Maybe because the food you eat, gets all jumbled up in your stomach or something I'm not sure! I've never thrown up when running, or after. I jUSt felt like I was going to. Maybe ask google or a doctor. (:
if you over runn and run faster than you can, then maybe you cant keep up with breath when u stop and your heart rate goes up so breathe really hard and puke, it happens to me all the time, just runn at your own pace and gett stronger everytime you run
Despite assertions to the contrary, it's not overly uncommon for this to happen. Your body requires energy to digest food, likewise, you require energy to run. When you push your body, whether by running, other extreme cardio workouts or even by being in survival situations, your body will empty out your stomach, because it doesnt have the energy to continue to digest food.
That is however the most common explanation, though eating too much before a run may be the problem, or some sort of sickness, but it's probly what I explained.
Denver Coplan, Specialist, US Army, Medical Corps.
it is because your body needs energy to digest food but you need that energy to run....so your body doesn't have enough energy to digest the food so then you throw up. Or you just eat to much before you run....YOU SHOULD WAIT AT LEAST 1/2 OF AN HOUR TO 1 HOUR AFTER YOU EAT TO RUN! :)