The Science Behind Post-Workout Drowsiness and How to Overcome It

Exercise is a type of activity that generally makes your body feel more energized. Your body releases some chemical hormones called endorphins in response to exercise. These hormones help your body restore normal functioning and relax muscles after exercise, as exercise itself is another name for utilizing the body's mechanical energy. But this is not always the case! Sometimes the body feels more tired than energetic. It is fine if you experience drowsiness or tiredness after a workout once or twice a week, but if this drowsiness comes in a daily manner, then you need to look at the roots of the cause.

Here are some reasons that may contribute to your drowsiness post-exercise!

You are doing too much.

It is okay if you feel drowsiness when you increase your exercise intensity or duration all of a sudden, but remember, you should not push your body to its limits. This generally means that your body needs an equal amount of rest period as exercise.

 

If you are moving towards a more vigorous intensity, then you should do it gradually. Let your body heal and adapt first.

Overdoing or catching on to the intensity faster decreases the chances of your body recovering post-exercise. Instead, it puts a toll on your overall health.

 

You are dehydrated.

Dehydration is sometimes the major culprit behind your poor performance in daily activities. Sleep and hydration have a huge impact on each other. When you are mildly dehydrated, you sleep more. Dehydration causes a drop in your blood pressure, leading to poor blood circulation in your body and decreased blood flow to your brain, hence inducing sleep. Dehydration also causes muscle spasms or cramps.

 

When you are dehydrated for a long time, it may cause you to lose your sleep. This is because dehydration causes a decrease in your sleep hormone, the melatonin hormone, which in turn disturbs your circadian rhythm and your sleep.

 

In the later hours of your sleep, your body releases a hormone called vasopressin. This hormone maintains your fluid-salt balance. So, if you are not sleeping much, you may feel dehydrated and may experience post-workout fatigue.

 

You are not getting enough sleep.

As stated earlier, your body needs equal time to recover after a workout. If you are not sleeping much at night, your body is not repairing itself from the damage that exercise may have caused, so you experience tiredness post-workout. It is known that athletes and individuals who engage in high-intensity workouts require more energy than those leading a sedentary lifestyle.

 

Lack of a proper diet

Your current dietary intake may not be providing you with adequate nutrition. Without the proper nutrients and fuel, it's difficult to perform at your best. Take as many proteins and carbs in your diet as your body requires. Do not leave any portion of the meal, and if you have any allergies, take supplements as prescribed by your dietician.

Eating food within 15 minutes of exercise burns calories faster and reduces the chances of hypoglycemia and glycogen depletion.

A drop or rise in your blood sugar levels.

During exercise, your body needs excessive energy, which comes from the breakdown of glucose in your body. A prolonged workout draws more glucose than normal, leading to a drop in your blood glucose levels; hence, you do not have enough glycogen reserves to produce more glucose and meet your muscles' increased glucose demand, so you feel tired.

 

Similarly, intense exercise (more intense than usual) sometimes increases blood glucose levels as your body releases adrenaline, the stress hormone, in response to exercise. When an organism needs immediate energy, adrenaline prevents insulin secretion from pancreatic beta cells, which allows the organism to access its internal nutrient reserves, hence increasing your blood glucose levels. One of the key symptoms of hyperglycemia is fatigue.

 

So, if your blood glucose levels are not well maintained, you may experience drowsiness, headaches, and fatigue.

 

Iodine Deficiency.

Iodine deficiency anemia may make you feel less motivated to do a workout session, and even if you do, your body may eventually feel tired, and you will not be able to continue your exercise.

Iron is essential for producing hemoglobin, which carries oxygen in your blood. Without enough iron, you may feel tired and drowsy due to a lack of oxygen in your tissues.

 

You may have other chronic disorders that may cause sleepiness.

 

Here are a few tips on what might help you if you are feeling post-workout drowsiness.

 

• Hydrate yourself adequately with at least 1 gallon or 3.7 liters of water daily before and after exercise but avoid too much water consumption during the exercise. 

• Do not hold your breath when exercising, as it may cause less oxygen supply to your tissues.

• Do cool-down exercises post-workout. Cool-down exercises prevent delayed onset muscle soreness (DOMS), muscle stiffness, or muscle cramps, and also induce relaxation post-workout.

• Avoid overdoing, as it uses a lot of energy and your body takes much longer to recover.

• Avoid working out in hot and humid environments if your body is not acclimatized, as it may cause heat-related illness.

Can I take a nap if I feel drowsy post-workout?

Yes, you can. While drowsiness is a sign that you are not treating your body well, taking a nap after exercise has its own benefits.

 

Napping for 15-20 minutes post-exercise increases the chances of your body's recovery. It reduces fatigue, promotes alertness, enhances athletic performance, and repairs muscles, but sleeping for more than 30 minutes may make you feel disoriented after waking up due to the deep sleep phase—a phenomenon called sleep inertia. It may also affect your nighttime sleep.

Conclusion:

Drowsiness or exhaustion after exercise may suggest that you are not taking care of your body properly. This may occur as a result of your peripheral nerve system being activated during exercising, among other things. PNS activation causes a rise in heart rate, respiration rate, and blood flow while lowering CNS activity, which makes people drowsy. Napping for 20 minutes after exercise allows your body to recuperate quickly.