Sleep extension improves serving accuracy: A study with college varsity tennis players

Objective: This study investigated the effects of sleep extension on tennis serving accuracy, as well as daytime sleepiness in college varsity tennis players. Methods: Twelve (seven females and five males) healthy students on a college varsity tennis team maintained their habitual sleep-wake schedule for a one-week baseline period followed by a one-week sleep extension period. Participants were requested to sleep at least nine hours, including naps, during the sleep extension period. Serving accuracy was assessed when participants were sleep deprived (prior to the sleep extension period) and after the sleep extension period. Levels of daytime sleepiness were monitored via the Epworth Sleepiness Scale and the Stanford Sleepiness Scale, and caffeine consumption was recorded throughout the study. Results: Participants slept significantly more in the second week - the sleep extension week - compared with the first week - the baseline week (8.85 vs. 7.14 h; p < 0.05). Following the sleep extension period, accuracy of the tennis serves improved significantly (35.7% vs. 41.8%; p < 0.05), and the Epworth Sleepiness Scale and Stanford Sleepiness Scale scores declined significantly (12.15 vs. 5.67; p < 0.05 and 3.56 vs. 2.67; p < 0.05, respectively). Conclusions: This study demonstrates that an increase in sleep of approximately 2 h per night significantly increased athletic performance in college varsity tennis players. (C) 2015 Elsevier Inc. All rights reserved.