Risk factors:
(1) intensive interval training with little chance to recover, especially if pursued compulsively/neurotically
(2) large amount of monotonous training
(3) physical stress with dehydration and/or injury
(4) psychological stresses associated with competitive sports
(5) outside psychological stresses for those with other commitments such as full time job, family, etc.
Physical changes:
(1) underperformance despite training (lower peak power, lower endurance)
(2) fatigue out of proportion to exertion, low vigor
(3) slow recovery following exercise
(4) raised resting pulse rate
(5) frequent minor infections, especially of the upper respiratory tract
Mood changes ("burnout")
(1) depression
(1a) loss of purpose and competitive drive
(1b) loss of libido
(1c) sleep disturbances (difficulty going to sleep, waking during the night, nightmares, early waking, waking unrefreshed)
(1d) excessive sweating
(1e) loss of appetite
(2) increased anxiety
(3) irritability, anger and outbursts
With overtraining performance deteriorates as training increases, rather than improving.
Differential diagnosis:
(1) over-reaching (athlete recovers quickly with rest)
(2) infectious disease
(3) psychological problem not due to sport
(4) metabolic disease
(5) nutritional deficiency, including anorexia nervosa
