Moderate-to-vigorous intensity physical activity is associated with modified fatigue during and after cancer treatment.

The primary objective was to investigate the association between the amount of time spent in moderate-to-vigorous intensity physical activity (MVPA) and cancer-related fatigue (CRF) before, during, and 2 years after start of treatment. The results of the present study are based on data from the study "Early rehabilitation of cancer patients." Two hundred and forty patients (109 females) with one of the following cancer types were included: breast, colorectal, prostate and testicular cancer, and lymphoma. Chalder's fatigue questionnaire (FQ) was used to map CRF at baseline, 4, 8, 12, and 24 months post-inclusion. Baseline was at the time of diagnosis, before treatment start. Physical activity was recorded using SenseWear armband (SWA) at baseline, 4 and 24 months post-inclusion. One hour increased MVPA daily at baseline was associated with lower fatigue with - 0.8 at 4 months' follow-up (p < 0.001), - 0.7 at 8 months' follow-up (p = 0.001), - 0.6 at 12 months' follow-up (p = 0.008), and - 0.5 at 24 months' follow-up (p < 0.043). The participants maintained and improved PA level at the two follow-up points. The results imply that the amount of time spent in moderate to vigorous intensity physical activity at baseline can modify cancer related fatigue during and after cancer treatment. The participants managed to maintain and improve their activity level at the two follow-up points. Future research should map fatigue and measure activity, with objective measurement units, at several measurement points to map activity level over time and to substantiate these results.