Are There Health Risks to Exercising Too Much?

Overtraining Can Keep You from Making Gains

When you exercise too much, your body responds by releasing the stress hormone, cortisol. Cortisol causes breakdown of muscle tissue so the amino acids can be used as fuel. If you’re trying to build lean body mass,

this can work against you. Moderate and high-intensity exercise both stimulate transient release of cortisol, but if you’re overtraining your levels will be chronically elevated – not a good thing for your muscles or your health.

Too much exercise also causes your body to hang on to fat, especially if you combine it with calorie restriction. Any time the body senses a fuel shortage, it adapts by slowing things down. This isn’t what most people want.

Exercising Too Much Can Decrease Your Immunity

People who exercise too much put themselves at greater risk for colds and flu viruses. Moderate amounts of exercise improves the function of the immune system, but if you overdo it, you could wind up with a nasty cold, or worse, the flu. Overtraining, especially if you don’t give yourself adequate rest time between sessions, suppresses immunity. One study showed that 13% of marathon runners became ill within a week of the race. Both high-intensity and high-volume overtraining can reduce immunity.