July 2, 2001 -- If exercise sets off your migraine headaches, here's a tip. Warm up -- go for a leisurely walk -- for 10 minutes before starting any strenuous exercise. According to a new study, it might just prevent those horrendous, delayed-reaction headaches from ever occurring.
"We speculate that if one warms up slowly before engaging in intense exercise, it will prevent the headaches -- much better than taking drugs," says study author João Araújo e Sá, MD, MSc, neurologist at the Centro Hospitalar de Coimbra and researcher at the Institute of Biomedical Research of Light and Image in Coimbra, Portugal.
His study shows that women prone to migraines already have high levels of a chemical called nitric oxide in their bodies. And sudden bursts of exercise -- even for as little as 30 seconds -- seem to release even more nitric oxide into the migraine sufferer's bloodstream.
The study compared 21 women prone to migraines and 12 women who don't get the headaches by having them perform intense bicycling for 30 seconds. The findings: 11 of the migraineurs (52%) got headaches between four and five hours after the exercise, while none of the other women did.
Nitric oxide levels were measured both before and after exercise. Even before exercising, women in the migraine group had nitric oxide levels that were higher than the other women. Those levels increased by an average of 20% after intense exercise, while the nonmigraine group had only a 14% increase in nitric oxide.
"Nitric oxide may be an important triggering mechanism in migraine," Sá tells WebMD. "It is not the only mechanism, but perhaps it starts here." This information could lead to new drugs that prevent nitric oxide release, he says.
Nitric oxide is a chemical that the body produces naturally for a number of functions -- to protect the heart, stimulate the brain, and kill bacteria. But overproduction of nitric oxide has been linked with onset of Alzheimer's disease and with migraines. Nitric oxide causes blood vessels to dilate -- and blood vessel inflammation has long been associated with migraines.
Sá advises women "to perform a nice warm-up before exercising. We ask them to gradually increase heart rate for about 10 minutes -- to take a slow walk. This seems to prevent the sudden burst of nitric oxide and onset of migraines."
He is currently conducting further studies of this theory.
"We've known that nitric oxide was involved in migraines, but little has been known about why it is released or the role it plays in migraine -- whether it simply dilates the blood vessels or whether it also affects nerve cells that cause pain," says Alan Rapoport, MD, director and founder of The New England Center for Headache in Stamford, Conn.
"They've found a mechanism that may be contributing to headaches," he tells WebMD. "I don't think it shows us that only nitric oxide causes these headaches, but it may be one of the contributing factors. I'd like to see more studies of this."