> Kreher and others believe that the mind plays an equally important role. Because your central nervous system influences your brain as well as your physiology, he theorizes that true overtraining syndrome is triggered by a combination of psychological and physical stress.
> “That’s the multi-system nature of the condition,” Kreher says. “The interaction of the mind and body is incredibly influential.” To finish a 100-mile race requires a psychological thrashing, and some runners have described a kind of post-race depression. As they try to rally to train for the next goal, perhaps beating themselves up for their prior performance, that mental stress, in addition to the physical depletion, could bring on OTS.