Here's something that surprises most beginners: the triceps make up roughly two-thirds of your upper arm's size, not the biceps. Yet almost every beginner arm routine defaults to curl after curl, chasing the muscle that actually contributes less to how big your arms look.
I fell into this exact trap for months — biceps curls felt like "the" arm exercise, so that's basically all I did. My arms grew slower than expected, and it wasn't until I started training triceps with the same effort I was putting into curls that I understood where most of my arm size was actually coming from.
A quick note before you start: if you have an elbow or wrist condition, check with a doctor or physical therapist about which movements and loads are appropriate for you.
The Biceps vs Triceps Balance
Your arm has two main muscle groups on opposite sides, and each responds to a different joint movement.
| Muscle Group | Movement | Share of Arm Size | Example Exercises |
|---|---|---|---|
| Biceps | Elbow flexion (bending) | Roughly one-third | Bicep curls, hammer curls |
| Triceps | Elbow extension (straightening) | Roughly two-thirds | Tricep dips, overhead extensions, close-grip push-ups |
The core idea: if your arm routine is mostly curls, you're spending most of your effort on the smaller contributor to arm size. A complete arm routine trains both, with real attention given to triceps rather than treating them as an afterthought.
Best Exercises by Muscle Group
Biceps
Bicep Curls — The classic movement: curling a dumbbell in each hand from a hanging position up toward your shoulder, keeping your elbows fixed at your sides.
Hammer Curls — Performed with palms facing each other instead of facing up, this variation shifts some emphasis onto the forearm alongside the biceps.
Triceps
Tricep Dips — Using a sturdy chair or bench, lowering and pressing your body up with your arms trains the triceps directly and requires no equipment beyond furniture you likely already have.
Overhead Tricep Extension — Holding a single dumbbell with both hands behind your head and extending your arms upward isolates the triceps through a full range of motion.
Close-Grip Push-Ups — Placing your hands closer together than a standard push-up shifts significantly more of the work onto the triceps — see our guide 10 Best Full Body Workout Exercises for Beginners for the standard push-up to build from.
Building a Complete Arm Routine
A well-rounded arm session gives real attention to both muscle groups, not just curls. A simple beginner-friendly example:
| Exercise | Sets x Reps |
|---|---|
| Bicep Curls | 3 x 10-12 |
| Hammer Curls | 2-3 x 10-12 |
| Tricep Dips | 3 x 8-12 |
| Overhead Tricep Extension | 3 x 10-12 |
Notice this gives triceps two dedicated exercises to biceps' two — matching effort roughly to the muscle's actual contribution to arm size, rather than defaulting to curls alone.
Common Mistakes With Arm Training
Only training biceps By far the most common arm-training gap. Curls feel like the obvious "arm exercise," but neglecting triceps means neglecting the larger portion of your arm.
Using momentum on curls Swinging the weight up using your back or shoulders instead of controlled bicep effort reduces how much the muscle is actually worked. Keep your elbows fixed and let the bicep do the lifting.
Training arms without also training compound movements Isolated arm exercises are useful, but movements like rows and presses — covered in our guide Best Dumbbell Workout for Beginners — also build real arm size as a side effect of training the whole upper body. For more on avoiding narrow training routines, see our guide 10 Common Workout Mistakes Beginners Should Avoid (And How to Fix Them).
A smart way to fit arm training into your week: pair biceps with back day, since rows already recruit them — see our guide Best Back Exercises — and pair triceps with chest or shoulder day, since presses already recruit them too, covered in our guides Best Chest Exercises and Best Shoulder Exercises.
Frequently Asked Questions
How often should beginners train arms? 1-2 dedicated sessions per week is generally enough for beginners, especially since arms are also worked indirectly during chest, back, and shoulder training.
Why aren't my arms growing even though I do curls every day? This is often a sign of over-focusing on biceps while neglecting triceps, which make up a larger share of arm size. Balancing both muscle groups usually produces better results than training biceps alone.
Can I build arm size with just bodyweight exercises? Yes, particularly for triceps — dips and close-grip push-ups are genuinely effective. Biceps are harder to isolate with bodyweight alone, which is where dumbbells become useful.
Do compound exercises like rows and presses count as arm training? Yes, to a real degree. Rows and presses work the arms as secondary muscles, which is part of why a complete routine — not just isolated arm exercises — supports overall arm development.
Final Thoughts
Next time you're tempted to squeeze in "just one more set of curls," redirect that set to triceps instead — it's the muscle actually doing two-thirds of the work you're trying to build.
Still building your overall routine? Our guide 10 Best Full Body Workout Exercises for Beginners is a solid place to start alongside this.
Which muscle group does your current arm routine train more — biceps or triceps? Let me know in the comments.