Lung Power with Belly Breathing. Belly breathing can help you run longer with less effort. When you take deeper breaths, you use more air sacs in your lungs, which allow you to take in more oxygen to feed your muscles. So when you’re running, concentrate on taking slow and deep breaths to strengthen your diaphragm. You can do this by running tall and practice coordinating your inhale/exhale with your footsteps. For example, inhale/exhale every 3 steps, then four etc. You can also practice this at home by lying on your back flat on the ground. Place a small book above your belly button/navel and focus on breathing to your belly which will lift the book up and down as you inhale and exhale.