TOP RULES FOR MASS

Full range of motion: Optimal mass requires every muscle fiber in the group to be worked, but that can't happen unless the muscle is allowed to stretch out completely, then contract fully.

High reps: In order to pump enough blood into the area and make sure all muscle fibers, even the deepest, are fatigued, do at least 10, preferably 12, reps per set.

Don't cheat: A muscle won't grow unless it's worked to its max, and it can't be worked to its max if the muscles around it fail first.