Best Exercises for Arms: What the Science Says About Biceps and Triceps

TL;DR: Triceps make up roughly two-thirds of your upper arm — if you want bigger arms, prioritize overhead triceps extensions and close-grip pressing alongside your curl variations.

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Why Most Arm Training Programs Get It Wrong

The standard approach to arm training involves a lot of curls — barbell curls, dumbbell curls, hammer curls, preacher curls — and whatever cable pushdown machine is available afterward. The biceps dominate programming while the triceps get token attention as a finisher.

This is anatomically backward. The triceps brachii has three heads and accounts for approximately 60 to 65 percent of upper arm cross-sectional area. The biceps brachii, the muscle everyone is actually trying to grow, represents only 30 to 35 percent. If you want bigger arms, the most impactful change you can make is to take triceps training more seriously.

This does not mean neglecting biceps — both muscles need direct work. But understanding the proportion of each muscle and what exercises actually load them effectively changes how you should structure arm training.

Tricep Anatomy and Why It Matters

The triceps has three heads:

• Long head: crosses both the shoulder and elbow joints; best loaded with the shoulder in a flexed position (overhead work)
• Lateral head: runs along the outer arm; creates the horseshoe shape; loaded by elbow extension under load
• Medial head: deeper, provides fullness; active across all triceps movements

The critical point is that the long head — the largest of the three — is only fully lengthened when the arm is raised overhead. Pushdowns and kickbacks, which keep the shoulder in a neutral or extended position, underload the long head. Research consistently shows that overhead triceps exercises produce greater muscle activation and hypertrophy in the long head compared to pressdown-only training.

If you only do pushdowns, you are leaving the biggest portion of the triceps undertrained.

Best Tricep Exercises

Overhead Tricep Extension (Cable or Dumbbell)

The overhead position fully lengthens the long head, creating significant passive tension and maximizing the stretch-mediated hypertrophy stimulus. A 2023 study by Kassiano and colleagues showed significantly greater long head growth with overhead extensions compared to pushdowns performed at equivalent volumes.

Use either a cable machine (single rope attachment) or a dumbbell. Seated variations provide more stability. Aim for 3 to 4 sets of 10 to 15 reps, emphasizing the fully stretched position at the top.

Close-Grip Bench Press

A compound movement that loads all three triceps heads with substantial weight. The close-grip bench allows progressive overload in a way that isolation exercises do not — you can consistently add weight to the bar over months. This is one of the most effective mass builders for the triceps and should be the primary compound option.

Hand placement: shoulder-width, not excessively narrow. Extremely close grip shifts stress to the wrists. Sets of 4 to 8 reps with heavy loads produce both strength and hypertrophy.

Tricep Pushdown (Cable, Bar or Rope)

A reliable isolation exercise with a simple movement pattern and easy load adjustment. The rope attachment allows wrists to pronate at the bottom, improving the squeeze at peak contraction. Best used as a secondary exercise after overhead work and close-grip pressing, not as the only tricep movement in a session.

Best Bicep Exercises

Incline Dumbbell Curl

The incline position places the shoulder in extension, fully stretching the long head of the biceps. This increases the range of motion under load compared to standard standing curls and produces greater peak contraction. Research on incline curls consistently shows high bicep activation across the full range of motion. Use a bench angle of 45 to 60 degrees.

Spider Curl (Prone Incline)

Lying face-down on an incline bench, the spider curl removes shoulder movement entirely, isolating the biceps and creating a long peak contraction. The stretched position at the bottom is a primary driver of hypertrophy. This is an underused exercise that deserves a regular spot in arm programming.

Cable Curl (Straight Bar or EZ Bar)

Cable curls maintain constant tension throughout the movement, unlike free weights where tension drops at the top of a dumbbell curl. This constant tension stimulus is a meaningful advantage for hypertrophy. Position the cable at floor level and perform curls with a controlled tempo, emphasizing the squeeze at the top.

Hammer Curl

Targets the brachialis — a muscle beneath the biceps that, when developed, physically pushes the biceps upward and increases arm thickness and peak. Hammer curls also work the brachioradialis and are less stressful on the tendons than supinated curls. Include them for complete arm development.

Exercise Comparison Table

| Exercise | Primary Target | Evidence for Hypertrophy | Overload Potential | Notes | |---|---|---|---|---| | Overhead tricep extension | Tricep long head | Strong | Moderate | Critical for full tricep development | | Close-grip bench press | All tricep heads | Strong | High | Best compound for triceps | | Tricep pushdown | Lateral + medial head | Moderate | Moderate | Skip as sole tricep exercise | | Skull crusher | All tricep heads | Moderate | Moderate-High | Joint stress for some | | Incline dumbbell curl | Bicep long head | Strong | Moderate | Underused; excellent for hypertrophy | | Spider curl | Both bicep heads | Strong | Moderate | Best stretch-position bicep exercise | | Cable curl | Both bicep heads | Moderate | Moderate | Constant tension advantage | | Hammer curl | Brachialis + brachioradialis | Moderate | Moderate | Important for arm thickness |

Volume Recommendations

Research on bicep and tricep hypertrophy suggests:

• Biceps: 10 to 20 sets per week, distributed across 2 sessions
• Triceps: 10 to 20 sets per week, distributed across 2 sessions

Note that compound upper body pressing (bench press, overhead press) also loads the triceps directly — these sets count toward weekly tricep volume. Similarly, heavy rows and pull-ups load the biceps under stretch. Direct arm work is an addition to these compound movements, not a replacement.

Start at the lower end of these ranges if you are adding dedicated arm work to an existing program that already includes compound pressing and pulling.

Sample Arm Day

This session works as a standalone arm day or as a finisher after push/pull sessions:

| Exercise | Sets | Reps | Rest | |---|---|---|---| | Close-Grip Bench Press | 4 | 5-8 | 2-3 min | | Overhead Cable Tricep Extension | 3 | 10-12 | 90 sec | | Incline Dumbbell Curl | 3 | 10-12 | 90 sec | | Spider Curl | 3 | 10-15 | 90 sec | | Cable Pushdown (rope) | 3 | 12-15 | 60 sec | | Hammer Curl | 3 | 10-12 | 60 sec |

Total working sets: 19. This is appropriate for a dedicated arm day. If arm work is bolted onto the end of a push or pull session, use half the sets.

Common Arm Training Mistakes

Using too much weight on curls — momentum from the hips and back takes the bicep out of the movement. Use a weight you can control through the full range of motion without swinging.

Ignoring the stretched position — peak tension at the fully lengthened position is a primary driver of hypertrophy. Choose exercises that place load through a full range and resist the urge to cheat the bottom of the movement.

Doing only pushdowns for triceps — a single-plane exercise that underloads the long head. Add overhead work.

Not training arms directly at all — some people rely entirely on compound pressing and pulling. This works to a point, but direct arm work adds meaningful volume and specificity for people prioritizing arm size.

Bottom Line

Bigger arms require serious tricep work. The overhead extension loads the part of the tricep most people leave undertrained. Incline curls and spider curls load the bicep through the stretched range where hypertrophy stimulus is highest. Build your arm program around these exercises, hit 10 to 20 sets per muscle group weekly, and apply progressive overload.

Use Protokl — the AI fitness app to track your arm training volume, monitor progressive overload, and log weekly sets per muscle group. For nutrition that supports muscle growth, use the macro calculator to set protein and calorie targets.