title: 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.
authors.affiliation: Department of Biostatistics, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, USA.
authors.forename: George A
authors.initials: GA
authors.lastname: Kelley
authors.affiliation: Department of Biostatistics, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, USA.
authors.forename: Kristi Sharpe
authors.initials: KS
authors.lastname: Kelley
mesh_terms: D000328:Adult; D015444:Exercise; D006801:Humans; D012890:Sleep
keywords: apnea; exercise; meta-analysis; sleep; systematic review
  