Regular workouts help prevent migraines just as effectively as relaxation therapy and a common prescription drug, scientists have found.
All three treatments reduced the frequency of some women's migraine attacks by as much as three quarters - although the average reduction was more modest.
Scientists from the University of Gothenburg in Sweden were surprised to find using an exercise bike three times a week could have such a potent effect.
The team, led by Dr Emma Varkey, studied 91 women aged between 18 and 65 years old from a single headache clinic in Sweden.
They had neurologist-diagnosed migraine, with or without aura, and got headaches two to eight times per month.
Previous studies have shown that both relaxation therapy and the prescription drug topiramate are able to prevent migraines. The latest study found exercise is just as effective.
"It was a bit surprising and very interesting that the change in number of migraine attacks was almost similar in all three groups," the Daily Mail quoted r Dr Varkey as saying.
"This non-pharmacological approach may therefore be an option for the prophylactic treatment of migraine in patients who do not benefit from or do not want daily medication," she added.
Dr Varkey said topiramate was best at reducing the intensity of migraines when they did come. However, the drug can cause side effects such as numbness, vertigo and depressed mood.
None of the women in the relaxation group or exercise group reported side effects, but eight women making up a third of the topiramate group did and three withdrew from the study as a result.