Presentation description

Among apparently healthy populations and clinical populations engaging in exercise in the afternoon and evening hours has shown greater improvements in physical function and other health-related outcomes compared with exercising in the morning hours. Proposed physiological mechanisms that contribute to these observations include: an increase in body temperature in the afternoon/evening hours, thereby improving skeletomuscular performance and exercise capacity; and a sustained increase in the expression of growth hormone, a hormone that facilitates muscle hypertrophy, recovery from exercise, and consequently increased muscular strength and function. We are the first to demonstrate the positive effects of afternoon/evening exercise in cancer patients and survivors, notably breast cancer, within a large retrospective analysis. As a next important step, we aim to test the effects of exercise time of day on cancer-relevant health outcomes prospectively. To do this, we are first carrying out a feasibility trial among women with stage I-III breast cancer undergoing chemotherapy. If successful, this work will contribute to easy to follow recommendations that clinical teams can provide cancer patients (e.g., when you're feeling well enough to exercise, exercise in the afternoon/evening as opposed to morning to optimize outcomes) within the very short period of time they have to discuss exercise in routine cancer care.