In reply to Kemics:
Yes, gave up drinking for 11 weeks.
Combined with training hard I went from punting 7B max to on sighting them for warm ups and sending 8A.
I am big and heavy (90kg), ditching the drink and eating right dropped me to 83kg with 9% body fat.
I can't do it all the time, but having a goal you really want keeps you focused. Keep telling yourself that the cheap side of you wants instant gratification (booze, fags, salty, sugary, fatty foods, long lie ins for no reason, not to try hard at anything, not sticking to the plan...), the stronger side of you knows that the bigger picture is to climb x in May and that you need to take thousands of small positive steps in that direction to get to where you want to be. Eating and drinking crap, poor nights sleep, bad routine, not training enough, being stressed at work or home doesn't fit with bigger picture.