Data analysis
The data were analyzed using Statistical Package for the Social Sciences version 21 software (IBM Corporation, Armonk, NY, USA). Exploratory analyses were used to determine if the data met the assumptions for statistical tests. Multivariate analysis of variance was used to compare the three groups at baseline and to compare the baseline characteristics for subjects who completed the study and those who withdrew or did not provide valid PA data. Repeated measures multivariate analysis of variance, controlling for age, was used to compare the three groups at baseline and after 4 months of intervention (n=49) and to compare the three groups at baseline, after 4 months of intervention, and at 12 months of follow-up (n=34). Significant interaction effects on the multivariate test were examined by univariate analysis of variance for repeated measures to determine differences between groups for individual variables. Data are presented as the mean ± standard deviation.