Psychomotor speed: possibly a new marker for overtraining syndrome.
Nederhof, Esther, Lemmink, Koen A P M, Visscher, Chris et al.·Sports medicine (Auckland, N.Z.)·2006
This study proposes that measuring how quickly someone can respond to mental tasks (psychomotor speed) might help identify athletes who are overtraining before serious problems develop. The researchers noticed that overtraining syndrome shares some features with chronic fatigue syndrome and depression, both of which involve slowed mental processing, and suggest this slowness could be an early warning sign.