The following research investigated if high intensity interval training could affect colon cancer survival (Devin JL, et.al., 2019).

One group of colorectal cancer survivors did 4 minutes of high intensity cycling at a peak heart rate of 85-95% repeated 4 times with 3 minutes of active recovery between each session.

The other group did 4 weeks of 12 sessions.

Blood samples were collected before the start of the study, immediately after exercising and 2 hours after finishing exercising.

The researchers found that samples taken immediately after exercising but not 2 hours later had significantly reduced colon cancer cell numbers.

They also found significant increases of the inflammatory cytokines interleukin‐6 (IL-6), interleukin‐8 (IL-8) and tumor necrosis factor‐α (TNF-alpha) immediately following the exercises.

This is interesting because the acute inflammatory response from the exercises killed cancer cells. This was followed by a decrease in inflammation.

A short burst of inflammation is not harmful but can be healthy when followed by a reduction of inflammation.

Reference

James L. Devin,corresponding author, Michelle M. Hill, Marina Mourtzakis, Joe Quadrilatero, David G. Jenkins, and Tina L. Skinner, Acute high intensity interval exercise reduces colon cancer cell growth, J Physiol. 2019 Apr 15; 597(8): 2177–2184.