Your arms will grow bigger and fuller than they ever have with just these 2 science-backed arm exercises.

With so many arm exercises out there, it's hard to know which ones actually work.

But you're probably doing too many arm exercises and focusing on the wrong areas. In fact, after cutting out all the fluff and focusing on just 2 science-backed arm exercises, my arms grew bigger and fuller than they ever have. 

And don’t just take my word for it. I asked the top natural bodybuilders and muscle growth researchers the same question.

"If you could only pick 2 arm exercises — 1 bicep exercise and 1 tricep exercise — to maximize growth, what would they be?"

And they all pointed to the same 2 weird arm exercises I’ve been using. 

Today, I’ll show you what these 2 arm exercises are, explain the science behind why they’re so effective, and teach you how to do them properly so your arms grow faster than ever. 

Biceps

So, like most people, out of the many arm exercises available for the biceps, I started in the gym with standard bicep curls. 

And I’m not gonna lie. They did the job.

But after I passed my “newbie gains” phase, my arms became a lot harder to grow.

Downsides Of Using Curls-Based Arm Exercises For Biceps

And that’s when I started learning more about the potential downsides of regular curls.

They challenge your biceps mostly in the middle position when your arm is flexed.

This is a similar challenge your biceps already get from your back exercises, such as rows and pull-ups, which also tend to be most difficult when your arm is in that same position.

Plus, because the biceps cross all the way over the shoulder, exercises like dumbbell curls don't stretch your biceps as much as they could by exercises where your arm stays behind you.

Which, at least based on research on other muscle groups, seems to be a powerful way to stimulate more growth. 

What's The Best Biceps Exercise?

But to discover the best exercise for your biceps, scientists from a brand new 2025 study ran an exercise comparison.

They split participants into 2 groups.

One group did only incline curls for 8 weeks, whereas the other group did preacher curls.

Although both these exercises work the biceps, the challenge they place on them is actually very different:

• During incline curls: Your arms hang behind your body, providing an even greater stretch on the biceps. But the exercise is still hardest right around the middle, just like regular curls. 
• During preacher curls: Your arm is placed in front of your body, so the biceps aren’t stretched as much. But unlike the incline curls, this setup challenges your biceps much more at the bottom position when your arm is almost fully extended.

Using this study design, the researchers wanted to find out which of these arm exercises causes more biceps growth:

1. An exercise that focuses more on “stretching” the biceps?
2. Or an exercise that focuses more on challenging the biceps the most at the bottom when the bicep is still quite stretched but just not stretched quite as much as it is during incline curls?

And the results were … well, confusing.

Incline curls led to more growth in the upper part of the arm, but preacher curls led to more growth in the lower part of the arm! 

Another study that’s yet to be released tested the same thing but used MRI for more accurate measurement and got similar results.

What You Want In A Biceps Exercise

So what does this mean? 

Well, theoretically, to maximize growth in all parts of your biceps, you’d want an exercise where:

1. The challenge is hardest at the bottom, just like they are with preacher curls
2. BUT without the arm held in front of the body, so the biceps are more stretched

This leads me to one of the “weirdest” bicep arm exercises most of the fitness experts I spoke to recommended.

Option 1

Starting with pro-natural bodybuilder and elite coach Alberto Nunez.

Alberto Nunez:

"I really like those preacher curl benches or tables that are really wide where I can lean back and have my humerus and slight, it's not full shoulder extension, but they're right at about my midline and basically perform a curl like this."

PhD student and science advisor for our BuiltWithScience+ app, Daniel Plotkin, explains why this exercise is so effective. 

Daniel Plotkin:

"I'm gonna have to go with a reverse preacher curl. 

It covers a lot of bases that wouldn't be covered with those compound back movements, where the exercises are typically hardest in the mid to shorten position. 

So, by lying back on a preacher curl bench, your biceps are still hardest near the bottom, just like they would be during a normal preacher curl, but your arms are positioned in more of a stretch because they aren’t held in front of your body."

Plus, it has another unique benefit that most dumbbell curls miss.

Alberto Nunez:

"I found it very beneficial to just have something on my arm when I'm curling.

I really like the stability aspect of it because when you think about it, arms, they can move all over the place.

That's something people forget.

It's like the bigger you get, probably the more strict form you need. It's very easy for you to use your own body weight to basically contaminate an exercise."

Option 2

However, Dr. Mike, PhD researcher and competitive bodybuilder, actually recommended an even “weirder” exercise that still applies a similar concept.

Dr. Mike:

"The flat bench dumbbell curl really puts that tension at the maximum stretch and length and position of the muscles. 

It has that same feel for your biceps that stiff-legged deadlifts, when done properly, have for your hamstrings.

You know what I'm talking about?

They're getting pulled apart with maximum tension at the stretch. There's just no replacement for that. Once you try it, it's like the crystal of champagne of bicep arm exercises.

You're like, man, fuck all the rest of this."

Now, I will admit this is possibly one of the "weirdest" bicep arm exercises I've seen, and even I was skeptical at first.

But even though pumps and soreness aren’t everything, after trying this exercise, I’m not kidding.

It gave me the biggest pump and post-workout soreness I’ve ever had, so much so that it’s easily become my current favorite. 

But, they lack the stability that the preacher bench provides, and supporting your arms in this free-held position can place a lot of demand on your front delts. 

So, an easy fix I’ve recently seen from biomechanics expert Coach Kassem is to position yourself sideways on the bench so that your arms are now supported by the bench.

You lose some stretch in your biceps, but it does make up for it with the extra stability.

But use caution.

These still require a good amount of shoulder mobility, and they will take some getting used to. So don’t force it if it feels off, and start light.

For example, I can do regular curls with 55 lbs, but for these, I’m using 30 lbs max.

Option 3

But because not everyone will have a preacher curl bench or feel comfortable doing the laying dumbbell curls, there’s a third option with cables.

I’ve shown this in past articles (e.g., this 'How to get wider biceps' article) but you set up the cables to about wrist height and then curl with your arms held behind your body.

While these lack the arm support you get from using a bench, you still tick the boxes in terms of the stretch and resistance challenge.

These 3 exercises are all very similar in terms of what they’re doing to the biceps, so give them all a shot and pick the one you find works best for you.

Triceps

But even with the best arm exercises for the bicep, your biceps only contribute about a third of your arm size.

The other two-thirds? The triceps. 

Unfortunately, most people use arm exercises — like pushdowns, close-grip presses, or dips — that don’t allow this muscle to reach its full potential.

Those arm exercises primarily work just 2 parts of the triceps:

1. Lateral head
2. Medial head

Which are what beef up the triceps from the front and side.

But the third head, the long head, is the biggest part of the triceps and beefs them up from the back and hangs down when you flex your arms.

So, what’s the better option?

A Tricep Exercise That Grows All 3 Heads

To figure out what the best triceps exercise out of all available arm exercises was (i.e., one that grew all 3 triceps heads), scientists from a 2022 study had subjects perform:

• Overhead extensions with one arm
• Pushdowns with the other arm

... for 12 weeks.

Now, because the long head crosses over the shoulder, whenever you do a triceps exercise with your arm overhead, this muscle gets stretched, which, as you know by now, seems to boost growth in certain muscles. 

But surprisingly, all 3 heads grew more with the overhead extensions, resulting in 1.4x more overall triceps growth than the pushdowns. 

Now, we don’t yet know why the other 2 heads grew more, and we could definitely use another study to confirm these findings, but the researchers used MRI, which is the gold standard of measurement, so the study is strong. 

This is also why every single expert I spoke to chose the overhead extension as their #1 triceps exercise out of all available arm exercises.

Alberto Nunez:

"Personally, I just like the overhead tricep extension with a rope. The 2 options are either standing using an easy bar or seated behind the back."

Dr. Mike:

"If you're already doing pressing for your chest, you're doing the motion for your triceps that has the other angles built in anyway, you might as well go overhead to get all those awesome benefits."

Daniel Plotkin:

"If I had to choose one, I'd go with an overhead tricep extension with a cable, usually with my hand wrapped through the D handle and my elbow propped up. 

It's one of the few triceps arm exercises that feels really good on my elbow, especially in that overhead position, and it checks a lot of boxes.

It's hardest in the lengthened position, puts the long head, the tricep in a lengthened position, so can't go wrong, feels good, is stable, and hits the long head in a way that isn't hit in other triceps arm exercises."

Which Variation Should You Use?

But what you may have noticed is that each expert I spoke to preferred a different variation... 

Why?

Alberto Nunez:

"I think this is where most people find they have elbow issues over time.

Very few people after the age of 30 do you see skull crushing like at 45. We've all done that. And when you see a young man doing it, you're like, oh, okay, you've probably got 5 more years of that, and then you'll be joining me over here in the cables.

So, especially with triceps, it's just picking the movement you feel is custom-made for you."

So, even though Dr. Mike loves the bar overhead extensions, my body structure finds it extremely uncomfortable because it locks my hands in a fixed position.

I’ve even injured myself a couple of times trying to force it.

My personal favorite right now is:

• Either Daniel’s recommendation, which is the cable overhead extension because it feels easiest on my joints
• Or even something as simple as the standing single-arm dumbbell overhead extension because it’s easy to set up and doesn’t rely on a cable machine being available

But try out the different variations.

What you’re looking for is a variation where you feel very little to no pain in your elbows or shoulders as you do it, yet feel a great pump in your triceps after you finish your set.

But whichever you choose, here’s the key:

• For cables: Bump up the cable to about hip height, and stand close to the cable so that the challenge is hardest closer to the bottom when the muscle is stretched.

• For the dumbbell version: Keep your upper arm locked straight up and down; don’t allow it to bend as you tire. 

And on all the variations, don’t stop halfway.

Get as deep a stretch in the triceps as possible by letting your hand come down behind your neck as far as it can.

TL;DR

• The downsides of regular curls for biceps are: 1) they challenge your biceps similarly to back exercises, and 2) they don’t stretch your biceps as much as behind-the-body arm exercises.
• Theoretically, a behind-the-body exercise that’s most challenging at the bottom should maximise growth in all parts of your biceps. There are 3 options: reverse preacher curls, flat bench dumbbell curls, and behind-the-body cable curls.
• Most tricep arm exercises work just the lateral and medial heads.
• A 2022 study found that overhead extensions led to better growth in all 3 tricep heads than pushdowns (1.4x more overall growth).
• There are many overhead extension variations — choose the one that’s most comfortable for you.

Implementing The 2 Arm Exercises

As for how to implement these arm exercises, while other arm exercises are still great and can help grow your arms, for the best results, you’ll wanna do these 2 specific movements for 3 sets of 10-15 reps at least 1-2 times per week.

And with my new app, BuiltWithScience+, all of this programming is taken care of for you.

We carefully select each exercise in your routine based not only on what’s been proven to be most effective but also on what suits your specific body the best and what equipment you have available to you.

Plus, it coaches you every week telling you exactly how much weight and how many reps to do based on how you’ve been progressing.

The same goes for your nutrition and tracking your body weight.

It’s the only fitness app you need.

You can try it completely free for 2 weeks by clicking on the link below:

Click the button below to try the BWS+ app for 2 weeks, for free, no strings attached:

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Then check out this article next to learn about the 2 best deltoid exercises to grow your shoulders.

Thanks for sticking to the end, and I’ll see ya next time!