共查询到20条相似文献,搜索用时 31 毫秒
1.
This study aimed to evaluate body composition, sleep, precompetitive anxiety and dietary intake on the elite female gymnasts’ performance prior to an international competition. Sixty-seven rhythmic gymnasts of high performance level were evaluated in relation to sport and training practice, body composition, sleep duration, daytime sleepiness by the Epworth Sleepiness Scale (ESS), sleep quality by the Pittsburgh Sleep Quality Index (PSQI), precompetitive anxiety by the Sport Competition Anxiety Test form A (SCAT-A) and detailed dietary intake just before an international competition. Most gymnasts (67.2%) suffered from mild daytime sleepiness, 77.6% presented poor sleep quality and 19.4% presented high levels of precompetitive anxiety. The majority of gymnasts reported low energy availability (EA) and low intakes of important vitamins including folate, vitamins D, E and K; and minerals, including calcium, iron, boron and magnesium (p?.05). Gymnasts’ performance was positively correlated with age (p?=?.001), sport practice (p?=?.024), number of daily training hours (p?=?.000), number of hours of training/week (p?=?.000), waist circumference (WC) (p?=?.008) and sleep duration (p?=?.005). However, it was negatively correlated with WC/hip circumference (p?=?.000), ESS (p?=?.000), PSQI (p?=?.042), SCAT-A (p?=?.002), protein g/kg (p?=?.028), EA (p?=?.002) and exercise energy expenditure (p?=?.000). High performance gymnasts presented poor sleep habits with consequences upon daytime sleepiness, sleep quality and low energy availability. 相似文献
2.
《European Journal of Sport Science》2013,13(8):681-686
AbstractNo published research has assessed sleep patterns of elite rugby union players following match-play. The present study examined sleep patterns of professional rugby union players, prior and post-match-play, to assess the influence of competition. Twenty-eight male rugby union players (24.4?±?2.9 years, 103.9?±?12.2?kg) competed in one of four competitive home matches. Player's sleep behaviours were monitored continuously using an Actiwatch® from two days before the match, until three days post-match. Repeated measures of analysis of variance (ANOVA) showed significant differences across the time points measured for time to bed (F?=?26.425, η2 ?=?0.495, p < .001), get up time (F?=?21.175, η2?=?0.440, p?<?.001), time spent in bed (F?=?10.669, η2?=?0.283, p?<?.001), time asleep (F?=?8.752, η2?=?0.245, p?<?.001) and percentage of time moving (F?=?4.602, η2?=?0.146 p?<?.05). Most notable, post hocs revealed a significant increase for time in bed the night before the match (p?<?.01; 95% CI?=?0?:?10–1?:?28?h; 9.7?±?13.5%) compared with the reference night sleep. Furthermore, time asleep significantly decreased post-match (p?<?.05; 95% CI?=??0:03 to ?1:59?h; ?19.5?±?19.8%) compared to two nights pre-match. Across all time points, sleep latency and efficiency for most players were considered abnormal compared to that expected in normal populations. The results demonstrate that sleep that is deprived post-match may have detrimental effects on the recovery process. 相似文献
3.
Parkour is a modern physical activity that consists of using the environment, mostly urban, as a playground of obstacles. The aims of this study were (i) to investigate age, anthropometric and training characteristics of Parkour practitioners, called ‘traceurs’ and (ii) to assess jump performances and muscular characteristics of traceurs, compared to those of gymnasts and power athletes. The mean age of the population of traceurs studied (n?=?130) was 19.4?±?4.3 years, women represented 12.4% of the total field and mean training volume was 8.1?±?0.5?hours/week. Vertical and long jump performances were analysed on smaller samples of participants (four groups, n?=?15 per group); and eccentric (?90°?s?1, ?30°?s?1), concentric (30°?s?1, 90°?s?1) and isometric knee extensors torques were evaluated by means of an isokinetic dynamometer. Traceurs showed greater (P?.01) drop jump performance (64.9?±?1.5?cm) than gymnasts (60.9?±?1.1?cm) and greater (P?.001) counter movement jump with arms (59.2?±?1.5?cm) than power athletes (53.0?±?1.4?cm). Standing long jump performances were greater (P?.05) for traceurs (282.7?±?5.2?cm) compared to other athletes (gymnasts: 273.9?±?7.3?cm; power athletes: 261.3?±?6.7?cm). Eccentric knee extension torques were greater (P?.05) for traceurs compared to other athletes. This study revealed that Parkour training induces major development of jump and muscular skills. The use of such training has several practical applications as it provides a better resistance to high eccentric load and helps reinforce musculoskeletal structures. 相似文献
4.
Ian C. Dunican Charles C. Higgins Maddison J. Jones Michael W. Clarke Kevin Murray Brian Dawson 《European Journal of Sport Science》2018,18(4):513-523
Objective: To examine the relationship between regular game-related caffeine consumption on sleep after an evening Super Rugby game. Methods: Twenty elite rugby union players wore a wrist-activity monitor to measure sleep for three days before, three days after and on the night of an evening Super Rugby game (19:00–21:00). Players ingested caffeine as they would normally (i.e. before and sometimes during a game) and saliva samples were collected before (17:00) and after (21:30) the game for caffeine concentration. Results: Compared to the nights leading up to the game, on the night of the game, players went to bed 3?h later (23:08?±?66?min vs 02:11?±?114?min; p?.001) and had 1:30?hh:mm less sleep (5:54?±?2:59 vs 8:02?±?1:24 hh:mm; p?.05) and four players did not sleep after the game. Post-game caffeine saliva concentrations were greater than pre-game levels in 17 players (Pre-game 0.40 µg/mL vs Post-game 2.77 µg/mL; p?.001). The increase in caffeine saliva concentrations was moderately associated with an increase in sleep latency (p?.05), a decrease in sleep efficiency (p?.05), and a trend for a decrease in sleep duration (p?=?.06) on game night. Conclusion: Caffeine consumption before a Super Rugby game markedly increases post-game saliva caffeine levels. This may contribute to the observed 3.5?h delay in time at sleep onset and the 1.5?h reduction in sleep duration on the night of the game. This study highlights the need for a strategic approach to the use of caffeine within a Super Rugby team considering the potential effect on post-game sleep. 相似文献
5.
Shannon O’Donnell Steve Bird Gregory Jacobson Matthew Driller 《European Journal of Sport Science》2018,18(5):611-618
Stress hormone and sleep differences in a competition versus training setting are yet to be evaluated in elite female team-sport athletes. The aim of the current study was to evaluate salivary cortisol and perceptual stress markers during competition and training and to determine the subsequent effects on sleep indices in elite female athletes. Ten elite female netball athletes (mean?±?SD; age: 23?±?6 years) had their sleep monitored on three occasions; following one netball competition match (MATCH), one netball match simulation session (TRAIN), and one rest day (CONTROL). Perceived stress values and salivary cortisol were collected immediately pre- (17:15 pm) and post-session (19:30 pm), and at 22:00 pm. Sleep monitoring was performed using wrist actigraphy assessing total time in bed, total sleep time (TST), efficiency (SE%), latency, sleep onset time and wake time. Cortisol levels were significantly higher (p?.01) immediately post MATCH compared with TRAIN and CONTROL (mean?±?SD; 0.700?±?0.165, 0.178?±?0.127 and 0.157?±?0.178?μg/dL, respectively) and at 22:00 pm (0.155?±?0.062, 0.077?±?0.063, and 0.089?±?0.083?μg/dL, respectively). There was a significant reduction in TST (?118?±?112?min, p?.01) and SE (?7.7?±?8.5%, p?.05) following MATCH vs. TRAIN. Salivary cortisol levels were significantly higher, and sleep quantity and quality were significantly reduced, following competition when compared to training and rest days. 相似文献
6.
Attenuated performance during intense exercise with limited endogenous carbohydrate (CHO) is well documented. Therefore, this study examined whether caffeine (CAF) mouth rinsing would augment performance during repeated sprint cycling in participants with reduced endogenous CHO. Eight recreationally active males (aged 23?±?2?yr, body mass 84?±?4?kg, stature 178?±?7?cm) participated in this randomized, single-blind, repeated-measures crossover investigation. Following familiarization, participants attended two separate evening glycogen depletion sessions. The following morning, participants completed five, 6?s sprints on a cycle ergometer (separated by 24?s active recovery), with mouth rinsing either (1) a placebo solution or (2) a 2% CAF solution. During a fifth visit, participants completed the sprints without prior glycogen depletion. Repeated-measures ANOVA identified significant main effect of condition (CAF, placebo, and control [P?.05; effect size (ES)?=?0.850–0.897]), sprint (1–5 [P?.005; ES?=?0.871–0.986]), and interaction (condition?×?sprint [P?.05; ES?=?0.831–0.846]), for peak and mean power. The control condition exhibited the highest peak power (overall mean 760?±?77?W) and mean power (overall mean 699?±?83W) over the five sprints (P?.001 in both instances). CAF peak power (overall mean 643?±?79?W) was significantly greater than placebo (mean 573?±?79?W [P?.05; ES?=?0.850]). Additionally, CAF mean power (overall mean 589?±?80?W) was significantly greater than placebo (519?±?82?W [P?.05; ES?=?0.397]). These data indicate that mouth rinsing a caffeinated solution reduces decrements caused by CHO reduction, which may benefit athletes wishing to train in a low-CHO state. 相似文献
7.
Mo’ath F. Bataineh Ali M. Al-Nawaiseh Mohammad H. Abu Altaieb David M. Bellar Omar S. Hindawi 《European Journal of Sport Science》2018,18(3):357-366
Mouth rinsing using a carbohydrate (CHO) solution has been suggested to improve physical performance in fasting participants. This study examined the effects of CHO mouth rinsing during Ramadan fasting on running time to exhaustion and on peak treadmill speed (Vpeak). In a counterbalanced crossover design, 18 sub-elite male runners (Age: 21?±?2 years, Weight: 68.1?±?5.7?kg, VO2max: 55.4?±?4.8?ml/kg/min) who observed Ramadan completed a familiarization trial and three experimental trials. The three trials included rinsing and expectorating a 25?mL bolus of either a 7.5% sucrose solution (CHO), a flavour and taste matched placebo solution (PLA) for 10?s, or no rinse (CON). The treatments were performed prior to an incremental treadmill test to exhaustion. Three-day dietary and exercise records were obtained on two occasions and analysed. Anthropometric characteristics were obtained and recorded for all participants. A main effect for mouth rinse on peak velocity (Vpeak) (CHO: 17.6?±?1.5?km/h; PLA: 17.1?±?1.4?km/h; CON: 16.7?±?1.2?km/h; P?.001, ηp2?=?0.49) and time to exhaustion (CHO: 1282.0?±?121.3?s; PLA: 1258.1?±?113.4?s; CON: 1228.7?±?98.5?s; P?=?.002, ηp2?=?0.41) was detected, with CHO significantly higher than PLA (P?.05) and CON (P?.05). Oxygen consumption, heart rate, respiratory exchange ratio, and rating of perceived exertion were not significantly different between treatments or trials (P?>?.05). Energy availability from dietary analysis, body weight, and fat-free mass did not change during the last two weeks of Ramadan (P?>?.05). This study concludes that carbohydrate mouth rinsing improves running time to exhaustion and peak treadmill speed under Ramadan fasting conditions. 相似文献
8.
Roman Farana Timothy Exell Gerda Strutzenberger Gareth Irwin 《European Journal of Sport Science》2018,18(3):423-430
Biophysical loading of the elbow and wrist is a potential reason for chronic lesions in gymnastics and present a real concern for coaches, scientist and clinicians. Previous research has identified injury risk factors during round-off (RO) skills in elite female gymnasts. The aim of this study was to investigate key elbow and wrist joint injury risk factors during different techniques of fundamental cartwheel (CW) and RO skills performed by young female artistic gymnasts. Seventeen active young female gymnasts performed 30 successful trials of both CW and RO from a hurdle step with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic (240?Hz) and kinetic (1200?Hz) data were collected for each trial. One-way repeated measures ANOVA and effect size (ES) were used for statistical analysis. The results showed statistically significant differences (P?.05) and large ES (>0.8) among hand positions for peak vertical ground reaction force (VGRF), peak elbow compression force, peak wrist compression force, elbow internal adduction moment and wrist dorsiflexion angle. In conclusion, the parallel and reverse techniques increase peak VGRF, elbow and wrist compression forces, and elbow internal adduction moment. These differences indicate that the parallel and reverse techniques may increase the potential of elbow and wrist injuries in young gymnasts compared with the T-shape technique; this is of particular importance with the high frequency of the performance of these fundamental skills. 相似文献
9.
Olivier Girard Sébastien Banzet Nathalie Koulmann Mounir Chennaoui Catherine Drogou Hakim Chalabi 《European Journal of Sport Science》2018,18(10):1346-1356
We tested the hypothesis that backward downhill walking (eccentric component) impairs both voluntary activation and muscle contractile properties in the plantar flexors and delays recovery as compared to a gradient and distance-matched uphill walk. Fourteen males performed two 30-min walking exercises (velocity: 1?m/?s; grade: 25%; load: 12% of body weight), one downhill (DW) and one uphill (UP), in a counterbalanced order, separated by 6?weeks. Neuromuscular test sessions were performed before, after, 24-, 48- and 72-h post-exercise, including motor nerve stimulations during brief (5?s) and sustained (1?min) maximal isometric voluntary contractions of the plantar flexors. DW (?18.1?±?11.1%, P?.001), but not UP (?6.0?±?7.7%, P?=.15), decreased torque production during brief contractions for at least three days post-exercise (P?.05). Voluntary activation during brief contractions decreased after DW (P?.05), but not UP, and recovered by 24?h. Both UP (?9.3?±?9.0%, P?=?.024) and DW (?25.6?±?10.3%, P?.001) decreased torque production during sustained contractions but voluntary activation (P?=?.001) was lower in DW than UP. Peak twitch torque and maximum rates of torque development and relaxation were equally reduced after UP and DW (P?.05), and recovered by 24?h. DW induced an increase in muscle soreness with peak values observed 48?h post-walking (P?.001), whereas post-UP exercise changes were non-significant (all P?>?.05). Using a direct comparison, the capacity to drive the plantar flexors during sustained contractions remains sub-optimal during the three-day recovery period in response to non-exhaustive, downhill backward walking in reference to an uphill exercise matched for distance covered. 相似文献
10.
Andrew J. Shaw Stephen A. Ingham Jonathan P. Folland 《European Journal of Sport Science》2018,18(5):630-638
Running downhill, in comparison to running on the flat, appears to involve an exaggerated stretch-shortening cycle (SSC) due to greater impact loads and higher vertical velocity on landing, whilst also incurring a lower metabolic cost. Therefore, downhill running could facilitate higher volumes of training at higher speeds whilst performing an exaggerated SSC, potentially inducing favourable adaptations in running mechanics and running economy (RE). This investigation assessed the efficacy of a supplementary 8-week programme of downhill running as a means of enhancing RE in well-trained distance runners. Nineteen athletes completed supplementary downhill (?5% gradient; n?=?10) or flat (n?=?9) run training twice a week for 8 weeks within their habitual training. Participants trained at a standardised intensity based on the velocity of lactate turnpoint (vLTP), with training volume increased incrementally between weeks. Changes in energy cost of running (EC) and vLTP were assessed on both flat and downhill gradients, in addition to maximal oxygen uptake (?O2max). No changes in EC were observed during flat running following downhill (1.22?±?0.09 vs 1.20?±?0.07?Kcal?kg?1?km?1, P?=?.41) or flat run training (1.21?±?0.13 vs 1.19?±?0.12?Kcal?kg?1?km?1). Moreover, no changes in EC during downhill running were observed in either condition (P?>?.23). vLTP increased following both downhill (16.5?±?0.7 vs 16.9?±?0.6?km?h?1 , P?=?.05) and flat run training (16.9?±?0.7 vs 17.2?±?1.0?km?h?1, P?=?.05), though no differences in responses were observed between groups (P?=?.53). Therefore, a short programme of supplementary downhill run training does not appear to enhance RE in already well-trained individuals. 相似文献
11.
Physiological or performance tests are routinely utilised to assess athletes’ recovery. At present, the ideal tool to assess recovery remains unknown. Therefore, the aim of this systematic review was to examine the change in creatine kinase (CK) and neuromuscular function as measured via a countermovement jump (CMJ) following a match in the contact codes of football. A comprehensive search of databases was undertaken with RevMan (V 5.3) used for statistical analysis. Our results demonstrated that CK pre- versus post-match (standardised mean difference (SMD)?=?0.90, 95% CI?=?0.50 to 1.31, p?.0001), CK pre- versus 24?h post-match (SMD?=?1.50, 95% CI?=?1.12 to 1.88, p?.00001), and CK pre- versus 48?h post-match all increased significantly (SMD?=?0.90, 95% CI?=?0.50 to 1.31, p?.0001), while CMJ peak power (PP) pre- versus post-match (SMD?=??0.59, 95% CI?=??1.12 to ?0.06, p?=?.03), and pre- versus 24?h post-match (SMD?=??0.80, 95% CI?=??1.31 to ?0.28, p?=?.002) decreased significantly. There was a significant relationship between the change in CK and the change in CMJ PP from immediately pre to immediately post (r?=??0.924, p?=?.025), and between CMJ immediately following a match and 24?h CK change (r?=??0.983, p?=?.017). In conclusion, CK levels increase and performance in the CMJ decreases following a match of a contact code of football. The identification of this relationship may allow coaching staff to implement a standalone measure of recovery. 相似文献
12.
Pierre Touzard Richard Kulpa Benoit Bideau Bernard Montalvan Caroline Martin 《European Journal of Sport Science》2019,19(6):765-773
Waiter’s serve (WS) is a specific tennis serve posture frequently observed in young players, and commonly considered as a technical error by tennis coaches. However, biomechanical impact of WS is unknown. The aims of this study were to identify the potential consequences of WS in young elite players relating to performance and injury risk, and to explain the kinematic causes of WS. Serve of 18 male junior elite players (Top 10 national French ranking, aged 12–15 years) was captured with a 20 camera, 200?Hz VICON MX motion analysis system. Depending on their serve technique, the players were divided into two groups (WS versus Normal Serve [NS]) by experienced coaches. Injury data were collected for each player during a 12-month-period following the motion capture. Normalized peak kinetic values of the dominant arm were calculated using inverse dynamics. In order to explain WS posture, upper limb kinematics were calculated during the cocking and the acceleration phases of the serve. Shoulder internal rotation torque, wrist proximal and anterior forces (P?.05) and elbow varus torque (P?.01) were significantly higher in WS group, with no difference from NS group concerning serve velocity. Moreover, significant lower shoulder abduction and higher wrist extension (P?.05) were observed for WS players during the cocking phase. Even if no significant difference was found between groups concerning injuries, higher upper limb joint loads suggested WS could be considered as pathomechanical in young elite players and could lead to upper limb joint injuries. 相似文献
13.
Hugo Ribeiro Zanetti Lucas Gonçalves da Cruz Camilo Luís Monteiro Lourenço Fernando de Freitas Neves Mário Leon Silva-Vergara Edmar Lacerda Mendes 《European Journal of Sport Science》2016,16(8):1232-1239
The purpose of this study is to analyse the effect of 12 weeks of non-linear resistance training (NLRT) on anthropometry, muscle strength and inflammatory biomarkers in persons infected with human immunodeficiency virus (PIHIV). Thirty previously sedentary PIHIVs were randomized into the NLRT (n?=?15) and control (CON, n?=?15) groups. NLRT group were submitted to 12 weeks of training, whereas the CON group maintained their daily habits. At baseline and after 12 weeks, both groups underwent anthropometric evaluations and blood sampling for the analysis of inflammatory biomarkers. Analysis of covariance using preintervention values as covariate was performed to determine the effects of exercise on anthropometry, muscle strength, cytokines levels and T cells. Significance was set at p?0.05. After 12 weeks of intervention, there was a decrease in subcutaneous body fat (p?.0001), neck, abdomen and waist circumferences (p .05), waist-to-hip ratio (p?=?.009), blood levels of interleukin (IL)-1β (p?=?.029), IL-6 (p?=?.005), IL-8 (p?=?.010), and tumour necrosis factor (TNF)-α (p?=?.001) and an increase in muscle strength (p?.0001), IL-10 levels (p?=?.030) and CD4+ (p?=?.004) and CD8+ (p?.0001) counts in the NLRT compared to CON group. Twelve weeks of NLRT promoted positive changes in the body fat, body circumferences, muscular strength and inflammatory profile in PIHIV. 相似文献
14.
Nessan Costello Kevin Deighton Joshua Dyson Jim Mckenna Ben Jones 《European Journal of Sport Science》2017,17(8):1044-1055
To ensure that elite adolescent athletes meet their unique training, growth and maturation demands, it is imperative to have access to valid measures of energy intake. Contemporary methods demand close attention-to-detail, meaning that athletes often do not fully adhere to real-time protocols. This study represents the first investigation of a real-time dietary assessment designed using a comprehensive behaviour change framework (COM-B). In a crossover design, 12 elite adolescent male rugby players recorded their energy intake via an estimated food diary (est-FD) and photography-based mobile assessment (‘Snap-n-Send’), combined with a 24-h dietary recall interview. Two 4-day assessment periods were divided into three separate recording environments: 96?h free-living and researcher-observed; 72?h free-living and 10?h researcher-observed. Assessment periods were one month apart. All foods and beverages were provided and weighed by the research team to quantify actual intakes. ‘Snap-n-Send’ reported a small mean bias for under-reporting across 96?h (?0.75?MJ?day?1; 95% confidence interval [CI] for bias?=??5.7% to ?2.2%, p?<?.001), 72?h (?0.76?MJ?day?1; 95% CI for bias?=??5.6% to ?2.1%, p?=?.004) and 10?h (?0.72?MJ?day?1; 95% CI for bias?=??8.1% to ?0.1%; p?=?.067) environments. The est-FD reported a moderate mean bias for under-reporting across 96?h (?2.89?MJ?day?1; 95% CI for bias?=??17.9% to ?10.2%; p?<?.001), 72?h (?2.88?MJ?day?1; 95% CI for bias?=??17.9% to ?10.1%; p?<?.001) and 10?h (?2.52?MJ?day?1;?26.1% to ?5.3%; p?=?.023) environments. Results evidence the ability of ‘Snap-n-Send’ to accurately assess the diet of elite adolescent athletes, signalling the exciting promise of this comprehensive and theoretical behavioural approach within valid dietary assessment. 相似文献
15.
Christopher Latella Ashlee Hendy Dan Vanderwesthuizen Wei-Peng Teo 《European Journal of Sport Science》2018,18(7):984-993
Objective: The acute responses to resistance training (RT) between males and females are poorly understood, especially from a neural perspective. Therefore, we aimed to compare the corticospinal and intracortical responses during fatigue and recovery following RT.Methods: Twenty-two participants (12M, 10F) completed one-session of RT (3?×?12 repetition maximum) unilateral leg extensions with 60?s recovery. Single- and paired-pulse transcranial magnetic stimulation measured changes in the motor-evoked potential (MEP), corticospinal silent period (CSP), CSP/MEP ratio, and intracortical facilitation/inhibition (ICF, SICI). The maximal compound wave (MMAX) measured peripheral excitability of the rectus femoris (RF) and maximal voluntary isometric contraction (MVIC) neuromuscular function of the leg extensors. Measures were taken immediately post, 30?min, 1 and 6?h post-training.Results: A significantly greater increase in MEP/MMAX ratio (p?=?.005) was observed for females immediately post-training compared to males. While no sex differences in MEP/MMAX ratio was observed at 30?min and 1?h post-training, a greater MEP/MMAX ratio for males was observed at 30?min (p?.001), which remained elevated up until 1?h post-training for males when compared to baseline (p?=?.003). CSP trended to decrease for males compared to females immediately post-training (d?=?1.93). MVIC was decreased post-training for males; 14.22% and females; 14.16% (P?.001), with MMAX reduced at 30?min for both groups (P?.001). No differences in the CSP/MEP ratio, SICI or ICF were observed (P?>?.05).Conclusion: The net output of corticospinal excitability is similar between males and females during fatigue. However, the mechanism in which this is modulated (increased MEP, decreased CSP) appears to be sex-specific. 相似文献
16.
Amelia Guadalupe-Grau Lorena Rodríguez-García Rafael Torres-Peralta David Morales-Álamo Jesús Gustavo Ponce-González Ismael Pérez-Suarez 《European Journal of Sport Science》2016,16(4):455-464
Objectives: This study was designed to investigate the association of gender, fibre type composition, and anaerobic performance with the basal skeletal muscle signalling cascades regulating muscle phenotype. Design: Muscle biopsies were obtained from 25 men and 10 women all young and healthy. Methods. Protein phosphorylation of Thr172AMPKα, Ser221ACCβ, Thr286CaMKII as well as total protein abundance of PGC-1α, SIRT1, and CnA were measured by Western blot and anaerobic performance by the Wingate test. Results: Percent type I myosin heavy chain (MHC I) was lower in men (37.1?±?10.4 vs. 58.5?±?12.5, P?.01). Total, free testosterone and free androgen index were higher in men (11.5, 36.6 and 40.6 fold, respectively, P?.01). AMPKα phosphorylation was 2.2-fold higher in men compared to women (P?.01). Total Ser221ACCβ and Thr286CaMKII fractional phosphorylation tended to be higher in men (P?=?.1). PGC1-α and SIRT1 total protein expression was similar in men and women, whereas CnA tended to be higher in men (P?=?.1). Basal AMPKα phosphorylation was linearly related to the percentage of MHC I in men (r?=?0.56; P?.01), but not in women. No association was observed between anaerobic performance and basal phosphorylations in men and women, analysed separately. Conclusion: In summary, skeletal muscle basal AMPKα phosphorylation is higher in men compared to women, with no apparent effect on anaerobic performance. 相似文献
17.
Andrés Pérez Tomás T. Freitas Jacobo Á. Rubio-Arias Elena Marín-Cascales Pedro E. Alcaraz 《European Journal of Sport Science》2019,19(5):636-644
The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO2max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO2max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?.01; ES?=?0.48). Also, POL group improved running economy at 10?km/h (Δ–5.4%; p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners. 相似文献
18.
Emma Kate Zadow Cecilia Marie Kitic Sam Shi Xuan Wu James William Fell Murray John Adams 《European Journal of Sport Science》2018,18(3):367-375
Exercise has been demonstrated to have considerable effects upon haemostasis, with activation dependent upon the duration and intensity of the exercise bout. In addition, markers of coagulation and fibrinolysis have been shown to possess circadian rhythms, peaking within the morning (0600–1200?h). Therefore, the time of day in which exercise is performed may influence the activation of the coagulation and fibrinolytic systems. This study aimed to examine coagulation and fibrinolytic responses to short-duration high-intensity exercise when completed at different times of the day. Fifteen male cyclists (VO2max: 60.3?±?8.1?ml?kg?1?min?1) completed a 4-km cycling time trial (TT) on five separate occasions at 0830, 1130, 1430, 1730 and 2030. Venous blood samples were obtained pre- and immediately post-exercise, and analysed for tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombin–anti-thrombin complexes (TAT) and D-Dimer. Exercise significantly increased plasma concentrations of TF (p?.0005), TFPI (p?.0006), TAT complexes (p?.0012) and D-Dimer (p?.0003). There was a time-of-day effect in pre-exercise TF (p?=?.004) and TFPI (p?=?.031), with 0830 greater than 1730 (p .001), while 1730 was less than 2030?h (p?=?.008), respectively. There was no significant effect of time of day for TAT (p?=?.364) and D-Dimer (p?=?.228). Power output, TT time and heart rate were not significantly different between TTs (p?>?.05); however, percentage VO2max was greater at 1730 when compared to 2030 (p?=?.04). Due to a time-of-day effect present within TF, peaking at 0830, caution should be applied when prescribing short-duration high-intensity exercise bout within the morning in populations predisposed to hypercoagulability. 相似文献
19.
Load carriage (LC) exercise in physically demanding occupations is typically characterised by periods of low-intensity steady-state exercise and short duration, high-intensity exercise while carrying an external mass in a backpack; this form of exercise is also known as LC exercise. This induces inspiratory muscle fatigue and reduces whole-body performance. Accordingly we investigated the effect of inspiratory muscle training (IMT, 50% maximal inspiratory muscle pressure (PImax) twice daily for six week) upon running time-trial performance with thoracic LC. Nineteen healthy males formed a pressure threshold IMT (n?=?10) or placebo control group (PLA; n?=?9) and performed 60?min LC exercise (6.5?km?h–1) followed by a 2.4?km running time trial (LCTT) either side of a double-blind six week intervention. Prior to the intervention, PImax was reduced relative to baseline, post-LC and post-LCTT in both groups (pooled data: 13?±?7% and 16?±?8%, respectively, p?.05) and similar changes were observed post-PLA. Post-IMT only, resting PImax increased +31% (p?.05) and relative to pre-IMT was greater post-LC (+19%) and post-LCTT (+18%, p?.05), however, the relative reduction in PImax at each time point was unchanged (13?±?11% and 17?±?9%, respectively, p?>?.05). In IMT only, heart rate and perceptual responses were reduced post-LC (p?.05). Time-trial performance was unchanged post-PLA and improved 8?±?4% after IMT (p?.05). In summary, when wearing a 25?kg backpack, IMT attenuated the cardiovascular and perceptual responses to steady-state exercise and improved high-intensity time-trial performance which we attribute in part to reduced relative work intensity of the inspiratory muscles due to improved inspiratory muscle strength. These findings have real-world implications for occupational contexts. 相似文献
20.
Carly Stewart Laurita Marconi Schiavon Maria Luisa Bellotto 《Sport, Education and Society》2017,22(4):511-527
It is acknowledged that knowledge and knowledge bases are an important part of coach and athlete learning and that the coach – athlete relationship is crucial to knowledge created, shared and used. This said knowledge about nutrition as constructed by elite gymnasts would seem particularly important in a culture long associated with weight control practices and disordered eating. This paper provides an insight into the ways that 10 Brazilian Olympic gymnasts construct ideas pertaining to nutritional knowledge across generational periods (between 1980 and 2004) where significant organisational change in Women’s Artistic Gymnastics in Brazil occurred and included the introduction of dieticians. Drawing upon different knowledge types and paying attention to the coaching context, the life histories of 10 Olympic gymnasts were used to open a window on knowledge construction pertaining to nutrition by three generations of gymnasts. The findings draw attention to two main illustrative themes. Firstly, coaches’ personal knowledge, whilst perceived as incomplete by gymnasts, reinforced a narrative of weight loss for gymnasts regardless of generation. Secondly, the younger generations of gymnasts perceived that the introduction of dieticians into structured provision enabled them to use better structured knowledge, and with it a sense of increased autonomy and corporeal learning via the construction of tacit embodied knowledge leading to healthier practices. Reflections are given to the role of the coach, dieticians and pedagogical actions, and the continued reshaping of knowledge in elite gymnastics. 相似文献