Although it is not particularly common, some runners experience a headache after running or performing some type of strenuous exercise.
For example, some runners may experience a headache after a long run or the pulsating discomfort of a migraine after a high-intensity weightlifting workout to supplement their running training program.
Understanding the causes of headaches is important in preventing and treating exercise-induced headaches.
In this guide to headaches after running, we will discuss the symptoms, the different types of headaches, the causes of headaches after strenuous physical activity such as running, and tips to prevent and manage exercise-induced headaches.
What Are the Symptoms of a Headache After Running?
Before we delve into the causes of headaches after running or other high-intensity workouts, it is important to present the disclaimer that this should not be taken as medical advice.
It is important to seek medical attention from your healthcare provider if you have concerns about headaches or are experiencing migraines, frequent headaches, or other symptoms such as dizziness, high blood pressure, low blood pressure, rapid heart rate, confusion, or nausea.
There are many causes of headaches and you may have an underlying condition or underlying cause aside from strenuous exercise contributing to exertional headaches.
Like any headache, post-exercise headache symptoms generally include dull, throbbing, or pulsating pain localized on one or both sides of the head or a throbbing sensation that you feel across your entire forehead.
What Causes A Headache After Running?
There are different potential causes of headaches after a run or after strenuous exercise.
Note that the causes of headaches from running or exercise discussed below are distinct from some of the other kinds of headaches, such as tension headaches or migraines.
These kinds of headaches are also quite common but have separate causes, so they are not discussed in detail here.
#1: Exertional Headaches
One of the primary causes of headaches after running or high-intensity workouts is the physical exertion itself.
Any type of physical exertion can cause an exertional headache, including strenuous physical activity along with more benign triggers such as an aggressive coughing fit or straining due to severe constipation.
According to the American Migraine Association, exertional headaches from exercise, now referred to as exercise headaches, tend to be triggered by high-intensity workouts, especially weightlifting while performing the Valsalva maneuver or doing a speed workout.1Primary Exercise Headache. (n.d.). American Migraine Foundation. https://americanmigrainefoundation.org/resource-library/primary-exercise-headache/
An exertional headache from running is more likely to occur when there is some additional strain, such as running in hot weather or running at altitude, or if you are doing a much higher intensity or longer run than you are used to or that is appropriate for your fitness level.
Exertional headaches typically present as a pulsating or throbbing pain around the temples or the sides of your head.
A post-run headache due to exertion usually resolves shortly after your run is over, but exertional headaches may persist for several hours, especially in cases where there is a secondary underlying cause for the headache, such as dehydration or low oxygen availability due to running at altitude.
According to the Mayo Clinic, there are primary exertional headaches and secondary exertional headaches.2Exercise headaches – Symptoms and causes. (n.d.). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/exercise-headaches/symptoms-causes/syc-20372276
Although both types of exertional headaches can be brought on by running, weightlifting, or some other form of cardio exercise or resistance training, a primary exertional headache has no known cause aside from the exertion whereas a secondary exertional headache has an additional underlying cause.
Examples of some of the underlying conditions for a secondary exertional headache include sinus infections, high blood pressure, or more serious medical conditions such as brain tumors.
In addition to the classic headache symptoms, a secondary exertional headache is often accompanied by other symptoms such as nausea, vomiting, blurry vision, or neck pain, depending on the secondary underlying cause for the post-exercise headache.
The exact cause of primary 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.
This reduces blood flow to the brain, and because blood carries oxygen, nutrients, and glucose, when the blood vessels are constricted, the relative availability of oxygen and nutrients to the brain decreases.
According to the Cleveland Clinic, primary exercise headaches may also be caused by an increase in the blood volume in blood vessels.3Exertion Headaches (Exercise Headaches): Causes, Symptoms & Treatment. (2021). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/21959-exertion-headaches
However, the pathophysiology underlying the cause of headache pain from increased blood flow is somewhat less clear.
#2: Dehydration
Dehydration is one of the most common causes of headaches after long runs or headaches after running in hot weather or altitude.4Popkin, B. M., D’Anci, K. E., & Rosenberg, I. H. (2020). Water, Hydration, and Health. Nutrition Reviews, 68(8), 439–458. PubMed Central. https://doi.org/10.1111/j.1753-4887.2010.00304.x
Staying well hydrated and getting plenty of electrolytes to replace those lost in sweat can help prevent dehydration headaches after running, but factors such as running in the heat or at altitude accelerate fluid loss, increasing the rate of dehydration.
Hydration when running in hot weather or at altitude or if you have a high sweat rate is critical because you lose fluids and electrolytes not only through sweat but also respiratory gasses (exhalation).
#3: Low Blood Sugar
Particularly if you run first thing in the morning or a run in a fasted state, you may experience a headache after running due to hypoglycemia, which is low blood sugar.
Glycogen is the primary fuel source for your muscles while running or performing high-intensity exercise.
Plus, you use up some of your muscle and liver glycogen overnight as you sleep.
Therefore, if you are not fueling on the run with carbs or running on an empty stomach, you may deplete your glycogen stores.
This can cause low blood sugar levels, and one of the common signs of hypoglycemia is a headache.
#4: Improper Breathing
Hyperventilating or holding your breath while performing strenuous physical activity can be a trigger for headaches.
Your brain needs enough oxygen, and holding your breath decreases oxygen availability.
Similarly, while you might think that hyperventilation would flood your body with excess oxygen, it is actually a very inefficient way to breathe and can also lead to lower blood oxygen levels.
#5: Extreme Temperatures and Sun Exposure
If you run in cold weather or on a hot, sunny day, the thermal strain and/or squinting due to the sun can increase tension in the face and body.
This can increase the risk of secondary exertional headaches.
Additionally, vigorous-intensity exercise in the summer or on a hot day will accelerate your sweat rate, contributing to the risk of dehydration headaches.
#6: Underlying Conditions
Other underlying medical conditions and medications can increase the risk of headaches both after physical activity and/or throughout the day.
People who have high blood pressure, also known as hypertension, tend to have a higher risk of headaches. Additionally, headaches are one of the common side effects of medications for high blood pressure, such as beta-blockers.
Similarly, medical conditions such as fibromyalgia, seizure disorders, and headache disorders, can increase the frequency of migraines and secondary exercise headaches.
Diabetes or difficulty regulating blood sugar levels can also cause migraines or headaches due to hypoglycemia or even high blood sugar.
How Can I Prevent Headaches After Running?
Preventing headaches after exercise involves trying to figure out the cause of headaches from workouts, namely trying to differentiate whether you are experiencing primary exercise headaches or secondary exertional headaches with an additional underlying cause.
Here are a few tips to help prevent headaches after running or performing strenuous workouts:
- Do a thorough warm-up and cool down. The small capillaries feeding your muscles and brain and other small blood vessels dilate when you start physical activity due to nitric oxide production. This may reduce the risk of primary exercise headaches.
- Make sure you are breathing with a steady, even rhythm from your belly rather than just your chest. Particularly when you are weightlifting, avoid holding your breath.
- Drink enough water before, during, and immediately after exercise. You may need electrolytes or sports drinks to supplement electrolytes lost in sweat.
- Don’t drink more than 800 mL of water per hour5Roy, B. A. (2013). Exercise and Fluid Replacement. ACSM’s Health & Fitness Journal, 17(4), 3. https://doi.org/10.1249/fit.0b013e318296bc4(about 27 ounces) without consuming electrolytes, and ideally have a sports drink with a 6-8% carbohydrate solution, during long runs to prevent hyponatremia, which is dangerously low sodium levels.
- Reduce the intensity of your workouts at altitude or before you have acclimatized to running in hot weather.
- Wear sunglasses and a visor when running in the sun to prevent squinting.
- Make sure you are fueling your body with enough carbohydrates before and during long runs to prevent hypoglycemia. Aim to consume 30-60 grams of carbohydrates per hour for workouts lasting 60 minutes to 2.5 hours.6Jäger, R., Kerksick, C. M., Campbell, B. I., Cribb, P. J., Wells, S. D., Skwiat, T. M., Purpura, M., Ziegenfuss, T. N., Ferrando, A. A., Arent, S. M., Smith-Ryan, A. E., Stout, J. R., Arciero, P. J., Ormsbee, M. J., Taylor, L. W., Wilborn, C. D., Kalman, D. S., Kreider, R. B., Willoughby, D. S., & Hoffman, J. R. (2017). International Society of Sports Nutrition Position Stand: Protein and Exercise. Journal of the International Society of Sports Nutrition, 14(1). https://doi.org/10.1186/s12970-017-0177-8
Remember to speak with your doctor if your headaches are frequent or accompanied by other symptoms.
For tips to run at altitude and avoid these headaches, check out our next guide:
