Just as we strength-train our hamstrings and calves to improve our ability to power over hills, we can tone the muscles used for breathing.
Assume an upright posture, preferably standing on flat ground. Keeping both knees loose, bend over from the waist, simultaneously pushing out all air from your lungs. Slowly return to a vertical position, inhaling at an equal rate. Fill your lungs to the greatest degree comfortably possible and hold this breath for a count of 20. If 20 seconds it too long, choose a timing that you can manage. While counting, extend both arms fully overhead. Relax, lower your arms and exhale slowly. Complete this cycle four times.
Standing upright, expel all the air from your lungs. Slowly breathe in, expanding your lungs to maximum capacity. Hold the air for as long as 20 seconds. While counting, rest both hands on your hips, thumbs facing front with pinkies touching in the small of your back. Release the air slowly and relax. Repeat three more times.
Lay in a comfortable position on your back. Rest one hand on top of your abdomen and the other on your chest. Breathe in deeply and slowly, pulling from your mid-section. When done correctly, the hand on your belly will rise higher than the other. Exhale slowly and completely through the mouth. Inhale fully through the nose, holding your breath at the end for seven seconds if possible. Slowly breathe out for a full count of eight. Squeeze your abdominal muscles toward the end, in order to discharge any residual air. Breath in this way for five complete cycles.