Does more sleep enhance recovery? Influence of post-exercise sleep extension on physiological, neuromuscular, and perceptual recovery

Introduction: Reduced sleep quantity and quality is common following team-sport competition, which can impair athletic performance and recovery. Sleep extension can improve athletic performance, however its effect on post-exercise recovery are unknown. We aimed to investigate the effects of sleep extension on post-exercise recovery.

Methods: Ten healthy males had recovery markers (countermovement jump height; CMJ, peak isometric knee extensor torque (PT), autonomic function (heart-rate variability; HRV), perceived effort (RPE), and subjective wellbeing) assessed at baseline (Pre) and 0 h, 1 h, and 2 h post a high-intensity interval exercise (HIIE) session. Participants then underwent 8 h (CON) and 10 h (EXT) time in bed (TIB) in a random order following HIIE, before recovery was re-assessed 16 h post HIIE. Wrist-watch actigraphy measured total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SEF), and wake after sleep onset (WASO). Multiple multi-level linear mixed models assessed the effects of EXT on recovery (standardised effect; ± 90% confidence interval). Results are shown as standardised effect sizes (<0.20 trivial, 0.21-0.60 small, 0.61-1.20 moderate, 1.21-2.0 large and >2.1 very large) ± 90% confidence intervals.

Results: The EXT increased TST (3.88; ±0.22) and SOL (1.01; ±0.86), and decreased SEF (0.67; ±0.66), without influencing subjective sleep quality (0.05; ±0.34) compared to CON. The EXT did not have a substantial influence on CMJ (0.08; ±2.50), PT (0.04; ±0.41), HRV (0.06; ±0.73), RPE (0.06; ±0.98) or total wellbeing (0.19; ±0.51) compared to CON.

Conclusion: A single night of 10 h in bed has unclear effects on markers of post-exercise recovery compared to 8 h in bed, potentially due to inflated confidence intervals for effects. These findings suggest that the effects of sleep extension are subject to large individual variation and support the need for an individualised approach to the use of sleep interventions to enhance recovery.