Correlates of 15-year maintenance of physical activity in middle-aged women.

BACKGROUND: Interventions to increase sustained physical activity are needed and should be based on proven theories.
PURPOSE: To gain a better understanding of the correlates of sustained physical activity in midlife women, we used longitudinal epidemiologic data to investigate links between sustained physical activity and constructs advocated by three basic behavioral and social science theories: (1) self-determination, (2) social cognitive, and (3) social networks. A random sample of 90 midlife women, stratified by level of physical activity over 15 years, was selected from the Chicago cohort of the Longitudinal Study of Women's Health Across the Nation (SWAN).
METHODS: Using data on self-reported physical activity collected over 15 years, women were categorized into consistently active, sporadically active, and sedentary. New data were collected on theory-relevant constructs, i.e., autonomous motivation (assessed by the Treatment Self-Regulation Questionnaire) and self-efficacy (assessed by the Self-Efficacy and Exercise Habits Survey). Every SWAN woman identified a close female friend who also completed the physical activity questionnaire.
RESULTS: SWAN women with higher autonomous motivation (p = 0.002) and higher self-efficacy (p < 0.001) were more likely to be consistently physically active in analyses adjusted for age, race, and socioeconomic status. Sixty-one percent of SWAN women with a history of consistent physical activity had a friend who is currently highly active, versus 38 and 23 % for sporadically active and sedentary women, respectively (test for trend p = 0.008).
CONCLUSION: In midlife women, constructs advocated by basic behavioral and social science theories were consistent with long-term patterns of physical activity behavior. Special focus should be given to these basic theories in the design of interventions to promote sustained physical activity in mid-life women.