Why do I loose my breath after 10 seconds of sprinting?

Out of shape? There could be several medical reasons, but the most common one is that you are simply out of shape. See your doctor to see if you are healthy enough for exercise (depends on type and intensity anticipated), but most everyone can start out by walking, then briskly walking, then running short distances, then longer. Could be asthma or exercise-induced bronchoconstriction. In doubt? See your md.