title: Meta-analysis of workplace physical activity interventions.
abstract: BACKGROUND
  Most adults do not achieve adequate physical activity levels. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from such programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research.
  
  
  METHODS
  Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008.
  
  
  RESULTS
  Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21); fitness (0.57); lipids (0.13); anthropometric measures (0.08); work attendance (0.19); and job stress (0.33). The significant effect size for diabetes risk (0.98) is less robust given small sample sizes. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on VO2max of 3.5 mL/kg/min; for lipids, -0.2 on the ratio of total cholesterol to high-density lipoprotein; and for diabetes risk, -12.6 mg/dL on fasting glucose.
  
  
  CONCLUSIONS
  These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity.
authors.affiliation: School of Nursing, University of Missouri, Columbia, Missouri 65211, USA. conn@missouri.edu
authors.forename: Vicki S
authors.initials: VS
authors.lastname: Conn
authors.forename: Adam R
authors.initials: AR
authors.lastname: Hafdahl
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Cooper
authors.forename: Lori M
authors.initials: LM
authors.lastname: Brown
authors.forename: Sally L
authors.initials: SL
authors.lastname: Lusk
mesh_terms: D015987:Effect Modifier, Epidemiologic; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D007588:Job Satisfaction; D007899:Leisure Activities; D009043:Motor Activity / Q000502:physiology*; D016272:Occupational Health; D017063:Outcome Assessment, Health Care; D010809:Physical Fitness; D015397:Program Evaluation; D011788:Quality of Life; D017132:Workplace / Q000706:statistics & numerical data*