Headache After Working Out? 5 Likely Causes And How To Fix It

We all know that exercise is fantastic for the body. 

Aerobic exercise, such as running, cycling, or jumping rope, strengthens your cardiovascular system, reduces your risk of diseases, boosts mental health, and burns calories, while resistance training increases muscular strength, strengthens bones, and can help build muscle, with tons of overlap in the benefits of exercise in between.

However, immediately after a workout, there can be mild, unpleasant sensations.

There are certain things we come to expect after exercise: our muscles might feel tired and even shaky, our body may feel depleted and ready for nutritious refueling and rehydration, and perhaps we even have some muscle soreness. But what if you have a headache after working out?

In this article, we will discuss exercise headaches and the reasons why you might be getting a headache when working out or a headache after working out, as well as what you can do about it.

We will cover: 

  • What Is An Exercise Headache?
  • Common Causes Of A Headache After Working Out
  • How to Prevent Headaches After Working Out

Let’s get started!

A person sitting on a gym bench with a headache from working out.

What Is An Exercise Headache?

Like any type of headache, an exercise headache involves either pain that is localized on one side of your head or a throbbing sensation that you feel across your entire head.

However, rather than having a generic cause or random onset, an exercise headache is associated with physical activity and comes on during or after a workout.

In most cases, an exercise headache is benign in nature and not a major cause for concern, but there are instances where it’s best to consult your doctor, particularly if you are frequently experiencing headaches when exercising.

Common Causes Of A Headache After Working Out

There are different potential causes of headaches when working out or a headache after a workout.

Here are some of the most common:

A person leaning over on a stationary bike with a headache from working out.

#1: Exertion

By definition, an exertional headache comes on with physical exertion, whether from an aggressive coughing fit, straining for a bowel movement, or, more commonly, with any type of strenuous workout.

For this reason, you can get an exertional headache when working out—particularly if you are lifting weights and forcefully exerting yourself, potentially without breathing regularly.

This type of exercise headache is also common when exercising in extreme temperatures—such as running on a very hot or very cold day—or at altitude.

Exertional headaches typically present as a pulsating or throbbing pain around the temples or along the sides of your head.

This type of headache often resolves shortly after the physical strain that caused it, but it’s also possible that an exertional headache will linger for several hours after your workout is over.

A person hands on hips, exhausted from running.

According to the Mayo Clinic, exertional headaches, which are also called exercise headaches, are classified as primary or secondary. 

Both types are triggered by physical activity or exertion and are particularly common with activities like running, rowing, weightlifting, tennis, and swimming. 

However, a primary exertional headache has no known cause aside from the exertion, whereas a secondary exertional headache is still triggered by exercise or exertion, but there is an underlying condition attributable to this response. 

Underlying conditions with secondary exertional headaches can range from a sinus infection to hypertension or even a brain tumor.

Secondary exertional headaches are usually accompanied by additional symptoms, such as nausea, vomiting, blurry vision, or neck pain.

The exact cause of exertional headaches is still somewhat unknown but is thought to be related to a constriction or narrowing of the blood vessels supplying the head and neck when you strain or exercise.

According to the Cleveland Clinic, getting headaches when working out may also be caused by an increase in the blood volume in blood vessels.

A person leaning against a tree with her hand of her head.

#2: Dehydration 

One of the most common causes of headaches after working out is dehydration.

When you exercise, you lose body fluids through sweat and expired respiratory gasses with heavy breathing.

Even if you try to stay on top of your fluid needs, long endurance workouts or exercising in the heat can lead to an overall loss of body fluid, and many athletes are either not aware of how much they sweat or do not make efforts to drink enough during a workout.

A headache while working out, or especially headaches after working out is one of the most common signs that you are dehydrated from your workout (or in general).

Other symptoms of mild dehydration include a sensation of thirst, fatigue, dizziness, lightheadedness, dry mouth, decreased urination, and constipation. 

When dehydration becomes more severe, you may also experience a lack of sweating, pitting edema of the skin, elevated heart rate, dark-colored urine, confusion, sunken eyes, low blood pressure, rapid breathing, seizure, and even death.

A headache after working out that is due to dehydration typically resolves shortly after fully rehydrating.

A person leaning against a wall with a bottle of water, dehydrated.

#3: Low Blood Sugar

Another cause of a headache after working out is hypoglycemia, which is the medical term for low blood sugar.

If you do fasted exercise, don’t fuel properly before your workout, and/or do a long endurance workout, your blood glucose levels can drop too low because your muscles use carbohydrates during exercise.

One of the main symptoms of hypoglycemia is a headache, along with shakiness, blurry vision, sweating, hunger, difficulty concentrating, and disorientation.

#4: Poor Technique 

It’s possible that your exercise technique or form can contribute to headaches while working out. 

For example, if you hold a lot of tension in your neck and shoulders while doing push-ups, lifting weights, or even running, it’s possible to get an exercise headache.

#5: Sun Exposure

You can get a headache with excessive sun exposure, such as after a long day at the beach or doing yard work in the sun for several hours. 

If it’s sunny and hot out and you’re pushing your body, it’s certainly not uncommon to get a headache while working out.

Sun exposure can be a trigger for headaches in a lot of people, even when they aren’t exercising. This is especially true if it’s hot out.

A person holding their head.

How to Prevent Headaches After Working Out

There are various things you can do to reduce the risk of getting headaches after working out, the effectiveness of which will vary depending on the primary cause of the exercise headache.

Here are a few tips:

#1: Warm Up

Exertional headaches can be exacerbated if you jump into strenuous exercise quickly from resting conditions. A gradual warm-up can help give your body time to adjust to the added strain, increase circulation, and dilate your blood vessels appropriately.

#2: Breathe

Exercise headaches brought on by straining or exerting yourself, particularly when performing the Valsalva maneuver, can be reduced by remembering to breathe deeply and slowly during exercise. 

If you are performing cardio exercise, such as running or intense cycling, try to take slow, deep breaths rather than rapid, shallow breaths.

A person drinking a glass of water.

#3: Drink More Water

As dehydration is one of the main causes of a headache after working out, make sure that you are drinking plenty of water before, during, and after exercise, particularly if you sweat a lot, are exercising in the heat, or doing a long workout.

You should be drinking a minimum of 4-6 ounces of fluid every 15-20 minutes during exercise, and more so if it’s hot out or if you’re sweating a lot. 

However, to prevent hyponatremia, do not exceed 800 mL per hour (about 27 ounces) without consuming the fluids with electrolytes, and ideally in a 6-8% carbohydrate solution.

#4: Ease Up

Particularly if you are exercising at altitude, give your body time to acclimate by reducing the intensity and duration of your workouts.

#5: Stay Out Of The Sun

If you are doing any type of outdoor exercise, such as running, cycling, playing sports, or taking a long walk, try to stay out of the sun or shield your eyes with a wide-brimmed hat and sunglasses to prevent eye strain from the glare of the sun.

A person eating a granola bar at sunset.

#6: Fuel Your Body

To prevent a hypoglycemia-induced headache after working out, instead of performing fasted cardio, make sure that you are fueling with a carbohydrate-rich snack before you work out. 

If you are going to exercise for more than 90 minutes or so, you should be taking in carbohydrates during your workout.

Aim to consume 30-60 grams of carbohydrates per hour for workouts lasting 60 minutes to 2.5 hours.

#7: Work On Your Form

Try to keep your muscles relaxed, especially in your neck and shoulders, while exercising.

If you continue to experience headaches after working out, consider talking to your doctor to see if there is another root cause or effective treatment option.

Do you also experience lower back pain from walking or working out? Check out the possible causes and tips to avoid lower back pain here.

A person with headphones in.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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