To ensure that your lungs can hold enough oxygen required by the body while running, practise some breathing exercises. If your breathing is too shallow then you might always be huffing and puffing while performing any cardiovascular exercises. Practising breathing exercises will help you increase your lung capacity and your lungs will be able to hold more oxygen. Diaphragmatic breathing, alternate nostril breathing or Nadi Shodhana and pursed-lips breathing are some breathing exercises that you can perform.