By RealJock Staff

This exercise provided courtesy of Billy Polson, founder and co-owner of DIAKADI Body training gym, voted best personal training gym in San Francisco by CitySearch in 2006.

Benefits
Hammer curls are tough to begin with, but doing them while balancing in a modified squat against a stability ball engages your whole body in a battle for stability, and, ironically, forces you to do the actual lifting of the dumbbells with your isolated biceps and brachialis muscles.

Muscles Worked
Biceps (brachialis)

Starting Position
Holding a dumbbell in each hand with your palms facing inward, lie back against a stability ball so that your body is supported from the upper buttocks to the lower back and your upper back is not touching the stability ball. Bend your knees into a modified squat with your hips bent, your knees at a 90-degree angle, and your feet planted about hip-width apart approximately two to three feet in front of the stability ball (see Photo 1).

Exercise

1. From the starting position, lift the dumbbells up and do a full hammer bicep curl, contracting your biceps up as far as you can. Keep your shoulders steady throughout the curl (see Photos 2 and 3).
2. From the top of the curl, reverse the motion and return to the starting position. Be sure to fully extend your arms to get a good stretch at the bottom of the curl (see Photos 4 and 5). Complete 10 reps for a full set.

About Billy Polson: Billy Polson is the founder and co-owner of DIAKADI Body training gym, which was voted the best personal training gym in San Francisco by CitySearch in 2006. A competitive swimmer and triathlete in his own right, Polson has over 15 years of experience working as a coach and trainer, and was recently named by Men's Journal Magazine (December 2005) as one of the Top 100 Trainers in America.