Why Are My Forearms So Skinny? 3 Exercises to Make them Bigger

published by: Debbie Luna
Last Updated:
November 14, 2022

The forearms are one of the most frequently seen parts of the body, regardless of whether one is shirtless or not. 

Because of this fact, many individuals may feel insecure about the size of their forearms, especially in relation to the rest of their body if they are otherwise muscular.

Fortunately, the size of your forearms are not set in stone - and, with proper exercise and diet, it is entirely possible to make them appear both larger in size and more toned in appearance.

Muscular Anatomy of the Forearm

An important point to understand is that the forearms are not in fact a single muscle, but actually several smaller muscles with a specific few making up most of the mass found therein.

These are the brachioradialis (of which makes up almost half of the entire forearm), the various smaller flexor muscles and the similarly sized pronator muscles.

forearm musculature

When bodybuilders and similar athletes wish to create thicker and more defined forearm musculature through the use of exercise, it is usually the brachioradialis and the flexor carpi radialis muscles that are focused upon.

Such a targeted training focus is simply because these two muscles are the largest superficial muscles found in the forearm, meaning that they are the most visible and therefore will have the greatest change when it comes to pure forearm appearance.

Genetics and Forearm Size

It should be noted that quite a bit of natural forearm size is due to an individual’s genetic makeup, with factors like muscle attachment points, bone density and even adipose tissue deposition all directly relating to how skinny someone’s forearms may or may not be.

Regardless of how “poor” your forearm genetics may be, however, it is still entirely possible to develop more defined and muscular forearms with the proper training methods.

Wrist Size

Unfortunately, there is very little that resistance training can do in regards to the size of someone's wrists. 

This particular caveat to forearm training is because of the relative thickness of all skeletal and connective tissue that surrounds the wrist area, leading to the size of an individual’s wrist remaining much the same no matter what sort of training they do.

How to Make Your Forearms Bigger With Exercise

Training the muscles of the forearms shares much the same principles with virtually every other type of muscular training; that of proper exercise performance supported by adequate rest and nutrition.

In addition to direct forearm muscle group isolation training, there is also some level of benefit that may be developed from the performance of exercises otherwise unrelated to the forearm muscles in a dynamic capacity.

Proper Exercises

The first and most important aspect of forearm muscle training is the proper development of training stimulus in said muscles.

Correct training stimulus may be achieved with isolation exercises that train the forearm muscles in both a dynamic and static capacity, meaning that, quite often, forearm workouts will involve more than a single exercise.

In addition to achieving the correct type of muscular contraction, the exerciser must also seek to develop the correct parts of the forearm. Since the entire reason behind this workout is the development of forearm muscle mass, the largest muscle groups found in the area should be the focus of the workout.

Adequate Rest and Diet

As any athletic coach would advise, achieving proper muscular development is not solely motivated by training stimulus; the body must also be allowed to build itself stronger than before with sufficient rest time, caloric intake and protein intake.

Days of rest should be taken between heavy forearm workout sessions, and the exerciser should ensure that they always eat an adequate amount of protein per day, with the specific amount depending on their body weight and training experience.

Forearm Training in Compound Exercises

In addition to direct forearm muscle group training, the muscles of the forearm can also be trained as a secondary benefit of performing certain heavy compound exercises like the barbell deadlift, pull-ups and even bicep curls.

As such - apart from being a more advisable approach - combining direct forearm isolation workouts with other exercises that target the rest of the body will only improve the size and strength of your forearms.

What Exercises Make the Forearms Bigger?

While any sort of training stimulus placed on the muscles of the forearms will elicit a hypertrophic effect, certain exercises are particularly adept at targeting the correct muscle groups within the forearms so as to maximize muscle mass developed.

Such exercises will usually target the aforementioned brachioradialis and flexor muscles, of which are responsible for the majority of the forearm in terms of pure tissue volume.

1. Hammer Curls

Hammer curls are among one of the most effective methods of achieving thicker forearms, with the added benefit of also training the biceps brachii due to its full kinetic activation of the arm.

dumbbell hammer curl

When performing this particular forearm builder, the exerciser will be best served maintaining a stationary elbow so as to maximize brachioradialis muscle activation while avoiding excessive momentum that may injure their wrist or shoulder.

Hammer curls work best as forearm mass builders when performed in the range of eight to fifteen repetitions for three sets or more.

2. Dumbbell Wrist Curls

A classic exercise for building wrist flexor strength and size, dumbbell wrist curls get a bad rap for placing excessive stress on the wrist of the exerciser. This may be mitigated by utilizing a low to moderate amount of weight and high volumes of repetitions per set.

dumbbell reverse wrist curl

Dumbbell wrist curls are best combined with hammer curls or other exercises that train the brachioradialis so as to achieve a more complete forearm-mass building workout. 

3. Plate Pinches

Plate pinches differ from other types of forearm muscle exercises due to the sort of training stimulus it provides.

Unlike such exercises like the dumbbell wrist curl, plate pinches activate all muscles of the forearms (save for the brachioradialis) in an isometric capacity, meaning that less hypertrophy is achieved in favor of muscular endurance and strength developments.

While, in this instance, the entire reason for forming a forearm workout routine is to develop forearm muscle mass, doing so will be vastly accelerated if the exerciser is able to also develop the strength and endurance of their forearms as well.

Plate pinches should be performed for up to five sets, with each set featuring the exerciser pinching their chosen weight plate until their grip gives out.

Programming a Forearm Workout Routine

Apart from ensuring that both static and dynamic exercises are performed during a forearm workout routine, the exerciser should also ensure that these exercises do not affect other sorts of training that they may be participating in.

As the forearms and hands are consistently used regardless of what sort of workout is performed, any forearm workout routine should either be performed after a training session or on days where the body has sufficient time to recover.

Furthermore, due to how delicate the tendons and bones of the wrist and hands are, the exerciser should strive to always perform such forearm exercises at a low to moderate level of resistance so as to avoid injury.

Generally, performing one to two dynamic forearm exercises and a single isometric exercise for up to four sets should be sufficient, so long as a high volume of repetitions are performed in each set.

Final Thoughts

To conclude this article, we would like to push forward the idea that it is not solely the forearms that should be trained, regardless of how skinny they may be.

A good foundation for developing a healthy and well-proportioned body lies in the proper training of the entire skeletal muscle system, and many individuals will see significant improvements in the size of their forearms from not only direct forearm workouts but also heavy compound exercises as well.


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2. S. Fryer, K. J. Stone, J. Sveen, T. Dickson, V. España-Romero, D. Giles, J. Baláš, L. Stoner & N. Draper (2017) Differences in forearm strength, endurance, and hemodynamic kinetics between male boulderers and lead rock climbers, European Journal of Sport Science, 17:9, 1177-1183, DOI: 10.1080/17461391.2017.1353135

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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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