共查询到20条相似文献，搜索用时 15 毫秒
1.
Howard T. Hurst Lee Rylands Stephen Atkins Kevin Enright Simon J. Roberts 《Journal of Science and Medicine in Sport》2018,21(3):263-267
Objectives
To investigate the influence of BMX helmets and neck braces on translational and rotational accelerations in youth riders.Design
Mixed model, repeated measure and correlation.Methods
Twenty three competitive youth BMX riders classified by age group (6–9 years, 10–13 years and 14–18 years) completed 6 laps of an indoor BMX track at race pace, 3 laps without a neck brace (NB) and 3 without brace (WB). A triaxial accelerometer with gyroscope was placed behind the right ear to determine the mean number of accelerations, translational and rotational, of the head between conditions and by age group.Results
Significant reductions by condition (p = 0.02) and by age (p = 0.04) were found for the number of accelerations, though no interactions (condition × age) were revealed. Significant increases by age (p = 0.01) were revealed for translational accelerations, whilst significant increases by condition (p = 0.02) were found for rotational accelerations. In addition, significant correlations were revealed between relative helmet mass and age (r = 0.83; p = 0.001) and relative helmet mass and number of accelerations (r = 0.46; p = 0.03).Conclusions
Accelerations at the head decreased with increased age, possibly due to the influence of greater stabilising musculature. Additionally, neck braces also significantly reduced the number of accelerations. However, the magnitude of accelerations may be influenced by riding dynamics. Therefore, the use of neck braces combined with strength work to develop neck strength, could aid in the reduction of head accelerations in youth BMX riders. 相似文献2.
Catherine Willmott Andrew S. McIntosh Teresa Howard Biswadev Mitra Bleydy Dimech-Betancourt Jarrod Donovan Jeffrey V. Rosenfeld 《Journal of Science and Medicine in Sport》2018,21(5):442-446
Objectives
To investigate changes from baseline on SCAT3 as a result of football game exposure, and association with X2 Patch measured head acceleration events in amateur Australian footballers.Design
Prospective cohort.Methods
Peak linear acceleration (PLA) of the head (>10 g) was measured by wearable head acceleration sensor X2 Biosystems X-Patch in male (n = 34) and female (n = 19) Australian footballers. SCAT3 was administered at baseline (B) and post-game (PG).Results
1394 head acceleration events (HEA) >10 g were measured. Mean and median HEA PLA were recorded as 15.2 g (SD = 9.2, range = 10.0–115.8) and 12.4 g (IQR = 11.0–15.6) respectively. No significant difference in median HEA PLA (g) was detected across gender (p = 0.55), however, more HEAs were recorded in males (p = 0.03). A greater number (p = 0.004) and severity (p < 0.001) of symptoms were reported PG than at B. No significant association between number of HEA or median PLA, and SCAT3 change scores (p > 0.05 for all), was identified for either gender.Conclusions
Increase in symptom severity post game was not associated with X2 measured HEA. Males sustained more HEA, however HEA PLA magnitude did not differ across gender. Further work on the validation of head acceleration sensors is required and their role in sports concussion research and medical management. 相似文献3.
Kerry S. O’Brien Walter Forrest Iain Greenlees Daniel Rhind Sophia Jowett Ilana Pinsky Albert Espelt Marina Bosque-Prous Anders Larrabee Sonderlund Matteo Vergani Muhammad Iqbal 《Journal of Science and Medicine in Sport》2018,21(4):335-341
Objectives
There is no research examining alcohol-related aggression and anti-social behaviour in UK or European sportspeople (athletes), and no research has examined relationships between masculinity, alcohol consumption, and alcohol-related aggression and antisocial behaviour in sportspeople (athletes). This study addresses this gap.Design
Cross-sectional.Methods
A sample (N = 2048; women = 892, 44%) of in season sportspeople enrolled at UK universities (response 83%), completed measures of masculinity, alcohol consumption, within-sport (on-field) violence, and having been the perpetrator and/or victim of alcohol-related violent/aggressive and antisocial behaviour (e.g., hit/assaulted, vandalism, sexual assault). Logistic regressions examined predictors of alcohol-related violence/aggression and anti-social behaviours.Results
Significant bivariate relationships between masculinity, within-sport violence, alcohol consumption, and alcohol-related aggression and anti-social behaviour were found for both men and women (p’s < .001). Logistic regression adjusting for all variables showed that higher levels of masculinity and alcohol consumption in men and women were related to an increased odds of having conducted an aggressive, violent and/or anti-social act in the past 12 months when intoxicated. Odds ratios were largest for relationships between masculinity, alcohol consumption, within-sport violence, and interpersonal violence/aggression (p’s < .001). A similar pattern of results was found for having been the victim of aggression and anti-social behaviour.Conclusions
Alcohol-related aggression and anti-social behaviour appear to be problematic in UK university sportspeople, and is related to masculinity and excessive drinking. Interventions that reduce excessive alcohol consumption, masculine norms and associated within-sport violence, could be effective in reducing alcohol-related aggression and antisocial behaviour in UK sportspeople. 相似文献4.
Zoe L. Hewett Kate L. Pumpa Caroline A. Smith Paul P. Fahey Birinder S. Cheema 《Journal of Science and Medicine in Sport》2018,21(4):352-357
Objectives
The purpose of this study was to investigate the effect of 16 weeks of Bikram yoga on perceived stress, self-efficacy and health related quality of life (HRQoL) in sedentary, stressed adults.Design
16 week, parallel-arm, randomised controlled trial with flexible dosing.Methods
Physically inactive, stressed adults (37.2 ± 10.8 years) were randomised to Bikram yoga (three to five classes per week) or control (no treatment) group for 16 weeks. Outcome measures, collected via self-report, included perceived stress, general self-efficacy, and HRQoL. Outcomes were assessed at baseline, midpoint and completion.Results
Individuals were randomised to the experimental (n = 29) or control group (n = 34). Average attendance in the experimental group was 27 ± 18 classes. Repeated measure analyses of variance (intention-to-treat) demonstrated significantly improved perceived stress (p = 0.003, partial η2 = 0.109), general self-efficacy (p = 0.034, partial η2 = 0.056), and the general health (p = 0.034, partial η2 = 0.058) and energy/fatigue (p = 0.019, partial η2 = 0.066) domains of HRQoL in the experimental group versus the control group. Attendance was significantly associated with reductions in perceived stress, and an increase in several domains of HRQoL.Conclusions
16 weeks of Bikram yoga significantly improved perceived stress, general self-efficacy and HRQoL in sedentary, stressed adults. Future research should consider ways to optimise adherence, and should investigate effects of Bikram yoga intervention in other populations at risk for stress-related illness.Trial registration
Australia New Zealand Clinical Trials Registry ACTRN12616000867493. Registered 04 July 2016. URL: http://www.anzctr.org.au/ACTRN12616000867493.aspx. 相似文献5.
Sebastian Ludyga Markus Gerber Keita Kamijo Serge Brand Uwe Pühse 《Journal of Science and Medicine in Sport》2018,21(8):833-838
Objectives
To examine the effects of a structured exercise program implemented during school break-time on working memory maintenance and neurophysiological indices of task preparation processes in adolescents.Design
Using class-wise random allocation, participants from four classes were divided into an exercise (n = 20) and a wait-list control group (n = 16). Over a period of eight weeks, the exercise group engaged in 20 min of combined aerobic and coordinative exercise on each school day.Methods
Prior to and after the intervention period, participants performed a computer-based Sternberg task for the assessment of working memory performance. Simultaneously, the contingent negative variation (CNV) of event-related potentials was measured.Results
The exercise group demonstrated a larger decrease in reaction time from pre- to post-test relative to the control group, F(1, 31) = 13.5, p < 0.001. No changes were found for accuracy on the Sternberg task across groups. Using cluster-based permutation testing, the analysis of event-related potentials revealed a significant increase of the initial CNV from pre- to post-test in the exercise group, cluster value = ?2376.2, p = 0.006, which was most pronounced for the fronto-central region, with no such effect observed for the control group.Conclusions
Daily engagement in a short combined aerobic and coordinative exercise program following the school lunch time break elicits benefits for working memory in adolescents. These changes are accompanied by improvements of task preparation processes, which allow the selection of a more appropriate cognitive control strategy. 相似文献6.
Joyce S. Ramos Lance C. Dalleck Fabio Borrani Robert G. Fassett Jeff S. Coombes 《Journal of Science and Medicine in Sport》2017,20(1):45-49
Objectives
The vulnerability of individuals with the metabolic syndrome (MetS) to cardiovascular events (CVEs) is attenuated by increased cardiorespiratory fitness (CRF), despite the presence of obesity as a usual component of MetS. To better understand the importance of CRF and body fat in treating this condition, we investigated the relationship between fitness and fatness with pancreatic beta cell function (BCF) indices that are known independent predictors of CVEs.Design
Cross sectional study.Methods
This study included 84 individuals with MetS. BCF indices were derived from a fasted steady state (basal disposition index [DI], proinsulin, proinsulin:insulin, and proinsulin:C-peptide) and dynamic conditions via an oral glucose tolerance test (1st and 2nd phase DI). CRF and body fat percentage (BF%) were assessed via indirect calorimetry (during a maximal exercise test) and dual energy X-ray absorptiometry, respectively.Results
CRF was positively associated with basal DI (r = 0.40, p < 0.001), 1st phase DI (r = 0.49, p < 0.005), and 2nd phase DI (r = 0.38, p = 0.02). Hierarchical multiple regression analysis showed CRF was associated with basal DI (β = 0.18, p = 0.04), 1st phase DI (β = 0.36, p = 0.04), and 2nd phase DI (β = 0.33, p = 0.03), independent of BF% and other confounding factors including age, sex, diabetic status, anthropometric measures, lipid profile, and insulin sensitivity. No significant associations were found between CRF and proinsulin measures. BF% was not significantly correlated with BCF indices.Conclusions
Increased CRF was independently associated with enhanced BCF. This study provides evidence that equal, if not more attention should be dedicated to CRF improvement relative to fat-loss for favorable pancreatic BCF and thus possible reduction in CV risk in individuals with MetS. 相似文献7.
Sanne L.C. Veldman Kara K. Palmer Anthony D. Okely Leah E. Robinson 《Journal of Science and Medicine in Sport》2017,20(1):50-54
Objectives
Evidence supports that girls are less proficient than boys at performing ball skills. This study examined the immediate and long-term effects of a ball skill intervention on preschool-age girls’ ball skill performance.Design
Randomized controlled trial.Methods
Girls (Mage = 47.24 ± 7.38 months) were randomly assigned to a high autonomy, mastery-based 9-week motor skill intervention (the Children's Health Activity Motor Program; CHAMP, 540 min; n = 38) or a control group (free-play; n = 16). Ball skill proficiency was assessed at pretest, posttest, and retention test (after 9 weeks) using the object control subscale of the Test of Gross Motor Development – 2nd Edition. Treatment efficacy was examined using linear mixed models. Two models were fit: one for short-term changes (pretest to posttest) and one for long-term changes (pretest to retention).Results
Linear mixed models revealed a significantly time*treatment interaction for both models. Post hoc analysis confirmed that girls in CHAMP experienced significant gains in ball skills from pretest to posttest (p < .001) and pretest to retention (p < .001). Moreover, girls in CHAMP were no different from the control group at pretest (p > .05) but had significantly higher ball skills scores at both posttest (p < .001) and retention (p < .001).Conclusions
This study demonstrates the positive effects of a ball skill intervention (i.e., CHAMP) on improving girls’ ball skills both short- and long-term. Findings suggest that early childhood interventions that focus on the development of ball skills in young girls might be an avenue to improve girls’ ball skill performance. 相似文献8.
9.
Brooklyn J. Fraser Leigh Blizzard Michael D. Schmidt Markus Juonala Terence Dwyer Alison J. Venn Costan G. Magnussen 《Journal of Science and Medicine in Sport》2018,21(9):935-940
Objectives
To assess whether childhood cardiorespiratory fitness (CRF) and muscular fitness phenotypes (strength, power, endurance) predict adult glucose homeostasis measures.Design
Prospective longitudinal study.Methods
Study examining participants who had physical fitness measured in childhood (aged 7–15 years) and who attended follow-up clinics approximately 20 years later and provided a fasting blood sample which was tested for glucose and insulin. Physical fitness measurements included muscular strength (right and left grip, shoulder flexion, shoulder and leg extension), power (standing long jump distance) and endurance (number of push-ups in 30 s), and CRF (1.6 km run duration). In adulthood, fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance (HOMA2-IR) and beta cell function (HOMA2-β).Results
A standard deviation increase in childhood CRF or muscular strength (males) was associated with fasting glucose (CRF: β = ?0.06 mmol/L), fasting insulin (CRF: β = ?0.73 mU/L; strength: β = ?0.40 mU/L), HOMA2-IR (CRF: β = ?0.06; strength: β = ?0.05) and HOMA2-β (CRF: β = ?3.06%; strength: β = ?2.62%) in adulthood, independent of the alternative fitness phenotype (all p < 0.01). Adjustment for childhood waist circumference reduced the effect by 17–35% for CRF and 0–15% for muscular strength (males) and statistical significance remained for all associations expect between CRF, fasting glucose and HOMA2-β (p > 0.06).Conclusions
CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin, insulin resistance and beta cell function in adulthood. Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis. 相似文献10.
Objectives
The purpose of this study was to investigate the prevalence of signs of anxiety/depression and distress among a sample of elite athletes in the United Kingdom (UK). A secondary aim was to identify the variables associated with signs of anxiety/depression and distress in the same sample.Design
A cross-sectional survey was distributed to a sample of elite athletes in the UK.Methods
A total of 143 elite athletes completed an online survey that consisted of demographic questions, the Greenhaus Scale assessing career satisfaction, the 12-Item General Health Questionnaire assessing signs of anxiety/depression and a distress screener based on the Four-Dimensional Symptom Questionnaire.Results
47.8% of the overall sample met the cut-off for signs of anxiety/depression and 26.8% met the cut-off for signs of distress. A significant association was found between gender and signs of distress (x2 = 8.64, df = 1, p = 0.003). Career dissatisfaction was a significant independent predictor of signs of anxiety/depression (OR = 0.836, p = 0.001) and distress (OR = 0.849, p = 0.003).Conclusions
The percentage of a sample of elite athletes in the UK showing signs of anxiety/depression and distress indicate that further cross-sectional research is required to understand the prevalence of mental health issues in the elite athlete population in the UK. Findings indicate that screening elite athletes for career dissatisfaction may support the early detection of signs of anxiety/depression and/or distress. Emphasis should be placed on understanding and improving the mental health of elite athletes in the UK. 相似文献11.
Danilo R. Silva Cláudia S. Minderico Fernando Pinto Paul J. Collings Edilson S. Cyrino Luís B. Sardinha 《Journal of Science and Medicine in Sport》2018,21(9):919-924
Objectives
We investigated the impact of a standing desk intervention on daily objectively monitored sedentary behavior and physical activity in 6th grade school students.Design
Cluster non-randomised controlled trial.Method
Two classes (intervention students: n = 22 [aged 11.8 ± 0.4 years]; control students: n = 27 [11.6 ± 0.5 years]) from a public school in Lisbon were selected. The intervention involved replacing traditional seated classroom desks for standing desks, for a total duration of 16 weeks, in addition to performing teacher training and holding education/motivation sessions with students and parents. Sedentary behavior (ActivPAL inclinometer) and physical activity (Actigraph GT3X+?accelerometer) were measured for seven days immediately before and after the intervention.Results
There were no differences in baseline behaviors between intervention and control groups (p > 0.05). At follow-up (16 weeks), it was observed that the intervention group had decreased time spent sitting (total week: ?6.8% and at school: ?13.0% relative to baseline) and increased standing (total week: 16.5% and at school: 31.0%) based on inclinometer values (p-value for interaction group*time <0.05). No significant differences in activity outcomes were observed outside school time (week or weekend) between groups.Conclusion
We conclude that a 16 week classroom standing desk intervention successfully reduced sitting time and increase standing time at school, with no observed compensatory effects outside of school time. 相似文献12.
An De Meester David Stodden Jacqueline Goodway Larissa True Ali Brian Rick Ferkel Leen Haerens 《Journal of Science and Medicine in Sport》2018,21(1):58-62
Objectives
This study examined the existence of a threshold level (proficiency barrier) of actual motor competence (MC) below which a child is not likely to attain 60 min of moderate-to-vigorous physical activity (MVPA) per day.Design
A cross-sectional study.Methods
Actual MC was assessed in 326 children (48.5% boys; age = 9.50 ± 1.24 years) using the Test of Gross Motor Development-2; MVPA was measured with ActiGraph GT3X + accelerometers. Perceived MC, included as a potential mediating variable, was assessed with the Self-Perception Profile for Children. Binary logistic (mediation) regression analyses controlling for sex and a chi-squared test were used to gain insight into the relationship between (the levels of) actual MC and the percentage of children meeting the MVPA guideline.Results
Actual MC significantly predicted the percentage of children meeting the guideline (B = .03, SE = .01, p < .001), even when controlling for sex. Perceived MC did not mediate this relationship. Children with high actual MC (65–100 percentile) were 2.46 (p = .003) times more likely to meet the guideline than children with low actual MC (0–27 percentile).Conclusions
The present study demonstrates the potential impact of low MC on children’s MVPA levels and suggests evidence for the existence of a proficiency barrier for meeting MVPA guidelines. Almost 90% of the children whose actual MC is below the ‘average’ threshold do not meet the MVPA guideline. As more children with higher levels of actual MC meet the guideline than their less competent peers, it is crucial to provide opportunities to sufficiently develop children’s actual MC. 相似文献13.
Darías Holgado Thomas Zandonai Mikel Zabala James Hopker Pandelis Perakakis Antonio Luque-Casado Luis Ciria Eduardo Guerra-Hernandez Daniel Sanabria 《Journal of Science and Medicine in Sport》2018,21(7):654-660
Objectives
To investigate the effect of tramadol on performance during a 20-min cycling time-trial (Experiment 1), and to test whether sustained attention would be impaired during cycling after tramadol intake (Experiment 2).Design
Randomized, double-blind, placebo controlled trial.Methods
In Experiment 1, participants completed a cycling time-trial, 120-min after they ingested either tramadol or placebo. In Experiment 2, participants performed a visual oddball task during the time-trial. Electroencephalography measures (EEG) were recorded throughout the session.Results
In Experiment 1, average time-trial power output was higher in the tramadol vs. placebo condition (tramadol: 220 W vs. placebo: 209 W; p < 0.01). In Experiment 2, no differences between conditions were observed in the average power output (tramadol: 234 W vs. placebo: 230 W; p > 0.05). No behavioural differences were found between conditions in the oddball task. Crucially, the time frequency analysis in Experiment 2 revealed an overall lower target-locked power in the beta-band (p < 0.01), and higher alpha suppression (p < 0.01) in the tramadol vs. placebo condition. At baseline, EEG power spectrum was higher under tramadol than under placebo in Experiment 1 while the reverse was true for Experiment 2.Conclusions
Tramadol improved cycling power output in Experiment 1, but not in Experiment 2, which may be due to the simultaneous performance of a cognitive task. Interestingly enough, the EEG data in Experiment 2 pointed to an impact of tramadol on stimulus processing related to sustained attention.Trial registration
EudraCT number: 2015-005056-96. 相似文献14.
Jaquelin A. Bousie Peter Blanch Thomas G. McPoil Bill Vicenzino 《Journal of Science and Medicine in Sport》2013,16(1):60-64
ObjectivesTo determine the effect of contouring of an in-shoe foot orthosis on plantar contact area and surface pressure, as well as perceived comfort and support at the foot-orthosis interface during stationary cycling.DesignA randomised, repeated measures control study.MethodsTwelve cyclists performed steady-state seated cycling at a cadence of 90 rpm using a contoured orthosis and a flat insert of similar hardness. Contact area (CA) and plantar mean pressure (PP) were measured using the PEDAR® system, determined for seven discrete plantar regions and represented as the percentage of the total CA and PP respectively (CA% and PP%). Perceived comfort and support were rated using a visual analogue scale (VAS).ResultsThe contoured orthosis produced a significantly greater CA% at the medial midfoot (p = 0.001) and lateral midfoot (p = 0.009) with a standardised mean difference (SMD) of 1.3 and 0.9 respectively. The contoured orthosis also produced a significantly greater PP% at the hallux (p = 0.003) compared to the flat insert with a SMD of 1.1. There was a small non-significant effect (SMD < 0.4) for the perceived comfort measures between conditions, but perceived support was significantly greater at the arch (p = 0.000) and heel (p = 0.013) with the contoured orthoses (SMD of 1.5 and 0.9, respectively).ConclusionsContoured orthoses influenced the plantar surface of the foot by increasing contact area as well as a perception of greater support at the midfoot while increasing relative pressure through the hallux when compared to a flat insert during stationary cycling. No difference in perceived comfort was noted. 相似文献
15.
Blair T. Crewther Neil Potts Liam P. Kilduff Scott Drawer Christian J. Cook 《Journal of Science and Medicine in Sport》2018,21(3):312-316
Objectives
Evidence suggests that stress-induced changes in testosterone and cortisol are related to future competitive behaviours and team-sport outcomes. Therefore, we examined whether salivary testosterone and cortisol reactivity to a mid-week stress test can discriminate a match outcome in international rugby union competition.Design
Single group, quasi-experimental design with repeated measures.Method
Thirty-three male rugby players completed a standardised stress test three or four days before seven international matches. Stress testing involved seven minutes of shuttle runs (2 × 20 m), dispersed across one-minute stages with increasing speeds. Salivary testosterone and cortisol were measured in the morning, along with delta changes from morning to pre-test (Morn-PreΔ) and pre-test to post-test (Pre-PostΔ). Data were compared across wins (n = 3) and losses (n = 4).Results
The Morn-PreΔ in cortisol increased before winning and decreased prior to losing (p < 0.001), with a large effect size difference (d = 1.6, 90% CI 1.3–1.9). Testosterone decreased significantly across the same period, irrespective of the match outcome. The Morn-PreΔ in testosterone and cortisol, plus the Pre-PostΔ in testosterone, all predicted a match outcome (p ≤ 0.01). The final model showed good diagnostic accuracy (72%) with cortisol as the main contributor.Conclusions
The salivary testosterone and cortisol responses to mid-week testing showed an ability to discriminate a rugby match outcome over a limited number of games. The Morn-PreΔ in cortisol was the strongest diagnostic biomarker. This model may provide a unique format to assess team readiness or recovery between competitions, especially with the emergence of rapid hormonal testing. 相似文献16.
Mechanical alterations during interval-training treadmill runs in high-level male team-sport players
Olivier Girard Franck Brocherie Jean-Benoit Morin Grégoire P. Millet 《Journal of Science and Medicine in Sport》2017,20(1):87-91
Objectives
To examine mechanical alterations during interval-training treadmill runs in high-level team-sport players.Design
Within-participants repeated measures.Methods
Twenty high-level male field-hockey players performed six 30-s runs at 5.53 ± 0.19 m s?1 corresponding to 115% of their velocity associated with maximal oxygen uptake (vVO2max) with 30-s passive recovery on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were performed and values were subsequently averaged over 20 s (8th–28th s) for comparison.Results
Contact time (+1.1 ± 4.3%; p = 0.044), aerial time (+4.1 ± 5.3%; p = 0.001), step length (+2.4 ± 2.2%; p < 0.001) along with mean loading rates (+7.1 ± 10.6%; p = 0.026) increased from the first to the last interval, whereas step frequency (?2.3 ± 2.1%; p < 0.001) decreased. Both centre of mass vertical displacement (+3.0 ± 6.0%; p < 0.001) and leg compression (+2.8 ± 9.7%; p = 0.036), but not peak vertical forces (0.0 ± 4.1%; p = 0.761), increased with fatigue. Vertical stiffness decreased (?2.8 ± 6.9%; p = 0.012), whereas leg stiffness did not change across intervals (p = 0.149).Conclusions
During interval-training treadmill runs, high-level team-sport players modified their mechanical behaviour towards lower vertical stiffness while preserving a constant leg stiffness. Maintenance of running velocity induced longer step lengths and decreased step frequencies that were also accompanied by increased impact loading rates. These mechanical alterations occurred early during the set. 相似文献17.
David S. Haydon Ross A. Pinder Paul N. Grimshaw William S.P. Robertson 《Journal of Science and Medicine in Sport》2018,21(12):1262-1267
Objectives
Use a task vehicle of sprint testing in wheelchair rugby (WCR) to explore the impact of small changes to test design using both group and individual analysis.Design
Exploratory, repeated measures, on-court studyMethod
25 national or international level wheelchair rugby players completed 5 × 5 m sprints under two conditions: (i) an acceleration from standstill in their own time, and (ii) an ‘active’ start, simulating a key aspect of performance. Video analysis and accelerometer data were used to measure key kinematic and performance variables with a focus on the first three strokes. Each player was grouped into a high-, mid-, or low-point group based on their sport-specific classification score. Group (paired sample t-tests) and individual (meaningful differences, performance coefficients, and Cohen’s d effect sizes) analysis assessed differences between the two conditions.Results
The low-point classification group performed significantly slower in the active start (p < 0.05). There were no differences in sprint time for the high- and mid-point groups. Mid-point players achieved greater peak accelerations for strokes two and three in the active start (p < 0.05). Individual sprint performances varied substantially, ranging from 8% decrease to 14% increase in sprint time for the active start. Meaningful differences in peak accelerations were demonstrated for 23 out of the 25 players.Conclusions
Small amendments to test design can lead to significant differences in individual athlete performance. Traditional group analyses masked important individual responses to testing conditions. There is need to further consider representative test design, and individual analysis for monitoring physical and skill performance. 相似文献18.
Beate Gaertner Amanda K. Buttery Jonas D. Finger Steffen Wolfsgruber Michael Wagner Markus A. Busch 《Journal of Science and Medicine in Sport》2018,21(5):489-494
Objectives
To examine cross-sectional and longitudinal associations between physical exercise and cognitive function across different age groups in a nationwide population-based sample of adults aged 18–79 years in Germany.Design
Cross-sectional/prospective.Methods
Cognitive function was assessed in the mental health module of the German Health Interview and Examination Survey for Adults (DEGS1-MH, 2009–2012, n = 3535), using a comprehensive neuropsychological test battery. Cognitive domain scores for executive function and memory were derived from confirmatory factor analysis. Regular physical exercise in the last three months was assessed by self-report and defined as no exercise, <2 and ≥2 h (hours) of exercise per week. A subgroup of DEGS1-MH participants who previously participated in the German National Health Interview and Examination Survey 1998 (GNHIES98, 1997–1999, n = 1624) enabled longitudinal analyses with a mean follow-up of 12.4 years.Results
Compared to no exercise, more weekly physical exercise was associated with better executive function in cross-sectional (<2 h: β = 0.12; ≥2 h: β = 0.17; all p < 0.001) and longitudinal analyses (<2 h: β = 0.14, p < 0.001; ≥2 h: β = 0.15, p = 0.001) using linear regression models adjusted for age, sex, education, smoking, alcohol consumption, fruit and vegetable consumption and obesity. Slightly weaker associations were found for memory in cross-sectional (<2 h: β = 0.08, p = 0.009; ≥2 h: β = 0.08, p = 0.026) and longitudinal analysis (<2 h: β = 0.09, p = 0.036; ≥2 h: β = 0.08, p = 0.114). There was no evidence of interaction between physical exercise and age.Conclusions
Higher levels of physical exercise were associated with better executive function and memory in cross-sectional and longitudinal analyses with no evidence for differential effects by age. 相似文献19.
Objectives
Overtraining syndrome (OTS) leads to worsened sports performance and fatigue. The pathophysiology of OTS has not been entirely elucidated, and there is a lack of accurate markers for its diagnosis. Changes in hormonal responses implicated in OTS were stimulated by exercise, which has limited their interpretation. Hence, we aimed to evaluate growth hormone (GH) and prolactin responses to a gold-standard and exercise-independent stimulation test, the insulin tolerance test (ITT).Design
Volunteers were recruited and divided into OTS-affected athletes (OTS), healthy athletes (ATL), and healthy non-active subjects (NCS) groups, after general and specific inclusion and exclusion criteria.Methods
We evaluated the responses of growth hormone (GH) and prolactin to the ITT, and compared between groups.Results
A total of 51 subjects were included (OTS, n = 14, ATL, n = 25, and NCS, n = 12). OTS disclosed significantly lower basal levels of GH (p = 0.003) and prolactin (p = 0.048), and GH (p = 0.001) and prolactin (p < 0.001) responses to ITT (p = 0.001), compared to ATL, but similar to NCS. OTS showed a later rise in GH levels in response to hypoglycemia, compared to ATL, but not to NCS. We suggest cutoffs for GH and prolactin levels to aid in the diagnosis of OTS.Conclusions
OTS-affected athletes show reduced GH and prolactin basal levels and responses to a non-exercise stress test compared to healthy athletes, but not to sedentary subjects. 相似文献20.
Katherine B. Owen Philip D. Parker Thomas Astell-Burt Chris Lonsdale 《Journal of Science and Medicine in Sport》2018,21(1):63-68