This exercise provided courtesy of Mike Clausen, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.
Dumbbell hammer curls isolate and build the brachialis portion of the biceps muscle, making them a great addition to your biceps program.
Sit on the short end of a flat bench with a dumbbell in each hand at your sides with your palms facing inward in an easy, open-handed grip. Hold your elbows in front of your ribs; this will help keep the biceps muscle engaged throughout the movement, and will prevent you from inadvertently swinging your body to lift the weight, an activity that makes trainers cringe (see Photo 1).
- From the starting position, keep your upper arms stationary and curl both weights up at the same time until you fully flex the muscle. Use a scooping motion as you begin lifting in order to lengthen the muscles before starting flexion. Do not alternate the weights. Keep your core engaged, your wrists straight, and your elbows in front of your ribs throughout the movement. At the top of the lift, flex your biceps (see Photos 2 and 3).
- When you have reached the top of the movement, reverse the motion and bring the weights slowly back down to the starting position, using your biceps to resist the weight as you lower the dumbbells. Be sure to keep your biceps engaged as you bring the weights back down. Do not fully lock your elbow at the bottom of the movement, and do not rest—begin your next curl immediately (see Photos 4 and 5).