The 2 TRX Arm Exercises That Grow Your Biceps and Triceps

I’ve spent 10 years testing arm training research using a TRX suspension trainer.

And my arms are thicker and more defined than they’ve ever been, using just two moves.

But some of what the research said should work didn’t with a TRX… 

And if your arm training has stalled, it’s almost always because of this.

So in this post, I’m going to show you the tricep move the research pointed me to instantly and the bicep experiments I had to scrap before I figured out what actually works.

Now most people think biceps when they think arm size…

But your triceps are actually two-thirds of your arm mass.

So let’s start there….

Don’t have time to read the post in full? Then watch the video below to learn the 2 TRX arm exercises that grow your biceps and triceps:

https://www.youtube.com/watch?v=vjPDT3k3EcE

The Best TRX Triceps Exercise

My triceps training used to focus on two TRX exercises:

1. TRX close-grip presses
2. TRX dips

My arms got defined, but they lacked any thickness.

That’s because those two exercises mostly work the lateral and medial heads.

But there’s a third head – the long head, which is actually the biggest part of the triceps,

And it’s what hangs down at the back of your arm for that thick look.

To test how to grow it, scientists ran a 12-week study.

One arm did cable pressdowns, similar to close presses.

The other arm did overhead extensions, where the long head gets stretched at the bottom…

The results?

All three heads grew 1.4 times more with the overhead extensions, measured by MRI, the gold standard.

So if you want to fully grow your triceps, you need a TRX exercise where:

1. the arm goes overhead
2. the long head gets stretched
3. the load is hardest in that stretched position.

And that one exercise has done more for my triceps than every dip and close-grip press combined…

TRX Skullcrushers

Skullcrushers are the king for arm size…

Watch this video below and I’ll take you through the effective tricep skullcrusher technique points…

https://youtu.be/dK45ATv3YWY

You see from the starting position at the top, you lower your arms down and behind your head. 

And at this bottom range your getting the deepest stretch on the tricep muscles under load.

It’s also the hardest position to press out of.

So you’ve got stretch plus maximum load, in exactly the same position the research said growth happens.

And it’s a near-perfect match to the cable overhead extension the studies are pointing at.

But here’s where the TRX actually beats the cables…

When you fatigue, you don’t have to stop and change the weight..

You just step forward and keep going. So there’s minimal break in tension to keep pushing on

This is the cleanest TRX-to-research match I’ve found anywhere in arm training.

Quick one before we get into biceps…

If you want this kind of training built into a full body plan? I’ve put together a free 4-week suspension trainer strength routine that hits your whole body.

Link’s below:

The Best TRX Biceps Exercise

Now bicep training is where things got interesting and where the research didn’t quite translate the way I expected…

So like most people training biceps with a TRX, I started out with standard curls.

And I’m not going to lie they did the job…

But after I got past those early gains, my biceps became a lot harder to grow.

You see TRX bicep curls challenge your biceps mostly in the middle position, when your arm is already half-flexed,

leaving the top and bottom positions relatively unchallenged…

So that’s when I started asking myself, was there a different exercise or better technique that would change that?

And I found a study in 2025 where scientists ran a comparison to find the best gym exercises for the biceps.

For 8 weeks one group did only incline curls where your arms hang behind your body giving the bicep a bigger stretch….

And the other group did only preacher curls where your arm is placed in front of your body…

But the results were confusing:

• Incline curls grew the upper bicep more.
• But preacher curls grew the lower bicep more.

So theoretically, to grow every part of your bicep:

1. You’d want an exercise that’s hardest at the bottom — like a preacher curl
2. But with the arm held behind the body, so the bicep is in a stretched position. 

So I started experimenting with a suspension trainer…

TRX Biceps Exercise 1

The first thing I tried was a single-arm curl, done from the side.

The idea was to angle my body so the working arm could get into a deeper stretched position at the bottom of the rep.

And on paper, it worked…

I could feel a stretch on the bicep at the bottom that I’d never felt on a standard curl.

The strap kept tension on the muscle the whole time.

But the problem was, over time it felt awkward on the shoulder joint.

Holding that arm out and slightly up while curling against the strap put the shoulder in a position it really didn’t want to be in.

So I moved on…

TRX Biceps Exercise 2

The second thing I tried was dropping the anchor point under the door with the strap pulling from below.

To get the biceps into that fully extended position at the bottom, you have to drop to your knees, and lean right back

This one did get me closer to what the research wanted.

With the anchor low, the biceps have to actively hold the stretched position against the strap.

You get a real, loaded stretch at the bottom of every rep.

But the problem with this one is the setup. 

It feels uncomfortable, and honestly, the marginal improvement in stretch wasn’t worth the discomfort…

The Honest Conclusion

Now this is going to sound anticlimactic…

My conclusion was that the standard TRX curl is still the best and probably only option…

Watch this video below and I’ll take you through the effective bicep curls technique points…

https://youtu.be/x4Jxl3QvF0s

But, and this is the part most TRX users miss, two small technique upgrades change everything about how well it works.

And they’re the reason my biceps came off a plateau and started growing again….

TRX Bicep Curls Technique Upgrade

The first technique upgrade is at the bottom

With beginners…

I tell them to keep a slight bend in the elbows so they don’t hang and lose tension on the biceps.

But once you’re past the basics, instead, straighten your arms fully and at the same time, actively contract your triceps.

Squeeze them hard, like you’re trying to straighten the arm even more.

This stretches the biceps which maintains tension because when one muscle contracts, the opposite muscle has to lengthen.

So contracting your tricep at the bottom forces the bicep into a deeper stretch than it could ever reach on its own.

It’s not the same depth you’d get from the arm fully behind your body,

But it’s the closest you’ll get on a suspension trainer to that lengthened position the research is pointing at.

The second upgrade…

is to rotate your wrist at the top so your little finger comes up and your thumb rotates down…

You’ll feel the bicep contract harder even harder, that combined rotation is what fully shortens the muscle.

You’ll feel the bicep contract harder even harder, that combined rotation is what fully shortens the muscle.

So you’re now challenging it through a bigger range of motion.

These two cues together are the biggest reason my biceps started growing again…

So how do you actually put these two exercises into your training routine for maximum arm growth…

Let me show you…

TRX Exercise Technique to Build Arms Fast

First, this doesn’t mean every other arm exercise like close presses, reverse curls, and hammer grip are useless.

They all still have a place in a well-rounded programme.

But if you want to maximise the time you’ve got and get the most growth out of every session, 

the skullcrusher and the upgraded curl are where most of your arm gains are going to come from.

But they’re useless unless you do them with muscle-Centric Technique:

1. Lock your body in stone.
2. Lower slowly until you feel the stretch at the bottom.
3. Squeeze hard to drive back up.
4. Hold the squeeze at the top.
5. No bouncing, no swinging.

For both, aim for three sets of 8 to 12 reps, two times per week. 

And don’t be surprised if you have to drop the difficulty compared to what you’re used to.

Doing them with slow control technique and full range of motion loads the muscle in ways most people have never trained before

so you’ll feel them differently compared to mindless conventional training.

Train them consistently for 8 to 12 weeks and your arms will look noticeably thicker in a t-shirt…

Without adding a single new exercise.

But honestly, even with the best arm exercises in the world…

If the rest of your body is lagging behind, your still going to look and feel half-baked.

To get the best results, you want to combine this arm training with full-body muscle building.

So checkout this post next and I’ll show you the eight essential TRX moves everyone needs to master to build full-body muscle, strength, and mobility.

Here’s to your fitness freedom

Coach Adam, aka TRX Traveller
Founder, Fitness Freedom Athletes