Thanks guys for all your suggestions. Looks like weight training wouldn't be a bad addition to the core exercises I do for a bad back.
Regarding the Niacin I take; I take 2000mg per day because of very high cholesterol and triglycerides. Have tried ALL the statins and they give me severe muscle pain. This much niacin has side effects of itching and burning....but my body is adapting to that. I had not heard about possible problems metabolizing carbs and will look into that.
Bluesdawg...you asked "what mountain". Answer: Neels Gap. You'll enjoy it when you do Six Gap this year.
I've decided to increase my hill training and have already scheduled an appt. with my Dr. to probably have a stress test. My episode may have just been a standard "bonk"...but it's been over twenty years since I've had anything like that happen and after only three miles on the mountain seems a little odd for me?
Finally, I'm heading back to the same place tommorw. If you see no further posts from me....I guess it was my heart after all.
Thanks.