Abstract
Physical activity (PA) has been identified as an essential component of effective weight loss programs for obese youth. The group-mediated cognitive-behavioural (GMCB) intervention model is based on social cognitive theory (Bandura, 1986) and group dynamics literature (Cartwright, 1951) and was developed to teach individuals self-regulatory skills important in leading an independently active lifestyle. The purpose of this pilot study was to examine the effects of a 12-week exercise and GMCB intervention on obese adolescent's PA behaviour, body composition and fitness at 13-weeks and 6-months post-intervention. Fifty-five obese adolescents (female = 33, BMI ? 95thpercentile; 10-16 years) completed this intervention. Assessments consisted of the 7-day Physical Activity Recall interview (Blair, 1984), dual-energy x-ray absorptiometry, Balke VO2 max test, and maximal voluntary contractions for the upper and lower body. All variables were assessed at baseline, 13-weeks and 6-months. Repeated measures MANOVAs were used to examine all data. Follow-up ANOVAs indicated significant main effects for time in the expected direction for both frequency, F(2, 52) = 17.72, p < .001, and volume of PA, F(2, 52) = 6.03, p < .01; percent body fat, F(2, 72) = 14.88, p < .001; lower body strength, F(2, 76) = 3.14, p < .05; and VO2 max, F(2, 25) = 2.45, p < .05. These findings suggest that an exercise program enhanced with GMCB sessions can result in favourable, long-term physical outcomes in obese adolescents.Acknowledgments: This research was supported by the Social Sciences and Health Research Council, The Lawson Foundation and The Children's Health Foundation.