Adherence to moderate-intensity exercise during breast cancer therapy

The aims of this pilot study were the following: 1) to examine patterns of adherence to a brisk walking program in women receiving adjuvant chemotherapy or radiation therapy for newly diagnosed breast cancer using a prospective, randomized, controlled experimental design; 2) to examine the influence of disease symptoms and treatment side effects on exercise levels; and 3) to suggest methods that may improve future clinical trials of moderate-intensity exercise in similar populations.

Fifty-two patients with newly diagnosed breast cancer were randomly assigned to one of two treatment arms: usual care or usual care plus exercise. Those assigned to the exercise group received a standardized, self-administered, home-based brisk walking intervention in addition to usual care. Each day subjects completed self-report diary forms that elicited information about activity levels, and the occurrence of symptoms and side effects during cancer treatment.

Analyses of self-reported daily activity levels revealed a diffusion of treatment effect. Fifty percent of the usual-care group reported maintaining or increasing their physical activity to a moderate-intensity level, while 33% of the exercise group did not exercise at the prescribed levels. Analyses of self-reported disease symptoms and treatment side effects did not reveal clinically meaningful differences between the two groups.

The results of this study suggest that women who exercised regularly before receiving a breast cancer diagnosis attempted to maintain their exercise programs. Women who lead sedentary lifestyles may benefit from a structured exercise program that includes information and support related to exercise adherence strategies.