Bending the arms with dumbbells is one of the most frequently performed exercises for the upper body. The hammer is a simple type of biceps flexion that helps to engage additional muscles in the upper and lower part of the arm for greater clarity and increased strength.

Many believe that this exercise can also help to increase the stability of the wrist and improve the grip strength.

Although this exercise is almost always performed with dumbbells, it can also be performed with ropes or ribbons if dumbbells are not available. Other typical equipment for flexing the arms on the biceps, such as a barbell or a kettlebell, is not suitable for this exercise because of the need to rotate the wrist.