Abstract des Autors

Overtraining is an imbalance between training and recovery. The consequences of overtraining include decreased performance, injuries, depressed immunity and psychological depression. The markers of overtraining are difficult to identify because of confusion regarding the cause of the syndrome. Suggested mechanisms include imbalanced amino acids and hormones, glutamine depletion, viral infection, liver and muscle glycogen depletion. Markers of overtraining may be categorised as performance, anatomical, physiological, biochemical, immunological and psychological. Overtrained athletes experience decreased performance and cannot meet previously attained performance standards. They also cannot supercompensate after a period of rest. Overuse injuries are common, sometimes affecting more than 50% of the athletes on a team. Predictive factors of overuse injuries include somatotype, previous injuries, skill level, gender, age, training experience, anthropometric characteristics, training volume and intensity, warm-up practics, training time, poor central motor control, equipment, facilities, joint mobility and muscle tightness. Physiological markers of overtraining are often confusing because symptoms, such as decreased heart rate and position of the lactate inflection point, are often similar to those seen with improved fitness. Changes in body mass and feeling of well-being are perhaps the best physiological markers of overtraining. Suggested biochemical markers of overtraining include endocrine imbalances (testosterone, cortisol, pituitary and hypothalamic hormones), disturbances of protein and amino acid metabolism (glutamine, nitrogen balance) and cell damage (creatine kinase). Immunological markers of overtraining have been extremely contradictory. The best measure is frequency of illness and infection. Psychological markers, such as the Profile of Mood States, are excellent indicators of overtraining. Researchers have suggested an impressive array of sophisticated tests to detect overtraining. However, the best measures continue to be the simplest changes in performance and self-rated perception of fatigue and well-being. Verf.-Referat