deadlift may be considered one of the best exercises you can possibly do for a mass-gainer workout. It works more muscles at once than any other exercise, making it an essential compound movement to do. It develops your back, glutes, legs, shoulders, core, and arms all at once! It even gets the much targeted trapezius muscles, or traps for short. Basically, every large muscle group you want to hit on can be done with this exercise. You want to start off with minimal weight at first to get your form down then build up slowly from there. I love doing this workout and it should be added to your routine.