Following completion of questionnaires, all participants will attend a group-specific orientation session. During this session, trained research staff will provide an introduction to the smartphone application used in the study and all relevant features, as well as a one-on-one physical activity counseling session in which staff members will work with participants to set initial aerobic and non-aerobic physical activity goals. During this time, participants will also be introduced to the goal-directed nature of the MAPS physical activity program. Short term (i.e., weekly) goals will specify the types of aerobic and non-aerobic activities that the individual will engage in, as well as the frequency and duration with which they will engage in these activities. Each participant's initial long-term goal will reflect federal physical activity recommendations. Accordingly, each participant will work toward achieving 150 minutes of moderate intensity aerobic activity, and at least two days of full-body muscle strengthening exercises within the 12-week intervention period. Staff will work with participants to modify these long-term goals based upon the participant's current abilities and physical activity level.