Exercise and sleep: a systematic review of previous meta-analyses

Conduct a systematic review of previous meta-analyses on exercise and sleep outcomes in adults and a meta-analysis of studies nested within these meta-analyses.

Meta-analyses of randomized controlled exercise interventions were included by searching nine electronic databases and cross-referencing. Dual-selection and data abstraction were conducted. Methodological quality of meta-analyses was assessed using AMSTAR and quality of evidence using GRADE. Random-effects models were used to pool results from the individual studies included in each meta-analysis.

Three meta-analyses representing 950 adults were included. Methodological quality ranged from 36% to 64% while quality of evidence was very low to low. Statistically significant improvements (P ≤ 0.05) were observed for the apnea-hypopnea index (AHI), overall sleep quality, global score, subjective sleep, and sleep latency. The number-needed-to-treat (NNT) and percentile improvements ranged from 4 to 7 and from 18.1 to 26.5, respectively. When overall sleep quality results from individual studies nested within different meta-analyses were pooled, statistically significant standardized mean difference (SMD) improvements were observed (-0.50, 95% CI -0.72 to -0.28). The NNT and percentile improvement were 7 and 19, respectively.

Exercise improves selected sleep outcomes in adults. To increase public health reach, a large, well-designed, and more inclusive meta-analysis is needed.