Hammer Curl vs Bicep Curl
The short answer. The main change is your grip: palms facing each other in the hammer curl, palms forward in the bicep curl. The hammer grip brings in more of the brachialis and the brachioradialis on your forearm, while the palms-forward grip puts the biceps in its strongest position. Pick the hammer curl for thicker arms and forearms, and the bicep curl for the biceps itself.
Differences at a glance
| Hammer Curl | Bicep Curl | |
|---|---|---|
| Main muscles (differs) | biceps, forearms | biceps |
| Movement pattern | Arm isolation | Arm isolation |
| Type | Isolation (one joint) | Isolation (one joint) |
| Equipment | dumbbells | dumbbells |
| Level | Beginner | Beginner |
| Joint stress areas (differs) | none listed | elbow |
| Grip (differs) | Neutral, palms facing each other | Palms forward, turned up as you curl |
| Main focus (differs) | Brachialis and brachioradialis, with the biceps | Biceps |
| Load you can use (differs) | Often a little heavier | Often a little lighter |
| Best for (differs) | Arm and forearm thickness, and grip-heavy sports | Direct biceps work |
Muscles worked
Hammer Curl
- Biceps (main muscle)
- Forearms (main muscle)
- Shoulders (front and side delts) (also works)
Bicep Curl
- Biceps (main muscle)
- Forearms (also works)
- Shoulders (front and side delts) (also works)
Which one should you do?
Choose the hammer curl if
- You want more work for your forearms and the muscle under your biceps.
- A palms-up grip bothers your wrists or elbows.
- You do a lot of pulling with a neutral grip, such as rows with a V-handle.
Choose the bicep curl if
- You want to train the biceps as directly as you can with dumbbells.
- You want a full turn of the palm, which the biceps does in addition to bending the elbow.
- You already train your forearms with heavy rows, pull-ups or carries.
Can you do both?
The easiest plan is to do one of each in your arm work. Start with the bicep curl while you are fresh, then do the hammer curl as a second exercise. You can also switch between them every few weeks if you train arms only once a week.
How the form differs
- In the hammer curl your thumbs point up for the whole rep. In the bicep curl your palms face forward.
- The hammer curl stops when your forearms are about vertical. The bicep curl comes up until the dumbbells are near your shoulders.
- The biceps also turns the palm up, so the bicep curl uses that job. The hammer curl keeps the palm still.
- In both, keep your elbows still at your sides and do not swing the weights.
Questions
Are hammer curls better than bicep curls?
Neither is better in every case. The hammer curl works the forearm and the brachialis more, and the bicep curl works the biceps more directly. Many programs use both.
Do hammer curls work the biceps?
Yes. The biceps still bends the elbow in a neutral grip. It simply shares more of the work with the brachialis and brachioradialis than in a palms-up curl.
Why can I lift more on hammer curls?
With a neutral grip, the brachioradialis is in a strong position and helps more. That is why many people can curl a little more weight with a hammer grip.