Shoulder workout: three heads, three jobs

The deltoid, the muscle that caps the shoulder, has three heads. The front head raises the arm forward and brings it across the chest, the side head raises it out to the side, and the rear head takes it back.¹ A routine that only presses trains mostly the first one.

This page goes head by head: what reaches each one in the studies, a session that covers all three in a gym or at home, and how it fits with the chest and back days you may already have.

The three heads, side by side

Two sources sit behind most of the table. In 13 men experienced in strength training who did a bench press, a dumbbell fly, a shoulder press and a lateral raise, the front head was most active in the shoulder press. The side head was roughly six to nine times as active in the lateral raise and the shoulder press as in the bench press or the fly. The rear head was most active in the lateral raise.¹ A 2024 systematic review of 33 studies ranked exercises head by head: chest exercises, flat and inclined, for the front; raises out to the side and reverse-fly movements for the side; and pull-ups for the rear.²

Both measured muscle activity with electrodes on the skin. That shows which head is working in an exercise, not how much it will grow, so the training studies further down carry more weight where they exist.

The overhead press: front and side

Pressing overhead is the base of the session. The authors of the American College of Sports Medicine's 2026 position stand suggest thinking of upper-body training in both horizontal and vertical directions;³ the overhead press is the vertical push, the one a week of bench pressing doesn't cover.

Seated or standing, barbell or dumbbells? In 15 healthy men tested at 80% of their max in all four versions, the standing dumbbell press produced the most deltoid activity and the lowest max: about 7% less than the standing barbell press and about 10% less than seated dumbbells.⁴ So standing dumbbells ask the most of the shoulders per pound, and sitting down let the same men press more with dumbbells. Either works. Pick one and keep it long enough to add weight to it. (Dumbbell vs barbell compares the two tools on other lifts too.)

1. Start at shoulder height, hands just outside your shoulders.
2. Press straight up until your arms are straight overhead.
3. Lower under control back to shoulder height. Standing, stay upright rather than leaning back to finish a rep.

Lateral raises: the head pressing misses

In a ten-week trial, 13 healthy men bench pressed three times a week, three or four sets of 12, while 11 others didn't train. The chest, the front of the shoulder and the triceps grew more than in the group that didn't train; the side of the shoulder lagged every other muscle measured.⁵ That's the case for a direct exercise.

• Dumbbells or a cable: either. 24 trained lifters, 16 men and 8 women, trained one arm with a dumbbell lateral raise and the other with a cable version: five sets each, twice a week for eight weeks, every set to failure in a 12-to-16-rep range. Side-delt thickness rose by 3.3% to 4.6%, with no meaningful difference between the arms.⁶
• Arms long. In 10 male competitive bodybuilders, the side head was more active in a lateral raise with straight elbows than with bent ones.⁷
• To shoulder height. In the eight-week trial, a set ended when the arm could no longer reach 90 degrees, level with the shoulder.⁶ That's a fair target for every rep.

Lateral raises use light weights. If you have to swing your body to get the dumbbells up, they're too heavy. They're also one of the exercises reps in reserve names as a good place to push a little closer to failure.

Rear delts: rows, pull-ups and reverse flies

The rear head gets more from a back day than it seems. In the 2024 review, pull-ups ranked highest for it, with the standard pull-up and an inverted row on suspension straps at the top of the list.² If your week already has pull-ups and rows (the back workout), the rear head is already doing part of the work.

For more, add a reverse fly: the arms swing out and back, the opposite of a chest fly. On a reverse fly machine, 19 resistance-trained men had more rear-delt activity with a neutral grip, palms facing each other, than with palms facing down.⁸ At home, a bent-over dumbbell reverse fly or a band pull-apart is the same movement. On a cable, the face pull is another option.

Do you need front raises?

Usually not, if you already press. The ten-week bench press trial grew the front of the shoulder along with the chest.⁵ In the 13-man study, the front head was about as active in the bench press as in the lateral raise.¹ A front raise works mainly the front head and the upper chest,⁷ and an incline press already reaches both: in 30 trained adults pressing at five bench angles, the front of the shoulder did more as the bench rose toward 60 degrees, while the upper chest peaked at 30.⁹

One way to count it comes from a 2026 meta-regression on training volume: the counting method with the strongest evidence scored a set that trains a muscle only indirectly as half a set.¹⁰ Applying that to the front of the shoulder is this page's own illustration, not something the paper states. On that count, ten hard sets of presses a week is about five for the front of the shoulder before any shoulder exercise. (The arm workout counts the triceps the same way.) Front raises make more sense in a week with little or no pressing.

A shoulder session, gym or home

Three exercises, in this order, after the presses on an upper or push day, or on a day of their own:

1. Overhead press, 3 sets of about 6 to 12 reps. Gym: dumbbells or a barbell, seated or standing, or a shoulder-press machine. Home: a seated or standing dumbbell press, or pike push-ups.
2. Lateral raise, 3 or 4 sets of about 12 to 16. Gym: dumbbells or a cable. Home: dumbbells or a band.
3. Reverse fly, 2 or 3 sets of about 12 to 16. Gym: the reverse fly machine, palms facing each other. Home: a bent-over dumbbell reverse fly or band pull-aparts.

If shoulders come straight after a chest day full of presses, two sets of the overhead press is usually plenty: the front head has had its work. Training shoulders twice a week on your split? Press on one day and do lateral raises on both. With only a set of dumbbells, the three-day dumbbell plan already gives every session a shoulder slot. How many hard sets to aim for across a week is counted the same way as on the chest workout.

Common mistakes

• Only pressing. Presses cover the front head. The side head needs raises.
• Bending the elbows as the set gets hard. It makes the raise easier and, in the bodybuilder study above, gave the side head less to do.
• No rows or pull-ups. They ranked highest for the rear head in the 2024 review, so a week without them leaves out its best-ranked work.²
• Front raises on top of a week of pressing. The presses already gave the front head its sets.
• Pressing through pain. Sharp pain is not soreness. Stop, and talk to a doctor or a physical therapist.

If you'd rather not plan it alone

Three exercises fit on an index card; fitting them around your chest and back days without doing the same work twice is the part a page can't do. Coaching is the version where your workouts live in the Trainerize app, built around the days you actually have, and a weekly call looks at the week you just had and rebuilds the next one. Coaching to build muscle explains how that works, and here's how to apply. Otherwise: check last week's log for each of the three heads, and add the one that's missing.