Building the Arms: Curls, Pulls, and What Actually Grows Them

Arm training gets more attention than almost anything else in a gym and less thought than almost anything else. People pick the curl they saw someone else doing, add three sets of pressdowns, and wonder why nothing changes.

What follows is the movement list, what each one actually emphasizes, an honest verdict on the popular ones, and a routine with real numbers attached.

What the Arm Actually Is

Most people say "biceps" and mean the whole front of the upper arm, but there is more than one muscle in that neighborhood. The biceps brachii has a short head and a long head, and it both flexes the elbow and supinates the forearm, which is the motion of turning the palm up.

Underneath it sits the brachialis, a pure elbow flexor that does not care which way the palm faces. Running up the thumb side of the forearm is the brachioradialis, which contributes to elbow flexion and works hardest when the grip is neutral or overhand.

Building those two is what pushes the biceps brachii up and out, so the lifter who only ever curls palms-up is leaving thickness on the table.

On the back of the arm, the triceps brachii has three heads that share one primary job, which is extending the elbow. The lateral head gives the outer arm its visible definition, the medial head sits deep near the elbow, and the long head is the largest of the three.

The long head is the one worth knowing about, because it is the only head that crosses the shoulder joint and therefore assists shoulder extension and adduction as well. Overhead work puts it in a lengthened position that pressdowns and dips do not, which is why a triceps program built only on dips leaves a third of the muscle undertrained.

Curls: Principal Movements and Auxiliary Movements

Every curl is an isolation exercise involving one articulation, which is elbow flexion. That does not make them all equal.

A principal curl loads the biceps hard across a full range of motion and can carry a training block on its own. An auxiliary curl biases one part of the movement or one part of the muscle, which is useful as a supplement and thin as a foundation.

The principal curls

The standing barbell curl is the most basic and most comprehensive curl there is. It trains the front of the upper arm generally and the inner forearms along with it, and if you only ever do one curl this is the one.

Execution is unglamorous. Underhand grip on a straight bar, feet about shoulder width, torso upright, elbows pinned to the sides, and only the forearm moves as the bar traces an arc from the thighs up toward the chest and back down.

The seated incline dumbbell curl is a genuine contender for best overall curl, because setting the bench back lets the arms hang behind the torso for a long, unobstructed range of motion. The standing dumbbell curl is the third principal option and the most forgiving, since alternating arms cuts down the body-swinging that ruins the barbell version for a lot of people.

The auxiliary curls

Preacher curls build fullness through the whole length of the biceps brachii. Wedging the back of the upper arm over the angled pad, usually with a kinked EZ bar, removes the cheat and keeps tension where you want it.

Hammer curls use dumbbells and a neutral grip, which shifts emphasis onto the brachialis and forearms, two muscles that live permanently in the biceps brachii's shadow and should not. Reverse barbell curls flip to an overhand grip and load the brachialis and outer forearms hard, so expect less weight and do not chase the number.

Zottman curls are a standing dumbbell curl with a deliberately moving grip. You start neutral at the sides, rotate to underhand by the midpoint on the way up, and reverse on the way down, so one rep trains the supinated and pronated positions in sequence.

Prone incline barbell curls, lying stomach-down on an incline bench, bias the peak contraction and sit in the same supplementary category.

The seated concentration curl is probably the most popular and most overused curl in circulation, and its emphasis is similar to the prone incline curl. Everybody who has ever seen a gym assumes it is a foundational biceps exercise.

It is not. It is an auxiliary movement, and a program with no concentration curls in it is not missing anything.

Grip position and what it emphasizes

Grip terminology gets mangled constantly, and the logic of curl selection depends on getting it right.

Neutral means palms facing each other and pronated means palms away, and those two get confused constantly. Run all three positions across a training week rather than arguing about which one is best.

The Triceps: Extension Under Load

The triceps are the larger share of upper arm mass and get the smaller share of the average lifter's attention. There is no complicated taxonomy here, because the triceps only extend the elbow.

The variables that matter are where the upper arm sits, how much load the position allows, and whether the long head ever gets stretched.

Dips, and the ladder to get there

A dip is a compound triceps builder that also loads the chest and front delts, and it is one of the few arm movements you can load heavily without a machine. The problem is that most people either can do a full parallel bar dip or cannot, with no plan for closing the gap.

Here is the ladder, easiest to hardest, and you move up once you can complete 3 sets of 8 clean reps at your current step.

1. Bench dip, knees bent, feet close to the body. Hands on the bench edge behind you, elbows tracking back rather than flaring wide, lowering until the upper arms are roughly parallel to the floor.
2. Bench dip, legs straight. Same movement with the heels further out, which shifts more bodyweight onto the arms.
3. Bench dip, feet elevated on a second bench. A large jump in difficulty, so expect the rep count to drop.
4. Hanging dip on parallel bars. Body suspended with arms extended, bend the elbows until the upper arms reach roughly parallel, then extend short of jamming the joint.
5. Weighted dip. A belt and a plate, or a dumbbell held between the ankles, once bodyweight sets exceed about 12 reps.
6. Ring dip. The same movement on a suspension system, which demands far more shoulder control and is a separate skill rather than the next rep number.

Shoulder position matters more here than depth does, so if the front of your shoulder complains at the bottom, shorten the range before you add a single pound.

Extension work the dips will not cover

Dips and pressdowns both train the triceps with the upper arm alongside the torso, which never puts the long head under real stretch. That is the gap, and it is also why lagging triceps are usually a sequencing problem rather than a volume one for anyone already pressing heavy on a structured chest day.

An overhead extension, done with a dumbbell, an EZ bar, or a rope, takes the arm to full shoulder flexion and lengthens the long head before the elbow extends. Two to three sets a week is the difference between a triceps program and a pressdown habit.

The lying triceps extension, or skull crusher, sits between the two positions and is a reasonable middle option, so keep the elbows from flaring and stop the set when the joint starts talking rather than the muscle. The close-grip bench press is the heavy option and belongs at the start of a session rather than the end.

Pull-ups and Rows Are Arm Training Too

The biceps and brachialis do serious work in every vertical pull and every row, whether or not you were thinking about them. Ignoring that is the most common reason arm programs are quietly overloaded.

The close-grip chin-up, hands roughly three to four inches apart with palms facing you, is arguably the best biceps mass builder that exists. Hang at full stretch, pull until the chest is close to the bar, and lower slowly enough to feel the load on the way down.

The wide-grip pull-up, palms away, shifts work toward the outer lats and middle back while still demanding a great deal from the brachialis. Wrap the thumbs around the bar, pull the shoulder blades down before the elbows bend, and stop short of a hard lockout at the bottom.

Seated cable rows and bent-over rows train scapular retraction as their main job while using the biceps brachii and brachialis heavily in assistance. Cable pulldowns do the same with a fixed load if a bar is out of reach.

One note on a movement you may have seen recommended. The behind-the-neck pull-up and the behind-the-neck pulldown both force the shoulders into extreme external rotation with the neck pushed forward, and in my view the risk profile is not worth whatever they add over the front-of-neck versions.

Working toward a one-arm pull-up

The one-arm pull-up is a legitimate long-term goal and a terrible short-term one. It also cannot be spotted, because there is nowhere for a second person to safely take load off a hanging single-arm pull.

The honest path runs through assisted variations. The side-to-side pull-up, where you pull toward one hand until the chin approaches that fist and alternate on the next rep, is the cleanest intermediate step, because it shifts most of the load to one side while the other arm still helps.

Beyond that, loop a band over the bar and under one foot to offload weight, or work eccentric-only singles where you start at the top and lower on one arm for 5 to 8 seconds. Neither requires a partner, and both progress in a way a spotter never could.

The Arm Volume Budget: Counting the Curls You Already Did

Almost every arm article tells you to add sets, and almost none of them count the arm work already sitting in your pressing and pulling. That is how a lifter ends up with 25 hard sets a week landing on a small muscle and no idea why the elbows ache.

This is a WorkoutHealthy planning estimate, not an industry standard and not a research finding. Its value is in forcing you to count at all.

The formula

Written in plain text, for each arm muscle group across one training week:

Direct-equivalent sets = (direct arm sets x 1.0) + (assisting compound sets x 0.5)

For the elbow flexors, the assisting compounds are your vertical pulls and rows. For the triceps, they are your horizontal presses, overhead presses, and dips.

Every assumption, stated out loud

• The 0.5 credit is a convention, not a measurement. We are asserting that a hard set of rows is worth about half a set of curls to the biceps, and nobody can hand you a verified number for this. Any article that gives you two decimal places is guessing with more confidence than the evidence supports.
• Only hard sets count. A set taken within roughly 2 to 3 reps of failure counts, and warm-ups and sets you cut short for the clock do not.
• The planning band is 10 to 20 direct-equivalent sets per muscle group per week. Below 10 most trained lifters stall, and above 20 the elbows tend to complain before the arms grow.
• The only input source is your own training log. Not an estimate and not a typical week, the actual sets you performed over the last 7 days.

A worked example

Take a lifter on a four-day upper and lower split whose arms will not grow. His week holds 4 sets of pull-ups, 4 of barbell rows and 4 of cable rows, plus 4 sets of bench, 3 of incline press and 3 of overhead press.

He does not need 20 sets of curls, he needs 8. If he is currently doing 16, the fix is subtraction rather than addition.

How the answer moves if the assumption moves

The credit fraction is the whole ballgame. At a 0.25 credit the same 12 pulling sets are worth 3 and the direct curl allowance climbs to 11 sets, while at a 0.75 credit they are worth 9 and the allowance falls to 5.

So the choice of fraction swings the curl prescription by roughly 3 sets in either direction at a typical upper body volume. If your elbows are sore and your arms are flat, assume the higher credit and cut curls, and if your compounds are light and machine-assisted, assume the lower one and add.

A Two-Day Arm Block You Can Bolt Onto Any Week

This is 8 direct biceps sets and 8 direct triceps sets a week, which lands inside the planning band for most people already doing a normal amount of pressing and pulling. Run each day at the end of a session that trained the same pattern.

Day A, after your pulling session

Day B, after your pressing session

Where it goes in the week and how it progresses

Put Day A and Day B at least 48 hours apart, which usually means Monday and Thursday on a four-day split. If you are running a strength-focused week built around the competition lifts, treat both as finishers at the end of a session when the arms are already fatigued.

If size is the priority, the bodybuilding option is to run these first as a pre-exhaust and accept that your compound numbers drop that day. Pick one approach and hold it for six weeks before judging it.

Progression is reps before load. Add a rep per set until you top the range everywhere, then add the smallest increment available and restart at the bottom of the range, which is the same progressive overload logic that underpins any hypertrophy program.

Elbows, Wrists, and Knowing When to Back Off

Arm training is a common source of nagging elbow pain, usually because volume climbed faster than tissue tolerance did. The tell is pain at the tendon near the joint rather than a burn in the muscle belly.

Two adjustments help more than anything else. Swap a straight bar for an EZ bar or dumbbells so the wrists are not forced into full supination under load, and cut the auxiliary curls first rather than the principal ones.

Grip work sits on the same tissue as your curls, so if you also run dedicated grip and forearm training, count it in the same weekly budget. Two heavy programs sharing one set of tendons is how people end up taking six weeks off.