I'd like to get in better shape, but I'm running into an unusual block (from what I can tell). Whenever I try to work out - say on an exercise bike - after 5-10 minutes I have to stop and spend a few minutes clearing out my mouth and throat. Saliva/mucous will literally build up to the point where I will start choking on it. It's thick enough that I can't just swallow during the workout, that just makes the issue happen earlier as it triggers my gag reflex. I can then resume, but I have to stop every couple of minutes after that to re-clear things. Generally after about ~20 minutes, everything is clear enough that I can continue as normal. However this is enough of a block that it usually keeps me from even trying to work out, since that "clearing out" process is very unpleasant.
I play hockey 1/week, and this also happens during that which causes issues with playing (it's actually started happening before I leave for hockey recently, which I'm assuming is a psychosomatic reaction of some sort).
I am not sure what could be causing this - whether it's disease, diet-related, or other - so my question is: Has anyone else had a similar issue, or heard of it, and know what worked to fix the problem?
Background info: Male, early 30s, 225 lbs/6' tall. Diet is poor, but I had a similar diet when I was a kid, played hockey then and had no issues like this.