共查询到20条相似文献，搜索用时 31 毫秒
1.
P. Sansone A. Tessitore H. Paulauskas I. Lukonaitiene H. Tschan V. Pliauga D. Conte 《Journal of Science and Medicine in Sport》2019,22(5):602-606
Objectives
To evaluate external and internal training load (TL) and hormonal responses in basketball 3-versus-3 small-sided games (SSGs).Design
Randomized repeated-measures study.Methods
Twelve male basketball players participated to four 3-versus-3 SSGs characterized by different tactical tasks (offensive; defensive) and training regimes (long-intermittent: three 4-min bouts with 2′ rest in between; short-intermittent: six 2-min bouts with 1′ rest in between). Variables measured were: PlayerLoad (PL); percentage of maximal heart rate (%HRmax); Edwards’ TL. Before and after the SSGs, saliva samples were collected to measure cortisol (C) and testosterone (T). Two-way (task; regime) repeated-measures ANOVA was performed for PL and %HRmax; C concentrations were analysed with a three-way (task; regime; time: pre/post) repeated-measures ANOVA; non-parametric analyses were performed for Edwards’ TL and T.Results
PL was moderately higher in offensive task (148.0 ± 16.8 AU) compared to defensive (137.1 ± 15.5 AU), and short regime (147.0 ± 18.2 AU) compared to long (137.9 ± 14.6 AU). %HRmax was moderately higher in offensive task (91.1 ± 4.1%) compared to defensive: (88.7 ± 5.4%), while it did not differ between regimes (long: 90.0 ± 5.6%) (short: 89.8 ± 4.2%); additionally, an interaction (task*regime) effect was found (ES: strong). Edwards’ TL was moderately higher in offense-long SSG (56.6 + 2.4 AU) compared to defense-short (52.4 + 4.4 AU). C increased after the SSGs (ES: strong). T decreased after offense-short (ES: moderate) and increased after defense-long (ES: moderate) SSGs.Conclusions
Tactical tasks and training regimes influence external and internal demands of basketball SSGs. Steroid hormones respond in SSGs. 相似文献2.
Ana B. Peinado Darías Holgado Antonio Luque-Casado Miguel A. Rojo-Tirado Daniel Sanabria Coral González Manuel Mateo-March Cristóbal Sánchez-Muñoz Francisco J. Calderón Mikel Zabala 《Journal of Science and Medicine in Sport》2019,22(3):335-341
Objectives
The aim of the present study was to test the effect of sodium bicarbonate (NaHCO3?) ingestion on performance during a simulated competition on a Bicycle Motocross (BMX) track.Design
Double-blind cross-over study.Methods
Twelve elite male BMX cyclists (age: 19.2 ± 3.4 years; height: 174.2 ± 5.3 cm; body mass: 72.4 ± 8.4 kg) ingested either NaHCO3- (0.3 g.kg?1 body weight) or placebo 90 min prior to exercise. The cyclists completed three races in a BMX Olympic track interspersed with 15 min of recovery. Blood samples were collected to assess the blood acid-base status. Performance, cardiorespiratory, heart rate variability (HRV) as well as subjective variables were assessed.Results
The main effect of condition (NaHCO3? vs. placebo) was observed in pH, bicarbonate concentration and base excess (p < 0.05), with a significant blood alkalosis. No changes were found in time, peak velocity and time to peak velocity for condition (p > 0.05). The HRV analysis showed a significant effect of NaHCO3? ingestion, expressed by the rMSSD30 (root mean square of the successive differences) (p < 0.001). There was no effect of condition on oxygen uptake, carbon dioxide production, or pulmonary ventilation (p > 0.05). Finally, there was no effect of condition for any subjective scale (p > 0.05).Conclusions
We present here the first field condition study to investigate the effect of bicarbonate ingestion over performance in BMX discipline. The results showed that NaHCO3?-induced alkalosis did not improve performance in a simulated BMX competition in elite BMX cyclists, although future studies should consider the effects of NaHCO3- on autonomic function as a component of recovery. 相似文献3.
Iris F. Lagas Duncan E. Meuffels Edwin Visser Floor P. Groot Max Reijman Jan A.N. Verhaar Robert-Jan de Vos 《Journal of Science and Medicine in Sport》2019,22(2):164-168
Objective
To assess whether targeted neuromuscular exercises can decrease knee loading of adolescent pre-professional footballers with high knee loading as identified with the field-based Drop Vertical Jump Test (DVJT).Design
Prospective controlled trial, conducted between August and November 2016 at Erasmus Medical Centre, The Netherlands.Methods
Pre-professional football players (aged 14–21 years) were evaluated at baseline and after 12 weeks follow-up with the field-based DVJT. The field-based DVJT is a standardised test in which a player drops from a box and jumps up immediately after landing; knee load is calculated based on five parameters. Players with high knee load (probability ≥ 0.75) from one club performed regular training(control group), and players with high knee load from another other club performed targeted neuromuscular exercises for 12 weeks (intervention group). The difference of change in knee load between both groups after 12 weeks was the primary outcome measure.Results
Of 107 eligible players, 75 had a high knee loading. Knee loading decreased in both groups after 12 weeks of training, but change in probability of high knee load was not significantly different between both groups (95% Confidence Interval [?0.012–0.082], p = 0.139).Conclusion
Targeted neuromuscular exercises had no additional effect in decreasing knee loading of adolescent male pre-professional football players compared to regular training.Trial registration number: The Netherlands Trial Register (ID number: 6044). 相似文献4.
Joy G. Shen Meredith B. Brooks Jessica Cincotta Justin D. Manjourides 《Journal of Science and Medicine in Sport》2019,22(2):232-238
Objectives
Caffeine has well-documented benefits on endurance athletic performance. Because of caffeine’s ergogenic effects of reducing perceived fatigue, it is hypothesized that as duration of athletic event increases, so will the effect size of caffeine upon performance. This study aims to examine the relationship between duration of endurance athletic event and the effect size of caffeine compared to placebo for athletic performance.Design
A systematic review and meta-analysis of placebo-controlled trials assessing the effects of caffeine in adults performing endurance athletic events.Methods
We searched MedLine, Web of Science, and review article references published through March 2016. We performed meta-analyses on placebo-controlled trials to determine the effect of the duration of an endurance athletic event on the standardized mean difference (Cohen’s d) between the caffeine and placebo groups for athletic performance.Results
Forty articles including 56 unique comparison groups were included. Pooled results showed a Cohen’s d of 0.33 (95% CI = 0.21, 0.45; p = 1.00; I2 = 0%). The effect of the duration of athletic event was significantly associated with Cohen’s d (Relative Risk: 0.005; 95% CI = 0.001, 0.009; p = 0.024). For a 30 min increase in duration of the athletic event, Cohen’s d will increase by 0.150.Conclusions
This study is the first to report on the statistical finding that the effect size of caffeine increases along with the increasing duration of the time trial event. Endurance athletes may especially benefit from caffeine for performance enhancement. 相似文献5.
Sian Williams Kevin Netto Renee Kennedy Jarrad Turner-Bryndzej Ryan Campbell Simon M. Rosalie 《Journal of Science and Medicine in Sport》2019,22(1):65-69
Objectives
Examine the running kinematics in healthy, physically active prepubescent children and to determine if specific biomechanical factors correlate with running performance.Design
Cross-sectional study.Methods
Fifteen children (age 9 years, ±11 months) completed a 1 km time trial before undergoing three-dimensional running motion analysis.Results
A strong positive correlation was observed between the biomechanical variables of stride length (p < .01), contact time (p < .01) and ankle dorsiflexion angle (p = .04) with time trial performance. Between variable analyses revealed a strong positive correlation between peak angles of hip adduction and knee flexion. There was no correlation between hip adduction and knee flexion peak angles or the vertical displacement of centre of mass with trial performance.Conclusions
The results of this study show that children with a better time trial performance display longer stride length, shorter contact time and mid or forefoot strike pattern. These findings have implications for targeted technique intervention in children’s running training to improve running performance. 相似文献6.
Objectives
To evaluate weekly heart rate variability (HRV) responses to varying training load among an Olympic rugby sevens team and to assess whether HRV responses informed on training adaptation.Design
Retrospective.Methods
Natural logarithm of the root mean square of successive differences (LnRMSSD), psychometrics and training load from a rugby sevens team (n = 12 males) over a 3-week period were retrospectively analyzed. Week 1 served as baseline while weeks 2 and 3 consisted of peak training loads from the 2016 Olympic preparatory period. Maximum aerobic speed (MAS) was evaluated at the beginning of weeks 1 and 3.Results
LnRMSSD (p = 0.68), its coefficient of variation (LnRMSSDcv) (p = 0.07) and psychometrics (all p > 0.05) did not significantly change across time. Effect sizes (ES) showed a small increase in LnRMSSDcv after the first week of intensified training (ES = 0.38) followed by a moderate reduction in week 3 (ES = ?0.91). Individuals with a smaller LnRMSSDcv during the first week of intensified training showed more favorable changes in MAS (r = ?0.74, p = 0.01), though individual changes only ranged from ?1.5 to 2.9%.Conclusions
In week 3, players accomplished greater external training loads with minimal impact on internal load while wellness was preserved. Concurrently, players demonstrated less fluctuations in LnRMSSD, interpreted as an improved ability to maintain cardiac-autonomic homeostasis despite increments in training load. Monitoring the magnitude of daily fluctuations in LnRMSSD in response to varying training loads may aid in the evaluation of training adaptations among elite rugby players. 相似文献7.
Joseph M. Northey Kate L. Pumpa Clare Quinlan Ashley Ikin Kellie Toohey Disa J. Smee Ben Rattray 《Journal of Science and Medicine in Sport》2019,22(5):580-585
Objectives
The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.Design
Pilot randomised-controlled trial.Methods
Seventeen female cancer survivors (mean: 62.9 ± 7.8 years) were randomised into three groups: high-intensity interval training (HIIT, n = 6); moderate-intensity continuous training (MOD, n = 5); or wait-list control (CON, n = 6). The HIIT and MOD groups exercised on a cycle ergometer 3 days/week for 12-weeks. Primary outcomes were cognitive function assessments utilising CogState. Secondary outcomes were resting middle cerebral artery blood flow velocity, cerebrovascular reactivity and aerobic fitness (VO2peak). Data were analysed with General Linear Mixed Models and Cohen’s d effect sizes were calculated.Results
All 17 participants who were randomised were available for follow-up analysis and adherence was similar for HIIT and MOD (78.7 ± 13.2% vs 79.4 ± 12.0%; p = 0.93). Although there were no significant differences in the cognitive and cerebrovascular outcomes, HIIT produced moderate to large positive effects in comparison to MOD and CON for outcomes including episodic memory, working memory, executive function, cerebral blood flow and cerebrovascular reactivity. HIIT significantly increased VO2peak by 19.3% (d = 1.28) and MOD had a non-significant 5.6% (d = 0.72) increase, compared to CON which had a 2.6% decrease.Conclusions
This study provides preliminary evidence that HIIT may be an effective exercise intervention to improve cognitive performance, cerebrovascular function and aerobic fitness in breast cancer survivors. Considering the sample size is small, these results should be confirmed through larger clinical trials. 相似文献8.
Breanne E. Kunstler Jill L. Cook Joanne L. Kemp Paul D. O’Halloran Caroline F. Finch 《Journal of Science and Medicine in Sport》2019,22(1):2-10
Objectives
To determine: (i) the behaviour change techniques used by a sample of Australian physiotherapists to promote non-treatment physical activity; and (ii) whether those behaviour change techniques are different to the techniques used to encourage adherence to rehabilitation exercises.Design
Cross-sectional survey.Method
An online self-report survey was advertised to private practice and outpatient physiotherapists treating patients with musculoskeletal conditions. The use of 50 behaviour change techniques were measured using five-point Likert-type scale questions.Results
Four-hundred and eighty-six physiotherapists responded to the survey, with 216 surveys fully completed. Most respondents (85.1%) promoted non-treatment physical activity often or all of the time. Respondents frequently used 29 behaviour change techniques to promote non-treatment physical activity or encourage adherence to rehabilitation exercises. A similar number of behaviour change techniques was frequently used to encourage adherence to rehabilitation exercises (n = 28) and promote non-treatment physical activity (n = 26). Half of the behaviour change techniques included in the survey were frequently used for both promoting non-treatment physical activity and encouraging adherence to rehabilitation exercises (n = 25). Graded tasks was the most, and punishment was the least, frequently reported technique used to promote non-treatment physical activity and encourage adherence to rehabilitation exercises.Conclusions
Respondents reported using similar behaviour change techniques to promote non-treatment physical activity and encourage adherence to rehabilitation exercises. The variability in behaviour change technique use suggests the behaviour the physiotherapist is promoting influences their behaviour change technique choice. Including the frequently-used behaviour change techniques in non-treatment physical activity promotion interventions might improve their efficacy. 相似文献9.
Kimberley L. Way Rachelle N. Sultana Angelo Sabag Michael K. Baker Nathan A. Johnson 《Journal of Science and Medicine in Sport》2019,22(4):385-391
Objectives
Greater arterial stiffness and poor 24 h blood pressure (BP) are recognized as indicators of poor cardiovascular health. Evidence has shown that high intensity interval training (HIIT) may be a superior alternative to moderate intensity continuous training (MICT) for improving cardiovascular disease risk factors such as cardiorespiratory fitness and vascular function. However, there are limited data comparing the effect of HIIT to MICT on central arterial stiffness and/or 24 h BP response. The purpose of this study was to compare HIIT versus MICT on central arterial stiffness and 24 h BP outcomes by systematic review and meta-analysis.Design
A systematic review and meta-analysis was conducted.Methods
Eligible studies were exercise training interventions (≥4 weeks) that included both HIIT and MICT and reported central arterial stiffness, as measured by pulse wave velocity and augmentation index and/or 24 h BP outcome measures.Results
HIIT was found to be superior to MICT for reducing night-time diastolic BP (ES: ?0.456, 95% CI: ?0.826 to ?0.086 mmHg; P = 0.016). A near-significant greater reduction in daytime systolic (ES: ?0.349, 95% CI: ?0.740 to 0.041 mmHg; p = 0.079) and diastolic BP was observed with HIIT compared to MICT (ES: ?0.349, 95% CI: ?0.717 to 0.020 mmHg; p = 0.063). No significant difference was found for other BP responses or arterial stiffness outcomes.Conclusions
HIIT leads to a superior reduction in night-time diastolic BP compared to MICT. Furthermore, a near-significant greater reduction in daytime BP was found with HIIT compared to MICT. No significant difference was observed for changes to central arterial stiffness between HIIT and MICT. 相似文献10.
Danielle T. Gescheit Stuart J. Cormack Rob Duffield Stephanie Kovalchik Tim O. Wood Melanie Omizzolo Machar Reid 《Journal of Science and Medicine in Sport》2019,22(1):11-15
Objectives
To profile multi-year injury incidence and severity trends in elite junior tennis players from a national program.Design
Prospective cohort.Methods
Injury data was collated by sex, age and region for all nationally-supported Australian junior players (58m, 43f 13–18y) between 2012–2016. Injury was defined as a physical complaint from training/matchplay interrupting training/matchplay determined by presiding physiotherapists and doctors. Severity represented the days of interrupted training/matchplay per injury. Injury incidence was reported per 1000 exposure hours. Incidence rate change and rate ratios (RR) ±95% confidence intervals were used to assess changes over time.Results
No difference in male and female injury incidence existed (2.7 ± 0.0 v 2.8 ± 0.0) yet male injuries were more severe (3.6 ± 0.6 v 1.1 ± 0.9 days). The lumbar spine was the most commonly and severely injured region in both sexes (4.3 ± 0.2, 9.9 ± 1.4 d). Shoulder injuries were the second most common in both sexes (3.1 ± 0.2) and with the second highest severity in males (7.3 ± 1.4d). Knee injuries were also common in males (2.3 ± 0.2) yet potentially reduced over time (0.4 ± 0.6 RR) as pelvis/buttock injuries increased (3.4 ± 14.0 RR). Females had high trunk and abdominal injury incidences (2.5 ± 0.3). Independent of sex, the injury incidence increased with age from 2.0 ± 0.1 (13y) to 2.9 ± 0.1 (18y).Conclusions
Despite no sex-based difference in injury incidence, male injuries resulted in more interrupted days of training/matchplay. The lumbar spine and shoulder were the most commonly injured body regions in both sexes. The number of injuries sustained by players also increased as they aged. 相似文献11.
12.
Richard C. Blagrove Kristina M. Holding Stephen D. Patterson Glyn Howatson Philip R. Hayes 《Journal of Science and Medicine in Sport》2019,22(2):239-244
Objectives
To determine the effect of performing depth jumps (DJ) pre-exercise on running economy (RE) and time to exhaustion (TTE) at the speed associated with maximal oxygen uptake (sO2max) in a group of high-performing junior middle-distance runners.Design
Randomized crossover study.Methods
Seventeen national- and international-standard male distance runners (17.6 ± 1.2 years, 63.4 ± 6.3 kg, 1.76 ± 0.06 m, 70.7 ± 5.2 mL kg?1 min?1) completed two trials. Following a 5 min warm-up at 60% O2max, participants performed a 5 min run at 20%Δ below oxygen uptake corresponding with lactate turn-point to determine pre-intervention RE. Participants then completed either six DJ from a box equivalent to their best counter-movement jump (CMJ) or a control condition (C) involving body weight quarter squats. After a 10 min passive recovery, another 5 min sub-maximal run was performed followed by a run to exhaustion at sO2max.Results
Compared to the C trial, DJ produced moderate improvements (?3.7%, 95% confidence interval for effect size: 0.25–1.09) in RE, which within the context of minimal detectable change is considered possibly beneficial. Differences in TTE and other physiological variables were most likely trivial (ES: <0.2). Individual responses were small, however a partial correlation revealed a moderate relationship (r = ?0.55, p = 0.028) between change in RE and CMJ height.Conclusions
The inclusion of a set of six DJ in the warm-up routine of a well-trained young male middle-distance runner is likely to provide a moderate improvement in RE. 相似文献13.
Felicity M. Bright Georgia K. Chaseling Ollie Jay Nathan B. Morris 《Journal of Science and Medicine in Sport》2019,22(3):371-377
Objectives
To investigate whether the exercise performance benefits with neck cooling in the heat are attributable to neck-specific cooling, general body cooling, a cooler site-specific thermal perception or a combination of the above.Design
Counter-balanced crossover design.Methods
Twelve healthy participants cycled in the heat (34 °C, 30% relative humidity), at a power output (PO) self-selected to maintain a fixed rating of perceived exertion (RPE) of 16. Each participant underwent four experimental trials: no cooling (CON), neck cooling (NEC), abdominal cooling (ABD), or neck cooling with menthol (MEN). Participants cycled for 90 min or until their workload reduced by <70% of their initial PO. Changes in PO, rectal temperature (Tre), mean skin temperature (Tsk), whole-body thermal sensation (TSwb) and thermal sensation of the neck (TSneck) were recorded throughout.Results
The mean reduction in PO throughout exercise was similar (p = 0.431) for CON (175 ± 10 W), NEC (176 ±12 W), ABD (172 ± 13 W) and MEN (174 ± 12 W). The ΔTre at the end of exercise was similar (p = 0.874) for CON (0.83 ± 0.5 °C), NEC (0.85 ± 0.5 °C), ABD (0.82 ± 0.5 °C) and MEN (0.81 ± 0.5 °C). TSwb was cooler (p < 0.013) in MEN (125 ± 8 mm) compared to CON (146 ± 19 mm), NEC (135 ± 11 mm) and ABD (141 ± 16 mm).Conclusions
No differences in exercise performance or thermal strain were observed in any of the cooling trials compared to the CON trial, despite significantly cooler TSwb values in the MEN and NEC trials compared to the CON trial. These findings differ from previous observations and highlight that the benefit of neck cooling may be situation dependent. 相似文献14.
Paul Macadam Kim D. Simperingham John B. Cronin 《Journal of Science and Medicine in Sport》2019,22(3):348-352
Objectives
Arm swing is a distinctive characteristic of sprint-running with the arms working in a contralateral manner with the legs to propel the body in a horizontal direction. The purpose of this study was to determine the acute changes in kinematics and kinetics when wearable resistance (WR) of 1 kg (equivalent to ～1% body mass) was attached to each forearm during over ground short distance (20 m) maximal sprint-running.Design
Cross-sectional study.Methods
Twenty-two male amateur rugby athletes (19.4 ± 0.5 years; 97.0 ± 4.8 kg; 180.4 ± 7.2 cm) volunteered to participate in the study. Radar and Optojump were used to examine kinematic and kinetics between WR and unloaded sprint-running conditions.Results
No significant (p < 0.05) differences were found at 2 m or 5 m between conditions, however, the WR condition resulted in a significant increase in 10 m, 20 m and 10–20 m split time (all, ～2%, small effect size) compared to the unloaded condition. Significant decreases were also found in theoretical maximum velocity (V0) (?1.4%, small effect size) and relative peak horizontal power production (Pmax) (?5.5%, small effect size). Step length (2.1%, small effect size) and contact time (6.5%, medium effect size) were significantly increased, while step frequency (?4.1%, small effect size) and flight time (?5.3%, medium effect size) were significantly decreased.Conclusions
WR forearm loading provides a movement specific overload of the arms which significantly alters step kinematics and sprint times ≥10 m. 相似文献15.
Sarah J. de la Motte Marleen M. Welsh Valerie Castle Dan Burnett Gary D. Gackstetter Alyson J. Littman Edward J. Boyko Tomoko I. Hooper 《Journal of Science and Medicine in Sport》2019,22(1):59-64
Objectives
Regular vigorous physical activity (PA) and high levels of physical fitness (PF) confer health benefits. Conversely, sedentary time is a risk factor for chronic illness, independent of PA. We evaluated associations between self-reported PA, sedentary time, and objective PF measures in military Service members.Design
Cross-sectional study including 10,105 Air Force Millennium Cohort participants with a valid physical fitness assessment (PFA).Methods
Linear regression assessed associations between self-report PA, screen time, and usual activity and abdominal circumference (AC) and VO2 max; logistic regression was used for PFA failure. We stratified by age and sex.Results
Men who self-reported high versus low levels of PA had greater AC (19–29 years: β = 0.23 in., 95% CI 0.07, 0.39; 30–39 years: β = 0.45 in., 95% CI 0.17, 0.72). High versus low self-reported PA was also associated with greater VO2Max (β =: 0.81–1.41 mL/kg/min). Self-reported strength training for ≥2 days/week was associated with greater VO2Max in 19–29 year old men (β = 0.84 mL/kg/min, 95% CI 0.09, 0.60) and 30–39 year old women (β = 0.74 mL/kg/min, 95% CI 0.02, 1.46). For younger men and women,<2 h of screen time/day was associated with greater VO2Max (Males 19–29 years: β = 0.23 mL/kg/min, 95% CI 0.44, 1.26; Females 19–29 years: β = 0.83 mL/kg/min, 95% CI 0.25, 1.42). PA was not associated with PFA failure, while screen time was (Males OR: 0.32–0.65, 95% CI 0.17–0.92, p < 0.001–0.016).Conclusions
Self-reported PA and screen time were associated with some objective PF measures, including VO2Max and AC. However, screen time alone was associated with PFA failure. 相似文献16.
Objectives
To identify temporal trends in muscular fitness of English children using allometric scaling for height and weight to adjust for the influence of body size.Design
Repeated cross-sectional study.Methods
We measured; height, weight, standing broad-jump, handgrip, sit-ups and bent-arm hang in 10-year-old boys and girls from Chelmsford, England in: 2014 (n = 306), 2008 (n = 304) and 1998 (n = 310). Physical activity was (PAQ-C) was assessed in 2008 and 2014. Muscular fitness was allometrically scaled for height and weight. We assessed temporal trends using General Linear Models (fixed factors: wave and sex) and reported effect sizes using partial eta squared (ηP2). We compared percentage change per year 1998–2008 with 2008–2014.Results
Ten-year-olds in 2014 were taller and heavier than in 2008 and 1998 but there were no differences in BMI. Compared with 2008, physical activity was lower in boys (ηP2 = 0.012) and girls (ηP2 = 0.27) assessed in 2014. There were significant main effects of wave for handgrip (ηP2 = 0.060), sit-ups (ηP2 = 0.120) and bent-arm hang (ηP2 = 0.204). Pairwise comparisons showed muscular fitness of both sexes was significantly lower in 2014 than in 1998. From 2008 to 2014 percent change per year in handgrip (1.6%) and sit-ups (3.9%) were greater than for the preceding decade (handgrip 0.6%, sit-ups 2.6%).Conclusions
Downward temporal trends in muscular fitness appear independent of secular changes in body size. We found a decrease in self-reported physical activity concurrent with the accelerated declines in fitness from 2008 to 2014. These findings suggest the declines in children are not engaging in physical activities which support development of muscular fitness. 相似文献17.
Ned Brophy-Williams Matthew W. Driller Cecilia M. Kitic James W. Fell Shona L. Halson 《Journal of Science and Medicine in Sport》2019,22(1):123-127
Objectives
To assess the effect of wearing compression socks on immediate and subsequent 5 km running time trials, with particular attention to the influences on physiological, perceptual and performance-based parameters.Design
Counter-balanced cross-over experiment.Methods
Twelve male runners (mean ± SD 5 km run time 19:29 ± 1:18 min:s) each completed two experimental sessions. Sessions consisted of a standardised running warm-up, followed by a 5 km time trial (TT1), a one hour recovery period, then a repeat of the warm-up and 5 km time trial (TT2). One session required the use of sports compression socks during the first warm-up and time trial (COMP), while the other did not (CON).Results
The decline in run performance in CON from TT1 to TT2 was moderate and significantly greater than that experienced by runners in COMP (9.6 s, d = 0.67, p < 0.01). No difference was found between experimental conditions for oxygen consumption, blood lactate or calf volume (p = 0.61, 0.54, 0.64, respectively). Perceptual measures of muscle soreness, fatigue and recovery were also similar between trials (p = 0.56, 1.00 & 0.61, respectively).Conclusions
Wearing sports compression socks during high intensity running has a positive impact on subsequent running performance. The underlying mechanism of such performance enhancement remains unclear, but may relate to improved oxygen delivery, reduced muscle oscillation, superior running mechanics and athlete beliefs. 相似文献18.
Eri Miyamoto-Mikami Haruka Murakami Hiroyasu Tsuchie Hideyuki Takahashi Nao Ohiwa Motohiko Miyachi Takashi Kawahara Noriyuki Fuku 《Journal of Science and Medicine in Sport》2017,20(1):98-103
Objectives
This study aimed to examine the association between a total genotype score (TGS) based on previously published genetic polymorphism candidates and differences in sprint/power performance.Design
Case–control association study.Methods
We analysed 21 polymorphisms, which have previously been associated with sprint/power performance and related phenotypes, in 211 Japanese sprint/power track and field athletes (77 regional, 72 national, and 62 international athletes) and 649 Japanese controls using the TaqMan SNP genotyping assay. We calculated the TGS (maximum value of 100 for the theoretically optimal polygenic score) for the 21 polymorphisms.Results
All groups exhibited similar TGSs (control: 55.9 ± 7.2, regional: 55.1 ± 7.1, national: 56.1 ± 7.4, and international: 56.0 ± 7.8, p = 0.827 by one-way analysis of variance). Nine of the 21 polymorphisms had the same direction of effect (odds ratio >1.0) as in previous studies, while 12 had the opposite direction of effect (odds ratio <1.0). Three polymorphisms (rs699 in AGT, rs41274853 in CNTFR, and rs7832552 in TRHR), which had the same direction of effect as in previous studies, were associated with international sprint/power athlete status (p < 0.05). However, after multiple testing corrections, the statistical significance of these polymorphisms was not retained.Conclusions
These results suggest that TGSs based on the 21 previously published sprint/power performance-associated polymorphisms did not influence the sprint/power athlete status of Japanese track and field athletes. However, our results maintain the possibility that three of these polymorphisms might be associated with sprint/power performance. 相似文献19.
Alexis A. Pihoker Austin M. Peterjohn Eric T. Trexler Katie R. Hirsch Malia N.M. Blue Kara C. Anderson Eric D. Ryan Abbie E. Smith-Ryan 《Journal of Science and Medicine in Sport》2019,22(4):472-477
Objectives
The purpose of this study was to determine the effects of pre- vs. post-workout nutrition on strength, body composition, and metabolism in trained females over 6 weeks of high intensity resistance training (HIRT).Design
Forty-three trained females (mean ± SD; age: 20.5 ± 2.2 yrs; height: 165.2 ± 5.7 cm; body mass: 66.5 ± 11.4 kg) were measured for strength, body composition, and metabolic variables before and after a HIRT intervention. Participants were randomized using a 2:2:1 matched block randomization scheme by baseline leg press strength into a group that consumed a 1:1.5 carbohydrate-protein supplement (16 g CHO/25 g PRO) pre-training (PRE), post-training (POST), or no supplement (CON).Methods
Dual-energy X-ray absorptiometry was used to evaluate fat mass (FM), lean mass (LM), and percent fat (%fat). Strength was analyzed using a one repetition max on the leg and bench press (LP1RM and BP1RM, respectively). Participants completed HIRT twice per week for 6 weeks. At the first and last trainings, metabolic variables [resting energy expenditure (REE) and respiratory exchange ratio, RER] were measured.Results
There were no significant differences between groups for any changes in body composition variables or LP1RM (p = 0.170–0.959). There were significant differences for BP1RM (p = 0.007), with PRE and POST experiencing greater increases than CON (p = 0.010 and 0.015, respectively). REE changes were not significant between groups (p = 0.058–0.643). PRE demonstrated greater fat oxidation (RER) at 30 min post-exercise (p = 0.008–0.035).Conclusion
Peri-workout nutrition is potentially important for upper body strength and metabolism. PRE may be more effective for promoting fat utilization immediately post-workout. 相似文献20.