You are looking at 71 - 80 of 4,572 items for :

  • Sport and Exercise Science/Kinesiology x
  • Physical Education and Coaching x
Clear All
Restricted access

José L. Areta

The female athlete triad is a condition where low energy availability is typically observed together with menstrual dysfunction and/or low bone mineral density. How this condition affects maximal work capacity in endurance athletes is not clear, and the recovery time course of menses with increased energy availability with concomitant high training load is unknown. This case study of an amenorrheic elite road cyclist reports resumption of normal menstrual function after weight gain during a 5-year period (2014–2019), while engaged in high training load and competition. The athlete (V˙O2max 3.54 L/min, 64 ml·min−1·kg−1, aerobic peak power output 300 W, 5.4 W/kg) reported amenorrhea (2013–2015) and oligomenorrhea (2015–2018). Training load increased from 2014 to 2019 (584–818 hr/year and 26,707–41,945 training stress score/year). Regular menses (every 23–35 days) resumed in June 2018, ∼5–6 months after a weight gain episode. During the period of menstrual dysfunction, body mass was 51.3 ± 2.25 kg (mean ± 95% confidence limit) and fat percentage was 19% (dual-energy X-ray absorptiometry, 2016), and after weight gain, body mass was 56.8 ± 2.63 kg and fat percentage was 25% (dual-energy X-ray absorptiometry, 2019). Crank-based power meter data showed absolute mean maximal power (in watts) improvement over the 5 s to 4 hr range through the 2014–2019 period, while relative mean maximal power (in watts per kilogram) likely peaked in the 2015–2016 season for 5 min, 20 min, and 30 min, but remained mostly unchanged across seasons. Results suggest that (a) the best relative power output associated with aerobic capacity (5 min to 1 hr) can be achieved during menstrual dysfunction, (b) high performance achieved despite an increase in body mass, and (c) resumption of menses is achievable while maintaining high training loads when coupled with high energy availability.

Restricted access

Janet L. Hauck, Isabella T. Felzer-Kim and Kathryn L. Gwizdala

This longitudinal study investigated monthly motor development and physical activity (PA) of infants with and without Down syndrome. Gross and fine motor skills (Bayley Scales of Infant Development-III) and PA (accelerometer) were assessed in 35 infants at eight time points during infancy. A multivariate mixed model identified time points when motor scores diverged between the groups. In infants with Down syndrome, bivariate correlations between monthly PA and motor changes were calculated, and multivariate analysis of variance probed the influence of early PA on motor-skill timing. Results indicate that differences in gross and fine motor skills first emerge at 2 and 4 months, respectively. In infants with Down syndrome, gross motor and PA changes between 4 and 6 months were positively correlated. Infants more active than the mean at 2 or 3 months achieved several prone and sitting skills earlier. These results highlight the adaptability of early infancy and the importance of early intervention.

Restricted access

Suzanna Russell, Angus G. Evans, David G. Jenkins and Vincent G. Kelly

Purpose: To determine the efficacy of 20 minutes of external counterpulsation (ECP) on subsequent 1.2-km shuttle run test (1.2SRT) performance and perceived recovery following fatiguing high-intensity exercise. Methods: After familiarization, 13 recreationally active males (21.4 [1.9] y) participated in 2 experimental trials in a randomized crossover design. At 8:00 AM, participants completed a 1.2SRT, followed by an individualized high-intensity exercise bout and 20 minutes of ECP or supine passive rest (control). At 2:00 PM a second 1.2SRT was completed. Completion time for 1.2SRT (measured in seconds), heart rate, and Borg rating of perceived exertion were compared across conditions. Total quality of recovery and 100-mm visual analogue scale of perceived benefit of recovery were assessed at multiple time points. Results: A significantly smaller decline in PM 1.2SRT completion time compared with AM (baseline) was found for ECP compared with control (P = .008; moderate, very likely beneficial effect size of −0.77 [−1.53 to 0.05]). Total quality of recovery was significantly higher for ECP than control (P < .001), and perceived benefit of recovery was higher following ECP (P < .001, very large, most likely beneficial effect size of 2.08 [1.22 to 2.81]). Conclusions: Twenty minutes of ECP was found to be an effective recovery modality for within-day, between-bouts exercise, positively influencing subsequent 1.2SRT performance and enhancing perceptual recovery. ECP may be applied as a viable alternative to optimize and accelerate the recovery process, particularly in the event of congested training or competition demands.

Restricted access

Ali Brian, Laura Bostick, Angela Starrett, Aija Klavina, Sally Taunton Miedema, Adam Pennell, Alex Stribing, Emily Gilbert and Lauren J. Lieberman

Children with visual impairments often exhibit difficulties with locomotor skills (e.g., the ability to move one’s body from one place to another), warranting the need for ecologically valid interventions with conditions that attempt to match the real world in a variety of settings. Parents and physical education teachers are the ones choosing to provide movement opportunities for children with visual impairments and must be included in any ecologically valid intervention strategy. This was a descriptive-analytic study. To support the greatest diversity in settings, the authors recruited 94 participants (blind = 44 and low vision = 50; M age = 13.01 years, SD = 3.26) from schools for the deaf and blind in the United States (teacher led, n = 17) or Latvia (teacher led, n = 57), through an online LISTSERV throughout the United States (parent led, n = 10), and a control subgroup (n = 10). At the pretest, no participant’s motor development met age expectations. Children with visual impairments from multiple locations and cultures significantly improved compared with controls who did not. Results were most favorable when the physical educator was the interventionist. However, further research is needed to replicate these findings.

Restricted access

Nicola Taylor, David Giles, Micha Panáčková, James Mitchell, Joel Chidley and Nick Draper

Purpose: To assess the validity and reliability of a novel movement-performance assessment tool for climbing/sport climbing. Methods: First, salient climbing movement-performance factors were identified through an iterative consultation process with 10 expert climbing coaches; the resulting Climber’s Movement Performance Assessment Tool (CM-PAT) contained 14 items in 5 categories. Second, 61 intermediate to advanced climbers ascended a single route, which was video recorded. Subsequently, 4 experienced (>10 y coaching) coaches used the CM-PAT to observe and score the climbers’ performance. Interrater reliability and comparisons with existing measures of climbing performance (6-mo self-reported ability, success and failure, climbing pace [m·min−1], and geometric entropy) were made. Results: Intraclass correlation coefficient (2,k) for the 4 raters demonstrated excellent reliability (>.81) between observers and good to excellent test–retest reliability (.71–.91). Pearson correlations between self-reported ability and CM-PAT scores explained 61% of the variance in self-reported climbing performance compared with 16% for geometric entropy and 52% for climbing pace. Considering differences in successful and unsuccessful climbers, the CM-PAT (P < .0005; d = 2.14), geometric entropy (P = .014; d = 0.67), and pace (P < .0005; d = 1.88) were able to differentiate between groups. Conclusions: The CM-PAT is the first sport climbing performance observational instrument to be developed through a thorough iterative process with expert coaches. Excellent interrater and test–retest reliability and excellent agreement with self-reported ability and with existing quantitative measures of performance support its recommendation for use in coaching and research contexts. Notably, a key advantage over existing measures is the identification of coachable elements of performance.

Restricted access

Xavier Woorons, François Billaut and Henry Vandewalle

Purpose: To determine whether high-intensity training with voluntary hypoventilation at low lung volume (VHL) in cycling could improve running performance in team-sport athletes. Methods: Twenty well-fit subjects competing in different team sports completed, over a 3-week period, 6 high-intensity training sessions in cycling (repeated 8-s exercise bouts at 150% of maximal aerobic power) either with VHL or with normal breathing conditions. Before (Pre) and after (Post) training, the subjects performed a repeated-sprint-ability test (RSA) in running (12 × 20-m all-out sprints), a 200-m maximal run, and the Yo-Yo Intermittent Recovery Level 1 test (YYIR1). Results: There was no difference between Pre and Post in the mean and best velocities reached in the RSA test, as well as in performance and maximal blood lactate concentration in the 200-m-run trial in both groups. On the other hand, performance was greater in the second part of the RSA test, and the fatigue index of this test was lower (5.18% [1.3%] vs 7.72% [1.6%]; P < .01) after the VHL intervention only. Performance was also greater in the YYIR1 in the VHL group (1468 [313] vs 1111 [248] m; P < .01), whereas no change occurred in the normal-breathing-condition group. Conclusion: This study showed that performing high-intensity cycle training with VHL could improve RSA and possibly endurance performance in running. On the other hand, this kind of approach does not seem to induce transferable benefits for anaerobic performance.

Restricted access

Devin G. McCarthy, Kate A. Wickham, Tyler F. Vermeulen, Danielle L. Nyman, Shane Ferth, Jamie M. Pereira, Dennis J. Larson, Jamie F. Burr and Lawrence L. Spriet

During play, ice hockey goaltenders routinely dehydrate through sweating and lose ≥2% body mass, which may impair thermoregulation and performance. Purpose: This randomized, crossover study examined the effects of mild dehydration on goaltender on-ice thermoregulation, heart rate, fatigue, and performance. Methods: Eleven goaltenders played a 70-minute scrimmage followed by a shootout and drills to analyze reaction time and movements. On ice, they either consumed no fluid (NF) and lost 2.4% (0.3%) body mass or maintained body mass with water (WAT) or a carbohydrate–electrolyte solution (CES). Save percentage, rating of perceived exertion, heart rate, and core temperature were recorded throughout, and a postskate questionnaire assessed perceived fatigue. Results: Relative to NF, intake of both fluids decreased heart rate (interaction: P = .03), core temperature (peak NF = 39.0°C [0.1°C], WAT = 38.6°C [0.1°C], and CES = 38.5°C [0.1°C]; P = .005), and rating of perceived exertion in the scrimmage (post hoc: P < .04), as well as increasing save percentage in the final 10 minutes of scrimmage (NF = 75.8% [1.9%], WAT = 81.7% [2.3%], and CES = 81.3% [2.3%], post hoc: P < .04). In drills, movement speed (post hoc: P < .05) and reaction time (post hoc: P < .04) were slower in the NF versus both fluid conditions. Intake of either fluid similarly reduced postskate questionnaire scores (condition: P < .0001). Only CES significantly reduced rating of perceived exertion in drills (post hoc: P < .05) and increased peak movement power versus NF (post hoc: P = .02). Shootout save percentage was similar between conditions (P = .37). Conclusions: Mild dehydration increased physiological strain and fatigue and decreased ice hockey goaltender performance versus maintaining hydration. Also, maintaining hydration with a CES versus WAT may further reduce perceived fatigue and positively affect movements.

Open access

Sergei Iljukov, Jukka-Pekka Kauppi, Arja L.T. Uusitalo, Juha E. Peltonen and Yorck O. Schumacher

The purpose of this research was to evaluate the performances of female middle- and long-distance runners before and after the implementation of a new antidoping strategy (the Athlete Biological Passport [ABP]) in a country accused of systematic doping. A retrospective analysis of the results of Russian National Championships from 2008 to 2017 was performed. The 8 best female performances for the 800-m, 1500-m, 3000-m steeplechase, 5000-m, and 10,000-m events from the semifinals and finals were analyzed. The yearly number of athletes fulfilling standard qualifications for international competitions was also evaluated. Overall, numbers of athletes banned for doping in 2008–2017 were calculated. As a result, 4 events (800, 1500, 5000 [all P < .001], and 10,000 m [P < .01]) out of 5 showed statistically significant deterioration in the performances when comparing before and after the introduction of the ABP. The 3000-m steeplechase was the only event that did not show statistically significant change. The highest relative decrease in the number of runners who met standard qualification for international competition was for the 5000-m event (46%), followed by 1500-m (42%), 800-m (38%), 10,000-m (17%), and 3000-m steeplechase (1%). In conclusion, implementation of the ABP was followed by a significant reduction in the performance of female runners in a country accused of systematic doping. It can be reasonably speculated that more stringent antidoping testing, more specifically the introduction of the ABP, is a key reason for this reduction.

Restricted access

Phillip M. Bellinger, Cameron Ferguson, Tim Newans and Clare L. Minahan

Purpose: To determine whether there is an association between external match load and contextual factors on subjective wellness in the days before and after Australian Rules football match play. Methods: A total of 34 elite male Australian football players completed a subjective wellness questionnaire in the days leading into the match (–3, –2, and –1 d), the day of (match day), and the days after each match (+3, +2, and +1 d). Players subjectively rated each item (mood, energy, stress, leg heaviness, muscle soreness, sleep quality, hours slept, and total wellness [a sum of the total response score]) on a visual analog scale ranging from 1 to 10, with 1 representing the negative end of the continuum. External load during competitive matches was quantified using accelerometer-derived PlayerLoad, and running activity was quantified using global positioning system technology across 2 competitive seasons. The relationships between perceptions of wellness (within-individual z score), external match load, and contextual factors (match result, match location, and between-matches recovery duration) were analyzed using linear mixed models. Results: Mixed-effect linear models revealed trivial effects of match-day wellness z score on subsequent external match load metrics. Match result (win) and PlayerLoad in the anteroposterior vector (au·min−1) were associated with an increased (estimate ± SE: 0.30 ± 0.13 z score) and reduced subjective wellness (−0.15 ± 0.06 z score), respectively. Conclusion: The results of this study suggest that prematch perceived wellness does not relate to external match load in elite Australian football players. The between-matches microcycle length appears to be sufficient to restore perceived wellness to values that do not affect the subsequent external match loads.

Restricted access

Everton C. do Carmo, Renato Barroso, Andrew Renfree, Natalia R. da Silva, Saulo Gil and Valmor Tricoli

Purpose: To verify the affective feelings (AFs) and rating of perceived exertion (RPE) responses during a 10-km competitive head-to-head (HTH) running race and compare them with a time-trial (TT) running race. Methods: Fourteen male runners completed 2 × 10-km runs (TT and HTH) on different days. Speed, RPE, and AF were measured every 400 m. For pacing analysis, races were divided into the following 4 stages: first 400 m (F400), 401–5000 m (M1), 5001–9600 m (M2), and the last 400 m (final sprint). Results: Improvement of performance was observed (39:32 [02:41] min:s vs 40:28 [02:55] min:s; P = .03; effect size = −0.32) in HTH compared with TT. There were no differences in either pacing strategy or RPE between conditions. AFs were higher during the HTH, being different in M2 compared with TT (2.09 [1.81] vs 0.22 [2.25]; P = .02; effect size = 0.84). Conclusions: AFs are directly influenced by the presence of opponents during an HTH race, and a more positive AF could be involved in the dissociation between RPE and running speed and, consequently, the overall race performance.