Arm Curl
The arm curl is the primary movement pattern for training the biceps and the muscles that support elbow flexion — the brachialis and brachioradialis. It’s a simple, direct movement that has earned its place in training programs at every level, from beginners to competitive bodybuilders.
The curl trains the bicep through its full function — flexing the elbow and supinating the forearm. That supination, the rotation of the forearm so the palm faces upward at the top of the movement, is worth paying attention to. It’s part of what the bicep does and fully expressing it through the range of motion produces more complete development than a curl performed with a neutral or fixed grip throughout.
Variations like the hammer curl, performed with a neutral grip, shift more emphasis to the brachialis and brachioradialis — the muscles that sit underneath and alongside the bicep. Including both supinated and neutral grip curling in a program produces more complete arm development than relying on one grip position alone.
As with all movements, range of motion and a controlled eccentric matter. Letting the weight travel through a full range — from full extension at the bottom to full flexion at the top — and controlling the lowering phase rather than dropping the weight is where the stimulus lives.
Below are the arm curl variations in the library.
Reference Card
Movement Pattern: Elbow flexion Primary Muscles: Biceps brachii Secondary Muscles: Brachialis, brachioradialis, forearm flexors
Variations
- Barbell arm curl
- Dumbbell arm curl
- Hammer curl
- Cable arm curl
- Preacher curl
- Concentration curl
- Incline dumbbell curl
- Machine arm curl
- Reverse barbell curl
- Reverse dumbbell curl
- Reverse cable curl
Considerations
- Supinate the forearm at the top of the movement — rotating the palm upward is part of the bicep’s full function
- Hammer curl variations shift emphasis to the brachialis and brachioradialis — include both grip positions for complete development
- Control the eccentric — dropping the weight on the way down shortens the stimulus
- Full range of motion from full extension to full flexion produces the best results
Programming Notes
- Works well at the end of a back session or in a dedicated arm session
- Responds well to moderate to higher rep ranges (8–15)
- Reverse curl variations also train the forearm extensors — useful for balanced forearm development