While some measure of fatigue after prolonged periods of exercise is fairly standard, there are nevertheless a subset of individuals who suffer from symptoms far beyond what might be expected in relation to the effort expended at the gym. Extreme fatigue following exercise could be caused by any number of underlying conditions, which must be treated independently to provide a cure.
The condition of experience extreme fatigue after exercise is commonly known as "exercise intolerance." Exercise intolerance is characterised by the following symptoms: excessive fatigue, muscle cramps or unexpected pain brought on by the rigours of training. Note that exercise intolerance is not a disease in and of itself, but a symptom of another condition.
Combating Exercise Intolerance
While many individuals suggest nothing more than increasing your duration of training to build up your tolerance, thus combating exercise intolerance, this approach is incorrect. According to Catherine Morgan, RN, the only "cure" for exercise intolerance is to treat the underlying problem. Only after identifying the real problem can you begin to work toward a solution.
Chronic Fatigue Syndrome
Chronic Fatigue Syndrome is one common cause of exercise intolerance. CFS is a fairly rare disease, affecting roughly 4 in 1,000 adults throughout the United States. CFS is not a well-understood condition, as no positive cause for the condition has been identified. Furthermore, there is no established cure--the normal course of action for a patient with exercise intolerance resulting from CFS is to attempt to relieve individuals symptoms, which can be a catch-22 situation where CFS is paired with exercise intolerance.
Overtraining is another common condition that can lead to the development of exercise intolerance. As its name implies, overtraining is merely taxing the body above and beyond its capacities to such an extent that it is unable to recover. This typically happens to athletes who are training hard for specific events. Think of exercise intolerance resulting from overtraining as attempting to make additional withdrawals from an already overdrawn savings account. A proper course of action for treating overtraining involves nothing more than rest, a healthy diet and sufficient hydration for a week or two until symptoms abate.
Metabolic Disease is another potential cause behind exercise intolerance. A condition known as carnitine palmityl transferase deficiency can result in the development of extreme fatigue post-exercise. As the causes and symptoms of metabolic disease are so varied, recommendation for a specific treatment plan to combat symptoms is best left up to your supervising physician.