The best way to put on noticeable muscle mass is to stick with strength and hypertrophy protocols. Hypertrophy-based protocols require 3-4 sets using a moderate weight (around 70-80 percent of your one-rep max). Studies have shown this type of training causes significant increases in the muscle-building hormones testosterone and growth hormone.
In between sets, make sure to give yourself 1-2 minutes of rest to help get your heart rate down. Keeping your heart rate lowered will help you protect those calories you're eating so you don't use them up while training.
The number of sets you do are just as important as the type of exercises you're doing to gain muscle. The best exercises for adding mass are big lifts, including:
- Bench presses
- Shoulder presses