How to prevent tiring forearms when doing bicep curls

Question

I'm trying to focus more on building my biceps (biceps brachii) on specific days (I'm not doing it every day; I work on different muscle groups or just rest on other days).

However, I noticed that when I do standing bicep curls with my dumbbells—I use both simultaneously—my forearms (medial antebrachial) tire out before I can really feel as though I'm working out my biceps.

I'm looking for different exercises or techniques to build the biceps brachii wherein I would not be tiring out the forearms as much—that is, such that they would not tire out before I have sufficiently 'worked out' my biceps. If anyone has any recommendations, that would be great!

When doing my own research online, I've come across ones that need me to buy some sort of workout chair (preacher chair, incline chair, etc), but I want to be able to do them exclusively using my dumbbells at home.

If this is the wrong place to be posting this, please let me know and direct me to where it should be posted. Thank you so much for your time, everyone!

Answer 1

One possible source of the problem would be the mechanics of the three primary muscles involved in elbow flexion: the single-joint brachialis and brachioradialis muscles, and the multi-joint biceps brachii. Since both heads of the biceps brachii attach to the scapula—at the coracoid process and supraglenoid tubericle for the short and long head, respectively—the position of the shoulder changes the length of the two muscle groups, and hence the degree and manner of activation involved in the performance of the curl.

We cannot isolate any of the muscle groups, but we can alter their degree and manner of activation by flexing or extending the shoulder (lifting or dropping the elbow relative to the front of the body). Simultaneous flexion of the shoulder and elbow results in a near-isometric contraction of the biceps brachii, theoretically affording it greater strength. This could consequently allow a greater lift while placing a relatively high load on the other muscles in the chain. Swinging the load flexes the shoulder, and this can cause the brachialis to fatigue early. (Note that the medial antebrachial is the nerve, not the muscle.) In order to maximise activation of the biceps brachii, the elbow must be fixed at the side of the body or behind it. Performing curls from a reclined position is one method of achieving this posture, which pre-stretches the biceps brachii.

The other possibility is excessive activation of the carpal flexors: the flexor carpi ulnaris, flexor carpi radialis, and palmaris longus (if it is present). Flexion of the wrist during the curl can works these muscles concentrically rather than isometrically. And since they are smaller than the elbow flexors, they therefore fatigue more easily. Fixing that the wrist straight during the lift ensures that the carpal flexors contract isometrically only, and are hence stronger and more resistant to fatigue.

There is a third possibility, that the muscles of the forearm are, for whatever reason, just weaker relative to the other muscles in the chain. This can happen if your training is unbalanced, or if your occupation otherwise stresses certain muscles more than others. In such cases, your programme may need to be adjusted to limit the overuse of those muscles.

I hope that helps you.

Answer 2

You should try to fix your biceps when you are doing this exercise (you can search biceps curl on google, you will find some photos and understand what I mean ). Do it nice and slow, do maximum 4-5 reps for building strength and 8-10 reps for building muscles, good luck.