Sources like this: http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/physical-activity-and-cancer/how-physical-activity-prevents-cancer point out that we can reduce our risk of some cancers by exercising.
But it seems to just be hypothetical, like "scientists think insulin can turn on signals that tell cells to multiply", and
"This can lead to the cells multiplying much more frequently than usual, to replace dead and damaged cells, increasing the chances of mistakes that could lead to cancer"
But human metabolism significantly increases during and after exercise, implying high rate of cellular division! Therefore, these 'hypotheses' seem questionable in their attempt at saying, "cells don't divide as much". I believe that these may be contributing factors, but I don't believe they're the main cause of most cancers in general. I am deeply skeptical that muscle inflammation requires less cell division than colon inflammation.
I have a hypothesis that exercise simply reduces cancer in the following manner: increase cellular movement, which increases the probability of the following:
1) t-cells tag foreign pathogens 2) white blood-cells capture foreign pathogens 3) damaged cells are repaired/found/killed faster
Statistically, increasing the entropy of a system would allow the individual components to cover a larger area in a shorter amount of time. Since the number of pathogens introduced into the system remains relatively constant while the interal system speeds up, it's like running a high-pressure jet stream of water and soap through pipes to clean them out. The soap (t-cells) and pressure (contractions of heart/blood vessels) together help clean the system effectively.
I'm having trouble finding evidence/support for this hypothesis, so if someone could point out the flaws in my hypothesis or point me to some sources to find out more, I'd be deeply appreciative.
