Participants randomized to the LIVESTRONG exercise program will attend a 12-week LIVESTRONG Program at one of the participating YMCA's in the greater Boston area or CT. We will have monthly teleconferences to discuss the study, recruitment, and the exercise program. Lastly, throughout the 12-week program, participants will record their attendance at the LIVESTRONG program as well as any exercise done outside of the program. We will provide them with a Physical Activity Log book to record their exercise.

Baseline data will be collected from all study participants before randomization. If a participant is randomized to wait-list control, then he/she will be told that he/she will start the LIVESTRONG program after three months and after he/she returns to Yale or DFCI to complete the 3-month clinic visit.

The LIVESTRONG at the YMCA is a twelve-week, small group (< 16 participants) program designed for adult cancer survivors. YMCA fitness instructors work with each participant to fit the program to their individual needs. The instructors are trained in the elements of cancer, post rehabilitation exercise and supportive cancer care. There are two YMCA fitness instructors overseeing each exercise session. Each session is 90 min in duration, twice per week, for 12-wks (total of 24 sessions). Each session begins with a warm-up, then aerobic exercise (e.g., treadmill) and resistance training exercises, followed by a cool-down period, and follows the recommendations of the American College of Sports Medicine.

Modifiable Physical Activity Questionnaire will be used to assess physical activity levels at baseline and 3-months to examine whether the LIVESTRONG program led to maintenance or further increases in physical activity levels compared with participants randomized to control.

Dual-energy X-ray absorptiometry (DEXA) scans will be used to assess body fat percentage, lean body mass, and bone mineral density at baseline and 3-months. Study participants will receive a copy of their 3-month DEXA report.

All participants will undergo a 6MWT at baseline and after the 12-week protocol period. Participants will wear tennis shoes and will walk indoors along a long, flat, straight, enclosed corridor, on a flat surface for 6 minutes. They will be instructed to walk continuously along an area at least 50 feet in length, back and forth, for 6 minutes.