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

Abstract

Objective: 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.

Methods: 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.

Results: 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.

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

Keywords: apnea; exercise; meta-analysis; sleep; systematic review.

Conflict of interest statement

CONFLICTS OF INTEREST

None.

© 2016 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

Figures

FIGURE 1

Flow diagram for selection of articles

FIGURE 2

Forest plot for changes in overall sleep quality. The black horizontal lines represent the 95% confidence intervals while the squares represent the point estimate. The first two black diamonds represent the overall point estimate and 95% confidence intervals from each meta-analysis, while the third black diamond represents the overall pooled point estimate and 95% confidence intervals from all individual studies included in each meta-analysis. All analyses are based on the random-effects model

FIGURE 3

Funnel plot for overall changes in sleep quality

FIGURE 4

Influence analysis for changes in overall sleep quality with each study deleted from the model once. The black horizontal lines represent the 95% confidence intervals, while the squares represent the point estimate. The black diamond represents the overall point estimate and 95% confidence intervals

FIGURE 5

Cumulative meta-analysis, ranked by year, for point estimate changes in overall sleep quality. The black diamond represents the overall point estimate and 95% confidence intervals