Barbell biceps curl: 7 common mistakes

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The barbell biceps curl is the basic exercise for the biceps. Many do it and many do it wrong. Below are seven things to keep in mind.


Perhaps the most common mistake with barbell bicep curls is using too limited a range of motion (ROM). You can do more reps as a result, but you don’t train your biceps over the entire range of motion. For optimal muscle growth, you must use an optimal ROM for almost all exercises.

However, with barbell biceps curls, there is no single optimal ROM. In fact, there are two options that we both consider optimal.

The first is the traditional biceps curl, where you start with your arms fully extended and your elbows locked in place. The concentric phase ends when your forearms touch your biceps and can’t go any further.

The second is where you use shoulder flexion to bring the bar up to your face. This will make your elbows come forward. This version is also defensible, because one of the functions of the biceps is to move the elbows forward.

The choice is yours. Plus, you can choose whether you’re standing completely upright or leaning slightly forward — a minor difference in stimulus, so mostly a matter of personal preference.

Make sure you use the same ROM in every set and every rep, otherwise you won’t be able to keep track of your progress (see also error 6).


You can also do more reps if you ‘drop’ the weight from above. But that means you miss the important stimulus that your biceps should receive in the eccentric (or negative) phase.

You don’t have to make that movement excessively slow, but you do have to do it in a controlled manner, as can be seen in the examples for error 1.


The biceps is a real show muscle and for many the biceps curl is a real show exercise. Yet no one in your gym cares that you squeeze out an extra rep with hanging and strangling. It is better to ensure that your performance remains intact until the last rep, and that you fail with your target muscle, the biceps.

In other words, don’t sway and sway your body to get more reps:

You do the biceps curl to train your biceps, not your hips and buttocks. So keep your body still — just your elbows moving and, depending on the ROM you prefer, your shoulders a little. When your biceps can’t handle any more reps, your set is over.


Strict implementation also does not mean that you have to go against the laws of nature. If you curl a (heavy) weight, your upper body will automatically lean back slightly. That’s okay, otherwise you’d fall over:


Creating an optimal mind-muscle connection, i.e. with the target muscle, does wonders for your gains. A 2018 study by muscle growth professor Brad Schoenfeld shows this once again. In this eight-week study, one group trained with a focus on squeezing the biceps, while the other group was instructed to simply lift the weight. The result? The group that focused on the muscle achieved almost twice as much muscle growth as the group that only completed the movement.

Numerous other studies also show that the mind-muscle connection is actually important for those who train for muscle growth. More about that in this article.


There is no magic grip for barbell biceps curls: the ideal grip is personal. As long as you don’t experience pain or discomfort in your shoulders, elbows and wrists, and as long as you can create a good mind-muscle connection with your biceps, your grip is good.

Keep your wrists in line with your forearm throughout the exercise. That way you activate your biceps more at the expense of your forearms:

Some prefer an ez-bar instead of a straight bar for biceps curls, especially to protect the wrists. That’s fine too.


There is also no magic reprange for barbell biceps curls, as long as you always operate in the same range and apply progressive overload.

Some people randomly thread some weight onto the bar and see where they end up. However, training for muscle growth means that you do the same exercise, with the same ROM, and in the same rep range, workout after workout. The only difference is that you try to go heavier in weight per workout and/or try to achieve a higher number of repetitions than the last time.

It is not recommended to train in excessively low or excessively high rep ranges. If you’re somewhere between 5 and 20 reps, you’re always good.

Last updated 20 November 2022.


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