I have studied drinking, and I have come to the conclusion that it is the anti-muscle. As far as bodybuilding goes it's everything you would never want to have in you, and here is why:
A recent study done by Muscle and Fitness showed that drinking caused an average loss of muscle somewhere around the 33% range. This is called 'alcoholic myopathy' and a decreased rate of protein synthesis has been liked to it.
Protein synthesis is important in the building of new muscle, so not only does alcohol destroy previously existing muscle, it also robs your body of the ability to produce any more muscle.
Lets talk about fat loss for a minute. Alcohol is empty calories, 7 calories per gram to be exact. And it slows your metabolism, a pretty mean combination. So while you are drinking, your half-assed metabolism has completely given up on burning fat, and is just trying to keep up with the flood of extra calories!
It Lowers Testosterone
But the biggest kick about alcohol for us guys is it lowers testosterone levels! Testosterone is what helps us build muscle. But that isn't all, it raises estrogen levels! My god guys, that means it's turning us into a women, no kidding. Bitch tits and changes in body fat storage all throughout the body are possible! This is insane, and people do this to their bodies for pleasure? Testosterone levels appear below average even up to a week later. So if you are going out and getting drunk every weekend, your testosterone levels may not have been normal for quite some time.
Stock up on ZMA it may be the only thing to help you, besides quitting of course. Dehydration is a side effect of drinking as well. Alcohol is a diuretic which makes you want to piss, over and over and over, which is removing all the water from your body. Hangovers are caused by this. Hangovers are cause by dehydration, and the lack of essential vitamins and minerals in your body which alcohol flushes out.
Also if you drink more alcohol than your body can process, the toxins build up, cause the "sick" feeling. Dehydration is also bad on the muscles considering muscle grow best when consumed in water. Which is how creatine works. Take away that water, and your muscles don't have a happy growing environment. And considering that most people are dehydrated most of their lives anyway, because the average person doesn't drink enough water, it makes you wonder just how smart it is to remove the little water they do have.
Don't Drink On Workout Night
People wonder when the best time to drink is if you have to do it. Well most people agree that it should be away from your workouts as it will affect them negatively. Don't drink the night of a workout because it slows protein synthesis which will harm recovery of the muscle. You might not want to drink heavily the day before a workout either as a hangover could really hinder your gym performance. Not to mention the fact that your testosterone levels won't be back to normal for a week!