Residents of neighborhoods with higher levels of poverty, lower education, and more female-headed families are less likely than others to exercise, according to the study.

It’s not simply that poorer people are less likely to exercise, researchers say. In fact, the study, which was done in Chicago, found that a person’s individual income wasn’t as important as the neighborhood he or she lived in for determining exercise levels.

Co-author Christopher Browning, an associate professor of sociology at Ohio State University, attributes it to residents not feeling "comfortable to go outside for activities.”

Other studies have blamed suburban-sprawl neighborhoods for making people fat because there's nowhere to walk.

Of course, there's always exercise tapes.