Assuming you are keeping up with your hydration and not finishing your run dehydrated, this might be an exertional headache (also known as a primary exercise headache). There are a few factors which can contribute to these headaches after a run. The underlying physiological issue is blood vessel constriction-dilation response in and around the neck and skull that occur with blood/fluid shifts during exercise. Poor running form and posture can cause muscle tension and tightness in the neck and upper back, which is a trigger for post-exercise headaches. Low blood sugar and dehydration can also contribute to this.
As for prevention, in the first instance, you’ll want to get checked by your doctor to ensure there is not an underlying condition that is exacerbated by running. If it is deemed “just” a primary exertional headache, then taking indomethacin or naproxen before your run can help. If medication isn’t your preferred route, then using a heating pad on your neck at the onset of the headache will dilate the vessels in and around your head, stopping the headache trigger. I realize it sounds counter-intuitive to use heat when you are hot, but the big change between exercise dilation and then post-exercise constriction is a significant contributor to primary exertional headaches—applying heat invokes the natural dilation response and can help stop the headache.
Also, be sure you are drinking adequately before, during, and after your long run; this can often be overlooked. As mentioned in previous Ask Stacy columns, the best way to determine your fluid needs is to do some bio-hacking using pee sticks. This test is done on a sample of your pee with a thin plastic strip treated with chemicals. It’s dipped into your urine, and the chemicals on the stick react and change color if levels are above normal. Things the dipstick test can check for include:
- Acidity or pH: If the acid is above normal, you could have kidney stones, a urinary tract infection or another condition.
- Protein: This can be a sign your kidneys are not working right. Kidneys filter waste products out of your blood, and your body needs protein.
- Glucose: A high sugar content is a marker for diabetes.
- White blood cells: These are a sign of infection.
- Bilirubin: If this waste product, which is normally eliminated by your liver, shows up, it may mean your liver isn’t working properly.
When it comes to hydration and fueling, of course, it is always best to experiment a lot in training to truly figure out what works for you. We are all unique here.
Got a question for Dr. Stacy Sims? Submit it here and she might answer it in an upcoming “Ask Stacy” column.