Do we know the biological mechanism to cause OTS, though? That would open up avenues for treatment and more precise prevention besides "rest more" (not that that's a bad preventative).
Yes, a lot of them. Non exaustive list:
- bone microfractures
- nervous system depletion
- tendon "microlesions" (not so sure about this term though)
- immune system blunting due to stress
- raised cortisol levels
- (possible) nutritional deficiencies given the increased exertion (or just metabolic bottlenecks)
A lot of it is anorexia by another name. There is a subspecies that involves compulsive exercise. Doing lots of athletics without proper nourishment is a good recipe for low performance and injury.