In their quest for sculpted biceps, most weightlifters compare hammer curls vs. biceps curls. 

Specifically, they want to know the differences, why they’re beneficial, how to perform each, and which is best.

In this expert comparison of the hammer curl vs. bicep curl, we’ll explore these points and more. 

Hammer Curl vs. Bicep Curl: What’s the Difference?

Hammer curls and biceps curls are isolation exercises that primarily train the biceps brachii, or “biceps muscles.” Both involve lifting a dumbbell by bending and straightening your elbow. 

The difference between hammer curls vs biceps curls is the grip: you perform hammer curls with a neutral grip (palms facing in) and biceps curls with a supinated grip (palms facing up).

Research offers several insights into the effect of this difference. 

Older research suggests hammer curls emphasize the brachialis and brachioradialis, two small muscles that add size to your upper arms and forearms. However, newer research partly challenges this finding, suggesting the brachioradialis is more active when performing curls with a supinated grip. 

A study published in the Scandinavian Journal of Medicine & Science in Sports found that the classic biceps curl lengthens the biceps more than the hammer curl, which may benefit biceps growth. And another study by the Università Degli Studi di Milano found regular biceps curls elicited more biceps activation than hammer curls. Unfortunately, methodological flaws make these results tricky to interpret.

Critically, research has yet to examine differences in muscle growth between these exercises. Since higher activation doesn’t always lead to greater growth, we need more research before determining if any significant differences exist between these exercises in practice.

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Hammer Curl vs. Bicep Curl: What Are the Benefits?

The primary benefit of the biceps and hammer curls is they effectively train your arm muscles, especially the biceps, helping you maximize your arm size and strength. They also train the forearm muscles to a high degree, which likely benefits grip strength and ensures your arms develop proportionally. 

Both enable you to train your biceps unilaterally (one at a time), too. The advantage is that you can lift more total weight than you can with bilateral exercises (exercises that train both sides of the body simultaneously), which may help you gain more muscle and strength over time.

Moreover, it can help you establish a stronger mind-muscle connection and find and fix muscle and strength imbalances.

One advantage specific to the hammer curl is that it emphasizes the brachialis muscles more effectively than other curl variations. The brachialis is a small muscle that lies beneath the biceps, which, when well developed, significantly adds to your upper arms’ size and circumference.

Hammer Curl vs. Bicep Curl: Form Differences

How to Do the Hammer Curl

Hammer Curl vs. Bicep Curl: Hammer Curl Form

  1. Stand with your feet shoulder-width apart, holding a dumbbell in each hand at your sides and your palms facing your thighs.
  2. Without twisting your wrist, bend your right elbow to curl your right hand toward your right shoulder.
  3. Reverse the movement and return to the starting position, then repeat the pattern with your left hand to complete one full rep.

How to Do the Biceps Curl

Hammer Curl vs. Bicep Curl: Biceps Curl Form

  1. Stand with your feet shoulder-width apart, holding a dumbbell in each hand at your sides and your palms facing forward.
  2. Without twisting your wrist, bend your right elbow to curl your right hand toward your right shoulder.
  3. Reverse the movement and return to the starting position, then repeat the pattern with your left hand to complete one full rep.

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Hammer Curls vs. Bicep Curls: Which Is Best?

The hammer curl and biceps curl are similarly effective biceps exercises, so neither is better or worse than the other. 

While research tends to suggest the regular curl trains both heads of the biceps (the long head and short head) more than the hammer curl, there’s evidence the hammer curl is more effective for training your brachialis and brachioradialis, two muscles vital for overall arm development. 

And that’s why comparing hammer curls vs bicep curls isn’t particularly beneficial. A more sensible approach is to include both in your training. 

A good way to do this is to include the hammer curl in your program for 8-to-10 weeks of training, take a deload, and then replace the hammer curl with the biceps curl for the following 8-to-10 weeks of training.

Then, you can either continue alternating between the exercises every few months like this or stick with the one you prefer.

This is how I like to organize my training, and it’s similar to the method I advocate in my fitness books for men and women, Bigger Leaner Stronger and Thinner Leaner Stronger. 

(And if you’d like even more specific advice about what exercises to include in your training program to reach your health and fitness goals, take the Legion Strength Training Quiz, and in less than a minute, you’ll know the perfect strength training program for you. Click here to check it out.)

Biceps Curls vs. Hammer Curls: FAQs

FAQ #1: Are hammer curls better than bicep curls?

Hammer curls aren’t necessarily better than bicep curls—they serve a different purpose. While hammer curls target the brachialis slightly more, biceps curls emphasize the biceps specifically. 

For most people, including both exercises in your routine will yield the best results.

FAQ #2: Do hammer curls make biceps look bigger?

Hammer curls work the brachialis slightly more than regular curls. While this muscle isn’t nearly as prominent as the biceps brachii, it can enhance the biceps’ appearance by creating a clearer divide between the biceps and triceps and enhancing your biceps “peak.”

FAQ #3: What is the most effective curl for targeting the biceps?

Research suggests that the regular biceps curl is the most effective curl for targeting the biceps. However, doing a variety of curls, including hammer curls, preacher curls, and incline curls, likely produces more balanced and complete growth than doing just one type of curl.

Adding variety can also reduce your risk of repetitive strain injuries and help keep training engaging and fun, which can make it more productive.

FAQ #4: Should I go heavy on hammer curls?

Aim to lift as much weight as possible on the hammer curl without compromising form. Most people find that this is slightly more than they can lift on the biceps curl. For most men, doing sets of 6-to-8 reps works well, whereas women typically prefer sets of 8-to-10 reps. 

FAQ #5: What’s the difference in muscle activation between hammer curl vs bicep curl?

Research on muscle activation differences between the hammer curl vs biceps curl has produced mixed results, though it generally suggests biceps curls are superior for training the biceps, whereas hammer curls train the brachialis more.

Importantly, no research has examined differences in muscle growth between these exercises. Since higher activation doesn’t always equal more growth, it’s uncertain how these differences affect long-term gains. 

+ Scientific References