A new series of health insights is on the way.
Important
A new series of health insights is on the way.
Our team is working behind the scenes to develop new research and practical health strategies for our readers. As we finish preparing what comes next, we invite you to browse one of our most read articles in our library below. See exactly what’s changing →
It’s common to be perfectly hydrated after a workout and still be hit with a terrible headache. For some, it starts as a subtle bump on both sides of the head. For others, it’s a sudden blow that stops them in their tracks. These are known as exercise headaches, which some describe as “the worst headache I’ve ever had.” According to the study, they affect up to 26% of adults.1
While an exercise headache doesn’t always mean something is seriously wrong, it’s also not a brush off. When your brain sends a signal like this, it’s worth listening. What’s frustrating is how unexpected they often feel. You drink water, you fuel properly, you get enough sleep and you’re still sidelined with pain. So, what’s really going on?
The answer has to do with how hydrated you are and how your body regulates pressure and blood flow under stress. You don’t need to give up your exercise routine to stop the cycle. First, you need to understand what triggers these headaches. That’s where science comes in.
Exercise headaches happen when your brain overheats.
An article in Discussion explores why some people get knee headaches despite staying hydrated and exercising regularly.2 He examines current theories and findings to explain what’s going on in your body when these headaches strike.
• Exercise headaches affect people in different ways depending on their balance: These headaches are more common in people who are new to vigorous exercise or who develop rapidly. They usually occur after a physically demanding session. But what’s considered “boring” really depends on your current fitness level, so even modest effort can trigger them if you’re not used to it.
• The pain lasts from a few minutes to two full days. However, sometimes they disappear in time. The article mentions that some people stop having these headaches after a few months of consistent training. This is because the cardiovascular system gradually gets better at handling physical stress and blood flow to the brain.
• The main reason is how your brain handles heat. Unlike the rest of your body, your mind doesn’t sweat. For cooling, it diverts more blood flow to the head during exercise. This puts a lot of pressure on your skull, which causes pain.
Additionally, during exercise, your arteries and veins dilate and deliver more blood and oxygen to your muscles and organs. The same thing happens in your brain, but in a confined space, this creates more pressure, especially when you’re already warm or dehydrated. When it’s hot outside, your body sends more blood to your brain in an attempt to cool you down. This overcompensation leads to increased intracranial pressure and headaches.
• Dehydration compounds the problem but is not always the root cause. While many people think that they get headaches from not drinking enough water, hydration alone is not the whole story. However, dehydration puts additional stress on the cardiovascular system, which makes the brain’s cold response more powerful — and more painful.
• Gradual improvement in physical activity may reduce headache risk over time. People who build slowly report fewer and milder exercise headaches, because their blood vessels are more efficient at expanding and dilating with less pressure.
Vision problems and nausea are red flags that should not be ignored.
Although most exercise headaches are harmless, some have been linked to serious conditions such as brain hemorrhage, infections, or elevated brain pressure.3 If you have these headaches for the first time or if they are sudden and severe, you should get them evaluated. The Cleveland Clinic breaks down how a fatigue headache differs from a typical headache.4
• There are some signs Migraine And it should be taken seriously – While pain on both sides of the head is common, the Cleveland Clinic emphasizes more serious symptoms such as changes in vision, nausea and vomiting. If you’re seeing blind spots, feeling dizzy or sick to your stomach after a workout, that’s not something to push about.
• As a general Stress headacheFatigue headaches often feel like a strong pulse – This builds up quickly during or after exercise. They also sometimes feel like thunder – sudden and explosive. These details are important because understanding your symptoms will help you communicate clearly with your doctor if you need help. Chronic conditions are rare but important to avoid.
• If you’ve never had one before, don’t put it off – For the first time, a knee headache, especially if it is severe or is combined with other neurological symptoms, should be evaluated by a medical professional. Confusion, fainting, severe sleeplessness, or a headache lasting more than two days are all red flags.
Once you understand what’s triggering your symptoms and get the green light from your doctor, you’ll have more confidence to push forward with your workout without worrying about the next headache hitting anywhere.
Why pushing too fast sets you up for a headache
According to Dr. Ashhar Ali, a neurologist at Henry Ford Health, starting an exercise program too aggressively runs the risk of causing your mind and body to react negatively.5 If your system hasn’t yet adjusted to the workload, the increased pressure can manifest as a headache. The adjustment is simple but requires patience: start slowly and give your body time to adjust.
• Dehydration is the main cause of headaches. While it’s possible to have an exercise headache despite drinking plenty of water, Ali emphasizes the systemic effects Dehydration On your mind. Not only does it relieve fatigue, but it also alters fluid balance, increases body pressure, and increases the likelihood of dilation of blood vessels in the head, which triggers the feeling of throbbing. “Headaches are another side effect of not drinking enough water,” he warns.6
• Overheating during exercise makes things worse – Exercise in Hot areasAnother trigger is direct sunlight, whether outdoors or indoors with poor airflow. Moreover, your choice of clothes is important. Heavy fabrics, dark colors, or non-breathable materials trap heat and force your body to work harder to cool you down. That extra burden puts pressure on the brain, causing pain.
• Altitude training isn’t for everyone, and if you’re not used to it, it’s a problem – Working at heights can be a headache, especially while traveling. At high altitudes, oxygen is thin, and your brain has to work harder to compensate.
In people who are not used to these conditions, the change in oxygen pressure often causes headaches associated with exertion. Ideally, take a few days to adjust before attempting strenuous exercise under these conditions.
• These headaches are often mistaken for something else: People often confuse these headaches with stress or muscle strain, when it’s actually the training environment and pace that’s to blame. This misdirection leads many to abandon simple fixes like rest, hydration, cooling, or adjusting their exercise routine.
How to stop headaches from derailing your exercise
If you’re dealing with a headache after a strength training session or if you’ve gone for a very vigorous walk, it’s not in your head, at least not in the way you think. The problem is not always humidity or a poor night’s sleep. Often, overheating, overexertion, or sudden changes in pressure are how your brain reacts.
Good news? You don’t have to live with it, and you don’t have to stop exercising. These are direct ways to correct the cause of the problem and clear your head while training. If you’re trying to get rid of exercise-induced headaches, here’s what I recommend:
1. Start with a slow warm-up and build strength over time – You can’t go from zero to sprint in five seconds, and your brain won’t like it. Give your blood vessels time to adjust by easing into your exercise routine. Start with gentle movements, light weights, or light walking. Whether you’ve been sedentary or getting back into fitness, your body needs time to learn how to regulate pressure and blood flow.
2. Hydrate before, during and after training: Even slightly dehydrated, your body has to work harder to pump blood, especially to your brain. This increases the risk of illness. Once your headache starts, don’t just drink water, go ahead. Drink throughout the day, not just during your session.
If you sweat a lot or train outdoors, you’ll want to consider a mineral-rich drink like coconut water or a homemade mixture of water, sea salt, and fruit juice to replenish what you’ve lost. In general, just listen to your thirst. A good rule of thumb is to check your urine. It should be pale yellow in color – if it is dark, the water has dried up.
3. Control the exercise environment – If you’re exercising in a hot, stuffy room or wearing heavy or dark-colored clothing, you’re setting yourself up for overheating. Switch to naturally breathable fabrics and avoid exercising in high temperatures. If you are indoors, use a fan or open a window. Your brain doesn’t cool like your skin, so anything that prevents overheating will help protect you.
4. Adjust your exercise at altitude or during travel – If you’re in the mountains or somewhere with thin air, your brain is working overtime just to get enough oxygen. It’s easy to push too hard without realizing it. If you are not used to high altitudes, avoid high intensity training for the first few days. While your body adjusts, focus on low-impact options like walking, yoga, or light bodyweight exercises.
Frequently asked questions about headache exercise
Q: Why do I get a headache even after I drink water after working out?
A: Exercise headaches aren’t always caused by dehydration. Your brain can’t cool itself by sweating like the rest of your body, so it sends more blood to your head to regulate temperature. This increases the pressure in your skull, which can cause pain, especially if you develop strength too quickly.
Q: Are exercise-induced headaches dangerous?
A: Usually, no. They usually disappear within a few hours to two days and improve over time as the cardiovascular system adapts. However, if it’s your first headache, or if the pain is sudden and severe, lasts more than two days, or is accompanied by symptoms such as nausea, vision changes, or confusion, you should get checked out to rule out more serious conditions.
Q: Who gets these headaches?
A: People who are new to vigorous exercise, who push too fast, train in extreme heat or altitude, or wear heat-trapping clothing may experience exercise headaches. Dehydration and poor air conditioning are major contributors.
Q: How can I stop these headaches from happening again?
A: Start with a slow warm-up, stay hydrated throughout the day, train in a cooler environment, and avoid high-intensity exercise in high temperatures or thin air.
Q: What signs should I look for?
A: Red flags include thunderclap headache (sudden and severe pain), fainting, stiff neck, confusion, vomiting, or vision problems. If any of these are present, or if the headache persists for more than 48 hours, it is important to be evaluated for more serious conditions, such as an arterial or brain hemorrhage.
