Reading through an old article on training by Malc Smith he talks about the extreme dieting he went through to climb Hubble and how it helped him jump two grades so it this obviously had a hugely beneficial effect on his climbing. He then goes on to says it was totally the wrong thing to do and he wouldn't recommend it but doesn't go into details about the down sides. Does anyone know the speciific reasons why not, rather than general comments about starvation diets etc, as I understand the potential long term health issues from sustaining this sort of thing. However, as a one off for an otherwise healthy person I can't see a downside (besides the fact I'm a greedy bastard and any attempt at this sort of thing will go the way of my "10 pull ups every morning" routine or my attempt to out a campus board up in the kitchen)