To get bigger arms, train both the triceps and biceps directly, with roughly 10 to 20 hard sets each per week in the 6 to 15 rep range, and get stronger at those movements over time. Most people fixate on the biceps, but the triceps make up the larger share of upper-arm mass — so if bigger arms are the goal, the triceps deserve at least as much attention.
Arms grow from a combination of the pressing and pulling you already do plus dedicated isolation work. Compound lifts hit the arms as assistants, but direct curls and extensions are what push arm size past what pressing and rowing alone provide.
The muscles involved
The upper arm is two muscle groups. The triceps have three heads — long, lateral, and medial — and together they extend the elbow; they form roughly two-thirds of the arm’s cross-section, which is why triceps work drives most of the size. The biceps sit on the front and flex the elbow and supinate the forearm; the brachialis underneath adds width when trained through neutral-grip work. The forearms round out the look and grip. For arm size specifically, prioritize triceps, train biceps hard, and don’t ignore the forearms.
Best exercise categories
For triceps, use two categories: pressing-style movements like close-grip bench and dips that let you load heavily, and extension movements like overhead extensions, pushdowns, and skullcrushers that isolate the muscle. Overhead work biases the long head, which most arms lack, so include at least one overhead variation.
For biceps, use curls in their variations: barbell and dumbbell curls for load, incline curls for a stretched position, and hammer curls to bring in the brachialis. Vary grip and angle rather than repeating one curl. Browse both in the exercises library, and see compound vs isolation for how direct arm work complements your big lifts. For deeper dives, see how to get bigger biceps and how to grow your triceps.
Volume and rep ranges
Aim for about 10 to 20 hard sets per week for each of the triceps and biceps, most people doing well around 12 to 16, split across two sessions. Remember that pressing already loads the triceps and pulling already loads the biceps, so count those assisting sets toward the total — you may need less isolation than you think. The sets per week for muscle guide covers this counting.
Arms respond well across the 6 to 15 rep range and often thrive toward the higher end, where you can keep tension on a small muscle without joint strain. Keep heavier compound-style arm work lower and isolation work higher, and end every set within a few reps of failure — reps left shows how.
How to progress
Small muscles still follow progressive overload. Add a rep or a little load each week, and use strict form as the constant — an arm curl that only moves more weight because you’re swinging isn’t progressing. Log your sets so you can see the curl or pushdown climbing over a block.
Run it as a mesocycle: start near the low end of your set range, add sets or load weekly, then take a deload week when progress stalls. The overall approach is laid out in the hypertrophy guide.
Common mistakes
The biggest mistake is training biceps hard and treating triceps as an afterthought, which caps arm size because the larger muscle is left underdeveloped. Give the triceps equal or greater priority. The second is swinging and using momentum on curls and extensions — small muscles need strict tension, not body english. The third is only ever doing arms at the end of long sessions when you’re too fatigued to train them hard; if arms are a priority, sometimes train them first.
Finally, arms are small muscles, so their growth is slow and easy to sabotage by under-eating; keep nutrition and protein adequate. And don’t confuse a pump with progress — the honest measure is whether your logged loads and reps trend up over a mesocycle.
Splitting volume correctly between triceps, biceps, and the compound work that already trains them is exactly the kind of bookkeeping Checkfit handles for you — an adaptive program, automatic weight selection, RIR-based progression, and nutrition targets set to your goal. Get Checkfit at checkfit.com.
