Overtraining can have serious consequences for your running and for your health in general. To begin with, overtraining is a common cause of runners' injuries. Pulled muscles and blisters are only the beginning. More serious injuries include runner's knee, shin splints and plantar fasciitis, a painful foot problem. All of these ailments can be caused or aggravated by too much training with too little rest.
Just as training stresses muscles, tendons and ligaments, it also causes wear on bones. Continued overtraining can lead to stress fractures, small cracks in your bones. These injuries are serious and need plenty of time to heal. Pushing ahead with your training makes them worse [source: Mann].
Overtraining interferes with running performance. OTS often leads to slower recovery from each training session, so the runner fails to make progress. Race times grow slower. Chronic overtraining can keep a runner from ever reaching his or her running potential. In the worst cases, it may end a runner's competitive career [source: Meehan].
The symptoms of overtraining may be confused with those of more serious medical problems. If OTS symptoms persist, you should consult a doctor who specializes in sports medicine. A physician can check for other causes of your condition. Anemia, some viruses and thyroid problems can all produce some of the same symptoms as overtraining. What you assume to be overtraining may actually be depression or chronic fatigue syndrome [source: Empfield]. A doctor can help you get a clear picture of what's going on in your case.
If you ignore the symptoms of overtraining, they may lead to more serious problems over time. Hormonal changes can affect many systems in the body. Anemia and iron deficiency often accompany overtraining. Overtraining can lead to chronic insomnia or depression. Colds, flu and other infections become more common as overtraining weakens your immune system. Some runners experience a loss of libido. Women may suffer from menstrual irregularity or the absence of their monthly period [source: Runbritain.com].
In some cases, severe overtraining has been shown to affect the responsiveness of the runner's heart. It no longer speeds up properly during exercise. This "tired heart" syndrome severely restricts running performance [source: Empfield].
You can avoid the dangers of overtraining by preventing the syndrome in the first place. Read on to find out how.