The 3 days/week exercise program prescribed to each participant randomized to either the exercise-only or the diet plus exercise groups consisted of an aerobic phase (15 minutes), a resistance-training phase (15 minutes), a second aerobic phase (15 minutes), and a cool-down phase (15 minutes). The first 4 months of the 18-month intervention was facility based. At any time after the first 4 months, participants who wished to exercise at home underwent a 2-month transition phase during which he or she alternated attendance between the facility and the home. Hence, some participants remained in a facility-based program, others opted for a home-based program, and some participants chose a combined facility–home-based program.
Participants were provided with an aerobic exercise prescription that included walking within a heart rate range of 50–75% of heart rate reserve. The resistance-training portion of the program consisted of 2 sets of 12 repetitions of the following exercises: leg extension, leg curl, heel raise, and step-up. Cuff weights and weighted vests were used to provide resistance. A 1–1.5-minute rest interval separated each exercise. Following 2 orientation sessions, participants began the exercise program using the lowest possible resistance. Resistance was increased after the participant performed 2 sets of 12 repetitions for 2 consecutive days.
For participants in the home-based program, weights were exchanged at the participant's request or after a determination was made during face-to-face or telephone contact to increase the weights. Telephone contacts were made every other week during the first 2 months of home-based exercise, every third week during the following 2 months, and monthly thereafter. Exercise and attendance logs were used to gather data and monitor progress. Exercise adherence was defined as the number of exercise sessions completed divided by the total number of prescribed sessions. All medical questions regarding the safety of exercise were referred to the participant's personal physician.