Physical Function In Breast, Prostate, And Colorectal Cancer Survivors: The Effects Of Circuit, Interval-based Exercise

Abstract

Cancer survivors experience many treatment-related side effects, including physical impairments. Declines in physical function are highly prevalent after cancer diagnosis and can persist many years after treatment. Low physical functioning is associated with morbidity and poorer survival rates in cancer survivors. PURPOSE: This pilot study aimed to assess the effects of a 16-week circuit, interval-based aerobic and resistance clinical exercise intervention on physical function in survivors of breast, prostate and colorectal cancers. METHODS: Breast, prostate, and colorectal cancer survivors with overweight or obesity were randomized 2:1 to an exercise intervention (n=60) or into usual care (n=30). The exercise intervention consisted of a 16-weeks circuit interval-based supervised and periodized program, training 3 days per week at moderate to vigorous aerobic (65-85% VO2max) and resistance (65-85% 1-repetition maximum) exercise. Physical function (functional power, functional lower limb strength, balance, gait speed, mobility and fall risk) was measured at baseline and post-intervention (week 17) using validated tests and batteries. Repeated measures ANCOVA was conducted to assess between and within-group differences. RESULTS: Participants were older cancer survivors (63.2 ± 10.8 years old), mostly obese (87%) and that had undergone chemotherapy + radiation therapy (75%). Adherence to the intervention was 92% and post-intervention assessments were available on 100% of participants. No differences were reported at baseline between groups. Compared with controls, sixteen weeks of circuit, interval-based aerobic and resistance exercise resulted in statistically significant improvements in functional power (32%, p<0.01), functional lower limb strength (42%, p<0.01), balance (18%, p<0.01), gait speed (14%, p<0.01), mobility and fall risk (21%, p<0.01). CONCLUSIONS A 16-week supervised circuit, interval-based aerobic and resistance exercise program produces improvements in physical function. Given the importance of physical function on quality of life and health-related outcomes, clinical exercise interventions should be implemented in cancer survivors to prevent physical impairment, morbidity and ultimately, mortality.