Winter-Proof Your Workout

Winter Woe: Your body's chemical switch has flipped to storing more fat.

Fix-it trick: Get your motor running. When University of Colorado researchers studied a group of 12 women and six men in both summer and winter, they discovered that their production of ATLPL, a chemical that promotes fat storage, almost doubled during the winter and dropped during the summer. But you're not doomed to don fat pants all season, scientists say. Exercise may increase SMLPL, the muscle enzyme that promotes the burning of fat, to offset the pudge-promoting effects of ATLPL. "We found that people who are normally physically active are more protected from weight gain," says study author Robert E. Eckel, MD. Get in at least 30 minutes of exercise on most days, whether it's Spinning, snowshoeing, or building a snowman.