Comparing the Effects of a Short Nap and Non-Sleep Deep Rest on Perceptual, Cognitive, and Physical Performance in Active Adults.

This study compared the effects of a 25-min nap opportunity and a 10-min non-sleep deep rest (NSDR) condition on perceptual, cognitive, and physical performance in physically active young adults. Sixty participants (26 female, 34 male; 22 ± 4 years) were randomly assigned to one of three groups (nap, NSDR, control; n = 20 each). All groups completed identical assessments immediately, 20 min, and 40 min post-intervention. Mixed-effects models, adjusted for sex, prior-night sleep, and weekly physical activity, revealed a significant group × time interaction for sleepiness, fatigue, readiness to perform, and handgrip strength (p < 0.05), whereas no significant group × time interaction was found for cognitive performance (reaction time and accuracy; p > 0.05). At 40 min post-intervention, the nap group reported lower fatigue than control (p = 0.01, Cohen's d = 0.98) and higher readiness to perform than both control (p < 0.001, Cohen's d = 1.48) and NSDR (p = 0.001, Cohen's d = 1.25). For handgrip strength, although a significant group × time interaction was observed, post-hoc comparisons showed no significant between-group differences at any time point. No significant effects were observed for the NSDR condition on perceptual, cognitive, or physical outcomes (p > 0.05). These findings indicate that a short nap can enhance perceived readiness and reduce fatigue after a brief latency period, whereas NSDR did not elicit significant effects under the present conditions.