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Tonal Coach performing a Bicep Hammer Curl with the rope

How to Do Bicep Hammer Curls for Strength and Size

Strengthen and better define your arms using bicep hammer curls. Compare hammer vs regular curl form, and use these insider tips to work your muscles.

Even if you're brand new to strength training, the bicep hammer can offer an accessible starting point to improving the physical makeup of your arms. 

The neutral grip makes the curl feel steady and surprisingly more natural compared to other upper-body lifts. Many beginners also say this version’s form is also easier to understand than a traditional curl, largely because the wrist stays in that natural position while still supporting a clean motion. 

A bicep hammer curl also will typically place greater emphasis on the forearms and deep elbow flexors, creating a subtly differing challenge between hammer curls vs regular curls. Many feel that difference almost immediately once they nail proper form. 

"The difference is in the grip itself, neutral position versus underhand, and what muscles get recruited to support the movement. Both are beneficial and slightly different," notes Tonal Coach and Strength Training expert Joe Rodonis.

This guide walks you through hammer curl cues that matter: spine and posture alignment, elbow path, hand position, tempo, and key muscles worked.

You’ll learn how the shape of your grip influences the form you maintain, and how different curl variations target the upper arm in slightly distinct ways. All to get you contributing the most intentional effort during each phase of the movement.

Contents
  1. Bicep Hammer Curls: Step by Step
  2. Bicep Hammer Curls: reps & intervals
    1. Average Duration of
    2. Estimated Calories Burned
    3. Recommended Number of exercises Per Week
    4. Warmup & Cool Down Exercises
    3.
  3. Muscle Groups Targeted
  4. Equipment Used for Bicep Hammer Curls
  5. Coaching Tips & Best Practices
  6. Who This Exercise is Best For
  7. Answers to FAQs about Bicep Hammer Curls
  8. Concluding words on Bicep Hammer Curls

Bicep Hammer Curls: Step by Step

1. Get in your starting stance.

  • Stand tall with feet flat, hip-width apart.
  • Distribute your weight evenly across your feet. 
  • Grab your dumbbells, letting them hang naturally at your sides with your arms fully extended. 
  • Rotate your palms to face inward.
  • Keep your shoulders relaxed and down rather than pulled up toward your ears.

2. Tuck and “hold” your elbows.

  • Keep your elbows close to the sides of your torso and positioned slightly out in front of your hips.
  • Keep them in this position. The elbows should not shift in any direction during a hammer curl. 

Tip: Arm stability is key for an effective hammer curl. You do not want your elbows and forearms to be swinging forward or backward. The main motion here is your elbows hinging.

3. Begin the curl.

  • Hinge at the elbows and guide the weights upward in a smooth arc pattern.
  • Maintain the neutral grip the entire time, wrists aligned with arms and always facing each other.

4. Stop the arc once your forearms are vertical.

  • Alternative cue: Stop the curl just shy of reaching your shoulders.
  • Avoid swinging the weights or leaning back for momentum.

5. Lower back down with control.

  • Retrace your arc slowly, hinging again only with your elbows. 
  • Focus again on that wrist-forearm alignment.

Reset and repeat. Release any tension in your shoulders if they’ve begun pulling up toward your ears. Begin the next rep once your posture feels re-stabilized.

Bicep Hammer Curls: reps & intervals

These ranges are general starting points or lifters, not strict prescriptions. Your ideal reps depend on experience, goals, load selection, and how quickly your arms fatigue.

  • Muscle growth: 6-20 reps
  • Strength endurance: 8-12 reps
  • Max strength: 4-8 reps

  • Beginner intervals: 2-3 working sets
  • Intermediate intervals: 2-4 working sets

Average Duration of Bicep Hammer Curls

Use these numbers as pacing suggestions. People naturally curl at slightly different speeds.

  • One hammer curl rep: ~4-6 seconds
  • One hammer curl set: ~40-65 seconds

Estimated Calories Burned

These calorie estimates act as broad ranges, and come based on an average adult completing 3 sets of 10 reps per set.

Effort level, muscle worked and recruited, rest times, and overall body size all influence your individual energy use.

  • Women (140-180 lbs): ~15-25 calories
  • Men (170-210 lbs): ~20-30 calories
  • Adults above 210 lbs: ~25-40 calories

Recommended Number of exercises Per Week

Most people can perform hammer curls 1-2x/week, adjusting that frequency based on how their arms feel and how many other curl variations they’re using. 

Alternating curl types in a thoughtful upper-body regimen can help support overuse and encourage more balanced development, if that’s part of your workout goals.

Warmup & Cool Down Exercises

Warm-Up (choose 1-3):

  • Light resistance band curls (30 sec)
  • Shoulder rolls (30 sec)
  • Gentle wrist mobility (30 sec)

Cool-Down (Choose 1-3, completed at the end of your full routine):

  • Biceps doorway stretch (30 sec)
  • Forearm stretch (30 sec each side)
  • Slow arm shake-outs (20-30 sec)

Muscle Groups Targeted

The bicep hammer curl primarily emphasizes the brachialis and brachioradialis muscles in your biceps, two muscles that still put in work during traditional seated or standing curls, but not quite as much. 

That’s thanks to the hammer curl’s neutral grip. A neutral grip, or one where the palms face each other, places the biceps brachii in a slightly different position where it contributes to your power but isn't its main driver. 

"This position brings in more of the muscles under the biceps, called the brachialis, and a big forearm muscle, brachioradialis," explains Coach Joe. "You’ll often feel it more through the outside of the upper arm and forearm, and it helps build 'arm thickness.'"

Trying out various curl types that use different grips (standard, neutral, or pronated) will help work the forearms in slightly different ways, and can place different loads on the wrists themselves. "Traditional supinated curls engage the bicep more directly with palms facing up on the curl," confirms Coach Joe.

This blend makes the hammer curl a helpful complement to an arm-focused workout, especially for beginners learning how different grips change the muscles worked during the movement.

Equipment Used for Bicep Hammer Curls
  • Dumbbells
  • Resistance bands
  • Cable with a neutral grip handles/attachment

At-home alternatives:

  • Grip-friendly bottles or small weighted household objects
  • Backpack or soft weighted bag held by the straps
  • Tonal System

Coaching Tips & Best Practices

"New lifters may find it hard to keep their palms facing up on a traditional curl. A neutral grip may feel more comfortable as they build up strength and support in the forearms. Both grips should be rotated in your routine to develop well-rounded strength in the arms."
Tonal Coach Joe Rodonis
"With the hammer curl, simply slowing down the rep on the way down (the eccentric) will increase tension on the working muscle (the bicep) and overtime will build that muscle and improve control. When we slow down the movement and stay in form, we remove momentum from the lift and increase mechanical tension on the working area."
Tonal Coach Joe Rodonis

Who This Workout is Most Effective For

Coach Joe believes the mechanics of hammer curls gives them unique advantages, especially for strength-training newbies or anyone with a history of joint pain.

"Hammer curls require less effort to hold that twist, which can make the movement feel smoother on the elbow and wrist," he explains. "Hammer curls also tend to spread the work across more muscles like the brachialis and forearm, so some lifters feel less concentrated stress in one spot while still getting a strong arm-building stimulus."

Hammer curls are great options for any of the following:

  • Beginners developing curl mechanics.
  • Lifters across experience levels exploring how hammer bicep curl vs. regular curls differ.
  • Anyone looking to train the upper arms with a neutral wrist position.
  • People wanting a curl variation that feels joint-friendly for them. 
  • Individuals building a simple, well-rounded arm routine.

Answers to FAQs about Bicep Hammer Curls

Hammer curls emphasize the brachialis, which technically sits underneath the biceps and is the strongest elbow joint flexor. Over time, strengthening the brachialis can change how your upper arm’s composition looks, often contributing to the appearance of “thicker” arm muscles. 

They don’t directly make the biceps “taller,” but they can support more rounded arm muscle development and elbow-bending strength without relying exclusively on traditional curls. 

The biceps “head” is a term usually used to describe the two pieces that make up the biceps brachii, a key muscle in your upper arms.  

It’s tricky to name one single exercise that evenly hits all portions of the biceps. Instead, it’s generally better to integrate several patterns into one complete workout to encourage balanced recruitment. 

Rotating through variations such as regular curls, incline curls, and hammer curls can help cover more angles. This variety helps keep your arm training more well-rounded and adaptable versus picking one “perfect” bicep head exercise. 

Remember, “easier” is relative.

"Hammer curls often feel easier on the elbows because the neutral “thumbs-up” grip is a more natural, comfortable position for many people," says Coach Joe. "With a supinated underhand grip, you have to keep your forearm rotated palm-up the whole set."

Many people find hammer curls more stable because that neutral wrist position. Comparatively, regular curls can feel slightly more demanding on the wrists or elbows. 

Ultimately, “easier” depends on your structure and what feels most coordinated, but hammer curls are often a beginner-friendly starting point for learning control and form while working muscles effectively.

They’re simply different. Typically, hammer curls emphasize the brachialis and forearms more strongly, while regular curls highlight the biceps brachii. 

Most people include both in their routines because they complement each other. The hammer bicep curl vs regular comparison isn’t so much about which is superior but about understanding how each one feels for your body, or which to do consistently to support specific muscle mass development.

Concluding words on Bicep Hammer Curls

The bicep hammer curl is a straightforward movement that helps beginners and experienced lifters alike support arm strength and power in a new way. With its neutral grip and grounded setup, it can encourage elbow control and steady tension throughout the entire curl motion.

 Once you learn its rhythm, it becomes a reliable tool you can revisit anytime you want a focused, joint-friendly arm exercise.

If you enjoy this kind of clarity-driven movement breakdown, Tonal’s exercise library offers 60+ additional guides. Explore what new movements you can begin bringing into your life.

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