Walking dose associated with lower cancer-related fatigue among patients with breast cancer

BACKGROUND: Cancer-related fatigue is a debilitating side effect among patients with cancer. Exercise is recommended to manage cancer-related fatigue; however, clinical guidelines lack specificity on modality, intensity, and duration. This study aimed to determine the optimal doses of walking to mitigate cancer-related fatigue. METHODS: In a nationwide, prospective cohort study of patients with stage I-IIIC breast cancer, we assessed walking volume (metabolic equivalent task [MET] hours per week) via Aerobics Center Longitudinal Study Physical Activity measure and cancer-related fatigue via Multidimensional Fatigue Symptom Inventory at prechemotherapy (T1), 1 month postchemotherapy (T2), and 6 months postchemotherapy (T3). A receiver operating characteristic curve analysis identified a cut point for walking volume needed for a clinically meaningful cancer-related fatigue reduction from T1 to T2 (-4.5 points Multidimensional Fatigue Symptom Inventory score). Linear mixed models controlling for age, body mass index, and other modes of moderate-vigorous intensity exercise characterized cancer-related fatigue at each time point. RESULTS: Among 577 participants (mean age = 53.4 years; 76% stage I-II), higher walking volume was associated with lower general, emotional, physical, overall cancer-related fatigue, and higher vigor postchemotherapy (T2; all P < .05). Those who walked at least 4.3 MET hours per week, equivalent to walking 88-172 minutes at a low-intensity pace (<2.5 mph) or 43-83 minutes at a moderate-intensity pace (2.6-4.5 mph) at pre, during, and postchemotherapy demonstrated statistically significantly lower cancer-related fatigue at postchemotherapy (T2) compared with those who walked less than 4.3 MET hours per week (P < .05). CONCLUSIONS: Our data indicate that higher walking volume was associated with lower cancer-related fatigue, and a minimum walking volume of 88-172 minutes at a low-intensity pace or 43-83 minutes of moderate-intensity pace may attenuate cancer-related fatigue following chemotherapy.