The inner bicep curl is a highly underrated mass-building movement for developing the bicep muscle. By having you lift the weights with your arms pinned to your sides and your shoulders rotated outward, the inner biceps curl shifts the emphasis of the exercise onto the short head of the biceps and creates a more intense muscle pump.
This guide shows you the proper bicep curl form to work the short (inner) head of your biceps.
Then we'll discuss the main advantages of the exercise.
Inner bicep curl exercise details
- Main Muscles: Biceps brachii
- Secondary Muscles: Brachialis, brachioradialis, forearm flexors
- Exercise Type: Strength
- Exercise Mechanics: Isolation
- Difficulty Level: Beginner
- Equipment Needed: Dumbbells
How to do an inner biceps curl
- Grab two dumbbells with an underhand grip and hold them by your sides.
- Externally rotate your shoulders (turn your elbows inward) so that your upper arms are braced against your lats, which should be flared out a bit.
- Curl the weights toward your front delts by moving your lower arms toward your biceps.
- As you lift the weights, supinate your wrists forcefully by turning your little fingers away from the midline of your body.
- Contract your biceps at the top of the rep and then lower the weights under control until your elbows reach full extension.
- Repeat for 3-5 sets of 8-15 reps.
You can also do the incline inner biceps curl if you have access to a weight bench. While this version takes more time to set up and obviously requires extra equipment, the incline of the bench helps to provide more consistent resistance for your biceps.
Inner bicep curl advantages
Inner bicep curls are a small twist on the regular curl that can have some big advantages in the muscle growth department when you use the proper lifting technique.
Builds the short head
The short (inner) head of the biceps is the part of the muscle that everyone sees when you flex your arm. It becomes more active when you curl with a wider grip, which is precisely what the dumbbell-based inner bicep curl tries to (with great success) mimic.
By having you lift the weights with your elbows pinned to your sides, the emphasis of the exercise automatically gets shifted onto the inner muscle fibers of your biceps without the need for you to grip the dumbbell any differently.
However, besides elbow flexion (moving your lower arm to your bicep), the biceps also perform forearm supination (turning your palms up). So even though you don't need to alter your grip to do this exercise correctly, you can force your biceps to supinate harder by gripping the dumbbell on the outside of the handle.
Then you want to forcefully turn your little fingers away from the midline of your body. This cue will dramatically increase the intensity of your bicep contraction and make every rep of inner biceps curls far more effective now that you're fulfilling both bicep functions simultaneously. 
Gives a great pump
Notice how I told you to brace your upper arms against your lats in the tutorial?
This happens naturally when you pin your elbows to your sides. But it comes with a significant advantage that you might not have realized.
Pushing your triceps into your lats creates a "pad" for you to press into. This makes it much easier to keep your elbows still and use the proper form, which in turn intensifies the peak contraction because, in this "braced" position, only your biceps can lift the weights.
So if you're looking for an exercise where you can reap the rewards of using good form, then the inner bicep curl is a great choice. So are no money curls, which are pretty much the same as the inner biceps curl if you perform the exaggerated wrist supination that I recommended above.
Easy to perform
If you have access to a pair of dumbbells and a desire to beef up your biceps, then you can do inner bicep curls and benefit from them. Since the exercise doesn't require any special equipment, it's the ideal movement to perform if you train at home and want to do a fast biceps workout.
The technique is also relatively simple. As long as you remember to forcefully supinate your wrists as you lift the weight, you can master the inner bicep curl by the end of your first session.
It's a beginner-friendly exercise that encourages the use of good form because your elbows are pinned to your body during the movement. For this same reason, it's also a valuable training drill for advanced lifters because it enables you to keep the tension exactly where you want it, namely, on the biceps.
Should you do inner bicep curls for your arms?
If you want to add mass to your arms and get a good muscle pump, then the inner bicep curl is an excellent exercise for the job. It's simple enough for novice lifters to perform, but it's tough enough on the biceps for bodybuilders to be able to add size to their physiques.
- Rudroff, T., Staudenmann, D., & Enoka, R. M. (2008). Electromyographic measures of muscle activation and changes in muscle architecture of human elbow flexors during fatiguing contractions. Journal of Applied Physiology, 104(6), 1720–1726. https://doi.org/10.1152/japplphysiol.01058.2007
- BSN Training. (2012, January 25). Standing Inner-Biceps Curl [Video]. YouTube. https://www.youtube.com/watch?v=F95ps05kwWk