Extreme Fatigue After Exercise

Extreme fatigue after exercise is a sign that it may be too demanding.
Image Credit: Pekic/E+/GettyImages

It's normal to be tired, sweaty and even sore after your workout. There's a limit, however, and if you feel like you have extreme fatigue after a workout, it might be a sign of a health problem.

Video of the Day

Feeling ill or weak after exercise isn't normal; While you might feel exhausted after a workout the next day, you should begin to recover fairly quickly. If you feel like you're not recovering, or you're more tired than you should be, it could be a sign that your workout was too intense or demanding on your body.


Signs and Symptoms of Rhabdomyolysis

When you work out, your body naturally breaks down muscle. It's a normal process, and usually, it isn't a problem. However, in extreme cases, it may cause health problems.

Your kidneys are particularly susceptible to protein breakdown. A substance called myoglobin is released when the muscles break down. Myoglobin goes into your bloodstream and can build up in the kidneys, causing kidney damage.

This is known as rhabdomyolysis, and it can happen even if you're not in the gym. Anything that causes your muscles to rapidly break down can trigger this condition. If you feel week and nauseous after your workout or have dark-colored urine, you might have rhabdomyolysis. Other symptoms include joint pain, muscle weakness and fatigue.


To find out if you have rhabdomyolysis, your doctor can run various urine tests. The tests look for chemicals that are released when your muscle is destroyed. To prevent it, you have to drink plenty of fluids and get more rest. You might even need fluids intravenously.

Read more: Dangerous Post-Workout Soreness

Overreaching and Overtraining Syndrome

There are two general problems associated with fatigue after exercise. Overtraining syndrome occurs over time from too much training. The other problem occurs very quickly and is known as overreaching. Both issues come from too much exercise and not enough rest.


The symptoms of overreaching usually resolve quickly once you stop exercising and get more rest. However, the symptoms of overtraining can last two months or more. If you have either problem, you'll notice that you're constantly fatigued and sore. You might also get sick more often due to a suppressed immune system.

Your mental health is affected by overtraining and overreaching too. Your sleep can be disrupted, and you may feel depressed. Women can experience the absence of menstruation.

Dehydration Causes Fatigue

Working out makes you sweat, which can feel good if you're properly hydrated. However, if you're not prepared for your workout and you lose too much fluid, you can get dehydrated.


Thirst isn't the only symptom of dehydration. You might notice that you're actually sweating and urinating less, as your body attempts to preserve fluids. You might get tired and feel dizzy as well. If you're playing a sport, your performance can also decrease.

In more serious cases, you can be confused and even faint from dehydration. Your heartbeat can become rapid or irregular. It's also possible to go into shock from dehydration.

Heat complicates dehydration. Since sweat is a tool that your body uses to cool off, exercising in a hot environment can make you lose fluids rapidly. If you're going to work out somewhere unusually warm, make sure to hydrate more than usual.

Be sure to drink plenty of water before your workout or sporting event to prevent dehydration. Afterward, you should continue to hydrate. You can weigh yourself before and after exercise to determine the number of pounds of fluid that you lost.

Low Blood Sugar and Fatigue

Exercise drains your body's stores of glucose. Normally, you have glycogen stored in your muscles, which powers contractions throughout your workout. You also have glucose floating around your bloodstream, ready to fuel cells that need it. During exercise, your body can use both the glycogen in muscles and the glucose in your blood, causing blood sugar levels to drop. This is known as hypoglycemia.

There are a wide range of symptoms that stem from hypoglycemia, which you might feel during your workout or after. Physical symptoms include shakiness, fast heartbeat, nausea, headache or general weakness. There are also mental symptoms like confusion, anxiety or nightmares. In extreme cases, you can have seizures from hypoglycemia.

To prevent low blood sugar during or after exercise, make sure you eat something with carbohydrates close to your workout. You probably don't need a full meal, but a quick snack with 20 to 30 grams of carbohydrates, such as an apple, should help. You can also have a sports drink, like Gatorade, that contains carbohydrates.

Read more: What Happens to Your Body When You Work Out Too Much?

Recovery Time From Exercise

If you're suffering from extreme fatigue after exercise, or you simply want to prevent it, you should adjust the style of workout you do. In general, the harder your workout, the more likely you are to suffer from extreme fatigue. The style of training you do matters as well.

There's a difference between lengthy and intense weightlifting workouts, according to a small July 2017 study published in the European Journal of Applied Physiology. The study, which included only 12 participants, looked at high-volume weightlifting workouts in particular, in which there are many sets and repetitions performed for each exercise. They compared those workouts to high-intensity yet shorter weightlifting workouts.

The subjects who engaged in high-volume weightlifting workouts experienced greater muscle damage and took longer to recover from training compared to the high-intensity group. In other words, the total amount of work you do in a workout might matter more than the intensity of the workout.

Preventing Fatigue After Exercise

Preparing for your workout with proper nutrition and hydration can help you avoid extreme fatigue after a workout. An article from the Hospital for Special Surgery recommends eating a well-balanced diet with carbs, protein and fat. They also recommend increasing your carbohydrate intake if you exercise regularly or harder than usual.

The Hospital for Special Surgery also recommends drinking 10 to 12, 8-ounce glasses of water per day to prevent dehydration. While exercising, they recommend drinking 125 to 250 milliliters of fluid every 10 to 12 minutes. Instead of water, you can drink an electrolyte-enhanced beverage during training for improved hydration.

After your workout, you should cool down instead of stopping suddenly. This helps keep the blood flowing while your body cools down completely. Once you've cooled down, you can eat, hydrate and sleep to improve your recovery and get ready for your next workout. Listen to your body and rest as much as you feel you need between workouts.