when you do your normal excercises, you lose weight (get smaller), that's what most of us are trying to do correct?
IF you are a serious body builder, and bulking, you would do your reps with such killer weight that every set you would go to failure, and the final sets, you would need a spotter because you are going to exterme failure, maybe only 3 or 4 reps.
In addition your caloric intake would have an affect on your ability to grow or not.
Doing so, tears your muscle fibers, and when they rebuild, they come back bigger and stronger, however, if you werent taking in the proper balance of p/c/f then you efforts would be diminished to a certain degree.
Like everything else, you will get conflicting answers because in what we are doing, it depends on many different things at the same time.
I am losing fat, but at the same time bulking up, and what it takes for me to do so is to take in 20 to 25% protein, 50 to 60% carbs, and15 to 20% fat