In a sample of 291 adolescents (mean age 13 yr), seven psychosocial factors, including family support, were examined in relation to accelerometry-derived physical activity (PA) measured after school and during the weekend. Gender-specific stepwise linear regression analyses determined which combinations of factors explained the variance in nonschool moderate to vigorous PA and nonschool total PA after adjusting for % BF, age, and maturity (p ≤ 0.05). Being praised by a family member and % BF explained 13% of the variance in female nonschool MVPA, while being praised and maturity explained 13% of the variance in nonschool total PA. Having a family member watch him participate, % BF, and age explained 11.5% of the variance in male nonschool MVPA, while having a family member participate with him explained 6.4% of the variance in nonschool total PA. Despite adolescents’ growing independence, family support continues to influence PA levels.
Morrissey and Janz are with the Dept. of Health and Human Physiology, University of Iowa, Iowa City, IA. Wenthe is with the Dept. of Occupational Therapy, Saint Ambrose University, Davenport, IA. Letuchy is with the Dept. of Epidemiology, University of Iowa, Iowa City, IA. Levy is with the College of Dentistry, University of Iowa, Iowa City, IA.