Introduction

Kettlebells, those metal orbs that look like cannonballs with handles, are finally making their way into gym classes. Until recently, most clubs reserved the weights for trainers working with clients, but word is out that the iron balls are an effective way to switch up your strength routine. The secret to their (and your) success is in the design: "Unlike a dumbbell, a kettlebell's weight is unstable—it shifts when you do—so you have to use more muscles to control it and stay balanced," says Chris Hall, a trainer in New York City who created this routine. "That raises the intensity." You'll work harder than you would during a normal strength workout, and get more sculpted. So grab a pair of these funnylooking gizmos today and give them a try.

The Plan
You'll need Two 4-kilogram (about 9 pounds each) or heavier kettlebells (find them at performbetter.com)

How It Works
Warm up with 5 minutes of easy cardio followed by 1 minute of the swing. Do 10 reps of each remaining move in order, without resting in between. Catch your breath for 60 seconds and repeat the entire circuit (starting with the swing) once or twice.

Sets:	1 to 2
Reps:	10
Starting Weight:	4-kilograms (about 9 pounds)