This will be surprising.
- (MAINLY) Increased blood flow
- Prevent tooth loss (pain in teeth after running, probably because of vessel dilation). Lots of posts about it but few that explain why. It’s likely increased blood flow to the eyes also helps vision.
- The importance of circulation cannot be understated. Circulation problems are associated with fingernail clubbing. There was a case of a patient who had clubbing on only one side due to cardiovascular problems on one side.
- Lack of blood flow causes limbs to die, i.e. gangrene.
- Other less important reasons
- Increased lymph clearance
- Body conditioning/strength, better sleep, mental wellbeing
Many years ago, I remember there was an electrical stimulation machine that researchers wanted to put on muscles so that it “exercises for them.” Looking back now, such a device is incapable of increased blood flow, meaning it likely has few benefits.
I notice the sauna dilates my blood vessels significantly. The data does not support cold plunges being helpful compared to saunas, but I find that sleeping in the winter air like Nordic babies do is some of the best sleep possible due to reduced allergies.
The risk of exercise is injury, which can come from a variety of reasons such as lifting too heavy, locking joints, or running so much that it becomes catabolic.
The frontpage Google search says:
- “Improves your sleep”
- “Exercise controls weight”
- “Improves your mood”
- “Manages blood sugar”
What makes the mainstream explanation so unhelpful is the genericness of it all. I do not feel like they actually get to the core reason of the significance of exercise, which I believe to be increased blood flow.