When ever im 3 minutes into training like shadow boxing, or doing a run, anything that I bust a sweat and exhaustion, my belly has burning sensation like I have overload of acid spilling in my stomach, and I cant continue my training, cuz it becomes excruciating. I've had this problem after a 1 year layoff and overeating. I've seen other forums talked about this, and how some people us pepto bismol, but theres been no real definite mention of this issue.
It's normal to experience some stomach upset after extreme cardio especially if you're bouncing/skipping/running a lot. But excruciating acid pain sounds unusual. Maybe you're eating to close to training? I like to do cardio on a completely empty stomach (no food for 3 hours beforehand) and after a good ****
Acid Reflux can have many causes. Does the same thing ever happen to you while sleeping? I agree with Sasto. See a Doctor who can order some tests to rule out anything serious going on. There are pills that can control Reflux. I take two of them, one Prescription and one over the counter. Sucralfate (Prescription) and Tagamet (Cimetidine - over the counter). They both can't be taken at the same time. And I have to wait a few hours after eating before taking Sucralfate.
I recommend this method, I've done it for years.. It's got be barred from a few gyms but I've never had stomach burn.