Seriously.... I wouldn't be doing any kind of exercise until you find out what the pains are - If it's cardiac related you're risking your life.
I had a burning sensation in my throat for 14 months which I thought was reflux or indigestion, it turned out I had 3 major blockages in my coronary arteries and ended up having a triple bypass.
Angina is caused by not enough blood to the heart muscle - mainly caused by blocked/narrowed coronary arteries.
The only 100% sure way of knowing if you have blocked arteries or not is by having a Cardiac Cath (Angiogram).
There was a time when they only occurred with heavy exercise, but now they come when I do as much as walk a short distance.
This sounds cardiac related to me.