Here's another reason to take the stairs: Just getting a little bit of exercise -- even if it's not the full U.S.-recommended 150 minutes a week -- still helps ward off heart disease, especially in women, according to a new review of studies. Researchers examined 33 studies and found that even people who exercise fewer than 150 minutes a week have a lower risk of coronary heart disease than people who don't exercise at all."The biggest health benefits we saw were for those who went from doing nothing to those doing something small," study researcher Jacob Sattelmair, an epidemiologist at the Harvard School of Public Health, told USA Today.