Influence of demographic, physiologic, and psychosocial variables on adherence to a yearlong moderate-intensity exercise trial in postmenopausal women

Background. Few studies have examined the long-term adherence to a yearlong exercise intervention among postmenopausal women. We examined the patterns of adherence to a yearlong exercise intervention and the influence of demographic, physiologic, and psychosocial variables on patterns of adherence among 173 sedentary, overweight, postmenopausal women. Methods. We collected demographic, physical activity (PA), physiologic, psychosocial, and medical history information at baseline and 12 months. The exercise prescription consisted of at least 45 min of moderate-intensity exercise 5 days/week for 12 months. We calculated several adherence variables. Associations between baseline variables and adherence levels were assessed in bivariate analyses and in multiple regression models. Results. Women randomized to the exercise group (N = 87) participated in moderate-intensity sports or recreational PA on 3.7 ± 1.4 days/week (79% of the prescribed 5 days/week) for 171 ± 88 min/week (87% of the prescribed 225 min/week) over the yearlong trial period. Sixty-eight percent of the exercisers had a yearlong average PA level exceeding the national recommendation of 150 min/week. Being in the preparation stage vs. the contemplation stage of the transtheoretical model and a history of participating in any sports or recreational PA were significant predictors of adherence. Conclusions. Our findings provide important information for the design of future PA interventions and health promotion programs.