Acute Effects of Sleep Extension on Fatigue, Inhibitory Control, Short-Term Vigilance and Neuromuscular Function in Youth Elite Ice Hockey Players: A Randomised Crossover Trial.

Sleep extension has previously been shown to acutely benefit athletic performance. However, studies investigating the effects of sleep extension on fatigue and cognitive performance are lacking. In this randomised crossover trial, 22 elite youth hockey players (17 ± 1 years; 1.83 ± 0.07 m; 82 ± 7 kg) took part in a 3-week protocol during the pre-season. The first week included two familiarisation sessions. During the second and third week of the protocol, athletes underwent a testing session before and after a night of normal sleep vs. sleep extension (10 h of time in bed). For each athlete, these conditions were randomised across weeks. Each testing session consisted of 2 h of hockey training followed by a 30-min colour Multi-Source Interference Task (cMSIT). Three countermovement-jumps (CMJs), three handgrip contractions and 3-min psychomotor-vigilance tasks (PVTs) were performed pre-training, post-training, and post-cMSIT. Sleep was objectively monitored using actigraphy and sleep logs. Athletes slept normally 7:04 ± 0:39 h:mm. In the sleep extension condition, athletes increased their sleep by 16% ± 11% (p < 0.001; η p 2 = 0.72). Sleep onset latency, WASO, and sleep efficiency were similar across conditions (all p > 0.016; η p 2 ≤ 0.11). cMSIT performance and fatigue improved by 8% (p < 0.001; η p 2  = 0.21) and 23% (p = 0.022; η p 2  = 0.02), respectively, following sleep extension. Performance on the PVTs, CMJs and handgrip contractions, while changing between pre-training, post-training and post-cMSIT, remained similar across conditions (p > 0.13; η p 2  ≤ 0.01). These results suggest that acute sleep extension is beneficial for improving perceived fatigue and performance on a long and demanding cognitive task (cMSIT), with no changes in less demanding cognitive tasks (PVT) or short physical tests.