To become a good runner requires lots of training and lots of stretching. Some people train at high elevations because air at higher elevations contains less oxygen. This gives you a slight edge when you return to oxygen-rich lower elevations. Also, increase your lung capacity by doing deep breathing exercises. Inhale as deeply as possible and exhale completely. This will stretch your lungs and accustomed your diaphragm to expelling all 'stale' air so that the next inhale is 100 percent fresh air. Just be careful you don't pass out while doing this exercise by hyperventilating. Good luck!