Journal of Social, Behavioral, and Health Sciences


Changes associated with the Youth Fit For Life physical activity intervention were assessed with 5- to 12-year-old children in after-school care ( N = 477). Body mass index (BMI), strength, and flexibility significantly improved over 12 weeks. Initial BMI was negatively related to observed changes, r = -.29, p < .001. Significant within-group improvements in tension, vigor, and physical self-concept scores, and levels of voluntary moderate-to-vigorous physical activity/week were also found in the 9- to 12-year-olds (n = 91). Multiple regression analysis indicated that changes in physical self-concept, exercise self-efficacy, and general self scores explained a portion of the variance in changes in voluntary physical activity that approached significance, R2 = .08, F = 2.55, p = .06. Revisions and extensions of the protocol were suggested.