Impact of Physical Activity Interventions on Anthropometric Outcomes: Systematic Review and Meta-Analysis

Vicki S. Conn, Adam Hafdahl, Lorraine J. Phillips, Todd M. Ruppar, Jo-Ana D. Chase

Considerable research has tested physical activity (PA) interventions to prevent and treat overweight and obesity. This comprehensive meta-analysis synthesized the anthropometric effects of supervised exercise interventions and motivational interventions to increase PA. Eligible intervention studies included healthy participants with reported anthropometric outcomes [e.g., body mass index (BMI)]. Extensive searching located 54,642 potentially eligible studies. We included data from 535 supervised exercise and 283 motivational interventions in our syntheses, which used random-effects analyses. Exploratory moderator analyses used meta-analytic analogues of ANOVA and regression. We synthesized data from 20,494 participants in supervised exercise and 94,711 undergoing motivational interventions. The overall mean effect sizes (ES, d) for treatment versus control groups in supervised exercise interventions were 0.20 (treatment vs. control within-group comparison) and 0.22 (between-group comparison). The ES of 0.22 represents a post-intervention BMI of 26.7 kg/m(2) for treatment participants relative to 27.7 kg/m(2) for controls. The corresponding mean ES for motivational interventions was significantly smaller (d = 0.09 for between group, d = 0.10 for treatment vs. control within-group). Control group within-group comparisons revealed slightly worsening anthropometric outcomes during study participation (d = -0.03 to -0.04). Moderator analyses identified potential variables for future research. These findings document significant improvements in anthropometric effects from both supervised exercise and motivational interventions.