Not the best person to answer as I have never taken gear but as a runner I can say for certain that a couple of weeks heavy drinking and little training can set you back months, I try not to these days as it gets harder to pull that fitness back to form. the extra weight you pile on doesn't help with times either

Again, years back I'd smoke week heavily and the crap I'd cough up after a long run would not be good at all, even now after the odd 'hazy' night I can feel the effects for days after on the chest.

Not exactly 'facts' as everyone will be different but true to me