An experimental design will be used to determine the short- and long-term impact of two nurse-delivered exercise teaching interventions on exercise adherence, physical fitness, self-esteem, and mood of middle-aged and older women. The research design is pre-test/post-test control group experimental design with five data collection points over a 2-year period. The sample will consist of 304 overweight (35% to 50% body fat) women, aged 49 to 70 years, who are sedentary and in low to moderately high risk categories for coronary heart disease. Women will be randomly assigned to a (1) health and fitness management education with aerobic training group that will receive progressive, intensity-controlled, low-impact aerobic exercise and muscle conditioning 3 days per week and weekly health and fitness information; (2) health and fitness management education only group; or (3) control group. Women will undergo a battery of fitness and psychological tests before and after 16 weeks of intervention and will be retested at 3 months, 6 months, and 18 months postintervention. Attendance and physical activity records will be kept. Factors that influence adherence or nonadherence to exercise over time will be identified through personal interviews and questionnaires at four time points. Analysis of data will be done through Analysis of Variance, Analysis of Covariance, Multivariate Analysis of Variance with repeated measures, t-tests, and other tests when appropriate. Content analysis using ETHNOGRAPH will be used to analyze interview data. This study will be conducted in two phases: (1) test interventions on women aged 49 to 59 years and, based on findings and pilot studies, modify interventions for appropriate and safe use with older women; and (2) test modified interventions on women aged 60 to 70 years. Study duration will be 5 years.