Role of Anaerobic Exercise in Overtraining
The development of optimal athletic performance is dependent on a carefully designed and executed training program. One of the benefits of such a program is the avoidance of over training and associated decreases in performance. Although the athletic community has been aware of the problem of over training, scientists are only beginning to determine the physiological and psychological causes and consequences. In addition, different types of training most likely result in a variety of symptoms and results. This brief review will address overtraining and its relationship to anaerobic exercise.
Overtraining is a general term used to describe both the process of training excessively and the fatigue states that may develop as a consequence. The indiscriminate use of this term and related terminology has led to some confusion. Therefore, it is necessary to define the use of over training terms in this article. The following definitions are adapted from previous reviews on over training.
Overload training is the process of stressing an individual to provide a stimulus for adaptation and super compensation. This includes increasing training volume and/or intensity beyond what the athlete is accustomed to.
Training fatigue, or acute fatigue, is the normal response that is experienced following one or several days of heavy training associated with an overload stimulus.
Overtraining is the process of training at abnormally high levels of volume or intensity. According to some authorities, this term also includes performance decrements accompanying this stressful training process.
Overreaching is a form of over training that follows short-term intensive training. This is sometimes a planned phase of a periodized training program. The symptoms of overreaching can be reversed by a longer than normal regeneration period: Overtraining syndrome or staleness refers to the final stage in a proposed continuum of increasingly severe chronic fatigue states that develop as a result of over training. This syndrome includes the many symptoms associated with over training, including decreased performance. Muscular overstrain is acute tissue damage induced by a single intensive training session that exceeds the muscular stress tolerance. This generally occurs after single or repeated bouts of excessive exercise that result in damage to muscle fibers. Muscular overstrain does not always accompany overreaching or overtraining. There appears to be a continuum of events in the development of performance decrements due to over training. This proposed sequence is shown in Figure 1.
Overtraining is characterized by many physiological and psychological symptoms as well as decreased athletic performance. Table 1 includes a partial list of these symptoms and characteristics. It is obvious from the number of symptoms that over training is a very complex problem, including both training-related and non-training related factors (e.g., social life,work or study stress).
Athletes develop physiological symptoms specific to the type of training or event. Thus, athletes performing predominantly anaerobic activities might exhibit different symptoms than those performing in endurance events. As a result, it has been suggested that endurance trained and strength trained subjects respond differently to severe training stresses. In a survey of overtrained athletes, it was found that 77 percent were involved in sports requiring high levels of strength, speed or coordination. It has also been suggested that explosive, non endurance type athletes develop symptoms associated with altered sympathetic system function (e.g., increased resting heart rate and blood pressure, weight loss), while endurance athletes develop symptoms associated with altered parasympathetic system function (e.g., low resting heart rate, poor endurance performance, rapid recovery of heart rate after exercise). In either case, physical performance may be affected before physical symptoms actually appear.