You don't have to be a professional athlete to overtrain. Even amateur fitness fanatics, especially runners and distance athletes, are at risk for overtraining as they reach optimum performance levels.

If you're planning on running a long race in the near future, keep reading. One expert on the symptoms and treatment of overtraining states a large percentage of people who train for 10ks, half-marathons and marathons are overtrained before the race begins. Cyclists and cross-country skiers need to watch out, too. Wow, I'm surprised. Figured overtraining was a rarity in the amateur ranks. Simply not so.

Exactly how a body succumbs to overtraining is not entirely known. One thought is constant training results in overactive cytokines, which in turn, trigger whole body inflammation. One current study is examining if intense, competitive training alters the way genes operate. Regardless, treatment begs plenty of rest and recuperation. Patience is essential, it can takes months to fully recover. Here are a few signs of overtraining:

• Fatigue persisting more than 72 hours after a workout, often coupled with insomnia.
• Three days or more of muscle pain and weakness.
• Rise in resting heart rate.
• Serious drop in performance for no apparent reason.
• A feeling of "heavy legs."
• Loss of appetite, irritability, anxiety or depression.
• Lowering ferritin levels (iron storage).
• Menstrual cycle irregularities
• Cuts/bruises that heal slowly.
• Few colds -- you're more at risk of overtraining if a nasty cold hasn't slowed you down.

If you'd like to learn more, check out Gretchen Reynolds' interesting article on overtraining in the New York Times.