Forty athletes participating in a study at Wheeling Jesuit University in West Virginia ran faster and performed more push-ups when they were exposed to the scent of peppermint than they did without the added aroma. One possible explanation is that the scent works by enhancing mood and motivation. When you're in a good mood, you can push yourself harder, says Dr. Alan Hirsch, neurological director of the Smell and Taste Treatment and Research Foundation in Chicago. In fact, Hirsch says, other pleasant aromas work too. Studies have shown that the smell of buttered popcorn or strawberries has a similar effect. But it's best just to expose yourself to the aroma and not the actual food, Hirsch adds. Eating and exercising at the same time is more likely to upset your stomach than it is to motivate you.