Exercise makes many people feel more energized. You may start a workout feeling sleepy and tired only to feel your energy level soar ten minutes into your workout. Once your body temperature rises and the blood starts flowing, you energized, psyched up, and you don’t want to stop!
But what if you feel consistently feel sleepy after a workout? Rather than tackle your to-do list with renewed vigor, you feel more like stretching out on the couch and taking a long nap. Sleepiness after a workout is a relatively common problem that you can often fix once you know the most common causes.
What does sleepiness after a workout mean and what can you do to avoid it?
Are You Hydrating Adequately?
Even mild dehydration can cause you to feel sleepy or fatigued after a workout. In fact, mild dehydration can set in even before you feel thirsty. Studies show if you’re feeling thirsty, you’re already dehydrated. Research also reveals that mild dehydration can manifest as hunger. Therefore, you might reach for a snack when what you really need is water.
Other common signs of dehydration include lightheadedness, dizziness, mild headache, and a depressed mood. If you’re feeling sleepy or tired after a workout, monitor your hydration status. One way to do this is to check the color of your urine. If you’re adequately hydrated, your urine should be a pale yellow or almost clear in color. If not, you’re not drinking enough fluid before and during your workouts.
Are You Eating Enough?
Intense exercise is exhausting, and the worst thing you can do after a workout is to get on with your day without refueling. You need carbohydrates to restore muscle glycogen and protein to help your muscles repair. Most sports nutritionists recommend consuming a meal or snack with a 3-to 1 ratio of carbohydrates to protein.
Although your body can process high-glycemic carbohydrates easier after a workout, it’s best to choose carbs with more staying power. Unprocessed carbohydrates rich in fiber are the best choice, as they’ll keep your blood sugar more stable than a sugary snack. Some possible snack options that should help you curb sleepiness:
- An apple with almond butter
- Hummus with whole-grain crackers
- Cottage cheese with fruit
- Yogurt with berries
- An egg omelet with vegetables
Give these healthier post-workout snack options a try if you feel wiped out after a workout. Also, eat a snack about an hour before your workouts and see if that makes a difference.
Could It Be a Medical Problem?
A number of health conditions and chronic, undiagnosed health problems can make you feel tired or sleepy after a workout. One of the most common health issues in women before menopause is iron-deficiency anemia. When you’re iron deficient, your red blood cells can’t carry as much oxygen to tissues and you feel sleepy and fatigued. If the anemia is extreme, you might also feel short of breath during exercise. The best way to find out if you’re anemic is to have a doctor check your hemoglobin and hematocrit and a complete iron panel.
Blood sugar problems, like prediabetes and diabetes, can also cause excessive sleepiness and fatigue if your blood sugar plummets after exercise. Another common health problem in women after menopause is hypothyroidism, an underactive thyroid gland. Your doctor can run a thyroid panel via a blood test to see if your thyroid function is normal.
Are You Taking Medications?
Some medications can cause you to feel sleepy, including certain antihistamines used to treat allergies. Medications used to treat anxiety or pain can do the same thing. Many people take antihistamines for allergies and don’t know they can have this effect. Fortunately, there are antihistamines that are less likely to cause sleepiness or fatigue. Your doctor can recommend the best one for you.
Another class of medications called beta-blockers that doctors prescribe for hypertension and some heart conditions can cause fatigue after exercise. These medications slow your heart rate and make it harder to reach your target heart rate when you work out. They also make exercise feel harder. If you’re on one and you feel tired, don’t stop it without consulting your physician. Stopping these medications suddenly can cause a rebound increase in heart rate that can be dangerous.
Are You Overdoing It?
Workouts are supposed to be challenging but don’t push yourself to the limit during every session. Alternate tough workouts with easier workouts to give your body a chance to recover. Excessive fatigue and sleepiness can be a sign of overreaching or pushing your body too hard. Feeling tired or sleepy after a workout could be a warning sign that your body needs more rest.
Other signs of overreaching include muscle soreness, no motivation, depression, lack of appetite, nausea, and irritability. Overreaching or the more serious overtraining syndrome also increases the risk of injury. Plus, excessive training without adequate rest suppresses the immune system and increases the odds of catching upper respiratory infection.
Keep track of how many hours you’re sleeping each night too. If you’re getting fewer than seven hours per night, it may explain why you feel sleepy after a workout. Exercise places added demands on your body. Some experts believe athletes need more sleep than sedentary people for this reason. If you work out frequently or do high-intensity workouts, seven hours may not be enough. You may need between eight and nine hours per night to feel your best.
The Bottom Line
These are some of the more common causes of feeling sleeping after a workout. Make simple changes first, like drinking more fluid during and after your workouts and eating a balanced, post-workout snack. Keep a sleep diary too. If making these changes doesn’t solve the problem, a trip to your health care provider is the next step. They can rule out causes such as medications, an underactive thyroid, blood sugar issues, and iron-deficiency anemia.
Exercise should energize you! It shouldn’t make you feel exhausted or sleepy after every workout. Take these steps and see if it makes a difference!
- N Am J Sports Phys Ther. 2009 Feb; 4(1): 13–20.
- SportsRec.com. “What Are the Causes of Fatigue in Sports?”
- Br J Sports Med 1998;32:107–110.