Build Biceps and Forearms That Popeye Would Envy With Hammer Curls

Hammer curls can build denser, stronger arms if you do them correctly. Here's our ultimate guide on nailing the hammer curl.

If there’s one unifying fact among strength athletes from different sports, it’s that’s they all appreciate (or at least have) a large pair of arms. Look up a picture of Shi Zhiyong — one of China’s most dominant weightlifters — elite powerlifter Taylor Atwood, and CrossFitter Tia-Clair Toomey-Orr, and you’ll notice they all own pretty impressive sleeve-huggers. Though these athletes all train for different feats of strength, bigger and stronger arms help them in their pursuits.

Strong biceps are more resilient to injury during heavy deadlifts. Biceps help a lifter pull the bar off of the floor during a clean & jerk. CrossFitters perform hundreds of pull-ups in competition sometimes, and the biceps are a vital muscle group in that exercise. The hammer curl offers a simple twist on the traditional dumbbell curl, fortifying an athlete’s grip strength and allowing for heavier weight to be lifted for more overall volume. Here’s how to do it. We can’t promise you’ll be an elite-level anything after learning the move, but we can almost guarantee some serious biceps gains.

How to Do the Hammer Curl

Below is a step-by-step guide on how to properly set up and perform the hammer curl. This guide covers the standard two-arm dumbbell hammer curl — a variation that allows you to line up the working arm with the resistance, increasing tension in the arms and reducing the risk of injury to the elbow and shoulder.

Step 1 — Grip the Dumbbells

Hammer Curl Step 1

Stand tall while holding a dumbbell in each hand. Keep your wrists tight, and squeeze your shoulder blades together so your shoulders lock into place — your biceps should be the only muscle engaged.

Coach’s Tip: If your goal is to strengthen your grip, increasing the overall grip diameter of the dumbbell — by using Fat Gripz — can help increase the muscular activity of your forearm muscles. (1) Due to the decrease in overall strength while using Fat Gripz, it’s recommended to perform additional training volume to target grip strength specifically.

Step 2 — Curl the Weights

Hammer Curl Step 2

With the shoulders set, squeeze the handles and maintain rigidity in the wrist — all you want to do is flex and extend your elbow. 

Don’t let the elbows swing too far forward or too far back. Otherwise, you risk losing tension in your biceps. The arc of the dumbbell should create almost a half-circle from the front of your hip to the front of your deltoid.

Lift the dumbbell above 90 degrees at the elbow where the thumb is at shoulder height. Once you have reached the top of the hammer curl, keep squeezing the biceps. Maintaining a controlled tempo throughout the rep can help improve exercise technique and increase the tension placed on the target muscle(s).

Coach’s Tip: You’ll feel the urge to lean back to swing the weight up. Don’t do this. If you have to swing the dumbbells, then your weights are too heavy. You won’t engage the biceps using momentum. Reduce the weight and use strict form.

Step 3 — Squeeze and Then Lower The Load

Hammer Curl Step 3

While keeping the elbow under the shoulder or slightly in front of the shoulder, return the dumbbells to the initial starting position under a slow and controlled tempo.

Coach’sTip: When lowering the weights, think of following the same arcing path you used when curling the dumbbell up to the top position.

Benefits of the Hammer Curl

Whether you’re a bodybuilder wanting to grow your arms, or a strength athlete wanting to increase your upper body strength and resistance to injury, the hammer curl affords many benefits to supplement your arm training.

Increased Bicep Size

The hammer curl has you curl with a neutral wrist, which is a sturdier position since it aligns with your elbow more naturally. This slight angle change increases activation of muscles like the brachialis, brachioradialis, and short head of the biceps brachii, further enhancing grip performance and muscle building potential of the arms. (2)

The gains in arm size come from the multiple muscle groups involved: brachialis, brachioradialis, and biceps brachii (most notably the short head). All three muscles span across the lower and upper arm and act as strong elbow flexor muscles, helping bring the arm from a resting extended position to fully flexed at the elbow. (2)(3)(4) When performed properly, hammer curls add bulk to the forearms and help add inches onto your biceps — making it a top pick for bodybuilders wanting to round out their physiques on stage.

Improved Grip Strength

Most people think of hammer curls as a biceps exercise — because it mainly is — but it can help you create crushing grip strength, too. The neutral-grip position that you hold the dumbbell in recruits more of the elbow flexor muscles in your forearms along with muscles like the flexor carpi radialis and extensor carpi ulnaris. Because you’re generally stronger in a neutral-grip position, you can also use heavier weight, overloading the forearms and biceps more than using exercises like concentration curls.

Wrist Stability

The hammer curl is done with the wrist in a neutral position (palms facing each other), rather than being supinated (palms facing your face) and/or pronated (palms facing the floor). Neutral-grip movements may increase the stability and strength of the muscles surrounding the wrist, enhancing overall injury resilience of the wrist joint and surrounding tissues.

Muscles Worked by the Hammer Curl

The hammer curl targets the upper and lower arm muscles — most notably the brachialis and brachioradialis — and can reinforce a stronger grip for deadlifts, pulling, and other strength and power movements.

The biceps flex the elbow — which is what allows you to sling a backpack over your shoulder or lift a beer to your lips (though save the beer for post-workout). Most strength-focused athletes, train the biceps during more complex lifts (such as deadlifts, cleans, pull-ups, tire flips, and heavy carries). Increasing biceps strength and size and overall development can improve not only the aesthetics of this muscle group, but also help minimize strain on the elbow and surrounding tissues during times of heavy training or overuse.

Brachialis

This upper arm muscle is responsible for pure elbow flexion and is the strongest flexor of the elbow when the grip is in a neutral position (without supination). (3) Increasing this muscle’s strength can improve grip performance in heavy lifts, prolong grip time to fatigue, and help to support greater wrist and elbow stability.

Brachioradialis

This forearm muscle is responsible for assisting the brachialis in elbow flexion and is responsible for supination and pronation of the forearm. (4) Developing this muscle (in addition to the brachialis) can improve grip strength and often enhance wrist stability and health.

Who Should Do the Hammer Curl

Below are some reasons why strength, power, and fitness athletes can benefit from performing the hammer curl.

Strength and Power Athletes

  • Powerlifters and Strongman Athletes: Strongmen and powerlifters need a firm grip to carry various implements (stones, frames, and cars) and pull heavy deadlifts. These athletes also strain their biceps during stone lifts, deadlifts, and carries, so it’s important to fortify the muscle by making it stronger. The hammer curl achieves both of these goals. 
  • Olympic Weightlifters: Although there isn’t much direct biceps involvement during Olympic lifts, the overall strength of the biceps, brachialis, and brachioradialis play an integral role in the safety of the elbow and shoulder joint — helping athletes stave off injuries that could keep them out of training or competition.

Functional Fitness Athlete

Hammer curls can improve pulling performance, grip strength, and wrist and elbow stability. If you are an athlete who struggles with upper body strength, grip performance during workouts, or are not stoked about your arm aesthetics, try adding some hammer curls into your accessory training.

Bodybuilders 

The hammer curl is a single-joint movement that can increase biceps and forearm hypertrophy and grip development. Bodybuilders should use the hammer curl in their training programs to increase arm size — addressing any weak points on their physique that may be lacking on stage.

Hammer Curl Sets, Reps, and Programming Recommendations

Below are three primary training goals and programming recommendations when utilizing the hammer curl into specific training programs. These are general guidelines for effectively training this movement and by no means should be used as the only way to program hammer curls.

For More Strength 

Training to build muscular strength can be achieved by utilizing high-intensity (high load) training paired with lower rep ranges and longer rest periods. The intent with strength-specific programs is to utilize the muscle mass to generate contractile force and train your nervous system — the system that recruits and activates our muscles to generate force more intensively and efficiently.

Do four to six sets of five to eight reps with moderate to heavyweight, resting two minutes between sets.

For More Muscle 

To build more muscles, you need to fatigue the muscle for between 30 to 40 seconds — which is roughly how long it takes most people to perform eight to 12 reps. Pick a weight you can lift comfortably for that rep range and then have at it.

Do three to five sets of eight to 12 reps with moderate weight. You can also manipulate training tempos — like slowing down the eccentric or pausing at the top — to increase time under tension.

For More Endurance

Also known as muscular endurance, this training focuses on training with low-moderate loads with shorter rest periods to challenge local muscular endurance, increasing total work capacity — total density of work per session — while potentially aiding in muscle and strength development. It is great when used in combination with other training or sport.

To increase the biceps endurance — or metabolic demand — you can do three to five sets of 12-20 reps with a light to moderate amount of weight.

Hammer Curl Variations 

Below are four hammer curl variations that coaches and athletes can employ to add variety and progression into their routine.

Hammer Curl 21s

21s are a repetition scheme that splits the full range of motion into two halves (the top half and the bottom half). In doing this, you can increase muscle damage, isolate sticking points, and develop weaker areas. 

Perform seven partial repetitions of the hammer curl (top half of the moment), followed by seven partial repetitions of the hammer curl (bottom half of the moment), directly followed by seven full range of motion repetitions of the hammer curl; for a total of 21 repetitions per set (14 partial reps and 7 full reps).

Single-Arm Dumbbell Hammer Curl

The single-arm dumbbell hammer curl allows you to line up the working arm with resistance, increasing tension in the arms and reducing the risk of injury to the elbow and shoulder.

You can also curl the dumbbell laterally, so the bottom of the dumbbell lines up with your pec muscles. Some people find this angle more helpful for “feeling” the muscle work. 

Incline Hammer Curl

The incline hammer curl is done with a lifter lying face-up in an adjustable bench at a slight recline (about 30-45 degrees from upright). 

This angled position minimizes shoulder involvement and keeps tension on the biceps at the end ranges of motion; better isolation of the biceps.

Facing In/Away Cable Hammer Curl

The cable hammer curl can be done on any functional trainer or adjustable cable tower. This variation allows you to take full advantage of the cable’s resistance profile and an all-around more even resistance across the range of motion. Your body’s positioning will help dictate which part of the rep is getting the highest amount of resistance. 

The facing away position challenges more of the lengthened or stretched position of the biceps muscle. In contrast, the facing in position will place more of a challenge in the mid-shortened range of the biceps muscle. 

Preacher Hammer Curl

The preacher hammer curl takes the standing or incline versions of the hammer curl to the next level as it helps stabilize the lifter and minimize shoulder involvement in the curl. Like the preacher curl set up, the lifter must place themselves in the seat so that the shoulder is fixed and cannot assist in swinging the load upwards or creating momentum to overcome a heavy load. 

The preacher bench also allows for the back of the arm to remain stable against the pad — creating an opposing force, giving more opportunity to create muscular tension throughout the exercise.

Hammer Curl Alternatives 

Below are four hammer curl alternatives coaches and athletes can use to increase hypertrophy, general strength, and muscle endurance.

Rope/Towel Curl

The rope/towel curl can be done with cables (with a rope attachment) or a kettlebell with a towel looped through the handle.

Using a towel for this exercise, you increase grip strength demands, position the wrist in a more neutral position compared to other curls, and increase overall upper body and grip strength.

Towel Pull-Up

The towel pull-up is similar to the rope/towel curl in that the lifter grasps the ends of a towel (that is draped over a pull-up bar) and performs pull-ups.

Hang onto towels really, really challenges the grip as the hands are in a more neutral position, and the hands are narrower than the shoulders, all of which will target the forearms and biceps.

Close-Grip Chin-Up

The close-grip chin-up will shift emphasis from the back muscles to the forearms and biceps. By placing the hands within shoulder width (with a neutral or semi-supinated grip), some lifters may experience discomfort, so if this is the case, you can limit the range of motion or opt for one of the other alternatives on this list.

To maximize the biceps engagement, focus on controlling the lowering portion of each rep and extending at the elbow while keeping the tension on the biceps musculature.

Dumbbell Hang Clean

The dumbbell hang clean is a functional fitness/CrossFit movement that is nearly identical to the hammer curl, except that the athlete uses momentum and the hips to clean the load up to the shoulder.

The flip side is that while the movement is less targeting the biceps and forearms (due to increased momentum), the athlete can often perform the movement with heavy loads and higher volumes, increasing overall arm and fitness training benefits and usefulness in their sport-specific strength.

FAQs

Do hammer curls increase grip strength?

Yes, hammer curls help place tension on the muscles responsible for grip strength and elbow flexion.

Can beginners perform hammer curls?

Yes, absolutely. Beginners can certainly perform the hammer curl and accompanying variations. Due to the straightforward nature of this exercise, beginners should be able to pick it right up and start increasing the size and strength of their arms in no time.

What muscles does the hammer curl work?

The hammer curl works multiple muscle groups in the arms. Some of the major muscle groups include:

  • Biceps
  • Brachialis
  • Brachioradialis

 

What is the difference between normal biceps curls and hammer curls?

Your grip position will change the focus of the arm curl exercise. More supinated variations (like the normal biceps curl) utilize more biceps brachii, whereas the more neutral wrist position (used in hammer curls) will utilize more of the brachialis and brachioradialis.

Are dumbbells better than using cables for hammer curls?

One is no better than the other. Like most things found in training, the purpose will help inform the best tool for the job. Dumbbells and cables have different ways of applying resistance to our bodies. Dumbbells utilize gravity (a natural force driving things down toward the ground). Cables provide the evenest form of resistive tension, applying the resistance directly in line with the cable itself. To maximize your training, you should utilize a multitude of training methods which will include free weights, cables, and machines.

References

  1. Krings, B. M., Shepherd, B. D., Swain, J. C., Turner, A. J., Chander, H., Waldman, H. S., … Smith, J. W. (2019). Impact of Fat Grip Attachments on Muscular Strength and Neuromuscular Activation During Resistance Exercise. Journal of Strength and Conditioning Research, 1. doi:10.1519/jsc.0000000000002954
  2. Jarrett, C. D., Weir, D. M., Stuffmann, E. S., Jain, S., Miller, M. C., & Schmidt, C. C. (2012). Anatomic and biomechanical analysis of the short and long head components of the distal biceps tendon. Journal of Shoulder and Elbow Surgery, 21(7), 942–948. doi:10.1016/j.jse.2011.04.030
  3. Plantz MA, Bordoni B. Anatomy, Shoulder and Upper Limb, Brachialis Muscle. [Updated 2020 Sep 18] StatPearls Publishing; 2021 Jan.https://www.ncbi.nlm.nih.gov/books/NBK551630/
  4. Lung BE, Ekblad J, Bisogno M. Anatomy, Shoulder and Upper Limb, Forearm Brachioradialis Muscle. [Updated 2020 Aug 10]. StatPearls Publishing; 2021 Jan. https://www.ncbi.nlm.nih.gov/books/NBK526110/