Family support for physical activity in girls from 8th to 12th grade in South Carolina.

OBJECTIVE To examine the relationship between perceived family support and other selected correlates of physical activity (PA) with changes in PA over time. METHODS A total of 421 girls in South Carolina completed questionnaires at 8th, 9th and 12th grades (1998-2003). Family support for PA, PA self-efficacy, perceived behavioral control, attitudes, availability of equipment, and PA were measured. RESULTS Growth curve analysis showed that family support, perceived behavioral control, and self-efficacy were independently related to age-related changes in PA as reflected by total METs. Girls who reported lower family support at the 8th grade measure had more rapid declines in PA, and a unit change in family support was related to approximately 1/3 of a standard deviation change in total METs. CONCLUSIONS Maintenance of support from family members may reduce the decline in PA independent of girls' self-efficacy and perceived behavioral control.