What's the difference between preacher curls and concentration curls? And which is best for building up your biceps muscles?
Concentration curls vs preacher curls: Muscle activation and mechanics
In terms of muscle activation, the difference between concentration curls and preacher curls isn't as significant as you'd think. Both exercises work the exact same muscle groups—biceps, brachialis, brachioradialis, forearm flexors—and both movements also emphasize the same region of the biceps, which is to say, the short (inner) head.
The reason for this short head emphasis is that both drills have you curl with your arms in front of your body, which biomechanically shifts more of the tension onto the inner head of the biceps.
You might have noticed that the exercise mechanics are strikingly similar as well. In fact, the concentration curl is kind of like a preacher curl in a sense because you're using the inside of your leg as a preacher pad in order to brace your arm.
The main difference is that concentration curls are hardest in the contracted position at the top of the rep, whereas preacher curls are most difficult in the stretched position at the bottom of the lifting motion.
As for activation of the secondary muscle groups (brachialis and brachioradialis), things are again equal because these two muscles perform elbow flexion only, which isn't affected by different curling positions.
Concentration curls vs preacher curls: Hypertrophy
Hypertrophy levels are arguably the most important point of comparison in the preacher curl vs concentration curl debate because virtually every weight lifter wants to improve the appearance of their biceps.
Preacher curls are better for overloading the biceps because you can perform them with a variety of barbells, which always enable you to lift heavier weights than you could with dumbbells.
With concentration curls, on the other hand, you're pretty much confined to dumbbells. While this is great for reducing and preventing bicep muscular imbalances, it does mean that you miss out on that high overloading potential that barbells provide.
Of course, you could just do a bent-over barbell concentration curl, but this exercise doesn't isolate your biceps as effectively as the regular concentration curl because you can't brace your arms against your leg.
Although preacher curls are undoubtedly more conducive to progressive overload than concentration curls, that doesn't necessarily mean that they'll build more muscle. As long as you're using good form, training close enough to failure, and increasing the resistance from time to time, you'll be doing everything in your power to maximize your bicep development.
Related Comparison: Preacher curl vs regular curl
Concentration curls vs preacher curls: Strength development
Again, since you can perform preacher curls with a bar, they're naturally more suited to lifting heavier weights. You can certainly lift heavy with dumbbells, but barbells are always going to let you overload your muscles with more resistance.
The catch is that preacher curls and concentration curls strengthen different parts of the lifting motion. Since preacher curls are most demanding when you're close to full elbow extension, they'll help you to develop bicep strength in the stretched position.
Concentration curls, on the other hand, pose the most challenge when your biceps are maximally contracted, which is naturally the weakest position for any muscle. So by helping you to get strong where you're meant to be weak, concentration curls may actually be the superior choice for strengthening your arms.
It depends on which way you look at it. Preacher curls let you lift heavier, but concentration curls (a great preacher curl replacement) are more challenging.
Should you do both exercises?
Should you do a preacher curl or concentration curl? Or can you perform both exercises?
Since each movement emphasizes different portions of the lifting motion, performing both drills is an excellent idea if you want to recruit a broad range of muscle fibers and maximize hypertrophy.
You can also see our spider curl vs preacher curl showdown if you want to know how the preacher curl compares to another popular bicep exercise.
Which one should you do first?
If you're a strength-focused lifter, start with preacher curls because they enable you to lift heavier poundages. Conversely, if you want to maximally isolate your biceps and get a great muscle pump, then concentration curls are your best bet because, although you have to lift lighter, the exercise still forces your biceps to contract harder.
Concentration curl vs preacher curl: The verdict
Should you do the concentration curl or the preacher curl for maximum bicep growth?
As you learned, the most effective exercise is the one that you can stick to long term. Increasing the resistance and training both consistently and intensely is what's going to get you those bicep gains.
But if you don't have the time or energy to do both exercises, then concentration curls are likely your best bet. Unlike preacher curls, concentration curls are easier to set up because all you need is a dumbbell and a seat, which is particularly handy if you train at home.
Concentration curls also challenge your biceps more because the exercise is most difficult where you're naturally meant to be weakest, which is to say, when your bicep muscle is fully shortened.
On the other hand, you can make a strong case for preacher curls being the better choice since they enable you to lift more weight. Also, they're arguably more efficient if you have access to a preacher bench because you can save time by training both arms together.
I hope that you found our concentration curls vs preacher curls showdown useful. As you can see, each exercise has its benefit and drawbacks, but if it were me, I'd go for the concentration curl for the extra convenience.
- Exercise Mechanics - Resistance Training Specialist. (n.d.). Resistance Training Specialist. https://www.resistancetrainingspecialist.com/rts-principles/exercise-mechanics/
- Hernandez, R. J., & Kravitz, L. (n.d.). Skeletal muscle hypertrophy. The University of New Mexico. https://www.unm.edu/%7Elkravitz/Article%20folder/hypertrophy.html