I'm at 48 at the moment but that's drugged up to the ears.
I remember seeing Induran (sp?) the Tour de France style bike racer being examined and being ultra fit he was clocking along at about 30 flat on the examination table.
I'd say 80 flopped in front of a computer hacking a forum is bad.
I was treadmilled for my UKSDM last year and they just kept increasing the slope and the speed until I hit 200bpm. Since I did not die (I assume that was the criteria because it felt pretty close) I passed.
See my earlier thread.
I normally run at low 50's... but 38/39 was tooooo low so got admited to 'ospickle..
OK now and had a couple of pints of Guiness to increase the blood after they took out an armful and a bit on Monday!