You see this question constantly by bodybuilders asking if alcohol will effect my muscle gains. Yes, I believe it will have a big effect on your gains.
Negative effects of alcohol on muscle building
The biggest reason why alcohol is one of the worst things you can do for muscle building is because it directly slows down protein synthesis. If protein isn’t being snythesized you can’t build muscle. To make matters worse, protein is always being broken down, its the balance between anabolism(protein sythesis) and catabolism (protein breakdown). New proteins have to be created (synthesized) to replace those destroyed in what is called protein turnover. When there is more protein synthesis than catabolism, you gain muscle. So by slowing down alcohol stopping protein synthesis, it is actually causing muscle loss because proteins are being broken down, but less are replacing them.
According to studies I’ve seen, the protein synthesis drops about 20%. Protein synthesis doesn’t return to normal until the body eliminates alcohol from the blood. Alcohol also is shown in studies to lower testosterone levels. This will also have a significant impact on your ability to gain muscle.
Negative effects of alcohol on fat loss and bulking
Not only is alcohol bad for muscle building, but its bad for losing fat and bulking. Normally your body burns a steady amount of fat in the kreb’s cycle. However, when alcohol is present, your body will prefer to use alcohol instead of fat, which is 7 calories per gram! Alcohol is almost as calorie dense as if you were drinking pure fat. Even during bulking alcohol will lead to excess fat gain. You will gain a lot of excess fat because your body can’t burn any fat. You’re already at a surplus for calories during bulking making you susceptible to some fat gain. Throw alcohol and it’s effect on testosterone and fat burning and you’ll look fat and bloated instead of muscular at the end of your bulk.