Your back contains multiple muscles. Going from bottom to top, you have the erector spinae, latissimus dorsi, rhomboids and trapezius, which also forms the top of your shoulders. The best back mass building exercises are ones that target each one of these specific areas. To ensure you get a maximum amount of muscle recruitment, you should do compound exercises. These exercises target more than one area at a time.
Upright rows target the trapezius and upper lats. Stand with your feet shoulder-width apart while holding a barbell in front of your thighs. Your hands should be 8 to 10 inches apart and your palms should be facing you. Keeping your core tight and back straight, raise the bar up to neck height, pause and slowly lower. When doing upright rows, keep your upper arms above your forearms.
Pull-ups target your lats, rhomboids, and traps. Grasp the pull-up bar with an overhand, slightly wider than shoulder-width grip. In a controlled motion, pull yourself up until your chest is level with the bar. Slowly lower yourself down. When doing pull-ups, do not allow your body to sway back and forth.
Pullovers are performed with a barbell and they build mass on your upper lats. Place your shoulders flat on a bench while holding a barbell straight above you with a shoulder-width grip. Your knees should be bent, your feet should be flat on the ground and your body should form a "T" with the bench at this point. After bending your elbows slightly, lower the bar down behind your head and toward the ground in an arcing motion. Once you feel a strong contraction in your upper lats, return the bar to the starting point.
Bent-over rows are performed with a barbell and they target your middle lats and rhomboids. Stand with your feet shoulder-width apart and hold the bar in front of your thighs with a shoulder-width grip. Slightly bend your knees and hips and let the bar hang straight down toward the floor. In a controlled motion, raise the bar up to your ribs, pinching your shoulder blades together, then lower the bar with a smooth controlled motion.
Deadlifts are a compound exercise that targets your middle to lower back region. Place a weighted barbell on the floor and stand behind it with your feet shoulder-width apart. After bending your knees and hips, grasp the bar with a shoulder-width grip, lift it off the floor and come to a standing position. Once you have paused for a second, pivot forward from your hips, maintaining a rigid spine with a natural curve at the lower back. Keep your chin up and do not allow your trunk to flex forward. Slowly lower the bar to your knees, keeping it close to your body.
Keep on Growing
Once you have established a baseline of strength, you will need to vary your workout in order to continue to grow. Sports coach Brian Mac recommends you begin with three sets of eight reps at 70 percent of your one repetition maximum, or 1RM, which is the amount of weight you can lift one time with good form on a given exercise. Building mass requires six to 12 RM sets to promote maximal growth. This equates to 70 to 85 percent of 1RM. Variations on simple sets will keep you growing. Try super-settting, alternating between two exercises that target the same muscle group with minimal time between exercises. Or try pyramids, beginning at your 12 rep max, then increasing the weight and doing maximal reps to fatigue. Repeat with minimal rest between sets until you can no longer perform one repetition.