Its called Air hunger. Air hunger may be caused by insufficient pulmonary minute ventilation, a sustained breath-hold constriction of the alveoli of the lungs, as in asthma, or high ambient levels of carbon dioxide in the air. So, considering ur age and good fitness and proportionate weight the serious heart and lung problems are ruld out . next possible cause could b part of ur taurette synd , i mean a of psychological origin. Nothing to worry , try these it wl improve .u can consult a psychiatrist or a psychologist they wl definitely help u . Here is a small list of things that can help u. Going out on a walk. Praying and using visualization. Walking and praying at the same time. Getting involved in something that takes my mind off of ur circumstances. anything that is calming and/or brings a feeling of happiness and relief may help u feel better. Maybe this is why most of us do not seem to have any issues while we are sleeping since our minds and bodies are calm and at peace. Perhaps our breathing normalizes itself while we are sleeping.