How do you know you are working out too much? Not going up in how much weight you can lift, tired, mood swings, muscles not growing, sore muscles these are some symptoms. Overtraining puts stress on your organs as well as your muscles and organs. Rest is as important as exercise for growth and health. If you are training for competition you have probably experienced negative gains from over exercising and not enough down time. There are studies done in over exercising that suggest it can cause heart disease.
Sometimes when people are growing and getting stronger they will overtrain or start taking drugs to help them heal faster which can put more stress on your body and injury.  If you are a competitive athlete or a few days a week exercise athlete, make sure you eat a good diet ,rest enough and have adequate down time.

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