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Purpose: The purpose of this experiment was to assess performance during repeated sprints utilizing self-selected recovery intervals in youth football (soccer) players at different stages of maturation. Methods: Quota sampling method was used to recruit 14 prepeak height velocity (PHV) and 14 post-PHV participants for the study (N = 28; age = 13 [0.9] y, stature = 162.5 [10.8] cm, mass = 50.2 [12.7] kg). Players performed repeated sprints comprising 10 × 30 m efforts under 2 experimental conditions: using 30-second and self-selected recovery intervals. Magnitude of effects for within- and between-group differences were reported using effect size (ES) statistics ± 90% confidence intervals and percentage differences. Results: The decline in sprint performance was likely lower in the pre-PHV compared with the post-PHV group during the standardized recovery trial (between-group difference = 37%; ES = 0.41 ± 0.51), and likely lower in the post-PHV group during the self-selected recovery trial (between-group difference = 50%; ES = 0.45 ± 0.54). Mean recovery duration was likely shorter in the pre-PHV compared with the post-PHV group during the self-selected recovery trial (between-group difference = 26.1%; ES = 0.47 ± 0.45). Conclusion: This is the first study to show that during repeated sprints with self-selected recovery, pre-PHV children have an impaired ability to accurately interpret physical capabilities in the context of the task compared with post-PHV adolescents. [ABSTRACT FROM AUTHOR]

Purpose: To explore pacing behavior and tactical positioning during the shorter 500- and 1000-m short-track competitions. Methods: Lap times and intermediate rankings of elite 500- and 1000-m short-track-skating competitors were collected over the 2012-13 season. First, lap times were analyzed using a MANOVA, and for each lap, differences between sex, race type, final ranking, and stage of competition were determined. Second, Kendall tau-b correlations were used to assess relationships between intermediate and final rankings. In addition, intermediate rankings of the winner of each race were examined. Results: Top-placed athletes appeared faster than bottom-placed athletes in every lap in the 500-m, while in the 1000-m no differences were found until the final 4 laps (P < .05). Correlations between intermediate and final rankings were already high at the beginning stages of the 50-m (lap 1: r = .59) but not for the 1000-m (lap 1: r = .21). Conclusions: Although 500- and 1000-m short-track races are both relatively short, fundamental differences in pacing behavior and tactical positioning were found. A fast-start strategy seems to be optimal for 500-m races, while the crucial segment in 1000-m races seems to be from the 6th lap to the finish line (ie, after ± 650 m). These findings provide evidence to suggest that athletes balance between choosing an energetically optimal profile and the tactical and positional benefits that play a role when riding against an opponent, as well as contributing to developing novel insights in exploring athletic behavior when racing against opponents. [ABSTRACT FROM AUTHOR]

Optic flow on the retina creates a perception of a person's movement relative to their surroundings. This study investigated the effect of optic flow on perceived exertion during cycling. Fifteen participants completed a 20-km reference cycling time trail in the fastest possible time followed by three randomly counterbalanced 20-km cycling trials. Optic flow, via projected video footage of a cycling course, either represented actual speed (TTNORM) or was varied by -15% (TTSLOW) and +15% (TTFAST). During TTSLOW, power output and ratings of perceived exertion (RPE), measured every 4 km, were lower during TTSLOW compared with TTNORM and TTFAST. There were no differences in heart rate or cadence. This study is the first to show that different rates of optic flow influence perceived exertion during cycling, with slower optic flow being associated with lower RPE and higher power output. [ABSTRACT FROM AUTHOR]

A within subjects experimental design (N = 16) was used where participants performed a 30-s Wingate anaerobic cycling test (WAnT) after 30-min rest and after 30-min back massage. Mood State was measured before and after each intervention and after the WAnTs. No significant change in mood was detected following rest or massage. However, WAnT performance was better following massage compared to rest. Mood disturbance increased following the WAnT in both the rest and massage conditions. The results suggest that preperformance massage had no effect on mood state yet seemed to facilitate enhanced WAnT performance. The relationship between massage and anaerobic performance remains unclear, however is almost certainly mediated by preperformance psychological factors other than mood state. [ABSTRACT FROM AUTHOR]