Lie comfortably on your back on a rug or mat. Place a pillow under your neck and another one under your knees if it feels comfortable. Place your hands on your stomach directly below the rib cage so the middle fingers are just touching at the tip. Breathe in slowly and deeply so that your belly rises and your fingertips separate. Continue this exercise for five minutes to train yourself to breathe deep into the abdomen.
Sit up in a straight and relaxed posture. Inhale while relaxing the belly and imagining your breath filling your stomach. Keep breathing in, filling your chest and feeling your rib cage expand until you can't breathe in further. Pause for a moment, then slowly breathe out. Relax your chest and let the air leave it. Once that air is gone, slowly pull in your belly to force the rest of your breath out. As your breathing starts to deepen, close your eyes and relax your facial muscles and eyes. Continue practicing the complete breath for five minutes.
Use warm-up breathing to take your relaxed, deep breathing into your athletic activities. Walk slowly for five to 15 minutes before you exert yourself, breathing deep into your belly, with your nose closed, at a calm, even pace. Allow your belly to fill completely on each inhale and pull all the way in on each exhale. After your walk, begin to jog at a walking pace or slightly slower. Continue breathing calmly through your nose as before. When you finish, begin to exercise, trying to breathe through your nose and into your belly as much as possible.