Athletes’ performance may improve by increasing their sleep duration. This would typically be achieved by increasing time in bed at night, but this may not always be possible. One potential solution is to nap during the day, however the time taken to reach optimal performance after waking from a nap is not known. PURPOSE: To examine readiness to perform, sprint ability, and reaction time 30, 60, 90 and 120 min after waking from a daytime nap. METHODS: Twelve soccer players (18.3±1.0 yrs) completed two conditions in a randomised order. In one condition, participants had 9 hours time in bed (22:00-07:00h) without napping the next day and in the other condition, participants had 7 hours time in bed (00:00-07:00h) with a 2-h nap the next day (14:00-16:00h). Sleep was assessed using polysomnography. Each day, participants completed four 30-min test sessions (every 30 min starting at 16:15h) that included a visual analogue scale for readiness to perform, a 7-min warm up, two 10-m sprints, and a 90-s reaction time task. Total sleep time was compared between conditions using a paired t-test. The effect of condition (no nap vs. nap) and test session (30, 60, 90, 120 min) on readiness to perform, fastest 10-m sprint, and mean reaction time were assessed by separate repeated ANOVAs. RESULTS: Total sleep time was similar between conditions (no nap 8.1±0.7 h vs. nap 8.0±1.0 h, p=0.87). There were main effects of condition (p<0.01) and test session (p<0.05) on readiness to perform, but no interaction between condition and session (p=0.09). Readiness to perform was lower in the nap condition (68.2±20.1) vs. the no nap condition (82.4±15.4), and at 30 min (68.0±20.8) vs. both 60 min (80.0±15.3, p=0.01) and 90 min (77.8±17.9, p=0.03). There was a main effect of test session (p=0.02) on reaction time, but no effect of condition (p=0.84) and no interaction between condition and session (p=0.26). Reaction time was faster at 120 min (211.3±20.0 ms) vs. 30 min (219.5±20.5 ms, p=0.01) and 60 min (219.8±20.8 ms, p=0.01). There were no main effects of condition (p=0.17) or time (p=0.37), and no interaction between condition and session (p=0.84) on sprint ability. CONCLUSIONS: The findings suggest that a daytime nap will not affect subsequent sprint ability or reaction time. However, athletes may feel less ready to perform after napping compared with not napping.
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