Overtraining is a serious problem in athletes marked by decreased performance, increased fatigue, persistent muscle soreness, mood disturbances, a lack of energy, and a multitude of minor medical and psychological problems (Uusitalo, 2001; Walker, 2003). In overtraining, the physiological homeostasis of the body, which is needed in the short-term to improve performance capacity, is prolonged and insufficient time is allowed for recovery between successive imbalances to the point that the body can no longer compensate. Short-term physiological imbalance is referred to as overreaching, but if this is continued without allowing the body time to adjust to the new levels of performance, then it becomes overtraining, and performance will decline. Recovery from overreaching may take two to three weeks: recovery from overtraining may take as long as many months or even years.
It is estimated that between 10 percent and 20 percent of athletes who train intensely experience overtraining resulting in a chronic decrease in performance and an impaired ability to train (Barzdukas, 1999, 27-31). There is no specific method for diagnosing overtraining and diagnosis of overtraining is usually done by taking a patient history, ruling out other diseases, and examining laboratory findings (Uusitalo, 2001). Changes in training regimen are important, and performance decline with an increased feeling of fatigue is the major sign of overtraining. Diseases such as Addison's disease, anemia and other nutritional deficiencies, asthma and allergies, cardiac disease, diabetes, thyroid dysfunction, infections, muscle diseases, and psychiatric disorders must all be ruled out as they can all mimic the symptoms of overtraining. Several laboratory parameters are said to indicate actual or impending overtraining including: decreased testosterone; increased cortisol; changes in catecholamines nocturnally, at rest, and after exercise; decrease in maximal blood...