Nausea and vomiting during and after extremely hard exercise?

I've done google and yahoo searches about this, but haven't had any luck. In high school, we would exercise until we were nauseated and eventually vomited. What is the cause of the nausea and vomiting? We were careful to exercise only after waiting 2 to 3 hours after eating.

I also see on television that other people exercise until they vomit also.

I haven't exercised to the point of nausea/vomiting since high school, which was over 20 years ago now. I still get nauseated when working out but have the sense to slow down or stop until the nausea goes away.

I just completed 2 semesters of college 100 level human anatomy and physiology. I'm just very curious about what's happening to the digestive system during extreme exercise.

I do triathlons...and one of the trickiest parts to a longer race is hydration and food. First, it takes some getting used to to be able to eat food when your hr is at 180 and you are peddling like mad to hold your speed on the bike. Most of the blood supply seems to be going to the quads and sometimes the stomach just "shuts down"...meaning everything you have been so carefully eating just comes right up and out....the stomach sort of says "the hell if i am going to be digesting ANYTHING right now". I mean I KNOW that I need approx 300 calories per hour on the bike along with 1 liter of fluid. But, if my stomach won't accept that ... I am quickly SOL. And then I have to start over with the food/hydration dance again. It doesn't happen much anymore...it seems the body becomes acclimated to digesting under extreme conditions.
I have been in swim practice and almost thrown up. I have been out running doing either speed work or tempo runs and thrown up. And, i have thrown up during races. It has been a few years..but it has happened. It is always under major physical stress though...for example, never during a long easy run or long easy bike ride. Always seems to occur under major duress.

You say you waited 2 to 3 hours after eating to exercise. I could never do that. I eat yogurt and cereal and then run 12-14 miles and bring Goo or Clif Shots with me along with some sort of hydration. I need some calorie input during a longer run or bike and definitely during a longer race like 1/2 ironman or ironman. In fact, during Ironman 2003 I think I ate in excess of 5000 calories during the race...but probably burned thru 9,000.

So, long answer. What happens to the digestive sys during extreme exercise? I think much of the oxygen carrying blood gets diverted to more immediate needs like heart, quads, lungs, diaphram, etc...and away from functions like digestion. Since the stomach now is not being provided what it needs to have to digest...it ejects the food. No reason to keep it there if it isn't going to get digested.

Good question though. It'll be interesting to see what others say...

My comment should read " I entered the Alpine Adventure Run but not completed." Report It

i think thats your body response of saying "stop"... and maybe you are getting really dehydrated... and you are not waiting enough for your food to be digesting...

It sounds to me as though you are depleting your electrolytes. You could try Gatorade or other sports drink, and see if that helps.

seems like your dehydrated