The lower arm muscles are notoriously tricky to work out with suspension trainers. Nonetheless, these TRX forearm exercises will help to strengthen your grip, wrists, and, of course, the forearms themselves.
Related post: Total Gym forearm exercises
Top 5 TRX forearm exercises
Each of these TRX forearm exercises works slightly different muscles. As such, there are no universal best exercises, so consider all of these drills equally effective in their own right for building the muscles of your lower arm. 
1. Reverse curl
While the TRX reverse curl does work the biceps, it also works the extensors of the forearm, including the brachioradialis. Since most people have overdeveloped forearm flexors in relation to their extensors, this drill will help you to build balanced upper and lower arms.
Suspend your TRX at head height or just above, and then shuffle your feet toward the suspension point so that your body is positioned at an angle. Also, make sure that your feet are together.
Begin by grabbing the TRX handles with a pronated (overhand) grip so that your knuckles are facing toward you and your elbows are fully locked out. I know that it’s a little harder, but try and use a thumbless grip if you can because studies show that this grip boosts forearm activation.
Pull your forehead toward the handles by flexing your elbows until the tops of your forearms are touching your biceps. Hold the contraction for a second or two—make sure to really squeeze that brachioradialis—and then lower your body under control until your elbows are almost completely locked out again. Repeat for 3-4 sets of 8-12 reps.
2. TRX forearm curl
Admittedly, wrist curls are easier to do with free weights than they are with suspension trainers. But since the TRX has a large grip component to it, this forearm curl variation can give you a surprisingly effective pump.
The setup is exactly the same as for the reverse curl that I just showed you: TRX suspended above you, feet together, body leaning back at an angle, and elbows locked out.
This time, however, you’re going to hold the handles with a supinated grip so that your palms are facing up. Then, while keeping your arms virtually locked out, flex your wrists so that your hands curl toward your forearms. Hold this contraction for a second and then repeat for 15-20 reps.
The range of motion (ROM) for this exercise is small, so don't expect tons of body movement. The key is to perform high reps so that you get enough time under tension to stimulate new growth. I recommend 15-20 reps to start with, but if that becomes too easy and you don't feel the burn, then you can go as high as 30 reps to really pump up those forearms.
To work your extensors, perform the same motion but with an overhand grip. Again, you’re flexing your wrists while keeping your elbows locked out and your upper arms still so that you can really isolate the forearms.
3. Pull-up holds
This unique TRX forearm exercise also works your back and core, but it really hammers the lower arms. If you struggle with your grip fatiguing prematurely during compound movements, then this is a great drill to do.
Suspend your TRX above head height (either to the ceiling or to a high pull-up bar) and shorten it as much as possible. Then, grab the handles with an overhand grip, place your legs straight out in front of you with your knees fully locked out, and ensure that your torso is positioned directly underneath the handles.
From here, make sure that your elbows are fully locked out, but also ensure that your back is slightly engaged. Don’t shrug your shoulders all the way up because this can strain the rotator cuffs.
Now that you’re all set, grip the handles tightly and try and hold the position for 60-90 seconds. It might feel easy at first, but since your legs are all the way out in front of you, you’re really going to start to feel the forearm burn once you hit the minute mark.
4. Zottman curl
Work your biceps while blasting your forearms with TRX Zottman curls. This exercise is one of the most effective TRX forearm exercises because virtually everyone has overdeveloped flexors in comparison to their extensors.
Suspend your TRX above head height, and then grab the handles with an underhand grip so that your palms are facing toward the ceiling. With your elbows completely locked out, shuffle your feet toward the suspension point so that your body is at an angle. This positioning means that you’re using more of your body weight as resistance.
Begin the set by curling your forehead toward the handles until you feel an intense bicep contraction. Then, immediately flip your grip to a pronated position—by rotating the handles—so that your palms are facing down. From there, lower your body while maintaining this overhand grip until your elbows are almost fully locked out.
The reason this exercise is so effective is that you’re using the strength of your biceps during the concentric part of the rep to overload your forearm extensors on the eccentric portion of the rep.
5. Hammer curl
TRX hammer curls should be a staple in your TRX forearm workout because it ‘hammers’ the brachioradialis while also adding mass to the biceps.
The trick is to grab your suspension trainer on the bottom part of the strap rather than on the handles. This enables you to use a proper neutral grip.
Again, suspend your TRX above head height and then grab onto the very bottom of the strap, underneath the handles. Then, lean your body back so that you have plenty of ROM for your arms.
Begin the rep by curling your head toward the handles and squeezing your biceps and brachioradialis as hard as you can. Hold the contraction for a second, and then lower your torso until your elbows are fully locked out. Repeat for 3-4 sets of 8-12 reps.
See Also: TRX bicep workout
Conclusion: Which TRX forearm exercises are the most effective?
You can do a surprising amount of TRX forearm exercises with this iconic suspension trainer. And it’s not like the setup is complicated, either.
Plus, since you’re working with your own body weight, you won’t be putting excessive pressure on your wrists because you’re not lifting free weights, which can often slip around and cause injury.
Overall, I recommend doing the regular forearm curl as well as the reverse variation so that you can isolate your forearms. In particular, you might want to do them at the end of a regular workout so that your lower arms aren’t too fatigued for your compound movements.
Also, consider doing the pull-up hold if you want to develop a —an attribute that's very important for TRX training in general.
- Boles, C. A., Kannam, S., & Cardwell, A. B. (2000). The Forearm. American Journal of Roentgenology, 174(1), 151–159. https://doi.org/10.2214/ajr.174.1.1740151
- Bohannon, R. W. (2019). Grip Strength: An Indispensable Biomarker For Older Adults. Clinical Interventions in Aging, Volume 14, 1681–1691. https://doi.org/10.2147/cia.s194543
- How to do a TRX arms exercise Bicep Hammer Curl for arm thickness. (2020, July 16). [Video]. YouTube. https://www.youtube.com/watch?v=BsFfU_UzoLE