Do you feel headache while exercising?

 Twenty minutes and two miles into Liz Carroll's fifth 10K race, the 34-year-old found herself slumped on the sidelines, a blur of runners passing her by. With a stabbing pain in her left temple and a wave of nausea weakening her resolve, she couldn't take another step. That initial twinge of pain she'd felt at the starting gun wasn't jitters after all: It was a migraine.
Approximately 45 million people in the United States suffer from chronic headaches, including migraines, and a surprising number -- 70 percent -- feel the pain while exercising, says a recent National Headache Foundation survey. How is it that exercise, a universal pathway to well-being, can also trigger one of the most common health problems -- a headache?
Actually, the impact exercise has on pain works both ways. "Most headaches develop when blood vessels around the brain are inflamed, which stretches the nerves within and sends shock waves of pain," explains Merle Diamond, MD, codirector of the Diamond Headache Clinic in Chicago. Regular cardio usually lessens this reaction, thanks in part to a boost of endorphins, the body's natural painkillers, which are released during exercise. Working out also improves blood flow to the brain and reduces muscle tension and fatigue -- all of which minimize blood vessel inflammation. What's more, physically inactive adults are at least one and a half times more likely to suffer from recurring headaches and migraines than those who exercise vigorously at least three times a week, a recent Swedish study found.
But sometimes the type of activity you're doing -- or the way you're doing it -- can lessen the healing effects of exercise, says David Buchholz, MD, associate professor of neurology at Johns Hopkins University in Baltimore. Understanding what sets off your occasional workout ache is essential to keeping your health and fitness on track.