While geared to sports medicine professionals, the 2014 position statement from the American Medical Society for Sports Medicine (DiFiori JP, et al.) provides helpful guidance to sports parents on the causes, risk factors, diagnosis, and treatment of burnout in youth athletes.

Response to chronic stress

Burnout is considered a response by a young athlete to chronic stress in which he or she ceases to participate in a previously enjoyable activity, withdrawing from the sport because they perceive it is not possible to meet the physical and psychological demands of the sport. 

Burnout is considered by experts to be part of a spectrum of conditions that includes overreaching and overtraining syndrome.

Overreaching may either be functional or nonfunctional: