This kinda thing feels like a
heart thing, but it tends to happen after meals. So id think blood sugar or
stomach maybe.
Truth be told the stairs at work get my heart pounding pretty good at the usual 140 ish range i'd wager, but never out of control and I never have chest pains. Just lightheaded and fatigued a lot.
In any case, thanks for the tip, I will keep that in mind. I sincerely hope its a digestion issue and not a heart issue.