Effects of sleep manipulation on athletic performance, cognitive function, and recovery: a systematic review of experimental studies

Sleep is important for recovery, cognitive and physical performance. Sleep manipulation (sleep extension, napping and sleep restriction) is a new way to enhance performance for athletes. This systematic review explored the effects of sleep manipulation on physical performance, cognitive performance and psychophysiological responses in the active and athletic population. The literature was searched in PubMed, Scopus, Web of Science, and Google Scholar for eligible studies published between 2011 and 2025, yielding 1,586 records. After removing duplicates and applying the exclusion and inclusion criteria, 15 intervention studies (randomized controlled trials and crossover) were identified. Data were extracted and the results synthesised in a structured narrative format due to variability in the designs and measures used. Sleep extension led to enhanced performance, including greater distance run in the shuttle run (+ 9.5 m), lower fatigue index (− 8.1%), shorter reaction time (− 43.6 ms), better sprint time (− 0.7 s) and improved accuracy ( ~ + 9%). Sleep extension led to a ~ 3% improvement in endurance, whereas sleep restriction led to a ~ 3% decrease in endurance, alongside higher fatigue and cognitive performance decrements. Daytime napping showed mixed results, with longer naps (60–90 min) enhancing maximum voluntary contraction (+ 74 N), distance (+ 89 m), and lowering perceived fatigue (− 1.9 units) and sleepiness (− 4.33 units). The effects of brief naps (20 min) were variable, with some minor performance deficits (+ 0.026 s in sprint time). Overall, sleep extension was generally associated with favourable physical, cognitive, and recovery-related outcomes, whereas sleep restriction was associated with adverse performance effects. The effects of daytime napping were more context-dependent and appeared to vary according to prior sleep status, nap duration, and subsequent performance demands.