We've mentioned many times that the biceps brachii origin and insertion gives this muscle (as the name heavily implies) a dual function. You can use this fact to take your TRX curls to the next level.
Since the biceps perform forearm supination as well as elbow flexion, you can recruit more of your brachioradialis and brachialis muscle fibers by putting your biceps in a position of mechanical disadvantage, which is to say, by using an overhand grip.
But the reason why the traditional dumbbell Zottman curl is so effective is that it makes use of your bicep strength during the concentric portion of the rep in order to overload your brachialis and brachioradialis with more resistance during the eccentric phase of the rep.
TRX Zottman curl exercise details
- Main Muscles: Biceps brachii, brachioradialis, brachialis
- Secondary Muscles: Forearm flexors, forearm extensors, abs
- Exercise Type: Strength
- Exercise Mechanics: Isolation
- Difficulty Level: Intermediate
- Equipment Needed: Suspension trainer
How to do TRX Zottman curls
- Suspend your TRX to a doorframe or any secure anchor point above head height.
- Take a step away from your door, and then grab the TRX handles with an underhand grip.
- Place your feet together and lean your body back slightly.
- Curl your face toward the handles and squeeze your biceps forcefully.
- Rotate your palms so that you're now holding the handles with an overhand grip.
- Lower your body slowly until your arms are completely extended.
- Repeat the motion for 3-5 sets of 8-12 reps.
TRX Zottman curl advantages
Zottman curls make an excellent addition to any TRX bicep workout because they train two key arm muscles—the brachioradialis and the brachialis—that many people need to improve.
They're excellent for the brachialis
The key to performing the TRX Zottman curl correctly is to make your arms work as hard as possible during every part of the lifting motion.
In practice, this means flexing your biceps forcefully once they're maximally contracted. But it also entails lowering your body slowly so that your muscles get to benefit and grow from the fiber-tearing tension that's part and parcel of the TRX Zottman curl eccentric phase.
Slow negatives are especially effective for the brachialis because it's a very fatigue-resistant muscle that responds best to slower rep tempos and plenty of time under tension. Therefore, to achieve the fastest and best results, you want to lower your body over a 3-5 second duration so that you can wear down this workhorse of a muscle.
You still want to perform the concentric part of the rep explosively in order to target the fast-twitch muscle fibers. But you also want to take special care to make sure that you don't rush the eccentric phase of the rep either.
You can do them almost anywhere
You can do forearm workouts with the TRX from virtually anywhere in the world, proving that you can find a suitable anchor point (which will be a doorframe for most people).
As such, you don't have to rely on the availability of gyms to get a great arm workout. Not only does this save money on membership fees, but it also means that you don't need to risk losing muscle by skipping workouts for months on end when you can't get to a gym.
And besides, who on earth wants to plan their life around gyms?
Apart from a suspension trainer, you don't need any fancy equipment to benefit from TRX Zottman curls, which makes them a particularly handy exercise if you travel a lot.
They're a closed chain exercise
Closed chain exercises are safe and highly functional. Performing a Zottman curl with resistance bands, on the other, while completely safe, has minimal carryover to compound movements.
And it's not like the TRX Zottman curl will make you a compound movement king, either.
However, since you move your body toward the apparatus during a TRX Zottman curl (rather than move the weight toward your body), it tends to strengthen your upper body as a whole more so than free weight versions because the core stability requirement is higher.
On the other hand, if you want pure muscle isolation, then open chain exercises, such as a Zottman kettlebell curl, are likely a bit better because they pretty much train the target muscles and nothing else.
Besides being highly functional, the TRX Zottman curl is a brilliant exercise for building muscle and developing strength in your biceps, brachioradialis, and brachialis. The convenience of this movement is also hard to beat because you can perform it pretty much anywhere.
The only downside (if you're a hardcore bodybuilder) is that it's slightly harder to maximally isolate the target muscles when you're doing a Zottman curl on a TRX because the core stability requirement is higher than when you use free weights.
Of course, this hardly matters for most people. You can build as much mass as your genetics will allow with this exercise if you perform it with the correct technique on a consistent basis.