Effects of exercise dose and type during breast cancer chemotherapy on longer‐term patient‐reported outcomes and health‐related fitness: A randomized controlled trial

The Combined Aerobic and Resistance Exercise (CARE) Trial compared different types and doses of exercise performed during breast cancer chemotherapy. Here, we report the longer‐term follow‐up of patient‐reported outcomes, health‐related fitness and exercise behavior at 6, 12 and 24 months postintervention. A multicenter trial in Canada randomized 301 breast cancer patients initiating chemotherapy to thrice weekly, supervised exercise consisting of a standard dose of 25–30 min of aerobic exercise (STAN; n = 96), a higher dose of 50–60 min of aerobic exercise (HIGH; n = 101) or a combined dose of 50–60 min of aerobic and resistance exercise (COMB; n = 104) performed for the duration of chemotherapy (median of 17 weeks). Primary outcomes were patient‐reported outcomes including quality of life, cancer‐related symptoms and psychosocial outcomes. Secondary outcomes were objective health‐related fitness (assessed at 12 months only) and self‐reported exercise behavior. A total of 269 (89.4%) participants completed patient‐reported outcomes at all three follow‐up time points and 263 (87.4%) completed the health‐related fitness assessment at 12‐month follow‐up. COMB was significantly superior to ( i ) STAN for sleep quality at 6‐month follow‐up ( p = 0.027); ( ii ) HIGH for upper body muscular endurance at 12‐month follow‐up ( p = 0.020); and ( iii ) HIGH for meeting the resistance exercise guideline at 6‐month follow‐up ( p = 0.006). Moreover, self‐reported meeting of the combined exercise guideline during follow‐up was significantly associated with better patient‐reported outcomes and health‐related fitness. Performing combined exercise during and after breast cancer chemotherapy may result in better longer‐term patient‐reported outcomes and health‐related fitness compared to performing aerobic exercise alone.