Getting a headache during or after exercise can be frustrating, especially if you have kept hydrated to prevent them. Known as exertional headaches, they affect about 12% of adults, though estimates range from 1% to 26% across studies.
These headaches typically present as a throbbing pain on both sides of the head and can last from minutes to days. They are thought to be caused by changes in blood flow to the brain, as intense exercise dilates blood vessels, increasing pressure.
Dehydration and heat can worsen exercise headaches. While the exact link is unclear, dehydration may increase strain during exercise, making headaches more likely. Heat also raises brain blood flow, as the brain cannot cool itself by sweating.
Most exercise headaches are harmless and resolve on their own, often disappearing after a few months of regular training. However, in rare cases, they can signal serious conditions like a subarachnoid haemorrhage or cervical artery dissection.
To reduce risk, experts recommend staying hydrated, warming up gradually, and keeping exercise intensity light to moderate for a few months to allow cardiovascular adaptation. If headaches persist or are severe, medical advice is advised.
