Having a positive attitude is how underdog sports teams come from behind to cinch victory. It makes for exciting games, but a positive attitude is also important for your personal health — it fights heart disease. New research from University of Pittsburgh Medical Center found that seeing the glass half full appears to protect the heart against disease and death, and conversely pessimism increases the risk of heart disease. The 15-year study of 97,000 postmenopausal women involved surveys designed to assess the participants sense of optimism. The women responded "yes" or "no" to statements like, "In unclear times, I usually expect the best," or "If something can go wrong for me, it will."

See if docs understand the power of positive thinking.

Psychologist and American Heart Association spokesman Barry J. Jacobs, PsyD, responded to the results of the study like this:

"There is a lot of conjecture about why this is, but we don’t really know why optimism seems to be so beneficial for health." He added "Someone who believes that life is not worth living probably isn’t the type of person who goes to the gym three times a week."

Interestingly enough, the optimists tended to be younger and have health insurance, where the pessimists were more likely to have chronic diseases like diabetes or high blood pressure. The study found that the women with negative attitudes also avoided exercise.

So do you see the glass as half full or half empty? Do you think pessimists can change? Could exercise be the key to happiness and heart health?