Effectiveness of Workplace Exercise Interventions on Body Composition: A Systematic Review and Meta-Analysis

Objective: The aim of this review was to analyze the effectiveness of workplace exercise interventions on body composition (BC). Data Source: Studies published in PubMed, Scopus, SPORTDiscus, Web of Science, CINAHL and PsycINFO, from the earliest time point until 8 July 2020. Study Inclusion and Exclusion Criteria: Inclusion criteria were worksite interventions, in adults, Randomized Controlled Trials (RCTs), real exercise practice, and measuring BC outcomes. Exclusion criteria were full-text non-available, abstract not in English, and exercise protocol missing. Data Extraction: 157 studies were retrieved and assessed for inclusion by 2 independent reviewers, who also used the Cochrane's Collaboration Tool to assess study quality and risk of bias. Data Synthesis: We performed a meta-analysis to determine the effect size of the interventions on BC outcomes reported in at least 5 studies. Results: Twelve RCTs were included (n = 1270, 66% women), quality of studies being low to high (25% moderate, 67% high). Interventions achieved a statistically significant decrease in waist circumference (SMD = 0.24; 95% confidence interval (CI): 0.06 to 0.41; p = 0.008), total mass fat (SMD = 0.21; 95%CI: 0.00 to 0.41; p = 0.047), and body adiposity index (SMD = 0.20; 95%CI: 0.00 to 0.41; p = 0.049). No changes were observed in body weight (SMD = 0.08 95%CI: -0.02 to 0.18; p = 0.128). Additionally, muscle mass increased in interventions that included strength training. There were no adverse events reported. Conclusion: The most effective workplace exercise interventions to improve BC combined supervised, moderate-intensity aerobic and strength training, for at least 4 months.