Jan. 5, 2005

ACC Sports Sciences Main Page

John M. MacKnight, M.D.
University of Virginia Sports Medicine

Sports such as swimming require long hours of training over lengthy competitive seasons. Although most athletes thrive in these training programs, they are at increased risk for the development of the "overtraining syndrome." Overtraining results from a number of physiologic changes that occur when the body can no longer adapt and recover adequately from the rigors of training. Appreciating the nuances of this condition, and recognizing the factors that contribute to its development are essential to minimize the likelihood of overtraining in the athlete.

Causes
There are a number of theories about the causes of overtraining syndrome. However, one common thread between these theories is that of abnormal responses of both the sympathetic ("fight or flight") and parasympathetic nervous systems to intense physical training.

"Young athletes appear to be at increased risk for overtraining from being pushed too hard and too fast, in many instances, by overzealous parents and/or coaches."

Such stimulation may lead, over time, to a fundamental change in the way that the body chemically responds to the physical stress of workouts. As a result, the beneficial effects that were once derived from the "adrenaline rush" of a hard workout are lost, and the athlete begins to feel less and less benefit coming from the work that they are doing.

Similarly, it is theorized that these same chemical changes strongly influence the central nervous system and account for a broad range of psychological effects as well. Other factors which may play a contributing role include poor caloric intake, personality type, altitude, jet lag, and sleep deprivation. Young athletes appear to be at increased risk for overtraining from being pushed too hard and too fast, in many instances, by overzealous parents and/or coaches.

Clinical Features
Athletes suffering from overtraining complain of a chronic sense of fatigue, "burnout," "staleness," generalized weakness, and progressively worsening athletic performance. A characteristic feature is a rise in the baseline heart rate. Most highly trained athletes have heart rates in the 50-60 beat per minute range. The highly fit but overtrained athlete may have a resting pulse of 80 or more; this should be a significant clue to the presence of this condition. Athletes will also demonstrate an increase in their rating of perceived exertion (PRE) at a given training level (i.e. they perceive that they are working harder to achieve the same degree of performance).

Overtrained athletes also note loss of appetite, weight loss, poor wound healing, sore throat, swollen lymph glands, "dead legs," excessive sweating, decreased competitive drive, irritability, restlessness, diffuse muscle and joint aches, decreased libido, and increased nighttime fluid consumption. These athletes often have a higher predisposition to illness, particularly respiratory illnesses, because of deleterious effects on the status of the immune system.

From a psychological standpoint, overtraining syndrome may have wide reaching effects in a number of areas. Emotional lability, frank depression, anxiety, poor concentration, and disordered sleep patterns are common manifestations. Apathy and loss of interest in training activities, particularly for athletes who have a participation goal rapidly approaching, should raise serious questions about the possibility of training-related burnout.

Management
The best management of a potential overtraining syndrome is prevention. It is imperative that anyone working closely with athletes who train at high levels appreciate that such a syndrome exists and that it can have devastating effects on the athlete's eventual performance. Maintaining respect for the possibility of overtraining, every attempt should be made to create a training regimen that will minimize the likelihood of "burnout."

A well-conceived training program uses incremental increases in training loads to stimulate "good" stress on the body. These stresses, in turn, generate physiologic adaptations that result in higher and higher levels of fitness. Such programs include periods of "overload" training that push the body to the limits of exercise tolerance while also allowing adequate recovery time. This is in keeping with a model known as "periodization of training" which systematically stresses athletes in different ways depending upon the particular "period" of the off-season or competitive season.

Athletes must be allowed to maintain balance when it comes to training and down time. Intense periods of training must be balanced with "off" or "light" days on which the body has a chance to rejuvenate and recover for the work that lies ahead. Emotional benefits are derived in the same way; the intense desire to train hard has to be maintained by similarly giving the brain "downtime" in which to recover. Needless to say, depression, apathy, and loss of enthusiasm for the sport can only have negative effects on training quality.

When a lack of training balance occurs, an overtraining syndrome may result. Once a diagnosis of overtraining is made, the athlete should be provided a concentrated "rest" period during which they are performing no significant training activities. Some authorities suggest that athletes should rest completely; others recommend a period of alternative activity at lower intensity (i.e. cycling instead of swimming) so as to maintain some degree of aerobic training effect. A change in activity can go a long way toward addressing the sense of "staleness" and boredom with their chosen sport while also allowing the athlete to do "something" athletically. Trying to impose a complete restriction of activity on a high caliber athlete can be a futile endeavor. It is probably wiser to devise an alternative sport low-level training program than to aim for complete abstinence.

Once the physical and psychological markers of overtraining have resolved (such as restoration of a normal resting pulse and resolution of depression/anxiety/apathy), athletes may be allowed to re-initiate their chosen sport in a scaled-down program that allows them to slowly increase duration and intensity over time. This allows the athlete to ease back into training without generating the same symptoms that warranted training cessation in the first place. This concept is similar to the gradual return to sport after a stress injury/fracture or prolonged fatiguing illness (i.e. mononucleosis).

With appropriate recognition and care, overtraining syndrome can be prevented and/or treated effectively so as to ensure the efficient return of the athlete to the highest levels of training and competition. In the case of the young athlete, fun should be a primary component of sports participation. Should you have questions or concerns regarding the possibility of overtraining in yourself or an athlete that you coach/supervise, seek the assistance of a sports medicine expert in your area for further information and a possible formal evaluation.

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