Bodybuilding is about developing a symmetrical body with even development of all muscle groups. But let’s face it, nothing is more impressive than a set of massive biceps that peak the way Arnold Schwarzenegger’s did, regardless of whether they overshadow the rest of the body.
While heavy barbell curls are the key to packing on major biceps mass, no exercise puts on the peak like dumbbell concentration curls. Sit at the end of a bench and lean forward to place the back of your arm against the inside of the same-side thigh. Start with your arm extended and curl the dumbbell toward your opposite-side pec.
Squeeze your biceps as hard as possible in the top position before slowly returning the dumbbell back to the start and repeating for reps. Perform all reps on one side and then repeat with the other arm. You can also do this exercise while standing and bending forward from the hips to let the dumbbell hang straight down. Because you turn your arm in toward your body when you do concentration curls, it helps to place more focus on the long head of the biceps, which makes up the mass of the biceps peak.
■ Alternative: cable concentration curls
WHEN TO CONCENTRATE: Concentration curls prevent you from cheating and force you to perform each rep with perfect form. Although that maximizes the focus on the biceps — especially the long head — it can limit the amount of weight you can curl. So leave concentration curls for later in the workout — after you’ve gone hard and heavy with barbell and other dumbbell curls.
FORM AND FUNCTION: The long head of the biceps originates on the back side of the scapula (shoulder blade). The short head of the biceps originates on the front side of the scapula. Both converge onto the same tendon, which attaches to the ulna and radius (forearm bones) to cause flexion of the elbow, such as during concentration curls, as well as supination of the forearm (turning the forearm out), such as during supinating dumbbell curls.