ± 5.80% r.h. on plasma growth hormone (GH and prolactin (PRL levels in non-trained healthy subjects. Twenty-four untrained healthy men participated in an 8-wk progressive two different endurance-training program. Subjects were divided into two groups: an in¬ter¬val running group (IR, and continuous running group (CR. Both groups were performed 3 days/wk. Growth hormone, PRL and VO2max levels were assessed at the beginning and the end of the training period. Body temperature (TB was also measured at the be¬ginning and immediately after each training. The exercise type affected plasma PRL (8.52 vs. 6.50 ng/ml IR and CT groups, P 0.38. Plasma GH level at the end of training pro¬gram increased from 0.42 to 1.48 ng/ml and 0.58 to 0.67 ng/ml for IR and CR groups. Expectedly, both training types increased TB, at a greater rate for IR group than CR group. In conclusion, an 8-wk regular exercise result in an increase in plasma PRL level, with¬out altering plasma GH level, which accompanied by elevated body temperature, regardless of the individual’s sporting rou¬ti¬ne. These suggest that untrained individuals could benefit from a regular exercise program as much as those doing the routine sport.

  1. The Performance and Development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

    CERN Document Server

    Sowden, Benjamin Charles; The ATLAS collaboration

    2015-01-01

    A description of the design and performance of the newly reimplemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is provided. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2 for the HLT. This new strategy will use a Fast Track Finder (FTF) algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 but with no significant reduction in efficiency. The performance and timing of the algorithms for numerous physics signatures in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performan...

  2. Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance.

    Science.gov (United States)

    Lopes, Thiago Jambo Alves; Simic, Milena; Alves, Daniel de Souza; Bunn, Priscila Dos Santos; Rodrigues, Allan Inoue; Terra, Bruno de Souza; Lima, Maicom da Silva; Ribeiro, Fabrício Miranda; Vilão, Patrick; Pappas, Evangelos

    2018-01-17

    The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets, and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a two-way mixed ANOVA. A total of 545 Brazilian Navy cadets (394 males) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean±SD, 95%CI and percentiles. For tests of muscle strength, power and endurance, males performed better than females (p<0.001). For flexibility tests, females achieved greater distances than males for the sit and reach test (p<0.001), but no difference for ankle dorsiflexion (p=0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, males presented higher values for lower limb strength and power, as well as trunk endurance than females, while females demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective; as the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.

  3. Reliability, sensitivity and validity of the assistant referee intermittent endurance test (ARIET) - a modified Yo-Yo IE2 test for elite soccer assistant referees

    DEFF Research Database (Denmark)

    Castagna, Carlo; Bendiksen, Mads; Impellizzeri, Franco M

    2012-01-01

    We examined the reliability and validity of the assistant referee intermittent endurance test (ARIET), a modified Yo-Yo IE2 test including shuttles of sideways running. The ARIET was carried out on 198 Italian (Serie A-B, Lega-Pro and National Level) and 47 Danish elite soccer assistant referees....... Reproducibility was tested for 41 assistant referees on four occasions each separated by one week. The ARIET intraclass correlation coefficients and typical error of measurement ranged from 0.96 to 0.99 and 3.1 to 5.7%, respectively. ARIET performance for Serie A and B was 23 and 25% greater than in Lega-Pro (P...... ARIET performance was significantly correlated with VO(2max) (r = 0.78, P ARIET (r = - 0.81, P

  4. The Design and Performance of the ATLAS Inner Detector Trigger for Run 2 LHC Collisions at 13 TeV

    CERN Document Server

    Kilby, Callum; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the LHC Run 2 data with collisions at both 50 ns and 25 ns are discussed. The HLT ID tracking algorithms are essential for the identification of nearly all physics signatures in the ATLAS trigger. In order to deal with the expected higher rates for LHC Run 2, the ID trigger was redesigned during the 2013-15 long shutdown to satisfy the demands of the higher energy LHC operation. The detailed performance of the tracking algorithms with the Run 2 data taken so far for the different trigger signatures in terms of both efficiency, and resolution is presented. The online processing times for running trigger tracking for the different trigger signatures are discussed in detail. Where appropriate, comparison of the new strategy for Run 2, with that adopted in Run 1 are made to demonstrate successful application and superior performance of the strategy adopted for Run 2.

  5. Use of performance indicators in the analysis of running gait impacts

    OpenAIRE

    Pàmies Vila, Rosa; González, Francisco; Kövecses, József; Font Llagunes, Josep Maria

    2017-01-01

    Foot-ground impact is a critical event during the running cycle. In this work, three performance indicators were used to characterize foot-ground impact intensity: the effective pre-impact kinetic energy, representative elements of the effective mass matrix, and the critical coefficient of friction. These performance indicators can be obtained from the inertial properties of the biomechanical system and its pre-impact mechanical state, avoiding the need to carry out force measurements. Ground...

  6. Interval endurance capacity of talented youth soccer players

    NARCIS (Netherlands)

    Visscher, C; Elferink-Gemser, MT; Lemmink, KAPM

    The purpose of this study, in which 113 talented Youth soccer players (M = 16.0 yr., SD = 15), selected by their age and level of performance participated, was to investigate interval endurance capacity needed to play at the highest level of competition in the age-category 12 through 18.

  7. Concurrent Training for Sports Performance: The Two Sides of the Medal.

    Science.gov (United States)

    Berryman, Nicolas; Mujika, Inigo; Bosquet, Laurent

    2018-05-29

    The classical work by Robert C. Hickson showed in 1980 that the addition of a resistance training protocol to a predominantly aerobic program could lead to impaired leg strength adaptations in comparison to a resistance-only training regimen. This interference phenomenon was later highlighted in many reports, including a meta-analysis. However, it seems that the interference effect has not been consistently reported, probably because of the complex interactions between training variables and methodological issues. On the other side of the medal, Dr Hickson and colleagues subsequently (1986) reported that a strength training mesocycle could be beneficial for endurance performance in running and cycling. In recent meta-analyses and review articles, it was demonstrated that such a training strategy could improve middle- and long-distance performance in many disciplines (running, cycling, cross-country skiing and swimming). Interestingly, it appears that improvements in the energy cost of locomotion could be associated with these performance enhancements. Despite these benefits, it was also reported that strength training could represent a detrimental stimulus for endurance performance if an inappropriate training plan has been prepared. Taken together, these observations suggest that coaches and athletes should be careful when concurrent training seems imperative in order to meet the complex physiological requirements of their sport. Therefore, this brief review will present a practical appraisal of concurrent training for sports performance. In addition, recommendations will be provided so that practitioners could adapt their interventions based on the training objectives.

  8. Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens.

    Science.gov (United States)

    Yeo, Wee Kian; Paton, Carl D; Garnham, Andrew P; Burke, Louise M; Carey, Andrew L; Hawley, John A

    2008-11-01

    We determined the effects of a cycle training program in which selected sessions were performed with low muscle glycogen content on training capacity and subsequent endurance performance, whole body substrate oxidation during submaximal exercise, and several mitochondrial enzymes and signaling proteins with putative roles in promoting training adaptation. Seven endurance-trained cyclists/triathletes trained daily (High) alternating between 100-min steady-state aerobic rides (AT) one day, followed by a high-intensity interval training session (HIT; 8 x 5 min at maximum self-selected effort) the next day. Another seven subjects trained twice every second day (Low), first undertaking AT, then 1-2 h later, the HIT. These training schedules were maintained for 3 wk. Forty-eight hours before and after the first and last training sessions, all subjects completed a 60-min steady-state ride (60SS) followed by a 60-min performance trial. Muscle biopsies were taken before and after 60SS, and rates of substrate oxidation were determined throughout this ride. Resting muscle glycogen concentration (412 +/- 51 vs. 577 +/- 34 micromol/g dry wt), rates of whole body fat oxidation during 60SS (1,261 +/- 247 vs. 1,698 +/- 174 micromol.kg(-1).60 min(-1)), the maximal activities of citrate synthase (45 +/- 2 vs. 54 +/- 1 mmol.kg dry wt(-1).min(-1)), and beta-hydroxyacyl-CoA-dehydrogenase (18 +/- 2 vs. 23 +/- 2 mmol.kg dry wt(-1).min(-1)) along with the total protein content of cytochrome c oxidase subunit IV were increased only in Low (all P every second day compromised high-intensity training capacity. While selected markers of training adaptation were enhanced with twice a day training, the performance of a 1-h time trial undertaken after a 60-min steady-state ride was similar after once daily or twice every second day training programs.

  9. Backward running or absence of running from Creutz ratios

    International Nuclear Information System (INIS)

    Giedt, Joel; Weinberg, Evan

    2011-01-01

    We extract the running coupling based on Creutz ratios in SU(2) lattice gauge theory with two Dirac fermions in the adjoint representation. Depending on how the extrapolation to zero fermion mass is performed, either backward running or an absence of running is observed at strong bare coupling. This behavior is consistent with other findings which indicate that this theory has an infrared fixed point.

  10. A LABORATORY TEST FOR THE EXAMINATION OF ALACTIC RUNNING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Armin Kibele

    2005-12-01

    Full Text Available A new testing procedure is introduced to evaluate the alactic running performance in a 10s sprint task with near-maximal movement velocity. The test is performed on a motor-equipped treadmill with inverted polarity that increases mechanical resistance instead of driving the treadmill belt. As a result, a horizontal force has to be exerted against the treadmill surface in order to overcome the resistant force of the engine and to move the surface in a backward direction. For this task, subjects lean with their hands towards the front safety barrier of the treadmill railing with a slightly inclined body posture. The required skill resembles the pushing movement of bobsleigh pilots at the start of a race. Subjects are asked to overcome this mechanical resistance and to cover as much distance as possible within a time period of 10 seconds. Fifteen male students (age: 27.7 ± 4.1 years, body height: 1.82 ± 0.46 m, body mass: 78.3 ± 6.7 kg participated in a study. As the resistance force was set to 134 N, subjects ran 35.4 ± 2.6 m on the average corresponding to a mean running velocity of 3.52 ± 0.25 m·s-1. The validity of the new test was examined by statistical inference with various measures related to alactic performance including a metabolic equivalent to estimate alactic capacity (2892 ± 525 mL O2, an estimate for the oxygen debt (2662 ± 315 ml, the step test by Margaria to estimate alactic energy flow (1691 ± 171 W, and a test to measure the maximal strength in the leg extensor muscles (2304 ± 351 N. The statistical evaluation showed that the new test is in good agreement with the theoretical assumptions for alactic performance. Significant correlation coefficients were found between the test criteria and the measures for alactic capacity (r = 0.79, p < 0.01 as well as alactic power (r = 0.77, p < 0.01. The testing procedure is easy to administer and it is best suited to evaluate the alactic capacity for bobsleigh pilots as well as for

  11. Suplementação de carboidrato não reverte o efeito deletério do exercício de endurance sobre o subseqüente desempenho de força Suministrar carbohidratos no revierte el efecto destructivo del ejercicio de endurance sobre el subsiguiente desempeño de fuerza Carbohydrate supplementation fails to revert the deleterious effects of endurance exercise upon subsequent strength performance

    Directory of Open Access Journals (Sweden)

    Marcelo Saldanha Aoki

    2003-10-01

    ólicos inducidos por el ejercicio de endurance. Nuestro objetivo fue verificar si el ingerir carbohidratos (CHO puede atenuar los efectos de una sesión aguda de ejercicio de endurance sobre el desempeño de fuerza. Con el fin de verificar esta hipótesis, 6 estudiantes universitarias (164 ± 5,9cm; 64,9 ± 7,2kg, con experiencia en entrenamiento de fuerza, fueron sometidas a un test para determinar el VO2pico (44 ± 4,3ml.min-1 y a un test de 1-RM para leg press (186 ± 22,5kg seguido de un test de repeticiones máximas (2 series de leg press realizado a 70% de 1-RM hasta el cansancio 1ª serie 21 ± 2,6 y 2ª serie 11 ± 1,9 repeticiones en días diferentes. Siguiendo un procedimiento doble-ciego los voluntarios fueron sometidos a dos condiciones experimentales, recibiendo una bebida placebo (P u otra conteniendo carbohidratos (6% - maltodextrina, antes (500ml y durante (500ml la realización de una sesión de ejercicio de endurance (carrera en trotadores, 70% de VO2pico por 45 minutos. Después del ejercicio de endurance, los voluntarios realizaron un test de 1-RM seguido del test de repeticiones máximas. No se observaron cambios en el test de 1-RM o en la concentración plasmática de glicosis entre las condiciones experimentales (P x CHO. El número de repeticiones máximas a 70%-1RM presentó disminución en ambas situaciones (P 1ª serie 13 ± 2,9 reps y 2ª serie 6 ± 2,1 reps; CHO 1ª serie 15 ± 2,5 reps y 2ª serie 7 ± 1,7 reps, p Previous studies indicated that endurance exercise might have an adverse effect on subsequent strength performance. The decrease in strength performance might be related to the changes promoted by endurance exercise in energy metabolism. Authors' aim was verify if carbohydrate (CHO feeding can attenuate the effects of endurance exercise on strength development. To verify that hypothesis, six female university students (164 ± 5.9 cm; 64.9 ± 7.2 kg with strength training experience were submitted to a VO2peak test (44 ± 4.3 ml.min-1 and an

  12. The genetics of human running: ACTN3 polymorphism as an evolutionary tool improving the energy economy during locomotion.

    Science.gov (United States)

    Pasqua, Leonardo A; Bueno, Salomão; Matsuda, Monique; Marquezini, Mônica V; Lima-Silva, Adriano E; Saldiva, Paulo H N; Bertuzzi, Rômulo

    2016-05-01

    Covering long distances was an important trait to human evolution and continues to be highlighted for health and athletic status. This ability is benefitted by a low cost of locomotion (CoL), meaning that the individuals who are able to expend less energy would be able to cover longer distances. The CoL has been shown to be influenced by distinct and even 'opposite' factors, such as physiological and muscular characteristics, which are genetically inherited. In this way, DNA alterations could be important determinants of the characteristics associated with the CoL. A polymorphism in the ACTN3 gene (R577X) has been related to physical performance, associating the X allele with endurance and the R allele with strength/power abilities. To investigate the influence of ACTN3 genotypes on the CoL. One hundred and fifty healthy male individuals performed two constant speed tests (at 10 and 12 km/h) to determine the CoL. Interestingly, the results showed that heterozygous individuals (RX genotype) presented significantly lower CoL compared to RR and XX individuals. It is argued that RX genotype might generate an intermediate strength-to-endurance phenotype, leading to a better phenotypic profile for energy economy during running and, consequently, for long-term locomotion.

  13. Acute short-term dim light exposure can lower muscle strength endurance

    OpenAIRE

    Arnold G. Nelson; Joke Kokkonen; Megan Mickenberg

    2015-01-01

    Background: Since it has been shown that spending 18 h under dim light conditions can result in reduced handgrip endurance, it was questioned whether or not a shorter exposure to dim light (i.e., 1 h) would have similar influence upon muscular endurance. Therefore this study compared the number of weighted knee extension lifts that could be done after spending 1 h in either dim or bright light. Methods: Participants (5 women, 11 men, college students 19–26 years) performed knee extension l...

  14. Changes in mitochondrial perilipin 3 and perilipin 5 protein content in rat skeletal muscle following endurance training and acute stimulated contraction.

    Science.gov (United States)

    Ramos, S V; Turnbull, P C; MacPherson, R E K; LeBlanc, P J; Ward, W E; Peters, S J

    2015-04-01

    What is the central question of this study? The aim was to determine whether mitochondrial protein content of perilipin 3 (PLIN3) and perilipin 5 (PLIN5) is increased following endurance training and whether mitochondrial PLIN5 protein is increased to a greater extent in endurance-trained rats when compared with sedentary rats following acute contraction. What is the main finding and its importance? Mitochondrial PLIN3 but not PLIN5 protein was increased in endurance-trained compared with sedentary rats, suggesting a mitochondrial role for PLIN3 due to chronic exercise. Contrary to our hypothesis, acute mitochondrial PLIN5 protein was similar in both sedentary and endurance-trained rats. Endurance training results in an increased association between skeletal muscle lipid droplets and mitochondria. This association is likely to be important for the expected increase in intramuscular fatty acid oxidation that occurs with endurance training. The perilipin family of lipid droplet proteins, PLIN(2-5), are thought to play a role in skeletal muscle lipolysis. Recently, results from our laboratory demonstrated that skeletal muscle mitochondria contain PLIN3 and PLIN5 protein. Furthermore, 30 min of stimulated contraction induces an increased mitochondrial PLIN5 content. To determine whether mitochondrial content of PLIN3 and PLIN5 is altered with endurance training, Sprague-Dawley rats were randomized into sedentary or endurance-trained groups for 8 weeks of treadmill running followed by an acute (30 min) sciatic nerve stimulation to induce lipolysis. Mitochondrial PLIN3 protein was ∼1.5-fold higher in red gastrocnemius of endurance-trained rats compared with sedentary animals, with no change in mitochondrial PLIN5 protein. In addition, there was an increase in plantaris intramuscular lipid storage. Acute electrically stimulated contraction in red gastrocnemius from sedentary and endurance-trained rats resulted in a similar increase of mitochondrial PLIN5 between

  15. Interrelationships between measured running intensities and agility performance in subelite rugby union players.

    Science.gov (United States)

    Jarvis, Stuart; Sullivan, Lee O; Davies, Bruce; Wiltshire, Huw; Baker, Julien S

    2009-01-01

    The purpose of this study was to investigate agility performance of rugby players using various intensity running tests. A further aim was to investigate if any differences existed between playing positions in relation to agility performance. Nineteen subelite players (mean +/- SD age, 23.0 +/- 5.4 years) participated in the study. Players underwent measurements of anthropometry (height, body mass, and sum of four skinfolds). Running tests investigated were speed (10 m and 40 m sprint), agility (T Test and Illinois), and multistage fitness tests (20 m, 10 m, and 5 m), with all tests for agility measured against the Illinois agility test. Results indicated that backline players produced significant correlations (P rugby-specific agility programs to aid performance may be of greater benefit and of higher priority in training programs designed for backs rather than forwards.

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

    Science.gov (United States)

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

    2017-01-01

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

  17. Pilates training improves 5-km run performance by changing metabolic cost and muscle activity in trained runners

    Science.gov (United States)

    Finatto, Paula; Silva, Edson Soares Da; Okamura, Alexandre B.; Almada, Bruna P.; Oliveira, Henrique B.

    2018-01-01

    Purpose Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet) and an improvement in running performance is feasible with strength training of the postural and trunk muscles. Methods Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16) or the Pilates group (PG, n = 16). Results Confirming our hypothesis, a significant improvement (p<0.05) was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min) compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min). Similarly, the PG (4.33±0.07 J.kg-1.m-1) had better responses than the CG (4.71±0.11 J.kg-1.m-1) during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG. Conclusions Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners. PMID:29561907

  18. Pilates training improves 5-km run performance by changing metabolic cost and muscle activity in trained runners.

    Directory of Open Access Journals (Sweden)

    Paula Finatto

    Full Text Available Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet and an improvement in running performance is feasible with strength training of the postural and trunk muscles.Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16 or the Pilates group (PG, n = 16.Confirming our hypothesis, a significant improvement (p<0.05 was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min. Similarly, the PG (4.33±0.07 J.kg-1.m-1 had better responses than the CG (4.71±0.11 J.kg-1.m-1 during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG.Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners.

  19. Effects of Marathon Running on Aerobic Fitness and Performance in Recreational Runners One Week after a Race

    Directory of Open Access Journals (Sweden)

    Fuminori Takayama

    2017-01-01

    Full Text Available It is not clear whether or not recreational runners can recover aerobic fitness and performance within one week after marathon running. This study aimed to investigate the effects of running a marathon race on aerobic fitness and performance one week later. Eleven recreational runners (six men, five women completed the race in 3 h 36 min 20 s ± 41 min 34 s (mean ± standard deviation. Before and 7 days after the race, they performed a treadmill running test. Perceived muscle soreness was assessed before the race and for the following 7 days. The magnitude of changes in the treadmill running test was considered possibly trivial for maximal oxygen uptake (V˙O2max (mean difference −1.2 ml/kg/min; ±90% confidence limits 2 ml/kg/min, unclear for %V˙O2max at anaerobic threshold (AT (−0.5; ±4.1% and RE (0.2; ±3.5 ml/kg/km, and likely trivial for both velocity at AT and peak (−0.2; ±0.49 km/h and −0.3; ±0.28 km/h. Perceived muscle soreness increased until 3 days after the race, but there were no clear differences between the values before the race and 4–7 days after it. These results show that physiological capacity associated with marathon running performance is recovered within 7 days after a marathon run.

  20. Effects of Marathon Running on Aerobic Fitness and Performance in Recreational Runners One Week after a Race.

    Science.gov (United States)

    Takayama, Fuminori; Aoyagi, Atsushi; Shimazu, Wataru; Nabekura, Yoshiharu

    2017-01-01

    It is not clear whether or not recreational runners can recover aerobic fitness and performance within one week after marathon running. This study aimed to investigate the effects of running a marathon race on aerobic fitness and performance one week later. Eleven recreational runners (six men, five women) completed the race in 3 h 36 min 20 s ± 41 min 34 s (mean ± standard deviation). Before and 7 days after the race, they performed a treadmill running test. Perceived muscle soreness was assessed before the race and for the following 7 days. The magnitude of changes in the treadmill running test was considered possibly trivial for maximal oxygen uptake ([Formula: see text]O 2 max) (mean difference -1.2 ml/kg/min; ±90% confidence limits 2 ml/kg/min), unclear for %[Formula: see text]O 2 max at anaerobic threshold (AT) (-0.5; ±4.1%) and RE (0.2; ±3.5 ml/kg/km), and likely trivial for both velocity at AT and peak (-0.2; ±0.49 km/h and -0.3; ±0.28 km/h). Perceived muscle soreness increased until 3 days after the race, but there were no clear differences between the values before the race and 4-7 days after it. These results show that physiological capacity associated with marathon running performance is recovered within 7 days after a marathon run.

  1. Characterisation of baroreflex sensitivity of recreational ultra-endurance athletes.

    Science.gov (United States)

    Foulds, Heather J A; Cote, Anita T; Phillips, Aaron A; Charlesworth, Sarah A; Bredin, Shannon S D; Burr, Jamie F; Drury, Chipman Taylor; Ngai, Shirley; Fougere, Renee J; Ivey, Adam C; Warburton, Darren E R

    2014-01-01

    Altered autonomic function has been identified following ultra-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these ultra-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following ultra-endurance race participation. Further, we sought to compare baseline measures among ultra-endurance athletes and recreationally active controls not participating in the ultra-endurance race. Recreational ultra-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational ultra-endurance athletes and at baseline, for recreationally active controls. Post-race, ultra-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p HRV and BPV measures. Recreational ultra-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class ultra-endurance athletes, though still within normal population ranges.

  2. Life-long endurance exercise in humans

    DEFF Research Database (Denmark)

    Mikkelsen, U R; Couppé, C; Karlsen, A

    2013-01-01

    Human aging is associated with a loss of skeletal muscle and an increase in circulating inflammatory markers. It is unknown whether endurance training (Tr) can prevent these changes. Therefore we studied 15 old trained (O-Tr) healthy males and, for comparison, 12 old untrained (O-Un), 10 Young.......05). Most importantly, life-long endurance exercise was associated with a lower level of the inflammatory markers CRP and IL-6 (p... physical endurance activity may play a role in reducing some markers of systemic inflammation, even within the normal range, and in maintaining muscle mass with aging....

  3. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    Science.gov (United States)

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  4. Moderate-intensity endurance training improves endothelial glycocalyx layer integrity in healthy young men.

    Science.gov (United States)

    Majerczak, Joanna; Grandys, Marcin; Duda, Krzysztof; Zakrzewska, Agnieszka; Balcerczyk, Aneta; Kolodziejski, Leszek; Szymoniak-Chochol, Dorota; Smolenski, Ryszard T; Bartosz, Grzegorz; Chlopicki, Stefan; Zoladz, Jerzy A

    2017-01-01

    What is the central question of this study? The main aim of the present study was to determine the effect of prolonged moderate-intensity endurance training on the endothelial glycocalyx layer integrity in relationship to the training-induced changes in oxidative stress and antioxidant defence in humans. What is the main finding and its importance? We have shown, for the first time, a protective effect of prolonged moderate-intensity endurance training on endothelial glycocalyx layer integrity, as judged by significantly lower basal and end-exercise serum concentrations of glycocalyx damage markers, i.e. syndecan-1 and heparan sulfate, accompanied by attenuation of oxidative stress and enhancement of antioxidant defence after training in previously untrained healthy young men. In this study, we evaluated the effect of 20 weeks of moderate-intensity endurance training (ET) on the endothelial glycocalyx layer integrity in relationship to the training-induced changes in antioxidant defence. Eleven healthy young, untrained men performed an incremental cycling exercise bout until exhaustion before and after 20 weeks of ET. Endurance training consisted of 40 min sessions, mainly of moderate intensity (∼50% of maximal oxygen uptake), performed four times per week. Venous blood samples were taken at rest and at the end of the maximal exercise test. Muscle biopsies from vastus lateralis were taken before and after the training. Endurance training resulted in a significant increase in physical capacity (P  0.05). Moderate-intensity ET exerts a pronounced protective effect on endothelial glycocalyx integrity at rest and during exercise, probably through an improvement of antioxidant defence that may represent the vasoprotective mechanisms highly responsive to moderate-intensity endurance training. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

  5. Uzobo, Endurance

    African Journals Online (AJOL)

    Uzobo, Endurance. Vol 11, No 1 (2016) - Articles Population and development in Nigeria: An assesment of the National Policy on Population and Sustainable Development Abstract PDF · Vol 12, No 1 (2017) - Articles Kin networks and migration in Sagbama Local Government Area of Bayelsa State Abstract PDF.

  6. Performance of the ALICE PHOS trigger and improvements for RUN 2

    International Nuclear Information System (INIS)

    Zhao, C; Røed, K; Skaali, T B; Liu, L; Rohrich, D; Kharlov, Y; Bratrud, L; Alme, J

    2013-01-01

    This paper will discuss the performance of the PHOS level-0 trigger and planned improvements for RUN 2. Due to hardware constraints the Trigger Region Unit boards are limited to an operating frequency of 20 MHz. This has led to some ambiguity and biases of the trigger inputs. The trigger input generation scheme was therefore optimized to improve the performance. The PHOS level-0 trigger system has been working with an acceptable efficiency and purity. Proposed actions to further improve the performance and possibly eliminate the impact of the biased trigger inputs will also be presented

  7. Calorie restriction and endurance exercise share potent anti-inflammatory function in adipose tissues in ameliorating diet-induced obesity and insulin resistance in mice

    Directory of Open Access Journals (Sweden)

    Yan Zhen

    2010-07-01

    Full Text Available Abstract Background Calorie restriction (CR and endurance exercise are known to attenuate obesity and improve the metabolic syndrome. The aim of this study was to directly compare the effects of CR and endurance exercise in a mouse model of diet-induced obesity and insulin resistance. Methods Adult male C57BL/6N mice were randomly assigned and subjected to one of the six interventions for 8 weeks: low-fat diet (LC, 10% fat, low-fat diet with 30% calorie restriction (LR, high-fat diet (HC, 60% fat, high-fat diet with 30% calorie restriction (HR, high-fat diet with voluntary running exercise (HE, and high-fat diet with a combination of 30% calorie restriction and exercise (HRE. The impacts of the interventions were assessed by comprehensive metabolic analyses and pro-inflammatory cytokine gene expression. Results Endurance exercise significantly attenuated high-fat diet-induced obesity. CR dramatically prevented high-fat diet-induced metabolic abnormalities. A combination of CR and endurance exercise further reduced obesity and insulin resistance under the condition of high-fat diet. CR and endurance exercise each potently suppressed the expression of inflammatory cytokines in white adipose tissues with additive effects when combined, but the effects of diet and exercise interventions in the liver were moderate to minimal. Conclusions CR and endurance exercise share a potent anti-inflammatory function in adipose tissues in ameliorating diet-induced obesity and insulin resistance.

  8. Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume

    DEFF Research Database (Denmark)

    Iaia, F. Marcello; Hellsten, Ylva; Nielsen, Jens Jung

    2009-01-01

    We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance...... by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training....

  9. Veterinary problems of endurance horses in England and Wales.

    Science.gov (United States)

    Nagy, A; Dyson, S J; Murray, J K

    2017-05-01

    Several studies have shown that a considerable proportion of horses are eliminated from endurance rides due to lameness and metabolic problems. Limited information is available on specific veterinary issues in endurance horses and there are no descriptive data on veterinary problems in a large population of endurance horses. The aim of this study was to describe veterinary problems occurring in endurance horses in England and Wales, the regions of the United Kingdom where endurance rides are organised and regulated by Endurance Great Britain (Endurance GB). A comprehensive online self-completed questionnaire was used for data collection (30th December 2015-29th February 2016) All members of Endurance GB who were the main rider of one or more endurance horses were eligible to participate. From the target population of 1209 horses, 190 questionnaires were completed by riders, resulting in a 15.7% response rate. The most common rider-reported veterinary problem was lameness, affecting 152/190 (80.0%) of endurance horses at some point during their careers and 101/190 (53.2%) of horses in the previous 12 months. Detailed information on the most recent episode of lameness was available for 147 horses. Seventy-six percent of these lameness episodes (112/147) had been initially identified by a veterinarian, but only 52% of these lameness episodes were investigated further by a veterinarian, despite the high proportion of horses affected by lameness and the proportion of horses with recurrent lameness episodes. The second most common veterinary problem was thoracolumbar region pain, followed by non-specific cough, skin disease and colic. Education of endurance riders may improve the number, quality and timing of veterinary investigations, especially for lameness and thoracolumbar region pain. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Solution-Space Screening of a Hypersonic Endurance Demonstrator

    Science.gov (United States)

    Chudoba, Bernd; Coleman, Gary; Oza, Amit; Gonzalez, Lex; Czysz, Paul

    2012-01-01

    This report documents a parametric sizing study performed to develop a program strategy for research and development and procurement of a feasible next-generation hypersonic air-breathing endurance demonstrator. Overall project focus has been on complementing technical and managerial decision-making during the earliest conceptual design phase towards minimization of operational, technical, and managerial risks.

  11. Enhancing team-sport athlete performance: is altitude training relevant?

    Science.gov (United States)

    Billaut, François; Gore, Christopher J; Aughey, Robert J

    2012-09-01

    Field-based team sport matches are composed of short, high-intensity efforts, interspersed with intervals of rest or submaximal exercise, repeated over a period of 60-120 minutes. Matches may also be played at moderate altitude where the lower oxygen partial pressure exerts a detrimental effect on performance. To enhance run-based performance, team-sport athletes use varied training strategies focusing on different aspects of team-sport physiology, including aerobic, sprint, repeated-sprint and resistance training. Interestingly, 'altitude' training (i.e. living and/or training in O(2)-reduced environments) has only been empirically employed by athletes and coaches to improve the basic characteristics of speed and endurance necessary to excel in team sports. Hypoxia, as an additional stimulus to training, is typically used by endurance athletes to enhance performance at sea level and to prepare for competition at altitude. Several approaches have evolved in the last few decades, which are known to enhance aerobic power and, thus, endurance performance. Altitude training can also promote an increased anaerobic fitness, and may enhance sprint capacity. Therefore, altitude training may confer potentially-beneficial adaptations to team-sport athletes, which have been overlooked in contemporary sport physiology research. Here, we review the current knowledge on the established benefits of altitude training on physiological systems relevant to team-sport performance, and conclude that current evidence supports implementation of altitude training modalities to enhance match physical performances at both sea level and altitude. We hope that this will guide the practice of many athletes and stimulate future research to better refine training programmes.

  12. Acute intraperitoneal injection of caffeine improves endurance exercise performance in association with increasing brain dopamine release during exercise.

    Science.gov (United States)

    Zheng, Xinyan; Takatsu, Satomi; Wang, Hongli; Hasegawa, Hiroshi

    2014-07-01

    The purpose of this study was to examine changes of thermoregulation, neurotransmitters in the preoptic area and anterior hypothalamus (PO/AH), which is the thermoregulatory center, and endurance exercise performance after the intraperitoneal injection of caffeine in rats. Core body temperature (Tcore), oxygen consumption (VO₂) and tail skin temperature (Ttail) were measured. A microdialysis probe was inserted in the PO/AH, and samples for the measurements of extracellular dopamine (DA), noradrenaline (NA) and serotonin (5-HT) levels were collected. During the rest experiment, 1 h after baseline collections in the chamber (23 °C), the rats were intraperitoneally injected with saline, or 3 mg kg(-1) or 10 mg kg(-1) caffeine. The duration of the test was 4 h. During the exercise experiment, baseline collections on the treadmill were obtained for 1 h. One hour before the start of exercise, rats were intraperitoneally injected with either 10 mg kg(-1) caffeine (CAF) or saline (SAL). Animals ran until fatigue at a speed of 18 m min(-1), at a 5% grade, on the treadmill in a normal environment (23 °C). At rest, 3 mg kg(-1) caffeine did not influence Tcore, Ttail, VO₂, extracellular DA, NA and 5-HT. 10 mg kg(-1) caffeine caused significant increases in Tcore, VO₂, Ttail and extracellular DA in the PO/AH. In addition, 10 mg kg(-1) caffeine increased the run time to fatigue (SAL: 104.4 ± 30.9 min, CAF: 134.0 ± 31.1 min, pcaffeine and exercise increased Tcore, VO₂, Ttail and extracellular DA in the PO/AH. NA increased during exercise, while neither caffeine nor exercise changed 5-HT. These results indicate that caffeine has ergogenic and hyperthermic effects, and these effects may be related to changes of DA release in the brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The effect of time constraints and running phases on combined event pistol shooting performance.

    Science.gov (United States)

    Dadswell, Clare; Payton, Carl; Holmes, Paul; Burden, Adrian

    2016-01-01

    The combined event is a crucial aspect of the modern pentathlon competition, but little is known about how shooting performance changes through the event. This study aimed to identify (i) how performance-related variables changed within each shooting series and (ii) how performance-related variables changed between each shooting series. Seventeen modern pentathletes completed combined event trials. An optoelectronic shooting system recorded score and pistol movement, and force platforms recorded centre of pressure movement 1 s prior to every shot. Heart rate and blood lactate values were recorded throughout the event. Whilst heart rate and blood lactate significantly increased between series (P  0.05). Thus, combined event shooting performance following each running phase appears similar to shooting performance following only 20 m of running. This finding has potential implications for the way in which modern pentathletes train for combined event shooting, and highlights the need for modern pentathletes to establish new methods with which to enhance shooting accuracy.

  14. Effect of salbutamol on neuromuscular function in endurance athletes.

    Science.gov (United States)

    Decorte, Nicolas; Bachasson, Damien; Guinot, Michel; Flore, Patrice; Levy, Patrick; Verges, Samuel; Wuyam, Bernard

    2013-10-01

    The potential ergogenic effects of therapeutic inhaled salbutamol doses in endurance athletes have been controversially discussed for decades. We hypothesized that salbutamol inhalation may increase peripheral muscle contractility, reduce fatigability, and improve force recovery after a localized exercise in endurance athletes. Eleven healthy, nonasthmatic male athletes with high aerobic capacities were recruited to be compared in a double-blinded, randomized crossover study of two dose levels of salbutamol (200 and 800 μg) and a placebo administered by inhalation before a quadriceps fatigue test. Subjects performed an incremental exercise protocol consisting in sets of 10 intermittent isometric contractions starting at 20% of maximum voluntary contraction (MVC) with 10% MVC increment until exhaustion. Femoral nerve magnetic stimulation was used during and after MVC to evaluate neuromuscular fatigue after each set, at task failure, and after 10 and 30 min of recovery. Initial MVC and evoked muscular responses were not modified with salbutamol (P > 0.05). The total number of submaximal contractions until task failure significantly differed between treatments (placebo, 72 ± 7; 200 µg, 78 ± 8; and 800 µg, 82 ± 7; P 0.05). Voluntary activation was unaffected by the fatiguing task and treatments (P > 0.05). Supratherapeutic inhaled doses of β2-agonists increased quadriceps endurance during an incremental and localized fatiguing task in healthy endurance-trained athletes without significant effect on neuromuscular fatigue. Further studies are needed to clarify the underlying mechanisms.

  15. Running economy and energy cost of running with backpacks.

    Science.gov (United States)

    Scheer, Volker; Cramer, Leoni; Heitkamp, Hans-Christian

    2018-05-02

    Running is a popular recreational activity and additional weight is often carried in backpacks on longer runs. Our aim was to examine running economy and other physiological parameters while running with a 1kg and 3 kg backpack at different submaximal running velocities. 10 male recreational runners (age 25 ± 4.2 years, VO2peak 60.5 ± 3.1 ml·kg-1·min-1) performed runs on a motorized treadmill of 5 minutes durations at three different submaximal speeds of 70, 80 and 90% of anaerobic lactate threshold (LT) without additional weight, and carrying a 1kg and 3 kg backpack. Oxygen consumption, heart rate, lactate and RPE were measured and analysed. Oxygen consumption, energy cost of running and heart rate increased significantly while running with a backpack weighing 3kg compared to running without additional weight at 80% of speed at lactate threshold (sLT) (p=0.026, p=0.009 and p=0.003) and at 90% sLT (p<0.001, p=0.001 and p=0.001). Running with a 1kg backpack showed a significant increase in heart rate at 80% sLT (p=0.008) and a significant increase in oxygen consumption and heart rate at 90% sLT (p=0.045 and p=0.007) compared to running without additional weight. While running at 70% sLT running economy and cardiovascular effort increased with weighted backpack running compared to running without additional weight, however these increases did not reach statistical significance. Running economy deteriorates and cardiovascular effort increases while running with additional backpack weight especially at higher submaximal running speeds. Backpack weight should therefore be kept to a minimum.

  16. Cardiac Output and Performance during a Marathon Race in Middle-Aged Recreational Runners

    Directory of Open Access Journals (Sweden)

    Véronique L. Billat

    2012-01-01

    Full Text Available Purpose. Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV and cardiac output (CO to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance and/or CO, per meter (i.e., cardiac cost. Methods. We measured the SV, heart rate (HR, CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min. Results. Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively. Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO×m−1 (r=−0.65, P<0.01 and positively correlated with the runner’s ability to complete the race at a high percentage of the speed at maximal SV (r=0.83, P<0.0002. Conclusion. Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners.

  17. Higher Precision of Heart Rate Compared with VO2 to Predict Exercise Intensity in Endurance-Trained Runners.

    Science.gov (United States)

    Reis, Victor M; den Tillaar, Roland Van; Marques, Mario C

    2011-01-01

    The aim of the present study was to assess the precision of oxygen uptake with heart rate regression during track running in highly-trained runners. Twelve national and international level male long-distance road runners (age 30.7 ± 5.5 yrs, height 1.71 ± 0.04 m and mass 61.2 ± 5.8 kg) with a personal best on the half marathon of 62 min 37 s ± 1 min 22 s participated in the study. Each participant performed, in an all-weather synthetic track five, six min bouts at constant velocity with each bout at an increased running velocity. The starting velocity was 3.33 m·s(-1) with a 0.56 m·s(-1) increase on each subsequent bout. VO2 and heart rate were measured during the runs and blood lactate was assessed immediately after each run. Mean peak VO2 and mean peak heart rate were, respectively, 76.2 ± 9.7 mL·kg(-1)·min(-1) and 181 ± 13 beats·min(-1). The linearity of the regressions between heart rate, running velocity and VO2 were all very high (r > 0.99) with small standard errors of regression (i.e. Sy.x at the velocity associated with the 2 and 4 mmol·L(-1) lactate thresholds). The strong relationships between heart rate, running velocity and VO2 found in this study show that, in highly trained runners, it is possible to have heart rate as an accurate indicator of energy demand and of the running speed. Therefore, in this subject cohort it may be unnecessary to use VO2 to track changes in the subjects' running economy during training periods. Key pointsHeart rate is used in the control of exercise intensity in endurance sports.However, few studies have quantified the precision of its relationship with oxygen uptake in highly trained runners.We evaluated twelve elite half-marathon runners during track running at various intensities and established three regressions: oxygen uptake / heart rate; heart rate / running velocity and oxygen uptake / running velocity.The three regressions presented, respectively, imprecision of 4,2%, 2,75% and 4,5% at the velocity

  18. The Reliability and Validity of a Four-Minute Running Time-Trial in Assessing V˙O2max and Performance

    Directory of Open Access Journals (Sweden)

    Kerry McGawley

    2017-05-01

    Full Text Available Introduction: Traditional graded-exercise tests to volitional exhaustion (GXTs are limited by the need to establish starting workloads, stage durations, and step increments. Short-duration time-trials (TTs may be easier to implement and more ecologically valid in terms of real-world athletic events. The purpose of the current study was to assess the reliability and validity of maximal oxygen uptake (V˙O2max and performance measured during a traditional GXT (STEP and a four-minute running time-trial (RunTT.Methods: Ten recreational runners (age: 32 ± 7 years; body mass: 69 ± 10 kg completed five STEP tests with a verification phase (VER and five self-paced RunTTs on a treadmill. The order of the STEP/VER and RunTT trials was alternated and counter-balanced. Performance was measured as time to exhaustion (TTE for STEP and VER and distance covered for RunTT.Results: The coefficient of variation (CV for V˙O2max was similar between STEP, VER, and RunTT (1.9 ± 1.0, 2.2 ± 1.1, and 1.8 ± 0.8%, respectively, but varied for performance between the three types of test (4.5 ± 1.9, 9.7 ± 3.5, and 1.8 ± 0.7% for STEP, VER, and RunTT, respectively. Bland-Altman limits of agreement (bias ± 95% showed V˙O2max to be 1.6 ± 3.6 mL·kg−1·min−1 higher for STEP vs. RunTT. Peak HR was also significantly higher during STEP compared with RunTT (P = 0.019.Conclusion: A four-minute running time-trial appears to provide more reliable performance data in comparison to an incremental test to exhaustion, but may underestimate V˙O2max.

  19. The Effect of Natural or Simulated Altitude Training on High-Intensity Intermittent Running Performance in Team-Sport Athletes: A Meta-Analysis.

    Science.gov (United States)

    Hamlin, Michael J; Lizamore, Catherine A; Hopkins, Will G

    2018-02-01

    While adaptation to hypoxia at natural or simulated altitude has long been used with endurance athletes, it has only recently gained popularity for team-sport athletes. To analyse the effect of hypoxic interventions on high-intensity intermittent running performance in team-sport athletes. A systematic literature search of five journal databases was performed. Percent change in performance (distance covered) in the Yo-Yo intermittent recovery test (level 1 and level 2 were used without differentiation) in hypoxic (natural or simulated altitude) and control (sea level or normoxic placebo) groups was meta-analyzed with a mixed model. The modifying effects of study characteristics (type and dose of hypoxic exposure, training duration, post-altitude duration) were estimated with fixed effects, random effects allowed for repeated measurement within studies and residual real differences between studies, and the standard-error weighting factors were derived or imputed via standard deviations of change scores. Effects and their uncertainty were assessed with magnitude-based inference, with a smallest important improvement of 4% estimated via between-athlete standard deviations of performance at baseline. Ten studies qualified for inclusion, but two were excluded owing to small sample size and risk of publication bias. Hypoxic interventions occurred over a period of 7-28 days, and the range of total hypoxic exposure (in effective altitude-hours) was 4.5-33 km h in the intermittent-hypoxia studies and 180-710 km h in the live-high studies. There were 11 control and 15 experimental study-estimates in the final meta-analysis. Training effects were moderate and very likely beneficial in the control groups at 1 week (20 ± 14%, percent estimate, ± 90% confidence limits) and 4-week post-intervention (25 ± 23%). The intermittent and live-high hypoxic groups experienced additional likely beneficial gains at 1 week (13 ± 16%; 13 ± 15%) and 4-week post

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

    Science.gov (United States)

    Rosenburg, Beth S.; And Others

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

  1. EnergyPlus Run Time Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Tianzhen; Buhl, Fred; Haves, Philip

    2008-09-20

    EnergyPlus is a new generation building performance simulation program offering many new modeling capabilities and more accurate performance calculations integrating building components in sub-hourly time steps. However, EnergyPlus runs much slower than the current generation simulation programs. This has become a major barrier to its widespread adoption by the industry. This paper analyzed EnergyPlus run time from comprehensive perspectives to identify key issues and challenges of speeding up EnergyPlus: studying the historical trends of EnergyPlus run time based on the advancement of computers and code improvements to EnergyPlus, comparing EnergyPlus with DOE-2 to understand and quantify the run time differences, identifying key simulation settings and model features that have significant impacts on run time, and performing code profiling to identify which EnergyPlus subroutines consume the most amount of run time. This paper provides recommendations to improve EnergyPlus run time from the modeler?s perspective and adequate computing platforms. Suggestions of software code and architecture changes to improve EnergyPlus run time based on the code profiling results are also discussed.

  2. Effect of plyometric vs. dynamic weight training on the energy cost of running.

    Science.gov (United States)

    Berryman, Nicolas; Maurel, Delphine B; Bosquet, Laurent

    2010-07-01

    The purpose of this study is to compare the effects of 2 strength training methods on the energy cost of running (Cr). Thirty-five moderately to well-trained male endurance runners were randomly assigned to either a control group (C) or 2 intervention groups. All groups performed the same endurance-training program during an 8-week period. Intervention groups added a weekly strength training session designed to improve neuromuscular qualities. Sessions were matched for volume and intensity using either plyometric training (PT) or purely concentric contractions with added weight (dynamic weight training [DWT]). We found an interaction between time and group (p < 0.05) and an effect of time (p < 0.01) for Cr. Plyometric training induced a larger decrease of Cr (218 +/- 16 to 203 +/- 13 ml.kg.km) than DWT (207 +/- 15 to 199 +/- 12 ml.kg.km), whereas it remained unchanged in C. Pre-post changes in Cr were correlated with initial Cr (r = -0.57, p < 0.05). Peak vertical jump height (VJHpeak) increased significantly (p < 0.01) for both experimental groups (DWT = 33.4 +/- 6.2 to 34.9 +/- 6.1 cm, PT = 33.3 +/- 4.0 to 35.3 +/- 3.6 cm) but not for C. All groups showed improvements (p < 0.05) in Perf3000 (C = 711 +/- 107 to 690 +/- 109 seconds, DWT = 755 +/- 87 to 724 +/- 77 seconds, PT = 748 +/- 81 to 712 +/- 76 seconds). Plyometric training were more effective than DWT in improving Cr in moderately to well-trained male endurance runners showing that athletes and coaches should include explosive strength training in their practices with a particular attention on plyometric exercises. Future research is needed to establish the origin of this adaptation.

  3. Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

    Science.gov (United States)

    Worms, F.

    1981-01-01

    The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone.

  4. Biological aspects of salivary hormones in male half-marathon performance

    Directory of Open Access Journals (Sweden)

    Radosavljević Branimir B.

    2016-01-01

    Full Text Available Physical effort is known to alter the blood levels of many hormones, but there are only a few studies about the biological changes of salivary hormones. The aim of this work was to determine whether salivary testosterone and salivary cortisol levels, measured two weeks before a half-marathon race, relate to running performance in male recreational athletes. A group of eleven male recreational athletes preparing for a half-marathon was included in the study. Saliva for testosterone and cortisol determinations was collected before and immediately after a 15-km training run, two weeks before the half-marathon. Individual official half-marathon times, expressed in hours, were used as a measure of performance. Mean testosterone concentrations were 1.07±0.33 nmol/L before the run and 0.88±0.35 nmol/L after the run (p<0.05. Mean cortisol concentrations were 12.28±8.46 nmol/L before the run and 38.08±19.63 nmol/L after the run (p<0.05. The pre-run salivary testosterone levels marginally correlated with the corresponding half-marathon running times (p=0.068, 95% bootstrap CI for slope -0.40 to -0.06. However, post-run salivary testosterone levels significantly correlated with the corresponding half-marathon running times (p=0.011, 95% bootstrap CI for slope -0.41 to -0.16, even considering correlations with the runners’ age. Salivary cortisol levels, either pre- or post-run, did not correlate with the corresponding half-marathon running times. The results of this study suggest that post-exercise salivary testosterone levels could have the potential to predict performance in endurance running, at least in recreational athletes. [Projekat Ministarstva nauke Republike Srbije, br. 175036

  5. [Comparison of cardiopulmonary endurance and muscular fitness in teenagers between Hong Kong and inland cities].

    Science.gov (United States)

    Hong, Y; Chan, K; Wang, Y

    1997-01-01

    A study on the data of the physique investigated in teenagers was carried out between Hong Kong and inland cities to compare their cardiopulmonary endurance and muscular fitness. Results revealed that cardiopulmonary endurance in school teenagers of both sex at different ages in inland cities was better than that in Hong Kong. Muscular strength and endurance of sports performance of teenagers, except for standing long jump, in Hong Kong were weaker than that in inland cities. It suggests that attention should be paid to the involvement of teenagers in physical education with the increase of people's living standard.

  6. Psychological stress moderates the relationship between running volume and CD4+ T cell subpopulations.

    Science.gov (United States)

    Rehm, K E; Sunesara, I; Tull, M T; Marshall, G D

    2016-01-01

    Endurance-based exercise training can lead to alterations in components of the immune system, but it is unknown how psychological stress (another potent immunomodulator) may impact these changes. The purpose of this study was to determine the moderating role of psychological stress on exercise-induced immune changes. Twenty-nine recreational runners were recruited for this study four weeks before completing a marathon. Each subject reported: weekly training volume (miles/wk) for the week prior to the study visit; completed the Perceived Stress Scale (PSS), the state version of the State-Trait Anxiety Inventory (STAI) and the Penn State Worry Questionnaire (PSWQ); and donated blood for assessment of CD4+ T cell subpopulations and mitogen-induced cytokine production. Participants ran an average of 30 (±13.4) miles (1 mile=1.6 km) per week. Average values (SD) for immune biomarkers were: regulatory T cells (Treg), 3.2% (±1.2%); type 1 regulatory cells (Tr1), 27.1% (±8.3%); T helper 3 (Th3), 1.8% (±0.7%); interferon gamma (IFNγ), 3.1 pg/ml (±1.0); interleukin (IL)-4, 1.4 pg/ml (±1.1); IFNγ/IL-4, 8.6 (±1.2); IL-10, 512 pg/ml (±288). There was a significant relationship between running volume and both Treg cell numbers (slope of the regression line (β)=0.05, p less than 0.001) and IL-10 production β=-10.6, p=0.002), and there was a trending relationship between running volume and Tr1 cell numbers (β=-0.2%, p=0.064). Perceived stress was a trending moderator of the running volume-Treg relationship, whereas worry was a significant moderator of the running volume-IFNγ and running volume-IFNγ/IL-4 relationships. These data indicate that various forms of psychological stress can impact endurance exercise-based changes in certain immune biomarkers. These changes may reflect an increased susceptibility to clinical risks in some individuals.

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

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Lukas Cipryan, Gerhard Tschakert, Peter Hofmann

    2017-06-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  10. Effect of different protocols of caffeine intake on metabolism and endurance performance.

    Science.gov (United States)

    Cox, Gregory R; Desbrow, Ben; Montgomery, Paul G; Anderson, Megan E; Bruce, Clinton R; Macrides, Theodore A; Martin, David T; Moquin, Angela; Roberts, Alan; Hawley, John A; Burke, Louise M

    2002-09-01

    Competitive athletes completed two studies of 2-h steady-state (SS) cycling at 70% peak O(2) uptake followed by 7 kJ/kg time trial (TT) with carbohydrate (CHO) intake before (2 g/kg) and during (6% CHO drink) exercise. In Study A, 12 subjects received either 6 mg/kg caffeine 1 h preexercise (Precaf), 6 x 1 mg/kg caffeine every 20 min throughout SS (Durcaf), 2 x 5 ml/kg Coca-Cola between 100 and 120 min SS and during TT (Coke), or placebo. Improvements in TT were as follows: Precaf, 3.4% (0.2-6.5%, 95% confidence interval); Durcaf, 3.1% (-0.1-6.5%); and Coke, 3.1% (-0.2-6.2%). In Study B, eight subjects received 3 x 5 ml/kg of different cola drinks during the last 40 min of SS and TT: decaffeinated, 6% CHO (control); caffeinated, 6% CHO; decaffeinated, 11% CHO; and caffeinated, 11% CHO (Coke). Coke enhanced TT by 3.3% (0.8-5.9%), with all trials showing 2.2% TT enhancement (0.5-3.8%; P < 0.05) due to caffeine. Overall, 1) 6 mg/kg caffeine enhanced TT performance independent of timing of intake and 2) replacing sports drink with Coca-Cola during the latter stages of exercise was equally effective in enhancing endurance performance, primarily due to low intake of caffeine (approximately 1.5 mg/kg).

  11. RHIC PC CNI POLARIMETER:STATUS AND PERFORMANCE from THE FIRST COLLIDER RUN

    International Nuclear Information System (INIS)

    JINNOUCHI, O.; ALEKSEEV, I.G.; BLAND, L.C.; BRAVAR, A.; BUNCE, G.; CADMAN, R.; DESHPANDE, A.D.; HAWAN, S.; FIELDS, D.E.; HUANG, H.; HUGHES, V.; IGO, G.; IMAI, K.; KANAVETS, V.P.; KIRYLUK, J.; KURITA, K.; LI, Z.; LOZOWSKI, W.; MACKAY, W.W.; MAKDISI, Y.; OGAWA, A.; RESCIA, S.; ROSER, T.; SAITO, N.; SPINKA, H.; SURROW, B.; SVIRIDA, D.N.; TOJO, J.; UNDERWOOD, D.; WOOD, J.

    2002-01-01

    Polarimeters using the proton carbon elastic scattering process in Coulomb Nuclear Interference (CNI) region were installed in two RHIC rings. Polarization measurements were successfully carried out with the high energy polarized proton beams for the first polarized pp collision run. The physics principles, performance, and polarization measurements are presented

  12. ATLAS Strip Detector: Operational Experience and Run1-> Run2 Transition

    CERN Document Server

    Nagai, Koichi; The ATLAS collaboration

    2014-01-01

    Large hadron collider was operated very successfully during the Run1 and provided a lot of opportunities of physics studies. It currently has a consolidation work toward to the operation at $\\sqrt{s}=14 \\mathrm{TeV}$ in Run2. The ATLAS experiment has achieved excellent performance in Run1 operation, delivering remarkable physics results. The SemiConductor Tracker contributed to the precise measurement of momentum of charged particles. This paper describes the operation experience of the SemiConductor Tracker in Run1 and the preparation toward to the Run2 operation during the LS1.

  13. More Men Run Relatively Fast in U.S. Road Races, 1981–2006: A Stable Sex Difference in Non-Elite Runners

    Directory of Open Access Journals (Sweden)

    Robert O. Deaner

    2011-10-01

    Full Text Available Recent studies indicate that more men than women run fast relative to sex-specific world records and that this sex difference has been historically stable in elite U.S. runners. These findings have been hypothesized to reflect an evolved male predisposition for enduring competitiveness in “show-off” domains. The current study tests this hypothesis in non-elite runners by analyzing 342 road races that occurred from 1981–2006, most in or near Buffalo, NY. Both absolutely and as a percentage of same-sex finishers, more men ran relatively fast in most races. During the 1980s, as female participation surged, the difference in the absolute number of relatively fast men and women decreased. However, this difference was stable for races that occurred after 1993. Since then, in any given race, about three to four times as many men as women ran relatively fast. The stable sex difference in relative performance shown here for non-elites constitutes new support for the hypothesis of an evolved male predisposition for enduring competitiveness.

  14. ATLAS Liquid Argon Calorimeter Performance in Run 1 and Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00286685; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{−2}$ s$^{−1}$ . Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region $\\eta < 3.2$, and for hadronic calorimetry in the region from $\\eta = 1.5$ to $\\eta = 4.9$. In the first LHC run a total luminosity of $27$ fb$^{−1}$ has been collected at center-of-mass energies of 7-8 TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately $3.9$ fb$^{-1}$ of data at a center-of-mass energy of 13 TeV recorded in this year. The well calibrated and highly granular Liquid Argon Calorimeter achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successful discovery of a Higgs boson in the di-photon decay channel. This contribution will give ...

  15. Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

    Science.gov (United States)

    Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

    2017-03-01

    The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO 2 max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO 2

  16. Impact of a supervised worksite exercise program on back and core muscular endurance in firefighters.

    Science.gov (United States)

    Mayer, John M; Quillen, William S; Verna, Joe L; Chen, Ren; Lunseth, Paul; Dagenais, Simon

    2015-01-01

    Low back pain is a leading cause of disability in firefighters and is related to poor muscular endurance. This study examined the impact of supervised worksite exercise on back and core muscular endurance in firefighters. A cluster randomized controlled trial was used for this study. The study occurred in fire stations of a municipal fire department (Tampa, Florida). Subjects were 96 full-duty career firefighters who were randomly assigned by fire station to exercise (n = 54) or control (n = 42) groups. Exercise group participants completed a supervised exercise targeting the back and core muscles while on duty, two times per week for 24 weeks, in addition to their usual fitness regimen. Control group participants continued their usual fitness regimen. Back and core muscular endurance was assessed with the Biering-Sorensen test and plank test, respectively. Changes in back and core muscular endurance from baseline to 24 weeks were compared between groups using analysis of covariance and linear mixed effects models. After 24 weeks, the exercise group had 12% greater (p = .021) back muscular endurance and 21% greater (p = .0006) core muscular endurance than did the control group. The exercise intervention did not disrupt operations or job performance. A supervised worksite exercise program was safe and effective in improving back and core muscular endurance in firefighters, which could protect against future low back pain.

  17. Running Performance Differences Between Men and Women (An Update)

    National Research Council Canada - National Science Library

    Cheuvront, C. N; Carter, R; DeRuisseau, K. C; Moffatt, R. J

    2005-01-01

    More than a decade ago it was reported in the journal Nature that the slope of improvement in the men's and women's running records, extrapolated from mean running velocity plotted against historical...

  18. Bovine Colostrum Supplementation During Running Training Increases Intestinal Permeability

    Directory of Open Access Journals (Sweden)

    Grant D. Brinkworth

    2009-12-01

    Full Text Available Endurance exercise training can increase intestinal permeability which may contribute to the development of gastrointestinal symptoms in some athletes. Bovine colostrum (BC supplementation reduces intestinal permeability induced by non-steroidal anti-inflammatory drugs. This study aimed to determine whether BC could also reduce intestinal permeability induced by endurance exercise. Thirty healthy adult males (25.0 ± 4.7 yr; mean ± SD completed eight weeks of running three times per week for 45 minutes at their lactate threshold while consuming 60 g/day of BC, whey protein (WP or control (CON. Intestinal permeability was assessed at baseline and after eight weeks by measuring the ratio of urinary lactulose (L and rhamnose (R excretion. After eight weeks the L/R ratio increased significantly more in volunteers consuming BC (251 ± 140% compared with WP (21 ± 35%, P < 0.05 and CON (−7 ± 13%, P < 0.02. The increase in intestinal permeability with BC may have been due to BC inducing greater leakiness of tight junctions between enterocytes or by increasing macromolecular transport as it does in neonatal gut. Further research should investigate the potential for BC to increase intestinal macromolecular transport in adults.

  19. Measurement of quadriceps endurance by fNIRS

    Science.gov (United States)

    Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

    2006-02-01

    In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

  20. Analysis of Tests Evaluating Sport Climbers’ Strength and Isometric Endurance

    Directory of Open Access Journals (Sweden)

    Ozimek Mariusz

    2016-12-01

    Full Text Available The present study was designed to determine which types of specific tests provide an effective evaluation of strength and endurance in highly trained competitive sport climbers. The research process consisted of three basic components: the measurement of selected somatic characteristics of the climbers, the assessment of their physical conditioning, and a search for correlations between the anthropometric and “conditioning” variables on the one hand, and climber’s performance on the other. The sample of subjects consisted of 14 experienced volunteer climbers capable of handling 7a- 8a+/b on-sight rock climbing grades. The strongest correlations (Spearman’s rank were found between climber’s competence and the relative results of the finger strength test (r = 0.7; much lower, but still statistically significant coefficients were found between the level of competence and the results of the muscle endurance tests (r = 0.53 – 0.57. Climbers aspiring to attain an elite level must have strong finger and forearm muscles, but most of all, they must be capable of releasing their potential during specific motor capability tests engaging these parts of the body. The forearm muscles of elite climbers must also be very resistant to fatigue. Since highly trained athletes vary only slightly in body mass, this variable does not have a major effect on their performance during strength and endurance tests.

  1. Effect of respiratory muscle training on exercise performance in healthy individuals: a systematic review and meta-analysis.

    Science.gov (United States)

    Illi, Sabine K; Held, Ulrike; Frank, Irène; Spengler, Christina M

    2012-08-01

    Two distinct types of specific respiratory muscle training (RMT), i.e. respiratory muscle strength (resistive/threshold) and endurance (hyperpnoea) training, have been established to improve the endurance performance of healthy individuals. We performed a systematic review and meta-analysis in order to determine the factors that affect the change in endurance performance after RMT in healthy subjects. A computerized search was performed without language restriction in MEDLINE, EMBASE and CINAHL and references of original studies and reviews were searched for further relevant studies. RMT studies with healthy individuals assessing changes in endurance exercise performance by maximal tests (constant load, time trial, intermittent incremental, conventional [non-intermittent] incremental) were screened and abstracted by two independent investigators. A multiple linear regression model was used to identify effects of subjects' fitness, type of RMT (inspiratory or combined inspiratory/expiratory muscle strength training, respiratory muscle endurance training), type of exercise test, test duration and type of sport (rowing, running, swimming, cycling) on changes in performance after RMT. In addition, a meta-analysis was performed to determine the effect of RMT on endurance performance in those studies providing the necessary data. The multiple linear regression analysis including 46 original studies revealed that less fit subjects benefit more from RMT than highly trained athletes (6.0% per 10 mL · kg⁻¹ · min⁻¹ decrease in maximal oxygen uptake, 95% confidence interval [CI] 1.8, 10.2%; p = 0.005) and that improvements do not differ significantly between inspiratory muscle strength and respiratory muscle endurance training (p = 0.208), while combined inspiratory and expiratory muscle strength training seems to be superior in improving performance, although based on only 6 studies (+12.8% compared with inspiratory muscle strength training, 95% CI 3

  2. A power recirculating test rig for ball screw endurance tests

    Directory of Open Access Journals (Sweden)

    Giberti Hermes

    2016-01-01

    Full Text Available A conceptual design of an innovative test rig for endurance tests of ball screws is presented in this paper. The test rig layout is based on the power recirculating principle and it also allows to overtake the main critical issues of the ball screw endurance tests. Among these there are the high power required to make the test, the lengthy duration of the same and the high loads between the screw and the frame that holds it. The article describes the test rig designed scheme, the kinematic expedients to be adopted in order to obtain the required performance and functionality and the sizing procedure to choose the actuation system.

  3. Kinesiological Analysis of Stationary Running Performed in Aquatic and Dry Land Environments

    Directory of Open Access Journals (Sweden)

    Lima Alberton Cristine

    2015-12-01

    Full Text Available The purpose of the present study was to analyze the electromyographic (EMG signals of the rectus femoris (RF, vastus lateralis (VL, semitendinosus (ST and short head of the biceps femoris (BF during the performance of stationary running at different intensities in aquatic and dry land environments. The sample consisted of 12 female volunteers who performed the stationary running exercise in aquatic and dry land environments at a submaximal cadence (80 beats·min-1 controlled by a metronome and at maximal velocity, with EMG signal measurements from the RF, VL, ST and BF muscles. The results showed a distinct pattern between environments for each muscle examined. For the submaximal cadence of 80 beats·min-1, there was a reduced magnitude of the EMG signal in the aquatic environment, except for the ST muscle, the pattern of which was similar in both environments. In contrast to the submaximal cadence, the pattern of the EMG signal from all of the muscles showed similar magnitudes for both environments and phases of movement at maximal velocity, except for the VL muscle. Therefore, the EMG signals from the RF, VL, ST and BF muscles of women during stationary running had different patterns of activation over the range of motion between aquatic and dry land environments for different intensities. Moreover, the neuromuscular responses of the lower limbs were optimized by an increase in intensity from submaximal cadence to maximal velocity.

  4. Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Rosas Fabián

    2017-08-01

    Full Text Available Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ± 2.4 years were assigned to either a plyometric training group receiving a placebo (PLACEBO, n = 8, a plyometric training group receiving beta-alanine supplementation (BA, n = 8, or a control group receiving placebo without following a plyometric training program (CONTROL, n = 9. Athletes were evaluated for single and repeated jumps and sprints, endurance, and change-of-direction speed performance before and after the intervention. Both plyometric training groups improved in explosive jumping (ES = 0.27 to 1.0, sprinting (ES = 0.31 to 0.78, repeated sprinting (ES = 0.39 to 0.91, 60 s repeated jumping (ES = 0.32 to 0.45, endurance (ES = 0.35 to 0.37, and change-of-direction speed performance (ES = 0.36 to 0.58, whereas no significant changes were observed for the CONTROL group. Nevertheless, compared to the CONTROL group, only the BA group showed greater improvements in endurance, repeated sprinting and repeated jumping performances. It was concluded that beta-alanine supplementation during plyometric training may add further adaptive changes related to endurance, repeated sprinting and jumping ability.

  5. Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players.

    Science.gov (United States)

    Rosas, Fabián; Ramírez-Campillo, Rodrigo; Martínez, Cristian; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; McCrudden, Emma; Meylan, Cesar; Moran, Jason; Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Diaz, Daniela; Izquierdo, Mikel

    2017-09-01

    Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ± 2.4 years) were assigned to either a plyometric training group receiving a placebo (PLACEBO, n = 8), a plyometric training group receiving beta-alanine supplementation (BA, n = 8), or a control group receiving placebo without following a plyometric training program (CONTROL, n = 9). Athletes were evaluated for single and repeated jumps and sprints, endurance, and change-of-direction speed performance before and after the intervention. Both plyometric training groups improved in explosive jumping (ES = 0.27 to 1.0), sprinting (ES = 0.31 to 0.78), repeated sprinting (ES = 0.39 to 0.91), 60 s repeated jumping (ES = 0.32 to 0.45), endurance (ES = 0.35 to 0.37), and change-of-direction speed performance (ES = 0.36 to 0.58), whereas no significant changes were observed for the CONTROL group. Nevertheless, compared to the CONTROL group, only the BA group showed greater improvements in endurance, repeated sprinting and repeated jumping performances. It was concluded that beta-alanine supplementation during plyometric training may add further adaptive changes related to endurance, repeated sprinting and jumping ability.

  6. Run II performance of luminosity and beam condition monitors at CMS

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Jessica Lynn [DESY, Hamburg (Germany)

    2016-07-01

    The BRIL (Beam Radiation Instrumentation and Luminosity) system of CMS consists of instrumentation to measure the luminosity online and offline, and to monitor the LHC beam conditions inside CMS. An accurate luminosity measurement is essential to the CMS physics program, and measurement of the beam background is necessary to ensure safe operation of CMS. Many of the BRIL subsystems have been upgraded and others have been added for LHC Run II to complement the existing measurements. The beam condition monitor (BCM) consists of several sets of diamond sensors used to measure online luminosity and beam background with a single-bunch-crossing resolution. The BCM also detects when beam conditions become unfavorable for CMS running and may trigger a beam abort to protect the detector. The beam halo monitor (BHM) uses quartz bars to measure the background of the incoming beams at larger radii. The pixel luminosity telescope (PLT) consists of telescopes of silicon sensors designed to provide a CMS online and offline luminosity measurement. In addition, the forward hadronic calorimeter (HF) delivers an independent luminosity measurement, making the whole system robust and allowing for cross-checks of the systematics. An overview of the performance during 2015 LHC running for the new/updated BRIL subsystems will be given, including the uncertainties of the luminosity measurements.

  7. The Impact of Endurance Training on Functional Parameters During the Preparation Phase among Cross-Country Skiers

    Directory of Open Access Journals (Sweden)

    Žiška Peter

    2016-05-01

    Full Text Available In the study, we have tried to demonstrate the effect of endurance training on changes in functional parameters during the preparation phase (12-week mesocycle among cross-country skiers. The group consisted of 10 male cross-country skiers (age: 21.4 ±5 year who completed control (1st 6 week mesocycle and experimental period (2nd 6 week mesocycle.We focused on the following time-varying parameters: changes in maximal oxygen uptake (VO2max, the level of aerobic (AeT and anaerobic thresholds (AT, maximum heart rate (HRmax and performance on the running treadmill. The intra-individual monitoring of each athlete revealed statistical significance of VO2max (mid_VO2max = 69.48 ± 5.72 l.kg-1.min-1, post_ VO2max = 70.96 ± 5.67 ml.kg-1.min-1; p≤0.05 and the level of AT (mid_AT = 86.2 ± 5.43 %, post_AT = 87.8 ± 5.59 %; p≤0.01 the performance on the running treadmill (mid_t = 14:54 ± 1:43 min., post_t = 15:30 ± 1:50 min.; p≤0.05.The significant changes were recorded in the AeT(pre_AeT = 70.3 ± 7.56 %, mid_AeT = 72.5 ± 7.59 %; p≤0.05 in theHRmax(pre_HRmax = 190 ± 8.04 bpm, mid_HRmax = 189 bpm, post_HRmax = 188 ± 7.34 bpm; p = n.s. during control period. We assume that the significant differences occurred as a result of adaptation changes due to training stimuli, which were induced by changes in functional parameters. Increased training volume in zone lower level of oxygen regime (A1, upper level of oxygen regime (A2 and upper level of lactate tolerance(T2 during experimental period elicited changes which reflected the increase functional parameters and performance on the running treadmill compared to that of control period.

  8. Effect of Carbohydrate, Caffeine, and Carbohydrate + Caffeine Mouth Rinsing on Intermittent Running Performance in Collegiate Male Lacrosse Athletes.

    Science.gov (United States)

    Dolan, Patrick; Witherbee, Kyle E; Peterson, Kimi M; Kerksick, Chad M

    2017-09-01

    Dolan, P, Witherbee, KE, Peterson, KM, and Kerksick, CM. Effect of carbohydrate, caffeine, and carbohydrate + caffeine mouth rinsing on intermittent running performance in collegiate male lacrosse athletes. J Strength Cond Res 31(9): 2473-2479, 2017-Recently, an interest has developed in the potential to rinse the oral cavity with key nutrients to impact various types of exercise and presumably sporting performance. Although multiple studies examining carbohydrate mouth rinsing have been completed, conflicting evidence surrounding caffeine mouth rinsing persists, and no research has explored its ability to impact high-intensity, intermittent running performance. This study investigated the independent and synergistic ability of carbohydrate and caffeine mouth rinsing to improve intermittent running performance. The Yo-Yo Intermittent Recovery Test-Level 1 (Yo-Yo Level 1) was completed in 10 collegiate (National Collegiate Athletic Association [NCAA] Division II) male lacrosse players after a 10-second mouth rinse with a solution of either carbohydrate (CHO), caffeine (CAF), carbohydrate + caffeine (CHO + CAF), placebo (H2O), or a no rinse control (CON). No significant improvements in Yo-Yo IRT-1 performance were found (p > 0.05). Perceptual indications of effort (i.e., rating of their perceived exertion [RPE]) were significantly lower (p ≤ 0.05) in CHO and CHO + CAF when compared with CON after speed level 11. Interestingly, RPE levels were nonsignificantly lower in all but one level of the Yo-Yo Level 1 for CHO in comparison with other groups. Carbohydrate and caffeine mouth rinsing seems to exert no impact on running performance before maximal intermittent running in a group of male collegiate lacrosse players.

  9. Glycogen availability and skeletal muscle adaptations with endurance and resistance exercise

    NARCIS (Netherlands)

    Knuiman, Pim; Hopman, Maria T.E.; Mensink, Marco

    2015-01-01

    It is well established that glycogen depletion affects endurance exercise performance negatively. Moreover, numerous studies have demonstrated that post-exercise carbohydrate ingestion improves exercise recovery by increasing glycogen resynthesis. However, recent research into the effects of

  10. Influence of music on maximal self-paced running performance and passive post-exercise recovery rate.

    Science.gov (United States)

    Lee, Sam; Kimmerly, Derek S

    2016-01-01

    The purpose of this study was to examine the influence of fast tempo music (FM) on self-paced running performance (heart rate, running speed, ratings of perceived exertion), and slow tempo music (SM) on post-exercise heart rate and blood lactate recovery rates. Twelve participants (5 women) completed three randomly assigned conditions: static noise (control), FM and SM. Each condition consisted of self-paced treadmill running, and supine postexercise recovery periods (20 min each). Average running speed, heart rate (HR) and ratings of perceived exertion (RPE) were measured during the treadmill running period, while HR and blood lactate were measured during the recovery period. Listening to FM during exercise resulted in a faster self-selected running speed (10.8±1.7 vs. 9.9±1.4 km•hour-1, Peffect P<0.001) and blood lactate at the end of recovery (2.8±0.4 vs. 4.7±0.8 mmol•L-1, P<0.05). Listening to FM during exercise can increase self-paced intensity without altering perceived exertion levels while listening to SM after exercise can accelerate the recovery rate back to resting levels.

  11. The Run-2 ATLAS Trigger System: Design, Performance and Plan

    CERN Document Server

    zur Nedden, Martin; The ATLAS collaboration

    2016-01-01

    In high-energy physics experiments, online selection is crucial to select interesting collisions from the large data volume. The ATLAS experiment at the Large Hadron Collider (LHC) utilizes the trigger system that consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT), reducing the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 1000 Hz. In the LHC Run-2 starting from in 2015, the LHC operates at centre-of-mass energy of 13 TeV providing a luminosity up to $1.2 \\cdot 10^{34} {\\rm cm^{-2}s^{-1}}$. The ATLAS trigger system has to cope with these challenges, while maintaining or even improving the efficiency to select relevant physics processes. In this paper, the ATLAS trigger system for LHC Run-2 is reviewed. Secondly, the impressive performance improvements in the HLT trigger algorithms used to identify leptons, hadrons and global event quantities like missing transverse energy is shown. Electron, muon and photon triggers covering trans...

  12. Effects of Adolescent Sport Practice on Health Outcomes of Adult Amateur Endurance Cyclists: Adulthood Is Not Too Late to Start.

    Science.gov (United States)

    Munguia-Izquierdo, Diego; Mayolas-Pi, Carmen; Peñarrubia-Lozano, Carlos; Paris-Garcia, Federico; Bueno-Antequera, Javier; Oviedo-Caro, Miguel Angel; Legaz-Arrese, Alejandro

    2017-11-01

    We investigated the effects of adolescent sport practice on the training, performance, and health outcomes of adult amateur endurance cyclists and compared health outcomes of 3 adult groups: amateur endurance cyclists who practiced sports during adolescence, amateur endurance cyclists who did not practice sports during adolescence, and inactive individuals. In 859 (751 men and 108 women) adult cyclists and 718 inactive subjects (307 men and 411 women), we examined adolescent sport practice, current training status, quality of life, quality of sleep, anxiety and depression, and cardiometabolic risk: body mass index, physical activity, physical fitness, adherence to Mediterranean diet, and alcohol and tobacco consumption. Independent of gender, no significant differences in training, performance, or health outcomes were observed between amateur endurance cyclists who practiced sports during adolescence and those who did not. Independent of gender, cyclists reported significantly better health outcomes than inactive individuals in all variables, except depression. Training, performance, and health outcomes did not differ between adult amateur endurance cyclists who practiced sports during adolescence and those who did not, but their health outcomes were significantly improved compared with inactive individuals, except for depression.

  13. Exercise performance and cardiovascular health variables in 70-year-old male soccer players compared to endurance-trained, strength-trained and untrained age-matched men

    DEFF Research Database (Denmark)

    Randers, Morten Bredsgaard; Andersen, Jesper Løvind; Petersen, Jesper

    2014-01-01

    Abstract The aim was to investigate performance variables and indicators of cardiovascular health profile in elderly soccer players (SP, n = 11) compared to endurance-trained (ET, n = 8), strength-trained (ST, n = 7) and untrained (UT, n = 7) age-matched men. The 33 men aged 65-85 years underwent...

  14. The Effect of Different Repeated-High-Intensity-Effort Bouts on Subsequent Running, Skill Performance, and Neuromuscular Function.

    Science.gov (United States)

    Johnston, Rich D; Gabbett, Tim J; Jenkins, David G; Speranza, Michael J

    2016-04-01

    To assess the impact of different repeated-high-intensity-effort (RHIE) bouts on player activity profiles, skill involvements, and neuromuscular fatigue during small-sided games. 22 semiprofessional rugby league players (age 24.0 ± 1.8 y, body mass 95.6 ± 7.4 kg). During 4 testing sessions, they performed RHIE bouts that each differed in the combination of contact and running efforts, followed by a 5-min off-side small-sided game before performing a second bout of RHIE activity and another 5-min small-sided game. Global positioning system microtechnology and video recordings provided information on activity profiles and skill involvements. A countermovement jump and a plyometric push-up assessed changes in lower- and upper-body neuromuscular function after each session. After running-dominant RHIE bouts, players maintained running intensities during both games. In the contact-dominant RHIE bouts, reductions in moderate-speed activity were observed from game 1 to game 2 (ES = -0.71 to -1.06). There was also moderately lower disposal efficiency across both games after contact-dominant RHIE activity compared with running-dominant activity (ES = 0.62-1.02). Greater reductions in lower-body fatigue occurred as RHIE bouts became more running dominant (ES = -0.01 to -1.36), whereas upper-body fatigue increased as RHIE bouts became more contact dominant (ES = -0.07 to -1.55). Physical contact causes reductions in running intensity and the quality of skill involvements during game-based activities. In addition, the neuromuscular fatigue experienced by players is specific to the activities performed.

  15. Frequency of exercise-induced ST-T-segment deviations and cardiac arrhythmias in recreational endurance athletes during a marathon race: results of the prospective observational Berlin Beat of Running study.

    Science.gov (United States)

    Herm, Juliane; Töpper, Agnieszka; Wutzler, Alexander; Kunze, Claudia; Krüll, Matthias; Brechtel, Lars; Lock, Jürgen; Fiebach, Jochen B; Heuschmann, Peter U; Haverkamp, Wilhelm; Endres, Matthias; Jungehulsing, Gerhard Jan; Haeusler, Karl Georg

    2017-08-03

    While regular physical exercise has many health benefits, strenuous physical exercise may have a negative impact on cardiac function. The 'Berlin Beat of Running' study focused on feasibility and diagnostic value of continuous ECG monitoring in recreational endurance athletes during a marathon race. We hypothesised that cardiac arrhythmias and especially atrial fibrillation are frequently found in a cohort of recreational endurance athletes. The main secondary hypothesis was that pathological laboratory findings in these athletes are (in part) associated with cardiac arrhythmias. Prospective observational cohort study including healthy volunteers. One hundred and nine experienced marathon runners wore a portable ECG recorder during a marathon race in Berlin, Germany. Athletes underwent blood tests 2-3 days prior, directly after and 1-2 days after the race. Overall, 108 athletes (median 48 years (IQR 45-53), 24% women) completed the marathon in 249±43 min. Blinded ECG analysis revealed abnormal findings during the marathon in 18 (16.8%) athletes. Ten (9.3%) athletes had at least one episode of non-sustained ventricular tachycardia, one of whom had atrial fibrillation; eight (7.5%) individuals showed transient ST-T-segment deviations. Abnormal ECG findings were associated with advanced age (OR 1.11 per year, 95% CI 1.01 to 1.23), while sex and cardiovascular risk profile had no impact. Directly after the race, high-sensitive troponin T was elevated in 18 (16.7%) athletes and associated with ST-T-segment deviation (OR 9.9, 95% CI 1.9 to 51.5), while age, sex and cardiovascular risk profile had no impact. ECG monitoring during a marathon is feasible. Abnormal ECG findings were present in every sixth athlete. Exercise-induced transient ST-T-segment deviations were associated with elevated high-sensitive troponin T (hsTnT) values. ClinicalTrials.gov NCT01428778; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article

  16. Effects of endurance and endurance-strength exercise on biochemical parameters of liver function in women with abdominal obesity.

    Science.gov (United States)

    Skrypnik, Damian; Ratajczak, Marzena; Karolkiewicz, Joanna; Mądry, Edyta; Pupek-Musialik, Danuta; Hansdorfer-Korzon, Rita; Walkowiak, Jarosław; Jakubowski, Hieronim; Bogdański, Paweł

    2016-05-01

    Obesity is a risk factor of nonalcoholic fatty liver disease. Although the standard therapy for obesity involves physical exercise, well-planned studies of the changes in liver function in response to different exercise intensities in obese subjects are scarce. The aim of the present study was to examine a question of how does exercise mode affect the liver function. 44 women with abdominal obesity were randomized into two exercise groups: endurance (group A) and endurance-strength (group B). Women in each group exercised for 60min 3 times/week for a 3-month period. Markers of liver function: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltranspeptidase (GGT), alkaline phosphatase (ALP) activities, and bilirubin levels were quantified. We found significant differences in ALT (pexercise. Blood ALT and AST tended to decrease in group B, increase in group A. Significant reduction in serum GGT level after exercise in both groups was observed (pexercise led to changes in serum ALP activity and total or direct bilirubin level. However, endurance-strength training resulted in significant decreases in serum indirect bilirubin (pexercise (group B). The mode of exercise does matter: endurance-strength exercise led to a greater improvement, compared to endurance exercise, in the