Hammer curls and barbell curls recruit the same collection of muscles. However, they differ slightly in technique and the weighted implements that are to be used. Because of the technique differences, three muscles involved in the exercise are recruited slightly differently in the two exercises. Both exercises can be incorporated within the same training session.
Technique Differences for Hammer Curls and Barbell Curls
Hammer curls and barbell curls utilize similar techniques, but have one minor difference. To perform barbell curls, first position your hands evenly on the bar and at shoulder-width with palms facing forward. Allow the barbell to hang down in front of you. Keep your elbows into the sides of your torso as you bend your elbows and bring the barbell up towards your shoulders. Control the barbell back down to starting position by extending your elbows. To perform hammer curls, hold a dumbbell in each hand and allow your arms to hang down on either side of you with your palms facing your thighs instead of forward. Bend your elbows to bring the dumbbells up to your shoulders and then control the weights back down to starting position.
Muscles Recruited for Biceps Curls
The primary muscle recruited in the barbell curl is the biceps brachii muscle. This means that the biceps produces the greatest amount of force. It originates up at your scapula and then runs down the front of your arm and inserts at your radius bone. Assisting in the movement is also your brachialis and brachioradialis. In the hammer curl, the primary muscle recruited is the brachioradialis. The brachioradialis muscle is smaller than the biceps. It originates on your humerus bone and then inserts on your radius bone. It becomes the primary mover when your elbow joint is in a mid-position between supination and pronation, as it is during hammer curls. Along with your brachialis, your biceps serves as an assisting muscle.
Weights Used for Hammer Curls vs. Barbell Curls
A weighted barbell is used for barbell curls. An Olympic barbell weighs 45 lbs. -- although other barbells can be a different weight -- and then you can increase the intensity by adding weighted plates. The hammer curl, however, is completed with dumbbells. You wouldn’t be able to position your elbow joint in the supination and pronation mid-position with a barbell.
Incorporating Curls Into Your Workout
Because they incorporate the same collection of three muscles -- the biceps brachii, brachialis and brachioradialis -- the hammer curl and barbell curl are often performed within the same workout. Those interested in building muscle mass in their arms would receive greater effects by doing both exercises. Complete four to six sets of barbell curls and four to six sets of hammer curls.