Aerobic Exercise, Resistance Exercise, or Flexibility and Relaxation Training in Inactive Older Female Breast Cancer Survivors

OBJECTIVES:

Primary:

• Compare the effects of aerobic exercise vs flexibility and relaxation training (control) on fatigue, aerobic capacity, functioning, and health outcomes in inactive older female breast cancer survivors.
• Compare the effects of resistance exercise vs flexibility and relaxation training (control) on fatigue, muscle strength, functioning, and health outcomes.

Secondary:

• Compare the relative effects of aerobic exercise vs resistance exercise on fatigue, physical functioning, physical health, and mental health.
• Determine the mediating effects of fatigue and fitness on the relationship between exercise and physical functioning.
• Compare the individual and relative effects of aerobic exercise vs resistance exercise vs flexibility and relaxation training (control) on body composition and on biomarkers of cancer recurrence.

OUTLINE: Patients are stratified according to current use of hormone manipulation therapy (none vs tamoxifen vs arimidex). Patients are randomized to 1 of 3 intervention arms.

• Arm I (progressive, aerobic exercise program): Patients undergo aerobic exercise training over approximately 45 minutes (not including warm-up or cool-down exercises) 3 days a week for 18 months. During the first 12 months, patients attend supervised aerobic exercise sessions 2 days a week and complete 1 home-based aerobic exercise session using a modified exercise program designed by the investigative team. During the final 6 months, patients undergo aerobic exercise using an at-home program designed by the investigative team. Aerobic exercise training comprises simple stepping routines using benches of various heights while wearing a wrist monitor to record heart rate. Volume of aerobic exercise, determined by intensity (heart rate at percentage of heart rate reserve tailored to the patient) and duration (minutes in the target heart rate range), is gradually and progressively increased over the first 9 months of the exercise program. Exercise volume remains at a moderate level for the remainder of the program to provide an optimal physiologic challenge at a safe and tolerable level.
• Arm II (progressive, resistance exercise program): Patients undergo resistance exercise training 3 days a week for 18 months. During the first 12 months, patients attend supervised resistance exercise sessions 2 days a week and complete 1 home-based resistance exercise session using a modified exercise program designed by the investigative team. During the final 6 months, patients undergo resistance exercise using an at-home program designed by the investigative team. Resistance exercise training comprises the use of hand weights and barbells (for upper body resistance) and exercises in weighted vests (for lower body resistance). Patients wear a weighted vest while performing lower body strength training (chair rises, 90-degree squats, toe raises, forward lunges, lateral lunges). Patients use hand weights for upper body strength training (upright row, 1-arm row, overhead press, chest press, chest fly, biceps curl, triceps extension). Volume of strength training, determined by intensity (weight tailored to the patient) and duration (number of sets), is gradually increased from low weight and high number of repetitions to more weight and fewer repetitions over the first 6 months of the training period. Exercise volume remains at a moderate intensity for the remainder of the training period to provide an optimal physiologic challenge at a safe and tolerable level.
• Arm III (flexibility and relaxation training [control]): Patients perform a series of whole body flexibility (stretching) and relaxation (guided imagery, progressive neuromuscular relaxation, focused breathing) exercises 3 days a week for 18 months. During the first 12 months, patients attend supervised flexibility and relaxation exercise sessions 2 days a week and complete 1 home-based flexibility and relaxation exercise session using a modified exercise program designed by the investigative team. During the final 6 months, patients undergo flexibility and relaxation exercises using an at-home program designed by the investigative team.

Muscle strength (measured by a one-repetition maximum test), aerobic capacity (measured by a 6-minute walk test), functional arm strength (measured by grip dynamometer), physical functioning (measured by the Physical Performance Battery), flexibility (measured by the Chair Sit and Reach Test and the Back Scratch Test), balance (measured by a one-legged stance [Romberg] test and a timed stance test), lymphedema (measured by the circumference of the upper arm, wrist, and a finger), body composition (measured by dual energy x-ray absorptiometry), and bone mineral density of the heel (measured by ultrasound) are assessed at baseline and periodically during the study. Patients also undergo blood and urine sample collection for cancer recurrence biomarker and bone remodeling biomarker studies.

Patients complete questionnaires at baseline and periodically during the study to assess demographic (i.e., age, income) and disease-specific (i.e., stage, treatment) variables, self-report mental and physical function, presence of chronic medical conditions, symptoms, fatigue, exercise outside the study exercise intervention, dietary intake, and psychosocial function.