Background: Observational studies associate physical activity (PA) with improved perceptions of children and adolescents' physical self-concept (PSC) and global self-concept (GSC). However, only a few PA-based interventions exist for improving PSC and their results have been inconclusive. Objective: To determine the effect of specific PA-based programmes on the PSC (including its sub-dimensions) and GSC of children and adolescents, and to assess possible moderators. Methods: The databases Web of Science, Scopus, SportDiscus, PubMed, CINAHL, and Cochrane Library were reviewed in February 2020. Only studies with pre-post measurements and control groups were included. The impact of PA-based interventions was explored through different meta-analyses and moderator analyses. Results: Altogether, 20 studies were included in the meta-analysis. Positive and significant effects of PA were determined on self-perceived physical appearance (g = 0.13; 95% CI = 0.03, 0.23), self-perceived sport competence (g = 0.30; 95% CI = 0.09, 0.51), self-perceived physical fitness (g = 0.19; 95% CI = 0.05, 0.32), PSC (g = 0.31; 95% CI = 0.10, 0.52), and GSC (g = 0.17; 95% CI = 0.01, 0.33). The existence of additional interventions in PA-based programmes (e.g., interventions focused on psychological factors or healthy habits) moderated the influence of PA on self-perceived sport competence and physical fitness. Moreover, environment and time were distinguished as moderators for self-perceived physical appearance and sport competence. Further, intervention type, gender, and frequency of intervention moderated the effects of PA on PSC. Conclusions: PA-based interventions, especially in school, seem to be beneficial for the development of positive physical self-perceptions.
Keywords: Adolescence; childhood; meta-analysis; physical self-concept.