By Michael Berg, NSCA-CPT
If the standing barbell curl is the reigning king of biceps bashing, the dumbbell curl is quietly biding its time for the throne. It directly engages the biceps through its main action — that is, to bend the arm at the elbow. Unlike the barbell, dumbbells don't allow a weaker side to compensate for a stronger one, making it a vital move to correct strength imbalances, and allows for grip variations to vary the stress on the biceps muscle, all in the name of more complete development.
Muscles Worked: Prime movers are the biceps brachii and brachialis; secondary and stabilizing muscles include the brachioradialis and forearm flexors.
Starting Position: Assume a shoulder-width stance, arms at your sides with a dumbbell in each hand, palms facing your hips. Your eyes should be focused forward and your core tight for balance.
Action: Holding your body steady with the only movement occurring at your elbow joint, curl one dumbbell up in an arc toward your same-side shoulder as you twist your wrist to a palm-up position, lifting it as high as you can without your elbow leaving your side. Squeeze your biceps hard for a one-count at the top, then lower to the start and repeat with the opposite arm. One curl per arm equals one full repetition.
Do: Pin your elbows in place at your sides — an old mental trick is to imagine a rod running through your torso and into each elbow, holding it in place.
Don’t: Shift your hips or contort your torso to swing the dumbbell. If you need to cheat the weight up, it’s too heavy for you. Lighten the load.
Variations: The twist of the wrist brings the brachialis into play at the start of the motion, followed by the biceps brachii as your palms turn up. You can attend to either muscle more directly throughout by remaining in the hammer (palms facing you) grip or the palms-to-the-ceiling grip. You can also curl each dumbbell simultaneously rather one arm at a time.
Uses: The dumbbell curl can be situated anywhere in a biceps routine, but the sweet spot is around the middle, after barbell or EZ-bar curls.
Advanced Technique: Alternating curls lend themselves well to running the rack at the end if a workout — either going up in weight or down. For instance, one especially cruel finisher takes you both directions. Say you start with 20-pound dumbbells for 10 reps. You rack those and immediately grab 25s for 10 more reps. Keep going in the same pattern, increasing the poundage until you reach a set where you can't complete all 10 reps, then backtrack step by step down the rack, pushing to failure at each weight.