How to get bigger arms: biceps, triceps and forearms, with the evidence

Presses and pulls count

Pulldowns alone grew the biceps as much as curls alone in 29 untrained men, and adding curls and extensions to pulldowns and bench presses added nothing measurable over 10 weeks.

Sources 1, 2

Curls still help

In 10 untrained men, curls grew the arm flexors about twice as much as one-arm rows (11.1% against 5.2%). If arm size matters to you, a few sets of curls a week are cheap insurance.

Source 3

One triceps move overhead

In one 12-week trial of 21 adults, overhead extensions grew the whole triceps about 40% more than the same work with the arm at your side (about 1.4 times as much), and the long head about 1.5 times as much. A 6-week trial of 9 women found no difference.

Sources 4, 5

Enough hard sets

About 10 or more hard sets a week each for your biceps and triceps, counting each set of rows, pulldowns or chin-ups as half a biceps set and each set of presses, push-ups or dips as half a triceps set.

Sources 6, 7

Any rep range, if the sets are hard

Light and heavy weights grew muscle similarly when the sets were hard, and going to failure wasn't needed.

Sources 8, 9

Months, and people vary

After the same 12 weeks of arm training, biceps size changed by anything from 2% smaller to 59% bigger in 585 adults, and part of that difference is genetic.

Sources 10, 11

The front of the arm

Three muscles bend your elbow: the biceps, which also turns your palm up; the brachialis underneath it; and the brachioradialis in your forearm. In 4 men measured with MRI (magnetic resonance imaging) scans, the brachialis did about 47% of the elbow-bending work, the biceps 34% and the brachioradialis 19%. Our biceps, brachialis and brachioradialis guides cover them.

Source 12

The back of the arm

The triceps has three heads that straighten your elbow, and the long head also crosses the shoulder, which is why raising your arm overhead stretches it. In the same 4 men, the triceps' largest cross-section matched all three elbow-bending muscles together. We found no measured source for the popular claim that the triceps is two-thirds of your arm.

Sources 12, 4

The forearms

The wrist and finger muscles underneath and on top of your forearm grip and steady the wrist. The brachioradialis works hardest with your palm down, so reverse curls train it; wrist curls, carries and hangs train the rest, as our grip strength guide explains.

Source 13

Arm size is muscle plus fat

A tape measure takes in the skin and fat over the muscle, so your arm can measure smaller while you lose fat even as the muscle grows (our reading).

Source 14

Where people differ

Women and men gain similar muscle relative to their starting size; men gain slightly more in absolute terms, mostly in the upper body, and in the 585-adult trial women gained more strength relative to their start. Gains slow with experience and come a little more slowly with age.

Sources 15, 16, 10, 17

Compound lifts grow the armsEmerging evidence

In 29 untrained men over 10 weeks, adding curls and triceps extensions to pulldowns and bench presses added no measurable arm muscle (6.5% against 7.0%) or strength. In 20 trained men over 8 weeks, adding arm exercises made no difference to arm size or strength, though size was measured with a tape. In another 29 untrained men, pulldowns alone grew the elbow flexors as much as curls alone (6.1% against 5.8%).

Sources 2, 18, 1

Curls add to rowsEmerging evidence

In 10 untrained men who trained one arm with curls and the other with one-arm rows for 8 weeks, the curling arm's elbow flexors grew 11.1%, against 5.2%. Small trials point both ways, so direct arm work is cheap insurance rather than a must.

Source 3

Overhead triceps work grew more, in one trialEmerging evidence

In 21 adults, one arm did cable triceps extensions overhead and the other the same work with the arm at the side: 5 sets of 10, twice a week for 12 weeks. On MRI scans, the whole triceps grew 19.9% overhead against 13.9% (about 40% more, or 1.4 times), and the long head 28.5% against 19.6% (about 1.5 times), even though the overhead weights were 34 to 39% lighter. In 9 novice women over 6 weeks, pushdowns and overhead extensions grew the triceps similarly. Two small trials that don't agree, so the overhead advantage is promising rather than settled.

Sources 4, 5

Training at long muscle lengthsEmerging evidence

In 19 young women, preacher curls through the stretched first part of the range grew the lower biceps more than curls through the last part. Half reps in the stretched position built as much arm muscle as full reps in 30 trained adults, and a review of 11 studies found training at long lengths, through a full range or the stretched half, tended to grow the biceps and triceps more. The same pattern showed in the thigh in 45 women.

Sources 19, 20, 21, 22

More sets, more growth, with diminishing returnsStrong evidence

Each extra weekly set added about 0.4% growth across 15 studies, and an overview of 137 reviews found 10 or more sets a week built more muscle. The returns shrink as the sets go up, and counting sets of compound lifts as half a set for the arm muscles predicted growth best.

Sources 23, 6, 7

Light or heavy, if the sets are hardStrong evidence

Across 28 studies of 747 adults, light, moderate and heavy loads built similar muscle when sets went to failure, and heavier loads built more strength. Across 15 studies, stopping short of failure cost little growth.

Sources 24, 8, 9

How often matters littleStrong evidence

An early review of 10 studies found twice a week beat once, but with the weekly sets matched, 25 studies found no real difference. Spread your arm sets in whatever way suits your week.

Sources 25, 26

Chin-ups work the biceps more than pull-upsEmerging evidence

In 25 adults, the chin-up, with your palms facing you, drew more biceps and chest activity than the overhand pull-up.

Source 27

Grip shifts the forearm, not the bicepsEmerging evidence

In 16 adults, biceps activity didn't change whichever way the palm faced, while the brachioradialis worked harder with the palm down. We found no trial comparing hammer and palms-up curls for growth.

Source 13

Push-ups grow the tricepsEmerging evidence

In 18 men over 8 weeks, push-ups grew the triceps as much as a light bench press at a matched load. Hard suspended push-ups thickened the elbow extensors by 16% in 8 men, in a study with no control group, and 4 weeks of progressively harder push-ups raised bench press strength as much as bench pressing in 23 men.

Sources 28, 29, 30

Supersets save timeEmerging evidence

A review of time-saving training found that supersets roughly halve session time while keeping the number of sets, and are probably more useful for size than for maximal strength. It recommends at least 4 hard sets per muscle a week.

Source 31

People vary hugelyStrong evidence

In 585 adults doing the same 12 weeks of arm training, biceps size changed by anything from 2% smaller to 59% bigger, and strength by 0 to 250%. In 41 pairs of male twins, genes specific to training explained about 20% of the differences in arm strength gained over 10 weeks.

Sources 10, 11

Weekly sets

About 10 or more hard sets a week each for your biceps and triceps, counting compound lifts as half a set. Someone doing 6 sets of rows and pulldowns a week gets about 3 biceps sets from them, so 6 to 8 sets of curls brings them to about 10, as our bicep curl guide works out.

Sources 6, 7

A starting point for direct work

Two or three hard sets of curls and two or three of triceps extensions, twice a week, is a sensible start (our editorial starting point). Our 4-day split gives 4 sets of each a week and the bro split about 9.

Reps and how hard

Sets of 10 to 15 for curls and extensions, as our arm workouts use, with most sets stopping 1 to 3 reps short of failure and the last within 0 to 2; 6 to 12 for bodyweight pulls and push-ups. In your first two weeks, keep 3 or 4 reps to spare. Very light weights, about a fifth of the most you can lift, built about half as much muscle in one trial reported in our bicep curl guide.

Sources 8, 9

Rest, and pairing moves

About 60 to 90 seconds between sets of curls and extensions, as our plans' notes say. Pairing a biceps move with a triceps move, as our arm workouts do, lets one muscle rest while the other works and saves time.

Source 31

How often

Two arm sessions a week is a practical default, and your chest, back and shoulder days already work your arms. With sets matched, training more often doesn't add growth.

Source 26

Use the stretch

Lower all the way on curls, and include incline curls and an overhead extension, which load your muscles where they're stretched.

Sources 19, 21

Progress

Add reps until every set reaches the top of its range, then add weight. Dumbbell jumps are big for curls, so you may need to reach 15 reps on every set first, as our bicep curl guide suggests.

With dumbbells

Our arm workout at home pairs curls with an overhead extension, hammer curls with close-grip push-ups, and concentration curls with kickbacks. Filled water bottles or a loaded backpack will do to start.

Without weights

Chin-ups and rows train your biceps (pulldowns grew them as much as curls in a trial, and chin-ups work the biceps more than pull-ups), and close-grip push-ups and bench dips train your triceps (push-ups grew them as much as a light bench press). Our new arm workout without weights puts them together.

Sources 1, 27, 28

Making bodyweight harder

Move up the steps: rows with your feet on a step, more chin-ups, diamond or feet-raised push-ups, then parallel bar dips, as our push-up and dips guides set out. Light loads build muscle when the sets are hard, and in 23 men, 4 weeks of progressively harder push-ups raised bench press strength as much as bench pressing.

Sources 30, 8

What the trials found

In 8 to 12-week trials of mostly untrained adults, the elbow-bending muscles grew by roughly 5 to 11%, and the triceps by about 10 to 20% over 6 to 12 weeks. Our bicep curl guide's own trials found up to about 25% in the arm flexors.

Sources 2, 3, 4, 5

Strength comes first

In the 12-week triceps trial, one-rep strength rose by 62 to 71% whichever way the arm was trained. Watch your log as well as the tape.

Source 4

People vary hugely

The same training can double one person's strength and barely change another's, and part of that is genetic. Compare yourself with your own log.

Sources 10, 11

Sore elbows

Some discomfort is fine: up to about 3 to 4 out of 10, settling within an hour, with your elbow no worse the next morning, as our elbow guides say. If it's worse, go lighter and slower, swap heavy or swinging curls for hammer curls, and see our elbow pain from pull-ups, chin-ups and curls guide.

Shoulder pain

Leave overhead extensions out and use pushdowns or kickbacks, keep bench dips shallow or skip them, and see our shoulder pain guides. Tingling in your ring and little fingers in deep extensions means shorten the range or swap the move.

Wrists

Close-grip and diamond push-ups load the wrists and elbows more; use push-up handles or dumbbells to keep your wrists straight. With pain on the thumb side of your wrist, curl palms up rather than with hammer curls, as our move pages advise.

Older adults

Adults over 50 gained lean mass in 49 studies, a little less at older ages, and training didn't raise the risk of serious harm. Start lighter, keep 2 or 3 reps to spare, and progress steadily.

Sources 17, 6

Go to an urgent treatment centre or A&E

A sudden pop or snap with pain at the front of the elbow during a lift, then bruising, a bulge in your upper arm and weakness turning your palm up, can be a torn biceps tendon. Don't wait for it to settle: go to an urgent treatment centre or A&E, as our elbow pain guide explains, because a torn tendon is best repaired within the first 2 to 3 weeks. A sudden pop with weakness straightening your arm can be a torn triceps tendon and needs the same. In the US, go to urgent care or the emergency department.

Call 999 (911 in the US)

If arm pain comes on suddenly with pressure, heaviness or squeezing across your chest. During any exercise, stop and get help for chest pain, unusual breathlessness, dizziness or fainting, as our plans advise.

Get help the same day

Very painful, swollen, tight arms with dark urine after an unusually hard or high-rep session can be rhabdomyolysis: call NHS 111 (in the US, your doctor or urgent care), as our elbow pain from pull-ups guide explains.

See a GP

If elbow or arm pain hasn't gone after a few weeks; in many areas you can refer yourself to an NHS physiotherapy service.

When training becomes a worry

Beat says a drive to be more muscular, sometimes called muscle dysmorphia, can be part of an eating disorder, especially in men. Worrying a lot about one part of your body and comparing your looks with others' can be body dysmorphic disorder, and the NHS lists exercising too much and very strict routines around food among the signs of an eating disorder. See a GP; our eating disorders guide has Beat's helplines.

Sources 32, 33, 34

"Triceps make up two-thirds of your arm"Mixed evidence

We found no measured source for it. In one MRI study of 4 men, the triceps' largest cross-section matched all three elbow-bending muscles together. The triceps is big and worth training, but the two-thirds figure isn't evidence.

Source 12

"Compound lifts are all you need" or "You must isolate your arms"Mixed evidence

Adding curls and extensions to presses and pulldowns added nothing measurable in two short trials, but curls beat rows for biceps growth in another. Do both if bigger arms matter to you.

Sources 2, 18, 3

"Hammer curls build bigger arms than normal curls"Mixed evidence

The biceps worked just as hard whichever way the hand faced, and no trial has compared the two for growth. Hammer curls are a good second curl, not a secret.

Source 13

"High reps tone, low reps bulk"Strong evidence

Light and heavy weights grew muscle similarly when the sets were hard; heavier weights built more strength.

Sources 24, 8

"Arm exercises burn arm fat"Strong evidence

In 104 adults who trained one arm for 12 weeks, MRI showed fat loss spread across both arms, and across 13 studies training a body part didn't reduce the fat over it.

Sources 35, 36

"Women get bulky arms from lifting"Strong evidence

Women gain muscle at similar rates to men relative to their size, and men gain more in absolute terms in the upper body. Muscle comes slowly, and you control the dose.

Sources 15, 16

"Train arms every day"Strong evidence

With the weekly sets matched, training more often didn't add growth, and sore elbows need recovery days.

Source 26

"Building muscle burns off fat by boosting your metabolism"Strong evidence

A kilo of muscle uses about 13 calories a day at rest, against about 4.5 for a kilo of fat, so 2 kg more muscle burns about 26 calories more a day. Muscle helps for many reasons; a big boost to your metabolism isn't one of them.

Source 37

"Fat turns into muscle"Strong evidence

Fat and muscle are different tissues, and one can't turn into the other. You can lose fat and gain muscle at the same time, which can look like one turning into the other.

Sources 38, 39