Out of all the different forearm muscles, it’s the flexors that are the easiest to train. Why?
Because they’re involved in virtually every back and bicep exercise. But even performing household chores, and especially doing manual labor, can create a pair of strong, functional forearms.
However, for those having problems with their flexor carpi radialis, it can be a useful idea to throw in some isolation exercises to strengthen the smaller forearm muscles.
Related flexor guides:
- Flexor carpi ulnaris exercises
- Flexor digitorum profundus exercises
- Flexor digitorum superficialis stretches exercises
- Flexor pollicis longus exercises
Flexor carpi radialis anatomy
The flexor carpi radialis is a long, superficial muscle that’s located in the anterior compartment of the forearm. It’s anterior in the sense that it’s located in the front of the forearm, but in practical terms, this means the underside of the forearm—the meat of your lower arm.
The flexor carpi radialis is also what’s called a fusiform muscle.  This simply means that it’s widest in the middle (much like the forearm) and tapers at both ends (like the wrist and elbow).
It originates from the medial epicondyle (an upper arm bone) of the humerus and inserts into the hand, hence why it’s a particularly long muscle.
In addition to wrist flexion, the flexor carpi radialis also performs wrist abduction, which is also called radial deviation.
Flexor carpi radialis exercises
Some muscles of the lower arm are quite complicated to train. However, since the flexor carpi radialis flexes the wrist along with the other 4 muscles of the forearm’s anterior compartment, it’s very straightforward to strengthen it. 
1. Flexor carpi radialis stretch
Here’s how to do the flexor carpi radialis stretch:
- Place your arm out in front of you and lock out your elbow.
- Rotate your arm so that your palm is supinated (facing up).
- Then, with your other hand, apply a gentle stretch to your forearm by pushing down on the fingers of your outstretched arm.
- Hold this flexor carpi radialis stretch for 10-20 seconds and repeat it with your other arm.
2. Wrist curl
There are many different ways to perform a wrist curl. However, using a dumbbell is by far the most straightforward method—especially if you work out at home and only have access to limited equipment.
- Grab a light dumbbell and place your forearm, palms up, on a desk or table. You can also use a weight bench if you’re at the gym.
- Next, allow your hand and wrist to hang off the end of the surface.
- Now slowly lower the dumbbell towards the floor by bending your wrist.
- Bring the weight back up by curling your hand towards your forearm.
- Squeeze your forearm flexors as you raise the weight up.
- Repeat for 2-4 sets of 12-20 reps (high reps are best for this exercise because the muscle fibers are slow-twitch).
3. Timed hold
You can do this exercise with any household objects (loaded shopping bags are particularly handy here) that have a bit of weight to them. However, if you have access to exercise equipment, using dumbbells is likely the most convenient method.
- Hold 2 weighted objects by your sides.
- Gip the items in the palms of your hands rather than with your fingers (this takes the strain off your elbows).
- Maintain the static hold for 30 seconds, working your way up to 45 seconds and then 1 minute before increasing the resistance.
How important is the flexor carpi radialis?
All muscles in the human body have some degree of importance because they allow us to function properly. However, the flexor carpi radialis isn’t so important that we need to perform specific exercises for it. That is, of course, unless we’re having trouble with it.
In this case, I recommend pairing a wrist curl with a stretch. This way, you build strength while also relieving some of the tightness that’s bound to build up in the muscle over time.
- Anconeus muscle exercises
- Brachioradialis workouts
- How to stretch your extensor carpi radialis brevis
- Exercises for the extensor carpi radialis longus
- Extensor carpi ulnaris stretch
- Extensor digitorum exercise
- Extensor pollicis brevis stretches
- Palmaris longus muscle exercises
- Pronator quadratus muscles exercise
- Pronator teres exercises
Which of the flexor carpi radialis exercises are the best?
While the anatomy is certainly interesting, and may, in fact, help you pass a few undergraduate exams, most people don't need to do special flexor carpi radialis exercises to strengthen this muscle.
Going about your general resistance training routine will provide plenty of stimulus for the forearm flexors because, in order to lift weights, you have to grip things, as simple as that sounds.
That said, since many people have tight lower arms from work, I recommend doing the flexor carpi radialis stretch to expand the fascia of the muscle and promote better blood flow around the limb.
You needn’t do more than 2 sets of this stretch, though. A little goes a long way when it comes to the flexor carpi radialis (and indeed the rest of the forearms) because it’s such a small muscle.
- Vasković, J. (2020, October 29). Flexor carpi radialis muscle. Kenhub. https://www.kenhub.com/en/library/anatomy/flexor-carpi-radialis-muscle
- Flexor Carpi Radialis. (n.d.). Loyola University Medical Education Network. http://www.meddean.luc.edu/lumen/MedEd/GrossAnatomy/dissector/mml/fcr.htm