The effect of exercise intensity on the inflammatory profile of cancer survivors: A randomised crossover study.

Abstract

Systemic inflammation has been clearly linked to poorer health outcomes from cancer diagnosis through to survivorship. There is accumulating evidence that exercise can reduce inflammation. However, the optimal intensity of exercise to reduce systemic inflammation is unknown. The aim of this randomised crossover study was to identify the difference between high- and low-intensity aerobic exercise on the inflammatory profile of cancer survivors after a single exercise session (acute) and a short training period (six sessions over 2 weeks). Participants (n=20) were randomised to either low- or high-intensity exercise. They underwent 2 weeks of stationary cycling at their assigned intensity and then underwent a 6-week washout period of no exercise before returning to complete 2 weeks of exercise at the remaining intensity. Twenty participants with a mean age of 56.4 (±9.4) years were enrolled and completed the intervention. There was no effect of exercise intensity after a single exercise session. After 2 weeks of training, there was a significant effect of intensity on chemokines CCL2 (mean difference ± SEM; 13.2pg/mL ± 5.0, p=.04) and CXCL12 (150.3pg/mL ± 51.8, p=.02), where CCL2 was decreased after low-intensity exercise and CXCL12 decreased after high-intensity exercise. Our data suggest that while exercise intensity may impact different cell types in the circulation, both low- and high-intensity exercise can positively modulate inflammatory markers. The potential to scale up low-intensity exercise over time is likely to be more broadly applicable and achievable for cancer survivor cohorts while still eliciting beneficial effects on systemic inflammation.