Before we get to what those super moves are, let’s pause for a quick anatomy lesson (trust us, this will help with your sculpting). As you may or may not remember from high school, there are three distinct muscles that make up the shoulder—the anterior, medial, and posterior deltoids—and each one is worked by different exercises. The anterior—a fancy word for “front”—is the part you see when you look at your shoulder in the mirror. It’s also the part of the shoulder that we tend to focus on most, in moves such as push-ups and shoulder presses. But when we spend too much time strengthening the anterior delt, the shoulder muscles become unbalanced. Not only can this affect your posture (when the front delts are strong and the rear delts are weak, the shoulders tend to roll forward), that structural imbalance is what leads to shoulder injuries, the most common being rotator cuff tears, says exercise physiologist Jacque Ratliff. When one part of it is stronger than the others, it’s not able to move the way it’s supposed to. That puts extra strain on the connective tissue that supports the shoulder, and when that tissue gets worn down or weakened, it’s more prone to tearing. MORE: 8 Moves For A Toned Back And it’s not just about injury prevention; when one shoulder muscle is more defined than the others, your upper body will look imbalanced. But when all three parts are strong and balanced, you’ll stand up straighter, see more tone, and have the look of someone who takes care of her body, says Ratliff. Now back to those 3 moves. In its study, ACE tested 10 of the most commonly recommended shoulder exercises, such as shoulder presses, dips, and push-ups, and found which ones best activated each part of the shoulder. The winners are below. Combine all three (aim for 3 sets of 12 to 15 reps of each move 3 times a week) and you’ve got the perfect shoulder sculpting routine.

  1. Dumbbell Shoulder PressBest for: The front of your shoulder (anterior delts) Stand with feet hip-width apart and knees slightly bent, holding 1 weight in each hand. Bend your elbows and raise weights over your shoulders. Slowly extend your arms overhead, bringing your biceps by your ears. Slowly lower weights back to shoulders.
  2. Rear Lateral RaiseBest for: The back of your shoulder (posterior delts) Grab a pair of dumbbells and bend forward at your hips until your torso is nearly parallel to the floor. Let the dumbbells hang straight down from your shoulders, your palms facing each other. Without moving your torso, raise your arms straight out to the sides until they’re in line with your body. Pause, then slowly return to the starting position. That’s one rep.
  3. Single-Arm Row*Best for:*The ACE study found the 45-Degree Incline Row to be the most effective move for toning the medial delts; the single-arm row is great at-home modification. The side of your shoulder (medial delts) In a staggered stance, with left foot 2 to 3 feet in front of the right, bend left knee and lean forward at a 45-degree angle to create a straight line from your back heel through the top of your head. Place left hand on left thigh and extend right arm toward floor, holding a weight in your right hand. Bend your right elbow and raise the weight toward your chest, then lower it back to starting position. Complete your reps and then repeat the move on the opposite side. MORE: 6 Moves To Shrug Off Shoulder Pain