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What Muscles Do Pull-Ups Work? A Muscle-by-Muscle Guide
By The Angles90 Editorial Team · Published 11.03.2026 · Last updated 11.03.2026
A pull-up works your latissimus dorsi (the lats) harder than any other muscle measured in a Mayo Clinic lab study of the movement, and the biceps, a forearm muscle called the brachioradialis, the rotator cuff, the muscles that move your shoulder blades, your chest and your trunk all contribute. In the 2010 Mayo Clinic study of 25 adults (Youdas et al., Journal of Strength and Conditioning Research), the lats averaged 117% to 130% of their activity in a maximal isometric test, ahead of the biceps at 78% to 96%.
Angles90® has been building pulling equipment since 2018, starting with a handle co-developed with the strength training ergonomics faculty at TU Munich. This guide goes muscle by muscle through three research sources: the 2010 study, a 2017 study of 19 strength-trained men (Dickie et al., Journal of Electromyography and Kinesiology) and a 2026 review of 23 EMG studies (Di Fonza et al., Journal of Functional Morphology and Kinesiology, published 08.12.2026). For how hand position changes the movement, see our guides to chin-ups and different pull-up grips. This one stays with the muscles.
What muscles do pull-ups work?
The Mayo Clinic study measured seven muscles in the same participants with the same protocol: the lats, biceps, infraspinatus, lower trapezius, pectoralis major, erector spinae and external obliques. Because the protocol was shared, its numbers can be compared with each other. The lats led by a wide margin.
| Muscle | What it does | Average activity, as a share of a maximal isometric test | Pull-up versus chin-up |
|---|---|---|---|
| Latissimus dorsi (lats) | Extends, adducts and internally rotates the upper arm (Di Fonza et al., 2026) | 117% to 130% | No significant difference reported |
| Biceps brachii | Elbow flexor (Di Fonza et al., 2026) | 78% to 96% | Higher in the chin-up |
| Infraspinatus | Rotator cuff muscle that rotates the upper arm outward and steadies the shoulder joint (StatPearls, 2026) | 71% to 79% | No significant difference reported |
| Lower trapezius | Shoulder-blade muscle | 45% to 56% | Higher in the pull-up |
| Pectoralis major | Chest muscle | 44% to 57% | Higher in the chin-up |
| Erector spinae | Back muscle along the spine | 39% to 41% | No significant difference reported |
| External obliques | Abdominal muscles at the sides of the trunk | 31% to 35% | No significant difference reported |
One note on the scale. Each reading is a percentage of that muscle's signal in a maximal isometric test, so a value above 100% means the pull-up produced more signal than the test did. Ranges in the table cover every exercise the study compared.
Which muscle does the most work in a pull-up?
The lats. Their job at the shoulder is extension, adduction and internal rotation of the upper arm, according to the 2026 review, which is the motion of drawing a raised arm down toward your body. The review adds a point worth keeping: no pulling exercise engages the lats to the complete exclusion of the muscles around them. So the lats lead and everything else helps.
What do the biceps and forearm muscles do?
The biceps came second in the Mayo Clinic data, and the 2026 review treats it as an elbow flexor, one of the muscles that bends your arm as you pull. Another elbow flexor, the brachioradialis, sits in the forearm and, per the StatPearls entry on the brachioradialis (updated 01.30.2024), stays active whether the palm faces you, away from you or sideways. In the 2017 study the brachioradialis, biceps and pectoralis major were all more active while pulling up than while lowering, by a statistically significant margin.
What do the shoulders and shoulder blades do?
Start with the infraspinatus, one of the rotator cuff muscles, which averaged 71% to 79%, third behind the lats and biceps. According to the StatPearls rotator cuff entry (updated 06.18.2026), the cuff's main job is steadying the shoulder joint by pressing the head of the upper arm bone into its socket, and the infraspinatus is one of the muscles that rotate the arm outward. Shoulder-blade muscles worked less hard but mattered for timing: the lower trapezius averaged 45% to 56%, and the 2026 review reports that the scapular muscles were recruited mostly at the start of the pull. In the 2017 study the middle trapezius showed the one clear grip effect, covered below.
Do pull-ups work your chest, back extensors and abs?
In part, as supporting muscles. Chest first: the pectoralis major averaged 44% to 57%. Along the spine, the erector spinae averaged 39% to 41%, and the external obliques at the sides of the abdomen averaged 31% to 35%. What the study did not measure was the rectus abdominis, the muscle at the front of the abdomen, so it cannot say whether that one works. Of these three groups, only the chest differed between the two exercises, and it was higher in the chin-up.
How does the work shift between the pull and the lowering?
The muscles do not switch on all at once. In the Mayo Clinic study the order was consistent: the lower trapezius and pectoralis major started the movement and the biceps and lats completed it. The 2017 study compared the pulling and lowering phases directly, and the table puts the two together.
| Part of the rep | What the research found | Source |
|---|---|---|
| Start of the pull | The lower trapezius and pectoralis major started the movement, and the scapular muscles were recruited mostly in the initial phase | Youdas et al., 2010; Di Fonza et al., 2026 |
| End of the pull | The biceps and lats completed the movement | Youdas et al., 2010 |
| Pulling up versus lowering | The brachioradialis, biceps and pectoralis major were more active while pulling up than while lowering, by a statistically significant margin | Dickie et al., 2017 |
In short, the pull asks more of your arm flexors and chest than the lowering does, and the shoulder blades get things going before the arms finish the job.
Do different grips change which muscles work?
A little, at the edges. Hand position moved some muscles in the lab and left the biggest one alone. In the Mayo Clinic study the chin-up, with palms toward you, produced more biceps and chest activity than the pull-up with palms away, and the pull-up produced more lower trapezius activity. A 2017 comparison of supinated, pronated, neutral and rope grips found similar activity across the eight muscles measured over a full rep, with one clear exception: the middle trapezius peaked at 60.1% of its maximal test with the overhand grip against 37.1% with the neutral grip. The 2026 review reports broadly similar lat activity across pull-up grips and says grip can reasonably be chosen for secondary goals, such as how much the elbow flexors take part. Our guides to neutral grip pull-ups and different pull-up grips cover each hand position in detail.
Where does a handle fit into a pull-up?
A bar fixes your hand position before the first rep, and hand position is what shifted the emphasis in the studies above. The A90 Grips are dynamic training grips: a pair of freely rotating handles on straps that attach to the pull-up bar you already have. Hold them neutral, palms-up or palms-down, or let them turn through the rep. Each handle is certified for 400 lbs (180 kg). There are four ways to hold them, which we call ERGO, POWER, POWER+ and FOREARM. We built them as a handle that adapts to you, not the opposite.
What can pull-up EMG not tell you?
EMG records electrical activity during a single session. The 2026 review calls EMG amplitude an indirect proxy for neural drive that does not, on its own, establish how well an exercise trains a muscle, and it notes that none of the studies it reviewed ran a training intervention measuring muscle growth or strength.
Samples are also small and young. The Mayo Clinic study had 21 men and 4 women with an average age near 25, the 2017 study had 19 men with the same average age, and the review says women and older adults are almost entirely absent from the evidence it covers. Numbers from different studies cannot be lined up directly either, because the studies differ in load, normalization and electrode setup, so this guide ranks muscles only within the Mayo Clinic data. Read the tables as a map of what a pull-up asks of your body. They say nothing about what training will change.
Pull-up muscles FAQ
Do pull-ups work your biceps?
Yes. The biceps came second of the seven muscles in the Mayo Clinic study, at 78% to 96% of a maximal isometric test, and it was more active in the chin-up than in the pull-up. In the 2017 study it was more active while pulling up than while lowering.
Do pull-ups work your chest?
Yes, as a supporting muscle. In the Mayo Clinic study the pectoralis major averaged 44% to 57% and was higher in the chin-up than in the pull-up, and the 2017 study found it more active in the pulling phase than in the lowering phase.
Do pull-ups work your shoulders?
They work the muscles around the shoulder joint and shoulder blade that these studies measured. Among them, the infraspinatus, a rotator cuff muscle, averaged 71% to 79% and the lower trapezius 45% to 56%. Deltoids were not measured in the Mayo Clinic study, so it has nothing to say about them.
Do pull-ups work your abs?
Partly. The external obliques, abdominal muscles at the sides of the trunk, averaged 31% to 35% in the Mayo Clinic study, and the erector spinae along the spine averaged 39% to 41%. Muscles at the front of the abdomen (the rectus abdominis) were not measured.
Do pull-ups work your traps?
Yes, the trapezius muscles that move the shoulder blades. The lower trapezius averaged 45% to 56% and was higher in the pull-up than the chin-up. In the 2017 study the middle trapezius worked harder with an overhand grip than with a neutral grip.
Do pull-ups work your forearms?
The brachioradialis, a forearm muscle that flexes the elbow, was more active while pulling up than while lowering in the 2017 study, by a statistically significant margin. The research cited here does not settle grip endurance, which is a separate question. Our grip strength training guide covers that side.
Is a pull-up a back exercise or an arm exercise?
Both, with the back in front: the lats led the Mayo Clinic data and the biceps came second. The 2026 review treats the pull-up as the bodyweight counterpart of the lat pulldown, and our neutral grip lat pulldown guide covers the machine version.
What should I do if pull-ups hurt?
Stop the set. Pain is a reason to get assessed by a qualified healthcare professional before you keep training the movement.
Angles90 products are training equipment, not medical devices. This article is general information about training, not medical advice, diagnosis or treatment. If you are training around pain, an injury or a medical condition, speak to a qualified healthcare professional before changing how you train.
The short version
A pull-up is led by the lats and backed by the biceps, with the rotator cuff, shoulder-blade muscles, chest and trunk in supporting roles. Work moves from the shoulder blades and chest at the start to the biceps and lats at the finish, and grip shifts the emphasis at the edges. If you want to feel how a handle that can turn through the rep behaves on your own bar, see how the A90 Grips fit the one you already train on.
Keep reading
- How to Do a Chin-Up: Form, Muscles Worked and Your First Rep
- Neutral Grip Pull-Ups: How to Do Them and What They Work
- Different Pull-Up Grips: 8 Variations, the Muscles They Work, and How to Choose
- How to Do an Inverted Row: Setup, Form and Progressions
- How to Do a Neutral Grip Lat Pulldown, and When to Switch Grips
- All articles on the A90 Blog