CAN EXERCISE ward off migraines?

UPDATE: A reader emails: “Per your link on your blog. I suffer cluster headaches which my GP tells me is a type of migraine. If I start to exercise or even just walk the dog for 30 minutes will reduce or stop the pain. This past summer I went on the Atkins diet to drop 30 pounds. I found being on a low carb diet eliminated the headaches. Once I lost the weight and resumed my old carb intake they came back. Went back to low carbs and the headaches are gone again. So I just watch what I eat. For the first time in years I no longer have to take medicine. I do miss potatoes especially smoked ones I do on the grill. Now I just have to watch for losing too much weight especially when I am very active.” Of course, exercise can cause migraines in some people, too. I’ve heard that Coenzyme Q10 helps, and I’ve had fewer since I started taking it, but I don’t know if that’s the cause. I’ve also worked out some of my computer-caused back and neck issues, and that may have something to do with it.