A small number of studies have shown reductions in the frequency and intensity of migraine following consistent aerobic exercise over several weeks. Aerobic means oxygen-utilizing. It requires continuous movement for 20 minutes or more at a time, such as walking, bicycling, swimming, running, or aerobic dancing. In our inpatient unit for chronic head pain, we found that 45% of those who were able to complete a 20-30 minute group walk at a moderate speed had at least temporary reduction in moderate to severe headache.
Unfortunately, some people also find that exercise can trigger or aggravate headache. A useful guideline is to move at a pace that can be tolerated for 20 minutes without a significant increase in pain, following the rule that "some is better than none." How much exercise is enough? Exercise should take place at least three days a week to accumulate significant benefit. Keeping a simple calendar record of exercise can help build motivation to increase the frequency of exercise. A good goal is to build up to a total of three hours a week.