In reply to fiend$ish:
well when you have stopped ranting........
It can't really be compared to the London marathon. (and before you all say of course.......) it's not like running 6 marathons in a row as you run them much more slowly (almost walk at times). I have several friends who run these ultra marathons reasonably regularly (one has just got back from the atacama desert doing one) so this is from the horses mouth.
fiend&ish - have you run a marathon?:!