Exercise volume starts as a dose-response relationship, with increased exposure leading to more health benefits. However, a tipping point exists, beyond which too much exercise is more detrimental than beneficial. This tipping point can be reached with either too much exercise without proper recovery or chronic underfunding.
“This tipping point is known as [OTS] and, in short, leads to a decrement in fitness level and possibly injury,” advises the American Council on Exercise (ACE). “Whether you are male or female, you are equally at risk for OTS, so recognizing the early signs and combating them can prevent detrimental fitness and health outcomes.”
Those who have a stressful occupation
Those who overtrain often feel guilty or anxious if they are not exercising. Thus, these individuals may continue to exercise even if they are sick or injured, which can be absolutely detrimental to health. Some people with OTS may even skip work or social events to exercise.
Hormonal dysfunction. Overtraining exerts a negative effect on the stress hormones cortisol and epinephrine. This hormonal imbalance can lead to emotional lability, trouble with concentration, bouts of irritability, depression, and difficulty with sleep..
Anorexia. Hormone imbalance also impacts hunger and satiety processes in the body. Although increased exercise should boost hunger, excess exercise can do the opposite. Consequently, weight loss can become a serious issue in those who overtrain.
Rhabdomyolysis. Some degree of rhabdomyolysis may be expected with certain types of very intense exercise. But, with OTS, high levels of rhabdomyolysis can lead to renal failure.
Impaired metabolism. Low-energy availability over a long period of time can negatively affect various organ systems and lead to iron deficiency anaemia, low testosterone levels in men, and low bone density.
Poor immunity. Overtraining can wear down the immune system, making it harder to stave off infections like upper respiratory infections.
Increased cardiovascular stress. With overtraining, even simple workouts become more effortful. Specifically, baseline heart rate rises in those who experience OTS, and it can be difficult for heart rate to return to normal after exercising, with longer periods of rest needed.
Decreased performance. One of the cardinal signs of overtraining is decreased athletic performance, regardless of increased training intensity or volume. This performance decrease can be related to impaired agility, slower reaction times, reduced running speeds, and decreased strength/endurance. To boot, overtraining can lead to loss of motivation.
Chronic injury. Muscle and joint overutilization eventually lead to full-time aches and pains. If these injuries persist for more than 2 weeks, as can happen with OTS, the injury may be substantial and warrant medical attention.
No diagnostic test exists for OTS per se, and suspicion is based on history and symptoms. If you suspect OTS, take a break for a week or two and see if you still have signs and symptoms. Treatment options for compulsive overtraining and associated eating disorders include cognitive-behavioural therapy, antidepressant drugs, and support groups.
