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Why Are Preacher Curls So Hard? (Explained!)

Regular dumbbell curls make up the foundation of many arm workouts in gyms all over the world.

Preacher curls are another popular exercise for that many people use to increase the size of their bicep peak.

With so many people trying to get bigger and stronger arms, there seems to be a constant search for the best and most challenging exercises to help increase the effectiveness of their training. 

In this article, we look at regular dumbbell curls and preacher curls to see which one proves to be more of a challenge and why some people find one harder than the other.

Are Preacher Curls Harder Than Dumbbell Curls?

This is a tough question to answer as it depends on how you measure the difficulty of an exercise.

In terms of the weight you’re able to lift in the two exercises, preacher curls could be considered harder as less weight is able to be lifted.

This is because your biceps are isolated during the movement so no other muscles can assist in the lift.

If you look at the exercises in terms of the number of muscles being used, dumbbell curls could be seen as harder as it brings more muscles into the movement resulting in an increased workload. 

It probably depends more on your gym experience, current fitness level, equipment quality, and personal preferences as to whether you find preacher curls or dumbbell curls harder.

Why Are Preacher Curls So Hard?

Momentum Is Removed

During preacher curls, your arms are supported by the pad on the preacher bench.

This prevents your arms from moving out of position and generating momentum through swinging or bringing other muscle groups into the exercise.

If you’re used to free moving exercises, like dumbbell curls, this can make preacher curls particularly challenging.

Biceps Are Isolated

Your biceps are assisted in many movements by other muscle groups, such as your forearms and shoulders.

However, during preacher curls, your biceps have to do pretty much all of the work themselves as they’re isolated during the exercise.

Isolating your biceps makes the exercise more challenging than it would be if you had other muscles assisting the movement.

Why Some People Find Dumbbell Curls Harder

More Weight Can Be Lifted

As your biceps aren’t isolated during dumbbell curls, you’re able to lift more weight than you can in preacher curls.

This can make dumbbell curls harder if you’re used to lifting lighter weights.

Lifting heavier weights puts more stress on the working muscles which makes the exercise more challenging.

More Muscle Groups Are Working

The more muscle groups that are working at any one time, the harder your body has to work.

This is another reason why some people find dumbbell curls harder than preacher curls.

As several muscle groups have to engage during the exercise, a lot of effort is required.

For example, your biceps are obviously working during dumbbell curls, but your forearms and shoulders are also working as stabilizing muscles.

Also, if you’re performing standing dumbbell curls, your core and back muscles will come into play.

During preacher curls, pretty much all of the work is done by a single muscle group, the biceps.

So the fact that dumbbell curls require activation of more muscles helps explain why some people find dumbbell curls to be the harder exercise.

Are Preacher Curls Suitable For Beginners?

When it comes to the technique and movements involved in preacher curls, most beginners will find them simple to perform.

However, most beginners don’t have an immediate need to perform isolation exercises like preacher curls.

They’re usually better off building a solid foundation of strength through compound exercises.

Preacher curls require a good amount of strength in the biceps to perform correctly and safely.

This is one reason why they may not be as suitable for beginners as other exercises.

That being said, under supervision from a fitness professional, preacher curls can be a suitable exercise for beginners.


In summary:

  • Preacher curls are hard because they isolate your biceps and the preacher bench removes momentum.
  • Some people find preacher curls harder whereas other find dumbbell curls harder.

That’s all for this article, but perhaps you’re interested in cable curl vs preacher curl? Or you might want to learn more about hammer curl vs preacher curl?

Hope this helped!