Exercise and Migraine: Prevention or Trigger?

Someone will tell you exercise prevents migraine. Someone else will tell you it sets one off. Both are describing something real, and the argument only exists because three different relationships get discussed as one.

One: exercise as a preventive, which has trial evidence

This is the strongest of the three and the least well known.

A meta-analysis of aerobic exercise for migraine pooled randomised and controlled trials and found significant decreases in the number of migraine days per month, rating the evidence as moderate quality. The population across those trials was 357 people, mostly women, average age around 38.

The dose is the useful part, because “stay active” is not a protocol. Participants exercised 30 to 45 minutes, two to three times a week, for ten weeks or more. The activity was ordinary — walking, jogging, cycling, cross-training. One trial reported reductions across several measures at the end of treatment: pain intensity down 18%, attacks per month down 23%, migraine days down 28%, and use of anti-migraine drugs down 24%.

Those are averages across a group and not a promise to any individual. What they establish is that the effect is real enough to be worth ten weeks of a person’s time, and that the amount required is smaller than most people assume.

Two: exertion making an attack worse, which is a diagnostic criterion

The second relationship is the one people mistake for evidence against the first.

Being aggravated by, or causing avoidance of, routine physical activity — walking, climbing stairs — is one of the four headache characteristics in the definition of migraine without aura. It is not a side note. It is part of how the condition is identified, which is why a clinician may ask you specifically whether stairs make it worse.

So an attack that gets worse when you move is behaving exactly as the criteria describe. That says nothing about whether exercising on your ordinary days is helping or hurting, and the two get conflated constantly.

The practical implication is only this: during an attack, exertion is not the answer, and pushing through generally makes the next few hours worse rather than shorter.

Three: exercise setting one off, which is its own thing

Some people do get headache brought on by exertion, and it is a recognised entity separate from ordinary migraine. It has its own pattern — typically arriving during or shortly after sustained effort.

Before assuming that is what is happening, three ordinary explanations are worth ruling out, because they are far more common and all of them are fixable:

• Not eating. Exercising after a long gap without food is one of the most reliable ways to arrive at an attack, and skipped meals is among the better-supported dietary factors in migraine generally.
• Dehydration, particularly in heat.
• A sudden jump in intensity. Going from nothing to a hard session is a different exposure from building up over weeks, and the trials that showed benefit all involved gradual, regular, moderate work rather than heroics.

A new headache that comes on abruptly during exertion, especially for the first time, is not something to work around. That one needs a doctor rather than an adjusted warm-up, and it needs one promptly.

How to start without producing an uninterpretable result

The mistake is starting exercise the same week you also fix your sleep, cut caffeine and start a preventive. Four changes at once means an improvement teaches you nothing.

Take a baseline first. One month of marks before you start: headache day yes or no, migrainous or not, and whether you took anything. Without that number the comparison at the end is against your memory of how bad things were, which is compressed and weighted toward the worst weeks.

Change one thing. Exercise, at the trial dose, for ten weeks. Not four.

Log the clear days. A record with only bad days in it produces a list, and what you need is a rate.

Write down what else changed each week — the column that stops a chaotic fortnight being read as evidence about exercise. The single-variable method in how to track migraine triggers without fooling yourself applies here unchanged, stretched from six weeks to ten.

Ten weeks is long, and it is the shortest run the trials used. A four-week attempt abandoned because nothing happened is the single most common way people conclude exercise does not work for them.

What to expect while you find out

Two honest things.

Some people get attacks in the first weeks of a new routine, from the intensity jump rather than from exercise as such, and that settles for many of them. It is also the point at which most people stop, which is worth knowing in advance.

And the benefit in the trials was a reduction in migraine days, not their disappearance. A drop from twelve days to nine is a meaningful result that will not feel like one from inside, which is exactly why the count matters more than the impression — the same problem that makes people abandon working preventives early.

Migraine Journal keeps migraine days per month on a rolling window, which makes a ten-week before-and-after a lookup. A wall calendar with a mark per attack does the job as well, and the free printable diary has a grid laid out for it.

Nothing here is medical advice, and what kind of exercise is appropriate for you is a question for your GP, particularly if you have other conditions or your attacks are frequent enough that you are considering preventive treatment. Take the ten-week comparison to that conversation — what to bring to a neurologist appointment covers the rest of the page it belongs on.