Your best partner on your next hike could be a stick of chewing gum. Researchers at Tokyo’s Waseda University found that gum elevates your heart rate as you walk, resulting in a higher energy expenditure. The mechanism is known as cardiaclocomotor synchronisation (CLS), which describes how your body synchronises with your heart rate as you walk. Because chewing gum slightly elevates your heart rate, you naturally increase your movements to match that pace, resulting in a higher step rate and walking speed.