Training guide
A chest fly opens your arms wide in an arc, elbows softly bent, then hugs them back together in front of your chest. Lower only until your arms are about level with your chest, keep the same elbow bend all the way, and pick a weight you can control for 10 to 15 reps. Do 2 or 3 sets after your presses.
Flys work the big chest muscle with your elbows held still, so your triceps get a rest. Machine and cable flys came close to the bench press for chest activity in one study, and machine flys grew the chest in an 8-week trial, but they don't shape an inner chest.
This guide covers dumbbell, cable and machine flys step by step on the 3D figure, how heavy and how many, flys against the bench press, and how to look after your shoulders.
Open your arms wide in an arc with your elbows softly bent, then hug them back together in front of your chest. Do it with dumbbells on a bench, cables, a pec deck machine or a band. A hospital shoulder handout advises never flying with straight elbows and never lowering the dumbbells below chest level.
Source 1
The pectoralis major, the big chest muscle, with the front of the shoulder helping and the biceps steadying the elbow. In 17 trained men, the bench press drew about 16% more chest activity than the dumbbell fly and much more triceps work; in 12 adults, chest activity was similar in both.
In a study funded by ACE (the American Council on Exercise) in 14 trained men, the pec deck drew 98% and a bent-forward cable crossover 93% of the bench press's chest activity, against 69% for incline dumbbell flys and 61% for push-ups.
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In a trial in 81 active young adults, the 27 who did 8 weeks of machine flys thickened their chest 5 to 7% and gained 10% in strength. In 15 untrained men, one set of pec deck flys grew the chest as much as three sets over 12 weeks, the upper and lower chest equally: flys don't shape an inner chest.
Much lighter than you press: trained men's 6-rep maximum fly was 40.5 kg for both dumbbells together, against 88.5 kg on the bench press. Do 2 or 3 sets of 10 to 15, resting 60 to 90 seconds, with the last set 0 to 2 reps short of failure, as our workouts and plans suggest.
Lower to about chest level with your elbows bent: cautious advice from a hospital handout and an NHS trust leaflet, since no trial has tested how far to go. A sudden pop or ripping feeling in your chest or armpit, then bruising or an uneven chest, needs checking the same day.
Lying on a bench, sitting at a machine or standing between cables or with a band, you open your arms wide in an arc with the elbows softly bent and fixed, then bring them together in front of your chest. Only the shoulder moves, which makes it an isolation exercise, and the bench press, which bends and straightens the elbow too, a compound one, as our compound vs isolation guide explains.
The pectoralis major is a broad muscle with two parts, one from the collarbone and one from the breastbone, joined in one tendon on the upper arm bone. It brings your arm across your body, turns it in and lifts it forwards.
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In 13 trained men, the front of the shoulder worked about as hard in the dumbbell fly (18.8% of a maximal effort) as in the bench press (21.4%), and less than in the shoulder press (33.3%); the side and back of the shoulder barely worked. Band flys shifted a little work from the chest to the front of the shoulder in 29 adults.
The dumbbell fly drew 57 to 86% more biceps activity than the bench press, to hold the elbow bent, and much less triceps work, because the elbow doesn't straighten.
Source 2
At the bottom of a fly your arm is out to the side and turned out, the position ACE calls vulnerable on the pec deck. In a cadaver study, the lowest chest fibres stretched most in the last part of the arm moving back, and heavy load on those stretched fibres is the proposed way the tendon tears.
Most of these comparisons use EMG (electromyography: electrodes measuring how hard a muscle works), which shows effort in a few reps, not what a muscle builds. The growth trials below matter more.
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Pec tears are more likely in men aged 30 to 60 and with anabolic steroid use, and about half of published cases happened in weight training. People with past shoulder problems may need a shorter range or a different exercise. Later in pregnancy, lying flat on your back for more than a few minutes isn't advised.
81 active young adults were split into three groups of 27 for 8 weeks. The fly group did 5 sets of 10 to 12 on a machine (90 seconds' rest, three days a week, adding weight when every set reached 12): chest thickness rose about 5 to 7% and strength about 10%. Fifteen minutes of chest stretching 4 days a week gave similar results, and the control group didn't change. One trial, read in full.
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15 untrained young men trained on the pec deck for 12 weeks in a within-person comparison of 1 set and 3 sets, each set to failure. The upper chest grew 17 and 18% and the lower chest 21 and 21%, with pec deck strength up 46 and 43%. No part of the chest grew more than another.
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In 17 trained men at their 6-rep maximum, the bench press drew more chest (about 16% over the whole lift), front shoulder and triceps activity than the dumbbell fly, while the fly drew more biceps activity. In 12 adults at their 6-rep maximum, chest and front shoulder activity didn't differ between the bench press, dumbbell press and dumbbell fly. Small studies of muscle activity.
In 14 trained men lifting 80% of their maximum for 5 reps, the pec deck drew 98% and the bent-forward cable crossover 93% of the bench press's chest activity; the chest press machine 79%, incline dumbbell flys and dips 69%, and push-ups 61%. ACE funded the study and reported it in its own publications, not a peer-reviewed journal.
In 29 adults, band flys drew slightly less chest and more front shoulder activity than dumbbell flys at the same 10-rep effort, a workable alternative. Across 8 small studies, elastic bands built strength about as well as weights and machines.
The American College of Sports Medicine's (ACSM) overview of 137 reviews found too little data to say whether single-joint exercises like the fly or multi-joint ones like the press build more muscle, or whether machines or free weights do. Across 13 studies, free weights and machines built similar strength and muscle.
In 26 trained men, adding 30-second loaded chest stretches between bench press sets for 8 weeks added no chest growth or strength. Training at long muscle lengths favoured growth in some muscles but not others, and the ACSM found too little data on range of motion for muscle growth. No trial has tested how far to lower in a fly.
A review found that up to 36% of resistance training injuries involve the shoulder, mostly from people's own recall of past injuries.
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In 365 published cases, 83% of pec tears happened while the muscle was working, not from a direct blow, and 48% during weight training. Heavy load on the stretched lowest fibres is the proposed mechanism, and one report describes a 33-year-old amateur, with no steroid use, who tore his chest muscle on a chest fly machine. Tears are rare, and these are case reports, so there are no rates for flys.
Muscle grew most with about 10 or more hard sets a week, each extra set adding a little with diminishing returns, and how many days you spread them over mattered little. Fly sets count fully for the chest; presses and push-ups count too.
Steps from our move page; the soft elbow bend follows the study protocol (about 150 to 160 degrees) and the hospital handout. Lowering to about chest level is cautious advice from that handout and an NHS trust leaflet; no trial has tested how far to go. Finishing on your thighs is our suggestion.
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The movement on the figure: Dumbbell fly
Steps from our move page; ACE advises against starting with the arms behind the body or crossing the handles past the middle.
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The movement on the figure: Cable fly
Steps from our move page; setting the arms a few clicks forward follows the hospital shoulder handout, which also says never to let the weight stretch your arms so far that your elbows pass behind your chin.
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The movement on the figure: Machine chest fly (pec deck)
Machine flys at 2 sets of 12 to 15, slow on the way back (our bodybuilding upper-body workout); cable flys at 3 sets of 12 to 15, resting 60 to 90 seconds (our push day workout B); the bent-forward crossover and the standing band fly at 2 to 3 sets of 10 to 15 (their move pages' editorial doses); dumbbell, incline and one-arm flys at 2 or 3 sets of 10 to 15 (our editorial starting point); the bodyweight fly on rolling bars at 2 to 3 sets of 5 to 8 (its move page's dose).
3D demoMachine chest fly (pec deck)Beginner · Strength machine
3D demoCable flyIntermediate · A cable machine
3D demoBent-forward cable crossoverIntermediate · A cable machine
3D demoLow-to-high cable flyIntermediate · A cable machine
3D demoDumbbell flyIntermediate · A dumbbell + A bench or box
3D demoIncline dumbbell flyIntermediate · A dumbbell + A bench or box
3D demoStanding band chest flyIntermediate · A band + An anchor point
3D demoOne-arm dumbbell flyIntermediate · A dumbbell + A bench or box
3D demoBodyweight fly on rolling barsAdvanced · EZ curl bar + Weight platesNo bench? The floor stops your arms at about chest level, the limit the hospital handout and NHS trust leaflet recommend; no study has tested the floor fly itself, and we have no 3D demo of it yet. In words:
Loop a band round a sturdy post behind you at chest height, step forward until it's taut, and sweep your arms together in front of your chest. Band flys worked the chest slightly less and the shoulder a little more than dumbbell flys, and bands built strength about as well as weights.
Push-ups train the chest well without a fly; our push-up guide takes you from the wall to the floor.
It drew more chest activity than the dumbbell fly in trained men, though not in a smaller mixed group, and it also trains the shoulders and triceps with about twice the weight.
The pec deck and a bent-forward cable crossover drew 93 to 98% of the bench press's chest activity in the ACE-funded study.
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Push-ups drew 61% of the bench press's chest activity in trained men and felt much easier to them; for most people they're the place to start, with our push-up guide.
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Not for health or strength if you press and do push-ups. There's too little data to say single-joint exercises build more muscle than presses, but flys add chest work without tiring the triceps, which is useful when your arms or elbows need a rest.
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Much lighter than pressing: trained men's 6-rep maximum fly was 40.5 kg for both dumbbells together against 88.5 kg on the bench press. Pick a weight you can control for 10 to 15 reps without your elbows straightening or the weights dropping below chest level, using our plans' starting-weight method.
2 or 3 sets of 10 to 15, with the last set 0 to 2 reps short of failure, as our plans say for small moves and our chest workouts use (cable flys at 3 sets of 12, or 12 to 15). In beginners, one set grew the chest as much as three, so start with one or two and build up. Count fly sets towards about 10 or more chest sets a week.
60 to 90 seconds between sets, as our plans suggest for isolation moves. Do flys after your presses, as our chest workouts do: lifting early in the session helped strength, while the order made no consistent difference to growth.
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A hospital shoulder handout starts weight training with 3 sets of 15 to 20 without going to failure, then moves to 3 sets of 10 to 15.
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Add reps until every set reaches the top of the range, then move up the smallest step: one plate on a stack, or the next dumbbell (double progression, as our plans describe). Fly jumps are big for a small movement, so be patient.
Chest thickness grew about 5 to 7% in 8 weeks in active adults, and 17 to 21% in 12 weeks in untrained men. Visible change takes months.
Keep a soft, fixed bend. Straight elbows put more strain on the shoulder and the elbow.
Source 1
Stop at about chest level; going deeper adds stretch where the chest tendon is most at risk under load.
If your elbows bend more as you tire, the weight is too heavy: the study ended a rep when the elbow angle changed.
Source 2
Set the pec deck's range a few clicks forward, and don't start a cable fly with your arms behind your body.
Flys suit 10 to 15 controlled reps; an NHS trust leaflet advises avoiding high weights for low reps once you return to flys after a pec repair.
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Press first, while you're fresh, as our chest workouts do.
A hospital shoulder handout says never to fly with straight elbows or lower the dumbbells below chest level, and an NHS trust leaflet for people returning after a pec repair says not to let the elbow drop below the level of the shoulder. That's cautious advice rather than a tested rule: no trial has compared fly ranges.
Set the arms a few clicks forward to limit how far back they go, and never let the weight stretch your arms so your elbows pass behind your chin, as the handout says. ACE advises against the pec deck for people with a history of shoulder problems.
For shoulder strengthening, pain up to about 5 out of 10 is acceptable if it's back to normal by your next session; for a pulled chest muscle, about 3 to 4 out of 10, settled within the day, with the stretched arm-out position coming back last. Sharp pain in the joint, a catch or a feeling of slipping means stop. That's from our shoulder pain from bench press and pec strain guides.
The shoulder is one of the areas most often hurt in weight training, up to 36% of injuries in one review, which is why the range and the weight matter.
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A sudden pop or ripping feeling in your chest or arm during a fly or press, then pain, weakness, bruising on the chest or inside of the arm, or a chest, armpit or nipple that now looks uneven, can be a torn chest tendon: stop and get it checked the same day. Repair has the best results soon after the injury.
Follow your team's plan. The NHS trust leaflet brings chest strengthening back from about 3 months, with the elbow no lower than the shoulder in bench presses and flys; our pec strain guide leaves heavy flys and the pec deck until about 6 months.
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Presses first: dumbbell bench and incline presses, push-ups at 3 sets of 6 to 15 (our upper body workout at home) and the dumbbell floor press at 2 to 3 sets of 8 to 12 (its move page's editorial dose); then the back of the shoulders with face pulls at 3 sets of 12 to 20 (our upper body workout at home) and band pull-aparts at 15 reps (our chest workout's warm-up).
3D demoDumbbell bench pressIntermediate · A dumbbell + A bench or box
3D demoPush-upIntermediate · No equipment
3D demoDumbbell floor pressIntermediate · A dumbbell
3D demoIncline dumbbell pressIntermediate · A dumbbell + A bench or box
3D demoFace pullIntermediate · A band
3D demoBand pull-apartIntermediate · A bandWhile your shoulder hurts, the NHS advises against making up your own strenuous exercises or using heavy gym equipment. Shorten the range, use the pec deck with its pin set forward, or swap to presses, and follow our shoulder pain from bench press guide.
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Avoid lying flat on your back for more than a few minutes later in pregnancy: do flys standing with cables or a band, or on an incline bench (our suggestion).
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Flys come back last, light, with the elbows no lower than the shoulder, as the NHS trust leaflet and our pec strain guide advise.
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Follow your surgeon's advice before pushing, pulling or lifting with your arms, as our heart surgery guide says.
Start with the machine fly or cable fly, which our move pages put before the dumbbell fly because the path is set or easier to control.
Our home chest workout uses push-ups, floor presses and flys with no bench. The gym chest workout uses cable flys at 3 sets of 12 after the bench press; push day workout B at 3 sets of 12 to 15; the bodybuilding upper-body workout machine flys at 2 sets of 12 to 15.
A 30-minute chest workout at home with a pair of dumbbells or a band: push-ups, dumbbell floor presses, flys and a squeeze press, with no bench needed.
30 minBeginner8 movesA band, A dumbbellA gym chest workout: bench press, incline dumbbell press, cable flyes, dips and a push-up finisher.
45 minIntermediate7 movesA band, A barbellPush day B: seated dumbbell press, dumbbell bench press, cable flyes, cable lateral raises, dips and skull crushers, with sets, reps and rest.
50 minIntermediate11 movesA band, A dumbbellA 60-minute upper-body session for muscle growth: incline presses, rows, pulldowns, flys, lateral raises, face pulls, pushdowns and curls, short of failure.
60 minIntermediate12 movesCardio machine, A bandAn upper body workout at home with no gym: push-ups, band rows, pike push-ups, face pulls, close-grip push-ups and Y-T-W raises, with dumbbell options.
30 minIntermediate13 movesA band, An anchor pointA 30-minute practice session for the bench press: shoulder blade work, push-ups and dumbbell presses, then the empty bar with the safety arms set.
30 minBeginner7 movesA band, A dumbbellFlys come round on chest or push days in these split plans.
The classic chest, back, legs, shoulders and arms week, built from our gym workouts, with what research says about training each muscle once.
5 training days45 minIntermediate6 days a weekA 6-day push/pull/legs plan for experienced lifters: two push, two pull and two leg days, with sets, reps, rest and lighter weeks.
6 training days55 minAdvancedFor chest pain that feels tight, heavy or squeezing, or spreads to your arms, neck, jaw, back or stomach; chest pain with sweating, feeling sick, light-headed or short of breath; or severe difficulty breathing. It could be a heart attack, so this comes before thinking about a strained muscle. Don't drive yourself to A&E.
A pop or ripping feeling during a lift, then bruising on the chest or inside the arm, an uneven chest, armpit or nipple, or weakness pushing: it can be a torn chest tendon. Seek medical care straight away: NHS 111 or an urgent treatment centre, or your doctor or urgent care in the US.
Sudden or very bad shoulder pain; you can't move your arm; your arm or shoulder has changed shape or is badly swollen; pins and needles that don't go away; no feeling in the arm or shoulder; or pain after an injury or fall. These can be signs of a broken or dislocated bone or a torn tendon.
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For shoulder pain that's getting worse or hasn't improved after 2 weeks, or a shoulder that's very difficult to move.
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For chest pain, feeling faint or unusual breathlessness, as our plans' safety note says.
We found no evidence for it. Twelve weeks of pec deck grew the upper and lower chest equally, and no study of an "inner chest" was found: it isn't a separate muscle.
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No fly study has tested it, and the only regional growth data, on the pec deck, found even growth. Use the angle your shoulders like.
Source 6
Presses and push-ups work the chest hard, and there's too little data to say single-joint exercises add more muscle. Flys are a useful extra, not a requirement.
Loaded stretches between sets added no growth in trained men, there's too little data on range for growth, and the stretched, arm-back position is where tears are thought to happen under heavy load. The hospital handout says no lower than chest level.
The pec deck drew 98% of the bench press's chest activity in one study, machine flys grew the chest 5 to 7% in 8 weeks, and free weights and machines built similar muscle across 13 studies.
Lie on a bench with a dumbbell in each hand over your chest, palms facing and elbows softly bent. Open your arms wide in a slow arc until the weights are about level with your chest, then hug them back up, keeping the same elbow bend throughout.
Mainly the pectoralis major, the big chest muscle, with the front of your shoulders helping and your biceps steadying your elbows. Unlike the bench press, they barely work your triceps.
The bench press works your chest a little harder overall, uses your shoulders and triceps too, and moves about twice the weight; machine and cable flys came close to it for chest activity in one study. Press first, then add flys for extra chest work.
All of them work. The pec deck and a bent-forward cable crossover drew 93 to 98% of the bench press's chest activity in one study, and machine flys grew the chest 5 to 7% in 8 weeks. Machines set the path for you; dumbbells only need a bench.
Much lighter than pressing: trained men flew about 40 kg for both dumbbells together, against 88 kg on the bench press. Pick a weight you can control for 10 to 15 reps without your elbows straightening.
2 or 3 sets of 10 to 15, resting 60 to 90 seconds, with the last set 0 to 2 reps short of failure. In beginners, one set grew the chest as much as three over 12 weeks.
Usually your arms are going too far back, your elbows are too straight or the weight is too heavy. Stop at about chest level, keep a soft elbow bend and set a pec deck a few clicks forward. If it still hurts, swap to a press or push-up and read our shoulder pain from bench press guide.
Rarely, but yes: tears happen when the stretched chest muscle is heavily loaded, and one was reported on a chest fly machine. A sudden pop or ripping feeling, then bruising, an uneven chest or weakness pushing, needs checking the same day.
No exercise singles out an inner chest. In beginners, pec deck training grew the upper and lower chest equally, so flys build the chest muscle as a whole.
Not if you press and do push-ups, which train your chest hard. Flys are a useful extra for chest size, or when your triceps or elbows need a rest.
Yes. Lie on the floor with dumbbells so your upper arms touch down at about chest level, or anchor a band behind you for a standing fly. Band flys worked the chest slightly less and the shoulders slightly more than dumbbell flys.
Both work your chest. No study has shown incline flys build the upper chest more, and the pec deck grew the upper and lower chest equally. Use the angle your shoulders like best.
Exercise education, not a personal prescription, and clinical review of these guides is pending. Check with a GP before starting hard training if you have a heart condition, chest pain, dizziness or breathlessness when active, and stop for sharp or increasing pain. Health disclaimer.
