I definitely fell into the "walking to and from buffalo wild wings" category.  During UPT, I subsisted primarily on a diet of hard liquor and Reese Cups.  I did the breathing exercise and strain my first couple of G exs then realized I didn't need to, so I just faked it by making the stupid breathing sounds the rest of the way through T-6s.  Granted, we only went to about 7 gs, but I never had any ill effects.  Maybe those last 2 gs are a motherfucker, I don't know.  The guys who were in great shape were also the same ones puking their guts out.  The best way to test G tolerance is probably to actually test G tolerance.  If only we had a couple of centrifuges ...