The definition of overtraining is personal. It is the point at which an athlete is training so hard and for so many hours that recovery does not occur with usual periods of rest. Athletic performance demands a balance of extreme effort and recovery. The athlete must expend a tremendous amount of energy on some days and also determine an adequate, but not excessive, number of days off, to be spent either resting completely or exercising with less intensity. Many recreational and competitive athletes tend to think that more exercise and effort is always better. Even if they are aware of the facts, the tendency is to want to exert themselves a little longer and a little harder during the next workout. -Harvard Health Publications Focus on Fitness, Part 6.