How exercise scheduling affects IL-6-mediated tumor suppression: a fixed exercise volume perspective

Recent investigations into exercise-induced tumor suppression suggest that higher exercise frequency enhances tumor control when the total duration of exercise within a specified time window is not constrained. An equally compelling avenue for exploration is the effect of increased exercise frequency under the condition of a fixed total exercise duration within the same time frame. Using a mathematical model of IL-6-mediated interactions between natural killer cells and tumor cells, here we explore how different combinations of exercise and rest intervals-while maintaining a constant overall exercise volume-affect tumor suppression. Our results reveal a nonmonotonic tumor response and key metrics such as the time of maximum tumor suppression and the duration of tumor suppression are found to decrease with increasing exercise frequency. Interestingly, unlike earlier study where increasing exercise frequency leads to increase in tumor suppression, here we find that under fixed exercise volume constraints, increased frequency diminishes therapeutic efficacy of exercise, suggesting exercise bouts with longer duration are more effective in suppressing tumors. These findings highlight the importance of considering total exercise volume when designing exercise-based cancer interventions.