Shoulders can be difficult muscles to build. It’s easy to get the size you want in your chest and arms, but still struggle with your deltoid muscles. To build big side delts, do exercises that isolate and specifically work those muscles. Make sure you’re working the muscles to fatigue. Design your training regimen so that you’re doing your shoulder work early in the week, when you’re well rested.
EditDoing Specific Exercises
- Do heavy dumbbell presses. The seated or standing military press is one of the most effective exercises to build the muscles in the deltoid muscle group. While this exercise can be done with a barbell or dumbbells, dumbbells can help you better isolate your shoulders.
- To do a dumbbell military press, also called an overhead press, start in a stable seated or standing position with the weights just above your upper chest. Your hands should be slightly past your shoulders.
- Extend your arms upward in a slow, controlled movement, straightening your elbows to lift the weight overhead. Then lower the weight back to start in a slow, controlled movement.
- Start with three sets of 10 repetitions of this exercise. Increase repetitions after a week, or add an additional set. Increase weight gradually as you build muscle strength. Your goal is to work your shoulders to fatigue.
- Use the Arnold press to increase your range of motion. The Arnold press requires full rotation of your shoulders, which can help build strength across the full range of motion in your shoulders. Start with your dumbbells just above your upper chest, with your palms facing your body.
- You’ll lift the weights just as you did in the overhead press, but as you lift your arms overhead, rotate the weight. Halfway through the lift, the dumbbells should be parallel on your sides. At the top, they’ll be in the same position as when you started except that your palms will be facing forward.
- Twist back down to lower the weights in a slow, controlled movement. Do three sets of 10 repetitions of this exercise to start.
- Include dumbbell side lateral raises. Dumbbell side lateral raises are a classic exercise if you want to isolate and build your side delts in particular. This exercise can be done sitting or standing. As with the other presses, the exercise is easier to do seated than standing.
- With a lateral raise, start with your arms by your sides. Lift the weight to shoulder height or just above, then lower in a slow, controlled movement. Do three sets of 10 repetitions.
- Be careful not to add weight too quickly on your lateral raises. While you can increase weight incrementally over time, it’s generally better with this exercise to add repetitions before you add weight.
- Add rotator cuff rotations to prevent injury. Strengthening your rotator cuff muscles with rotator cuff rotations can protect against shoulder injuries. Rotations should be done using a cable machine.
- To do an internal rotation, grab the cable with the arm closest to the machine. Hold your elbow flexed at a 90 degree angle and pull the cable inwards towards your belly.
- To do an external rotation, grab the cable with the arm farthest from the cable machine, and perform a reverse movement, rotating your arm outwards away from your belly.
- Do ten to twelve repetitions. The weight should be heavy enough that your muscles feel fatigued afterwards.
- Do rear flyes. Rear flyes are a dumbbell exercise that can help build up your delts. Start by lying stomach-down on an incline bench. Hold a dumbbell in each hand with your palms facing inward towards each other. Bring your arms forward so that they’re in front of you and perpendicular to the bench.
- While you exhale, move the weights away from each other until your arms are parallel to the ground. Squeeze your shoulder blades as you move.
- While you inhale, slowly move the weights back to the starting position. Start by doing three sets of ten repetitions.
- Try upright rows to target your shoulders. Hold a barbell in an overhand grip, keeping your hands just under shoulder-width apart, your arms slightly bent at the elbows, and your back straight. The bar should rest on your upper thighs.
- Exhale and raise the bar by pulling your elbows up and out until the bar is just below your chin, keeping your elbows higher than the rest of your arms. Pause for a second at the top.
- Then, inhale as you slowly lower the bar back down to your starting position. Start with three sets of ten repetitions.
- Concentrate on compound movements with heavy weights. Lift the heaviest weight you possibly can for the number of repetitions you have planned to build muscle mass. Compound movements that involve more than one joint typically give you the best results over time.
- While your goal may be to build big side delts, it’s just as important to build the other two muscles in the deltoid muscle group, as well as the supporting muscles in your arms, chest, and upper back.
- The Arnold press is an example of a compound exercise, because two joints are involved – your elbows and your shoulders. That exercise works your shoulders, but also the supporting muscles in your arms and upper back.
- Build your triceps. To build big side delts, you have to be able to work your muscles to failure. If you have relatively weak triceps, they will fail before your shoulders reach the point of muscle fatigue. Building strength in your triceps is essential if you want to build your shoulders. Dumbbell kickbacks are one good exercise to build your triceps muscles.
- Get on the floor on all fours, or stand next to a weight bench with one knee on the bench and one foot on the floor. Keep your back as flat as possible, and hold the weight with your upper arm parallel to your body and your elbow bent at a 90-degree angle.
- Kick the weight back, extending your elbow until your whole arm is parallel to your body. Turn your palms so they’re facing upwards. Then, lower back to the starting position with a slow, controlled movement. Start with three sets of 10 repetitions of this exercise.
- Try dumbbells instead of barbells. You’ll often get better results with dumbbells if you’re trying to build overall shoulder mass. Dumbbells are somewhat harder to control than barbells, and have a longer range of motion so you’re working the entire muscle.
- You also may want to alternate, doing the same exercises with dumbbells, then with a barbell later in the week.
EditDesigning Your Training Regimen
- Do shoulder work early in the week. If you want to build big side delts, pack your shoulder-isolating exercises into your routine in your first workout following your rest day, so you are at your most fresh and rested.
- If you’re well rested, the exercises will have the maximum impact when you work your shoulders to fatigue. You will continue to build muscle throughout the week as you engage your shoulders in other exercises.
- Overhead press twice a week. Since this specific movement is not repeated in any of your other exercises, you can overhead press about twice a week. Give yourself a few days to recover in between sessions.
- Include upper back work with every session. The muscles in your upper back support your deltoid muscles. Build your upper back muscles at the same time you’re building your shoulder muscles, so you won’t have an imbalance.
- Do lateral raises no more than twice per week. Since several of the exercises work these muscles, doing it more often can cause them to become fatigued and overworked.
- Work the entire muscle group. Even though your goal is to build big side delts, your shoulders still should be balanced. Include exercises that work all three muscles in the deltoid group. Imbalances can lead to pain and injury.
- Before you start doing shoulder exercises, learn the anatomy of the shoulders so you can understand how the muscles work together.
- The lateral, or side, deltoid, is the particular muscle you want to build. It sits on the top of your shoulder. The anterior deltoid is on the front of your shoulders, near your chest, while your posterior deltoid runs along the back of your shoulders.
- Pay attention to how your shoulders feel during chest and back work. Since your shoulders are involved in back and chest exercises, they can become easily overworked if you don’t give them enough rest. If they’re feeling really fatigued, lower the intensity of your workout so they can recover.
EditTweaking Your Form
- Favor technique over weight. With any shoulder exercises you do, the correct form will build muscle mass faster than if you keep piling on weight with sloppy form. Over time, doing exercises with poor technique may result in strain or injury.
- If you’re exercising in a gym, get a trainer or experienced weightlifter to critique your form before you develop any bad habits.
- If you plan to work out at a home gym, you still may want to have a personal trainer or experienced friend come by and check out your technique, especially if these are new exercises to you.
- Lift seated rather than standing. It is much easier to isolate your deltoids and work them harder when you’re in a seated position. When you’re standing, you may find that you’re using secondary muscle groups, rather than letting your shoulders do the work.
- Standing lifts engage your core and lower body, making them better whole body exercises. But especially if you’re just starting out, you may find it easier to perfect your form from a seated position first.
- Check your grip. If you’re lifting a barbell rather than dumbbells, where you place your hands on the bar determines which muscles are engaged. 
- Keep your grip wider on the bar, with your hands a little wider than shoulder-width apart.
- If your grip is narrow, with your hands closer together, you won’t isolate the deltoids as well because the muscles in your arms, upper back, and chest will be doing most of the work.
- Enlist a spotter for heavier weights. You want to use the heaviest possible weights you can if you want to build muscle mass. But as the weight gets heavier, you risk injury if your muscles give out and you have to drop the weight.
- When using heavy weights, it’s not a good idea to lift at home alone. Get a buddy to come over and work out with you, or join a gym.
- Talk to your health care provider before you add new exercises to your regimen, particularly if you had a back or shoulder injury sometime in the recent past.