Progressive increases in training stimulus are necessary for improvements in endurance events (Morgan, et al, 1987). Athletes strive for positive adaptations following training overload (Silva 1990). They typically recuperate within 12-24 hours after an intense training session. However, an athlete may not have sufficient time to fully recuperate after chronic bouts of training (Morgan, et al, 1987). Overtraining is thought to be caused by training loads that are too demanding of the athlete's ability to adapt (Murphy & Fleck, 1990; Silva 1990). It occurs when the body's adaptive mechanisms repetitively fail to cope with chronic training stress (Silva 1990). This results in performance deterioration instead of performance improvement (Morgan, et al, 1987; Murphy & Fleck, 1990, Silva 1990).
Overtraining may lead to physiological and psychomotor retardation, chronic fatigue, depressed appetite, weight loss, insomnia, decreased libido, muscle soreness and elevated depression and tension. In addition, other metabolic, hormonal, muscular, hypothalamic, and cardiovascular changes often accompany the overtrained state (Morgan, et al, 1987). Overtraining is characterized by negative affective states such as anxiety, depression, fatigue, anger, lack of self-confidence, and decreased vigor (Murphy & Fleck, 1990).
Authors have expressed differing views in terminology when describing overtraining and its affiliated states. For example, Silva (1990) describes progressive stages; staleness, overtraining, and burnout. In contrast, Morgan, et al (1987) suggests overtraining can lead to staleness, whereas overtraining reflects a process and staleness represents an outcome, or product (Morgan, et al, 1987). Despite the continuing debate of semantics, it is recommended to keep the terminology simple when speaking to an athlete unfamiliar with the subject.
In effort to detect overtraining, Bompa & Carrera (2015) suggest athletes monitor the following perameters in addition to morning heart rate:
- Number of hours
- Quality of Sleep
- Very Deep, Normal, Restless, No Sleep
- Very Rested, Normal, Tired, Very Tired, Painfully Tired
- Very Strong, Good, Poor, Ate because should, Did not eat
- Training Willingness
- Very Strong, Good, Poor, Unwilling, Did not train
- Competitive Willingness
- High, Average, Low, None
Not surprisingly, rest has been suggested to alleviate many of these symptoms caused by overtraining. If this is not practical, tapering had been shown to improve psychological states if sufficient time is allocated (Morgan, et al, 1987).
Other methods to help avoid staleness, which can lead to overtraining include mini break periods, occasional changes in routine, and placing less pressure on athletes, particularly if incorporated in the later part of the season. Severe overtraining and burnout may require a long recovery period and should be expected to be slow (Silva 1990).
The athlete should be informed that staleness, overtraining and burnout are all commonly experienced during a collegiate athlete's "career" (Silva 1990). This may be especially true for a young athlete who may be thought of as an "overachiever"
When the athlete resumes training, modifications to the athlete's workout may help prevent future reoccurrences of overtraining. The athlete's training should only include stress(es) similar to the metabolic pathways and motor skills needed for that particular sport. All cross training should be secondary during off season training and may even be eliminated during seasonal training. For example, an athlete primarily requiring power or speed in their sport may be compromising performance training for cardiovascular endurance, particularly during the sports season. Auxiliary training should be abbreviated or scheduled less often to decrease the occurrence of psychological staleness, physical burnout, and ultimately psychological burnout.
Overtraining had been erroneously described as an absolute state. In actuality, overtraining or any of its related states should be viewed as a continuum; from optimally recuperated to extremely overtrained. It is conceivable that an athlete may be slightly overtrained yet still achieve only modest gains in performance. Obviously, the more desirable situation would be optimal recuperation and consequently greater gains.