Popping a mint does more than just refresh your breath. Peppermint may boost your running performance and help you shed flab, a new Iranian study reveals. When men drank mineral water mixed with three drops of peppermint essential oil every day for 10 days, their running stamina and power improved and the amount of fat they burned doubled. Pre-workout peppermint may relax your muscles, increase the amount of oxygen transported to your muscles and brain, and lower your lactate levels, says study author Dr Abbas Meamarbashi. Sucking on mints can have the same effect.