A Longitudinal Study of the Effects of Instrumental and Emotional Social Support on Physical Activity in Underserved Adolescents in the ACT Trial

Background Few previous studies have examined the influence of instrumental and emotional social support on physical activity (PA) longitudinally in underserved adolescents. Purpose This longitudinal study was a secondary analysis of the Active by Choice Today (ACT) trial examining whether instrumental social support predicts increases in PA in underserved adolescents, above and beyond emotional social support provided by family or peers. Methods Students in the sixth grade ( N = 1,422, 73 % African American, 54 % female, M age = 11 years) in the ACT trial participated. At baseline and 19 weeks, previously validated measures of social support (family instrumental, family emotional, and peer emotional) were completed and moderate-to-vigorous PA (MVPA) was assessed using 7-day accelerometry estimates. Results A mixed ANCOVA demonstrated that baseline ( p = 0.02) and change in family instrumental support ( p = 0.01), but not emotional support from family or peers, predicted increases in MVPA across a 19-week period. Conclusions Future interventions in underserved adolescents should enhance opportunities for instrumental support for PA.