While going for a run can trigger a runner’s high for some people, others may experience a headache instead. Exercise-induced headaches or exertion headaches were first described in 1968. These headaches occur during or after an intense period of physical activity, such as running, sneezing, heavy lifting, or sex. The symptoms of exertion headaches can vary from person to person, but they usually involve a pulsating sensation on both sides of the head, which can be similar to a migraine. The headaches can last anywhere from a few minutes to a couple of days, and some people may experience multiple episodes. Despite affecting up to 26 percent of adults and 30 percent of adolescents, there is still limited scientific data on exertion headaches.
Causes and Symptoms
Exertion headaches are most common in people aged 22 to 40, although they often begin before the age of 30. Men, in particular, are more likely to suffer from them, with around 80 percent of sufferers being male. When we exercise, blood flow to the brain increases to ensure it has enough oxygen to keep our body moving. However, this increase in blood flow also means that there is an increase in the amount of CO2 and heat that our brains need to get rid of. To cope with this, our blood vessels expand, and this stretching can cause pain.
Exercising in hot weather is one example that can trigger exertion headaches. Since the brain naturally runs at a hotter temperature than the rest of the body, it cannot dissipate heat through the skin by sweating. The only way it can get rid of heat is by widening the blood vessels to increase blood flow through the brain, helping to take away some of the heat. Since hot and humid weather already increase the brain’s temperature, adding exercise into the mix only makes it hotter, leading to an even greater swelling of our blood vessels to cope. This may explain why some people only get the characteristic pulsating headache when they exercise on a hot day.
Training at altitude also increases the likelihood of exertion headaches. This is because the blood’s oxygen-carrying capacity is reduced at altitude, causing more blood to go to the brain to supply all the oxygen it needs. This leads to swelling and triggers pain. People with a personal or family history of migraines may also be more likely to get exertion headaches, as changes in blood vessel size that bring on migraines are also involved in exertion headaches.
Exertion headaches will resolve shortly after stopping exercise, usually within an hour or two, once your heart rate has decreased and there is less demand for oxygen from the brain. However, if your headache is also linked to dehydration, it will likely take longer to resolve until you’ve replenished your fluid levels, which typically takes about three hours. If symptoms persist or your headache is particularly painful, over-the-counter pain medications such as paracetamol or ibuprofen may help.
For those who experience exertion headaches frequently, prescription drugs may reduce symptoms and decrease the chances of these headaches from happening. However, there are also things you can do to prevent exertion headaches from occurring in the first place. Gradually easing back into exercise after a long period of inactivity can help, as your cardiovascular system may not be fit enough to cope with the demands of strenuous exercise. Additionally, warming up gradually before exercising can help your circulatory system cope with changes in blood pressure and flow. Staying hydrated is also essential to ensure the brain’s blood vessels can function correctly. Adequate rest can ensure the brain works at its best and help you feel less sensitive to pain.
Although exertion headaches can be annoying, they should not prevent you from exercising, especially in warmer weather when they can be more common. Avoiding hot days or altitude and trying other types of exercise that do not have a sustained peak heart rate level, such as yoga or weightlifting, may also be beneficial. While further research is needed to establish the causes and treatments of these headaches definitively, being aware of the triggers and taking precautions can help manage symptoms and allow you to continue enjoying the benefits of exercise.