Effects of Acute Sleep Loss on Physical Performance: A Systematic and Meta-Analytical Review

Abstract

Background: Sleep loss may influence subsequent physical performance. Quantifying the impact of sleep loss on physical performance is critical for individuals involved in athletic pursuits.

Design: Systematic review and meta-analysis.

Search and inclusion: Studies were identified via the Web of Science, Scopus, and PsycINFO online databases. Investigations measuring exercise performance under 'control' (i.e., normal sleep, > 6 h in any 24 h period) and 'intervention' (i.e., sleep loss, ≤ 6 h sleep in any 24 h period) conditions were included. Performance tasks were classified into different exercise categories (anaerobic power, speed/power endurance, high-intensity interval exercise (HIIE), strength, endurance, strength-endurance, and skill). Multi-level random-effects meta-analyses and meta-regression analyses were conducted, including subgroup analyses to explore the influence of sleep-loss protocol (e.g., deprivation, restriction, early [delayed sleep onset] and late restriction [earlier than normal waking]), time of day the exercise task was performed (AM vs. PM) and body limb strength (upper vs. lower body).

Results: Overall, 227 outcome measures (anaerobic power: n = 58; speed/power endurance: n = 32; HIIE: n = 27; strength: n = 66; endurance: n = 22; strength-endurance: n = 9; skill: n = 13) derived from 69 publications were included. Results indicated a negative impact of sleep loss on the percentage change (%_Δ) in exercise performance (n = 959 [89%] male; mean %_Δ = - 7.56%, 95% CI - 11.9 to - 3.13, p = 0.001, I² = 98.1%). Effects were significant for all exercise categories. Subgroup analyses indicated that the pattern of sleep loss (i.e., deprivation, early and late restriction) preceding exercise is an important factor, with consistent negative effects only observed with deprivation and late-restriction protocols. A significant positive relationship was observed between time awake prior to the exercise task and %_Δ in performance for both deprivation and late-restriction protocols (~ 0.4% decrease for every hour awake prior to exercise). The negative effects of sleep loss on different exercise tasks performed in the PM were consistent, while tasks performed in the AM were largely unaffected.

Conclusions: Sleep loss appears to have a negative impact on exercise performance. If sleep loss is anticipated and unavoidable, individuals should avoid situations that lead to experiencing deprivation or late restriction, and prioritise morning exercise in an effort to maintain performance.

Fig. 1

Types of sleep loss encountered

Fig. 2

PRISMA flow chart (study selection methodology). Some publications contained multiple participant pools. In these instances, the individual participant pools were termed ‘studies’. Some studies investigated the influence of more than one sleep-loss protocol (i.e., deprivation, early or late restriction). In these instances, the separate study arms were treated as individual investigations, and termed ‘trials’. Each individual task from a given trial was termed ‘outcome measure’. ESM Table S1 provides the original search breakdown; ESM Table S2 provides the origin of included publications; and ESM Table S3 provides the reference and reason for exclusion of full-text publications. HIIE high-intensity interval exercise, ESM electronic supplementary material

Fig. 3

Relationship between time awake and the mean percentage change (95% CIs shown by the grey shaded area) in exercise performance for all tasks (combined exercise categories). Circle diameter corresponds to the weight of the outcome measure from each trial. a Sleep restriction (n = 121): mean %_Δ =  − 0.36, 95% CI − 0.52 to − 0.19; p < 0.001. Green circles represent ‘sleep restriction’ (not further defined); blue circles represent ‘early restriction’; and orange circles represent ‘late restriction’. b Sleep deprivation (n = 97): mean %_Δ =  − 0.30, 95% CI − 0.59 to 0.01; p = 0.051. Deprivation: participants did not sleep for an extended period of time (i.e., whole night); early restriction: participants delayed sleep (i.e., went to sleep at a later time); late restriction: participants awakened earlier than normal. CIs confidence intervals