Do you know the advantages of gaining muscle? Sure, you look great on the beach, but there's a lot other benefits to it as well. Here, let me explain.
You want to burn calories? Doing a lot of cardio does it, but not as affective as resistance training. (ie, lifting weights)
See, when you do cardio type workouts, you are constantly moving and, therefore, you are constantly burining calories, but when the workout is over guess what? The calorie buring is slowed WAY down. There's nothing wrong with that, a work has happened and you should feel good about yourself.
But, we're talking about an advantage of gaining muscle, right? And, for the purposes of this writing, we're focusing more on burining calories.