Reverse Curls vs Hammer Curls: Which is Best for the Biceps?

published by: Debbie Luna
Last Updated:
August 17, 2022

Though the standard bicep curl is considered the go-to exercise for developing the biceps brachii muscle, the hammer curl and the reverse curl are two variants that are just as qualified for such purposes - each with their own distinct differences that make them uniquely suited for certain situations.

However, in order for us to decide on which particular variation of the curl should be added to your workout program, it is important to first identify what exactly makes one different from the other.

The main points of distinction between the reverse curl and the hammer curl relate to the manner in which they place the hands, with the reverse curl featuring an overhand or pronated grip while the hammer curl is performed with a neutral grip.

What is the Reverse Curl?

The reverse curl is a free weight isolation exercise meant to target the biceps brachii and musculature of the forearm to a moderate level of exertion.

dumbbell reverse curl

It is most often performed with the use of an E-Z curl bar or a straight bar, though performing reverse curls with a pair of dumbbells can be especially effective at correcting muscular imbalances of the forearms.

Benefits of Reverse Curls

The main benefit derived from proper reverse curl performance is its capacity to reinforce both the mechanics of the forearms as well as the gross athletic ability of such muscles. 

In particular, the pronation and flexion biomechanics of the wrist are reinforced quite well by reverse curls. This can result in a reduced risk of injury and improved function during pulling exercises that directly recruit the forearms.

dumbbell reverse curl muscles

Furthermore, elbow flexion is also reinforced as the reverse curl works not only the main flexor and extensor forearm muscles, but also the brachioradialis - of which makes up the largest portion of the forearm.

Muscles Worked by Reverse Curls

Like other curl variations, the reverse curl works the biceps brachii as its primary mover muscle - alongside the brachioradialis, brachialis and the various smaller muscles of the forearms.

What is the Hammer Curl?

The hammer curl is a free weight isolation exercise primarily performed so as to target the brachioradialis and biceps muscles of the upper arm, usually with a moderate level of resistance and volume so as to avoid injury or overtraining.

dumbbell hammer curl

Hammer curls are almost always performed with a pair of dumbbells, as the neutral grip and range of motion involved makes the usage of neutral grip bars or even ordinary barbells entirely inapplicable for such purposes.

Benefits of Hammer Curls

Hammer curls are one of the most effective exercises for developing pure forearms muscle mass, as its highly effective training of the brachioradialis muscle will target the largest muscle group in the forearm.

In addition to this, the subsequent development of the forearm and brachioradialis muscles will result in reinforcement of the elbow extension biomechanic, aiding in the performance of pressing movements such as the push-up or overhead press.

Muscles Worked by Hammer Curls

Being an isolation exercise, the hammer curl trains the biceps brachii as its main purpose.

However, as a consequence of the neutral grip involved in the exercise, the brachioradialis and brachialis are also recruited to a significant extent, alongside the forearm muscles in a synergistic capacity.

dumbbell hammer curl muscles

This equates to the hammer curl being excellent for both upper arm and forearm mass, developing both equally within a single movement.

Which Exercise is Better for Forearm Mass?

Though reverse curls activate the extensor and flexor muscles of the forearms, they unfortunately lose out in comparison to the hammer curl when speaking of the brachioradialis.

The importance of this muscle is simply due to the fact that it makes up for nearly half of the muscle mass located in the forearm, meaning that targeting it will serve an exerciser well if they wish to build thick and muscular forearms.

While reverse curls can feasibly build the forearms in terms of raw mass, hammer curls will do so in a more rapid and efficient manner - though, for the best possible results, combining the two as part of a forearm workout is the most advisable choice.

Which Exercise is Better for Forearm Strength?

While hammer curls are considered to be the superior exercise for building bigger forearms, it is in fact reverse curls that are superior in terms of developing forearm strength and endurance.

This is simply because the flexor and extensor muscles of the forearms are responsible for a number of different biomechanics involving the hands and wrists, such as grip strength and wrist flexion.

As such, directly targeting these muscle groups with the reverse curl while simultaneously reducing biceps brachii involvement in the exercise can lead to a direct carry-over of forearm strength to other athletic activities.

Which Exercise is Better for Biceps Gains?

Once again, it is the hammer curl that is arguably superior to the reverse curl in terms of biceps brachii development, as the neutral grip featured in the hammer curl allows for a greater level of resistance to be used per repetition.

This factor, alongside the reduction in forearm flexor and extensor muscle recruitment in favor of the biceps, will result in faster and greater biceps muscular hypertrophy than in comparison to reverse curls.

While this is not to say that reverse curls cannot build strong and sizable biceps, the hammer curl is the more efficient choice in such a regard.

Which Exercise is Better for Strength Developments?

When tallying up the various muscle groups that receive strength developments from either exercise, we can conclude that it is the reverse curl that provides significantly better carry-over to other exercises, as the forearms are used in nearly every athletic activity.

Comparatively, the biceps are used less frequently, and as such it is the reverse curl that is the more advisable choice if only one exercise must be picked.

However, in terms of acclimation to high levels of resistance, the hammer curl is the better choice - meaning that for athletes of strength-specific sports such as powerlifting or strongman competitions, allowing for greater loading with the use of the hammer curl will aid in their conditioning.

In conclusion, both the reverse curl and the hammer curl have their respective applications in terms of pure strength development, with the reverse curl being more appropriate for general exercises while the hammer curl is more sports-specific in use.

Safety Differences Between Reverse Curls and Hammer Curls

Despite the fact that both the reverse curl and the hammer curl are perfectly safe when performed with correct form and proper training methods, individuals with a history of injury may wish to minimize their risk of aggravating such injuries by picking the safer of the two options.

However, it is not as simple as one exercise being considered safer than the other - as depending on what sort of injury one wishes to avoid, the reverse curl or hammer curl may in fact be a riskier option to pick.

Reverse Curl Safety

Due to the angle of resistance, positioning of the forearm and reduced total weight involved in the reverse curl - it is this particular curl variation that is considered to be generally safer than the hammer curl, especially if the exerciser has a history of elbow or shoulder joint injuries.

However, because of the position the reverse curl places the wrist in, it is an entirely unsuitable exercise for individuals who have sustained a wrist injury in the past, especially if the reverse curl is being performed with the use of a straight bar instead of an E-Z curl bar.

Hammer Curl Safety

Unlike the reverse curl, the hammer curl is considerably more dangerous for individuals with a history of elbow or shoulder injuries, as its higher level of resistance paired with the angle of resistance involved can quickly result in elbow tissue damage if performed with excessive momentum or weight.

However, as a benefit of the neutral wrist angle that is used during the hammer curl, it is in fact quite safe for exercisers with a history of wrist or hand injuries - making it comparatively superior to the reverse curl in this particular aspect.

In Conclusion, Which Exercise is Better?

In terms of growing your biceps and brachioradialis, it is the hammer curl that is the clear winner.

However, for other purposes or for training the various smaller muscles that make up the forearms, it is the reverse curl that will serve the purpose better. This is especially applicable for individuals whose elbow injuries are aggravated by other curl variation exercises.

For the most effective arm-building workout however, combining both reverse curls and hammer curls so as to train the forearms and biceps collectively is the best possible approach.

References

1. Marcolin G, Panizzolo FA, Petrone N, Moro T, Grigoletto D, Piccolo D, Paoli A. Differences in electromyographic activity of biceps brachii and brachioradialis while performing three variants of curl. PeerJ. 2018 Jul 13;6:e5165. doi: 10.7717/peerj.5165. PMID: 30013836; PMCID: PMC6047503.

2. Kostek, Mark T.; Knortz, Karen. Kinesiology Corner: The Bicep Curl and the Reverse Bicep Curl. National Strength Coaches Association Journal: December 1980 - Volume 2 - Issue 6 - p 55-55

3. Oliveira LF, Matta TT, Alves DS, Garcia MA, Vieira TM. Effect of the shoulder position on the biceps brachii emg in different dumbbell curls. J Sports Sci Med. 2009 Mar 1;8(1):24-9. PMID: 24150552; PMCID: PMC3737788.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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