Post-Workout Fatigue: What's Normal, What's Not?

It's normal to feel tired after a workout. Mild muscle ache is common, too. But what if you're completely exhausted? Post-workout fatigue that persists after you cool down or interferes with your lifestyle is not normal.

Vigorous exercise is a healthy challenge for every body. Your heart and lungs work hard to circulate oxygen and energy through your blood to all the muscles and organs involved in exercise. Your muscles flex, stretch, and pull fluids, nutrients, and energy from your body to keep you moving.  When you exercise to the point where you've depleted your water and energy stores, you become exhausted. It's nature's way of making you stop before you hurt yourself.

Most healthy people recover quickly. But what if you don't?  That might be because you're not refueling properly after exercise or because of injury or illness.

Lack of fuel. What you put into your body after exercise is as important as what goes into it beforehand. Your body is like a car. It needs fuel to run and is a lot of trouble to restart if it completely runs out of gas. Avoid making your body run on empty. 

Water is crucial to hydrate cells and flush lactic acid (a metabolite formed during energy production) through muscles. Dehydration decreases circulatory fluid volume and blood pressure. Lactic acid build-up makes muscles sore and tired.

Exercise causes small tears in muscle tissue and stress on bones and organs. 

As tissues heal, they become stronger, but all these healing, hydrating and cell-building tasks require energy. That's why consuming enough water, carbohydrates, and proteins before and after a workout are key.

Injury. Sometimes the first sign you've hurt yourself is fatigue. Injury is usually followed by pain, but if your muscles are too tired to move, take the hint and rest.

Strains, sprains, ligament pulls and general overuse all tax the body's energy reserves. 

Think back over your recent exercise sessions and ask if you're pushing yourself too hard. Rest for a couple days. Then dial your workout down a couple notches and see if that helps you recover more quickly. If you're still exhausted after a gentler workout, it's time to see the doctor.

Illness. Several potentially serious health conditions can cause post-workout fatigue. Heart disease, diabetes, hormonal imbalances, autoimmune disorders, arthritis, asthma, and other conditions can all leave a body exhausted.   See your doctor if fatigue is knocking you out of the game.