Some of us exercise merely for the sake of staying in shape and feeling healthy. But for some, the point is to build muscle for an impressive physique. If you're someone who's interested in the muscle growth process, you should know that alcohol certainly isn't helping -- and, in fact, it's probably holding you back.

According to Sean Nalewanyj, author and natural bodybuilder, there are 5 main ways in which alcohol works against building muscle mass.

1. It negatively affects protein synthesis
2. It lowers testosterone levels and increases estrogen
3. It causes dehydration
4. It depletes the body of vitamins and minerals
5. It increases fat storage

Not that you can never go out and have a good time, but doing it too often -- even every weekend -- may make all the work you're doing in the gym a waste of time.

And even if you're not trying to bulk up, the same still applies. As with most things, moderating your alcohol intake is key if you're looking to stay fit.