How to do the dumbbell fly

The dumbbell fly works your chest through a big stretch without your triceps taking a share of the load. It's the fly most people can do anywhere there's a bench, which is its main appeal. The trade-off is that gravity only pulls straight down, so your chest works hardest at the bottom of the rep and very little at the top, where the dumbbells sit over your shoulders. That makes it a stretch-focused exercise. Use light weights, respect the bottom position, and it's a useful addition after your presses.

How to do a dumbbell fly

1. Sit on the end of a flat bench with the dumbbells on your thighs. Lie back and bring them to your chest the same way you would for a dumbbell bench press, then press them up over your chest.
2. Turn your palms to face each other and soften your elbows. Bend them about 15 to 20 degrees. That angle stays locked in for the whole set.
3. Set your shoulder blades and feet. Pull your shoulder blades back and down into the bench and plant your feet flat on the floor. Your chest should feel slightly lifted.
4. Open your arms out to the sides in a wide arc. Lower the dumbbells slowly, over two or three seconds, as if you're opening your arms to hug someone. Your hands travel out and down, not straight down.
5. Stop when your elbows are about level with the bench. At that point your upper arms are roughly in line with your torso and you should feel a strong stretch across your chest. If you feel it deep in the front of the shoulder, you've gone too far.
6. Bring the dumbbells back up along the same arc. Squeeze your chest as your hands come together over it, and stop when the dumbbells are a few inches apart above your chest.

The rep should feel hardest in the bottom third and easy at the top. That's normal for dumbbell flys, not a sign that you're doing something wrong.

Cues that keep it a fly

"Hug a barrel." Your arms stay rounded as if around a big barrel for the whole rep. It helps you keep the elbow angle fixed.

"Elbows lead, hands follow." Think of your elbows moving out and down on the way down, and in and up on the way up. It stops the dumbbells drifting toward your face.

"Open wide, not deep." The dumbbells travel out to the sides. If you think about going deeper instead of wider, most people overshoot.

Common mistakes

Bending and straightening your arms during the rep. If your elbows fold as the dumbbells come down and then straighten on the way up, you're pressing, not flying, and your triceps take the load. Locking your arms fully straight is the opposite problem: it puts a lot of strain on the elbow and the biceps tendon at the stretched position. Pick a soft bend at the start and hold it. If you can't hold it through the last reps, the dumbbells are too heavy.

Going too deep. Letting the dumbbells sink well below the bench feels like a better stretch, but past the point where your elbows are level with your torso, the extra range mostly comes from your shoulder joint, which is exactly where people get hurt on this lift. Stop at the bench line. People with very mobile shoulders sometimes go a little lower, but the default should be level with the bench.

Using too much weight. Flys don't need heavy dumbbells, because the leverage is long: a 30 lb (14 kg) dumbbell held with nearly straight arms puts a lot more load on your chest and shoulder than the same dumbbell in a press. Too heavy shows up as jerky reps, bent elbows and a bouncy bottom position. Most people should use about a third to a half of what they'd use for a dumbbell press.

Dropping into the bottom. A fast, loose descent loads the shoulder hardest at the moment it's most stretched. Take two or three seconds down, stop, and reverse without bouncing.

Clinking the dumbbells at the top. It feels like a good finish, but your chest is barely working there anyway. Stop a few inches apart and start the next rep.

Breathing

Breathe in as your arms open and let your chest rise into the stretch. Breathe out as you bring the dumbbells back together. A steady breath each rep is enough on a lift this light.

Sets, reps and weight

Do 2 or 3 sets of 10 to 15 reps after your main chest pressing, with 60 to 90 seconds of rest. Pick dumbbells that let you hold the same elbow angle and pause briefly at the bottom of every rep. Stop the set a rep or two short of failure; unlike machine flys, failing a dumbbell fly means dropping a weight while your shoulder is fully stretched, which isn't worth it.

To progress, add reps first. Once you can do 15 good reps on every set, move up a pair (5 lb or 2 to 2.5 kg per hand) and work back up from 10. Slowing the lowering to four seconds is another way to make the same dumbbells harder while you wait for the next jump.

Here's roughly what people use for normal working sets. Weights are per dumbbell:

Dumbbell Fly working weights by bodyweight and experience, per dumbbell

Bodyweight	beginner	intermediate	advanced
130 lb (59 kg)	10 lb (5 kg)	20 lb (9 kg)	30 lb (14 kg)
160 lb (73 kg)	15 lb (7 kg)	25 lb (11 kg)	35 lb (16 kg)
190 lb (86 kg)	15 lb (7 kg)	30 lb (14 kg)	40 lb (18 kg)
220 lb (100 kg)	20 lb (9 kg)	35 lb (16 kg)	50 lb (23 kg)
250 lb (113 kg)	20 lb (9 kg)	40 lb (18 kg)	55 lb (25 kg)

Lower numbers than you might expect are fine here. The fly is a stretch exercise, not a strength test, and there's no prize for moving heavier dumbbells through a shorter range.

Variations and alternatives

• Chest fly machine: the seated pec deck. It keeps tension on your chest at the squeeze and makes the stretched position safer. If your gym has one, we'd choose it over dumbbells for most chest sessions.
• Cable crossover: a standing fly between two cables, with constant tension and a pulley height you can change.
• Incline dumbbell fly: the same movement on a 30-degree bench, for more upper chest work. Use slightly lighter dumbbells than on the flat version.
• Floor fly: lying on the floor instead of a bench, so the floor stops your elbows at a safe depth. A good way to learn the movement or train around a cranky shoulder.
• Dumbbell bench press: if flys bother your shoulders, a press with a slow lowering phase still gives your chest a stretch.

Dumbbell fly questions

Are dumbbell flys worth doing?

They're worth it if you enjoy them and they don't bother your shoulders. They give your chest a hard stretch under load, which is a good stimulus for growth. But cable or machine flys do the same job and keep tension on at the top as well, so if you have access to those, you don't need dumbbell flys too.

How deep should I go on a dumbbell fly?

Until your elbows are about level with the bench and you feel a strong stretch across your chest. Don't chase a deeper position. If the front of your shoulder hurts at the bottom, shorten the range, or do floor flys for a few weeks.

Should my palms face each other on a dumbbell fly?

Yes, that's the standard grip and the most comfortable for most shoulders. A slight angle either way is fine if it feels better on your shoulders, as long as the elbow bend stays the same.