Evolutionary medicine
A long time ago, more people used to exercise than people do now. Back then, when people didn’t exercise, it was usually because they were sick or hurt.<ref></span>Abuissa H, O'Keefe JH, Cordain L (2005). "Realigning our 21st century diet and lifestyle with our hunter-gatherer genetic identity" (PDF). Directions Psych. 25: SR1–SR10. Archived from the original (PDF) on 2008-12-17. Retrieved 2008-08-21</ref> When a person would rest, it would change mechanisms in the body, and would lead to inflammation. Some people believe that people who don’t exercise have more inflammation in their bodies. This can cause more sicknesses.<ref></span>Charansonney OL, Després JP (August 2010). "Disease prevention--should we target obesity or sedentary lifestyle?". Nature Reviews. Cardiology. 7 (8): 468–72. doi:10.1038/nrcardio.2010.68. PMID 20498671. S2CID 9560960.</ref>