Pure grip training is not the most effective way to stimulate forearm growth because it focuses on the finger flexors (flexor digitorum profundus and flexor digitorum superficialis).
Maximal forearm hypertrophy requires wrist work over a full range of motion.
In addition, grip training is heavily dependent on tendon strength and the efficiency of the central nervous system.
While there are many benefits to developing tendon strength and CNS power, forearm hypertrophy requires a different tactic – high reps and a multitude of exercises targeting all forearm muscles with the necessary intensity and movement amplitude.
Wrist Flexors & Finger Flexors
The finger flexors are the muscles that pull the fingers into a fist.
The wrist flexors pull the palm closer to the elbow (wrist flexion).
The finger flexors are engaged during wrist flexion, but the wrist flexors do not participate in finger flexion because their insertions end at the wrist.
To understand the idea a little better, you can try the following exercise:
Step 1: Make a fist.
Your forearm will bulge a little.
Step 2: Flex/clench your wrist.
Your forearm will bulge substantially more.
Here’s what’s happening. The first step activates only the finger flexors whereas the second wakes up the wrist flexors and the finger flexors.
|Wrist Flexors||Finger Flexors|
|Flexor Digitorum Superficialis||Flexor Digitorum Profundus|
|Flexor Digitorum Profundus 4 Heads||Flexor Digitorum Superficialis|
|Flexor Carpi Radialis|
|Flexor Carpi Ulnaris|
|Palmaris Longus (absent in 14% of the population)|
|Flexor Pollicis Longus|
As you can see in the tables above, wrist flexion is dependent on a total of 5-6 muscles whereas finger flexion wakes up only two.
Complete hypertrophy of the forearm flexors requires wrist flexion and cannot be achieved solely through finger flexion.
Subsequently, exercises like pull-ups and deadlifts are actually inferior movements for that particular purpose.
A better choice would be to do wrist curls, wrist rolling and barbell finger rolls with wrist flexion.
Somewhat ironically, for the very same reason, wrist training is an inferior way to build grip strength as it does little to condition the finger tendons and the CNS. If you want to get a better grip, wrist curls are not on top of the list.
A Note on the Palmaris Longus
The muscle known as Palmaris Longus is considered an “evolutionary leftover” that flexes the wrist and tightens the palmar aponeurosis. Experts consider it a weak wrist flexor that doesn’t provide substantial flexing power. 14% of the population doesn’t even have that muscle. Some people have it on one arm but don’t on the other.
When the palmaris longus is absent, the other wrist flexors and the palmaris previs compensate.
Wrist Extensors & Finger Extensors
|Wrist Extensors||Finger Extensors|
|Extensor Carpi Radialis Longus||Extensor Digitorum|
|Extensor Carpi Radialis Brevis||Extensor Digit Minimi|
|Extensor Digitorum||Extensor Indicis|
|Extensor Digiti Minimi||Extensor Pollicis Brevis|
|Extensor Carpi Ulnaris|
|Abductor Pollicis Longus|
|Extensor Pollicis Brevis|
|Extensor Pollicis Longus|
The finger extensors open the palm whereas the wrist extensors bring the outer part of the hand towards the elbow (wrist extension).
Optimal development of all extensors requires “wrist work”. Finger exercises (e.g., fingers extensions against a band) will not be enough as they don’t target all wrist extensors.
Recommended exercises: Reverse curls, hammers curls, reverse wrist curls, wrist roller.
Forearm Pronators and Supinators
A complete forearm workout includes forearm supination and pronation.
Supination = rotating your forearm until the palm faces up
Pronation = rotating the forearm until the palm faces down.
The muscles that supinate the forearm are the supinator, the biceps and the brachioradialis.
The muscles that pronate the forearm are pronator teres, pronator quadratus and the brachioradialis.
Out of all pronator and supinator muscles, the brachioradialis has the biggest impact on forearm size.
- pronation and supination against a resistance band or with an objected weighted on one end;
- reverse curls to target the brachioradialis which works as an elbow flexor too;
Frequently Asked Questions
Do hand grippers increase forearm size?
Hand grippers build “crushing grip strength”, but they are one of the least productive methods for increasing forearm size because the wrist doesn’t move much, and only the finger flexors are under fire.
When forearm hypertrophy is the goal, wrist curls, barbell finger rolls with wrist flexion at the end and wrist rollers produce better results.
Will farmer walks increase the size of my forearm?
Farmer walks are a supporting grip exercise. Similar movements are not optimal for forearm hypertrophy by themselves because they work mainly the finger flexors and lack a concentric (positive) and an eccentric (negative) phase.
I am a beginner. Should I train my forearms directly?
If you are a total beginner (e.g., someone who can’t do a pull-up), you would be better off learning the basic movements before doing isolation work. At that point in your development, you wouldn’t benefit much from highly specialized forearm training.
However, after a couple of months, you may consider doing direct forearm work if you want to maximize the potential of your forearms.
Is direct forearm training really necessary? Aren’t basic exercises sufficient?
If you have good forearm genetics (long muscle bellies), then you may not need to target the forearms directly – general back and arm exercises would be enough.
But if your forearms are a lagging body part and/or you want to boost their growth as much as possible, direct work involving a lot of wrist flexion and extension is your best bet.
Don’t listen to 5×5 gurus saying that your forearms and biceps will grow from holding the bar during squats because they won’t.
How often should I work my forearms?
The forearm can handle a lot of punishment if you build up to it. But in general, more than 3 times a week would be too much for the average individual. Going beyond would get you really close to the point of diminishing returns.
Will forearm training thicken my wrists?
Your wrists will get stronger, but they won’t get much thicker as the joints are made of connective tissues and do not hypertrophy.
The tendons get denser over time but the process is incredibly slow (think years) and even then, the overall circumference of the wrist won’t increase much.
I have time only for 1-2 forearm exercises. What should they be?
- barbell finger rolls with wrist flexion
- reverse biceps curls
- Wrist rolling in both directions
Example Forearm Routines
1. No specialized equipment
The routine below is simple and skips some forearm movements, but it can be done in almost any gym and hits all major muscles contributing to overall forearm growth.
Barbell or dumbbell finger rolls with wrist flexion – 3×8-12
Hammer curls – 3×8-12
Reverse curls – 3×8-12
2. Specialized equipment
Barbell or dumbbell finger rolls with wrist flexion – 3×8-12
Towel hammer curls (you can loop a towel through a barbell plate for those) – 3×8-12
Wrist roller – 2-3 sets each side
If you are a forearm fanatic, add pronation and supination exercises with a sledgehammer for example.