A new study from the University of Alabama at Birmingham examined the relationship between exercise and stroke in a large biracial group of men and women in the United States. A total of 27,000 stroke-free blacks and whites ages 45 and older participated in the study. The results showed that physical inactivity was reported by 33 percent of participants and was associated with a 20 percent increased risk of stroke. Those who reported they exercised at least four times a week were less likely to…