Considering that the biceps and triceps are two of the smaller muscles in the human body they typically get a lot more attention than their larger counterparts.
But which muscle should be stronger?
Your biceps and triceps should actually be the same strength, although for many people this is rarely the case. Looking at possibly the most popular exercise for each muscle, you should be lifting the same weight for barbell bicep curls and skull crushers. If you find one of these movements easier than the other this points to a potential strength imbalance between the muscles.
The Bicep vs. Tricep Size Ratio
I’m sure it comes as quite a surprise that the biceps and triceps should be as strong as each other.
I know for a fact that most people would disagree and potentially provide proof otherwise.
As an example, most of you will probably be able to lift more weight with a one-arm dumbbell curl than you would with a tricep kickback.
So, this may lead you to believe that the biceps are stronger than the triceps.
However, in truth, these aren’t like-for-like exercises.
The angle of your body is completely different between the two exercises.
Plus, the tricep kickback isolates the tricep muscle to a far greater extent.
Whereas, performing dumbbell bicep curls bring the forearms and brachialis more into play.
I know some trainees like to compare biceps curls to tricep extensions., but even then you should be able to lift significantly more with tricep extensions.
With that being said, just as many people would say that the tricep is stronger than the bicep simply because of the size difference.
The Anatomy of the Upper Arm
I think most people are aware that the tricep is approximately twice the size of the bicep.
Firstly, the bicep is made up of two separate bundles of muscles, referred to as heads.
You have the long head and short head of the biceps.
The triceps have three bundles of muscles (heads), which are the lateral, long, and medial heads.
However, this is where it gets interesting if you’re looking to train to get big arms.
The triceps make up approximately 55% of the upper arm, whereas the biceps make up 30%.
So, this only gives us a total of 85%.
What about the other 15% then?
The remaining 15% of the upper arm is occupied by the brachialis muscle.
The brachialis in most parts is “hidden” under the bicep, although it can be seen on the outside of the upper arm.
But, the more you train the brachialis, the bigger it gets, and this can actually make your arms appear a lot bigger.
In effect, the more muscular the brachialis gets the further it pushes your biceps and triceps away from each other.
So, the result is that your arms look a lot wider.
Just in case you were wondering, the best exercises to train the brachialis are cross-body hammer curls and standard hammer curls.
Going back to the biceps and triceps, it’s extremely interesting to note that the bigger muscle is not automatically the stronger one.
I’m sure that may come as a shock to you.
In fact, there are various antagonist muscles (opposite muscles) in the human body where the smaller muscle is stronger than the bigger muscle.
This is typically because the smaller muscle has a mechanical advantage due to its location.
But when it comes to biceps and triceps, regardless of the size difference, they should be the same strength.
The Bicep vs. Tricep Strength Test
You can actually take two extremely popular arm exercises and test the strength of your biceps and triceps against each other.
Firstly, grab a barbell in order to do bicep curls.
Load the barbell with a weight that you would typically perform 8-10 curls.
Curl the barbell approximately 8-10 times, but make sure that you stop before failure.
Rest for a few minutes – remember this is a test, not an actual workout, so you want your arms to be completely rested.
Now perform skull crushers with the exact same barbell.
You should be able to complete more-or-less the same number of reps prior to hitting failure.
You can forgive one rep either way.
Plus, you may note that you “feel the burn” more in your triceps than biceps.
However, I would personally say that skull crushers are a better isolation exercise than barbell bicep curls.
With that being said, you should be able to lift the same amount of weight with the same amount of ease or difficulty for both exercises.
So, please do try this test and see how you get on.
Do You Have a Strength Imbalance?
I’m going to take a wild guess and say that many of you will have tried the above test and found that the biceps and triceps weren’t equal in strength.
If I’m going to be completely honest, I know this isn’t the case for me.
In fact, the weight that I lift for 8 reps during bicep curls has me struggling at around the 5-6 rep mark with skull crushers.
This was actually a huge surprise to me.
I always figured that my triceps were stronger than my biceps due to how I train.
Basically, one exercise I do more than any other is push ups.
I typically drop to the ground and perform push ups at any given moment in my day.
It’s not unheard-of for me to have performed 300-500 push ups in a day without actually realising it.
But, I will generally perform at least 100 push ups every single day (with the occasional day of rest here-and-there).
With that being said, because of my huge number of weekly push ups I will limit the number of pushing exercises I do in the gym.
But still, I would’ve assumed that this would have made my triceps stronger than my biceps.
How wrong can you be?
I guess this comes down to the fact that I’m a proponent of pulling twice as much as I push in the gym environment.
However, I know for a fact that for many of you this probably isn’t the case.
In fact, the two most popular exercises in the gym are bicep curls and the bench press.
I’m sure there are many people who train these two movements multiple times a week.
I would even say that the bench press could be the only tricep stimulation that some people have on a weekly basis.
And when you consider all the curling, whether with a barbell or dumbbells, that goes on in the gym, the triceps may soon be lagging behind.
Then again, there are those who will train the triceps far more than the biceps due to the size difference of the muscles.
In reality, it should be about finding balance and having biceps and triceps that are just as strong as each other.
Key Learning Points
- Biceps and triceps SHOULD actually be the same strength.
- If one muscle group is significantly stronger than the other this points to a training imbalance, e.g. always training biceps, never training triceps.
- The triceps take up approximately two-thirds of the upper arm area.
- Test your bicep/tricep comparative strength by first performing barbell biceps curls, then resting, and performing skull crushers with exactky the same barbell. You should be able to perform the same number of reps for both exercises.
- Many people have a strength imbalance due to how they train, i.e. more push-based training than pull-based training, more bicep work than tricep.
- To make your arms look wider you should also be training the brachialis muscle.
Hi, I’m Partha, owner and founder of My Bodyweight Exercises. I am a Level 3 Personal Trainer and Certified Strength & Conditioning Specialist through the Register of Exercise Professionals, United Kingdom. I have been a regular gym-goer since 2000 and coaching clients since 2012. My aim is to help you achieve your body composition goals.