Why Are Bicep Curls Important?

Biceps curls are a classic strength-training exercise. Whether you do curls with free weights such as dumbbells, barbells and kettlebells or you prefer biceps curl machines, this exercise bulks up the front of the upper arm. But achieving big guns isn't the only reason to do this exercise. The biceps curl and its variations such as the hammer curl and preacher curl are important for more than just aesthetics.

Isolating the Biceps

Biceps curls and its variations are the only exercise that isolates the biceps with a concentric contraction. Other exercises such as rows and chinups work the biceps, but only along with the larger muscles of the back. Exercising the biceps with only rows or chinups gives the back muscles the chance to do most of the work, which doesn't guarantee results in the biceps.

Principle of Specificity

The principle of specificity states that your muscles only adapt and gain strength or endurance in the motion that you work them. If you rely on exercises such as rows and chinups to strengthen the biceps, then the biceps only become strong with these specific movements and in a reduced range of motion compared to the complete elbow flexion you do during bicep curls. This principle also means that if you instead perform isometric exercises to strengthen the biceps, you only build isometric strength at the exact angle that you do the static biceps exercise. Isometric strength in the biceps is strength without movement, which may be important too but is not related to concentric and eccentric strength, which is what biceps curls build through movement.

Injury Prevention

Biceps curls also help prevent injuries. Weak biceps may result in a biceps tendon rupture or the development of conditions such as elbow tendonitis or bicipital tendonitis of the shoulder. Performing biceps curls with heavy dumbbells or a barbell even once a week in addition to your other weight training significantly reduces your chances of injury. What is a heavy weight is subjective. Typically if the weight fatigues your muscles after five repetitions, but is not too heavy that you are unable to complete five reps, then that is the correct weight for strength gains.

Weak Link

The biceps are often the weak link for exercises such as rows. If the back muscles are significantly stronger than the arms, they lift most of the weight during exercises. Biceps curls force the arms to work independently of the back muscles so that not only do the biceps get stronger, but your ability to perform other exercises increases, too.