Buddy Up: The Partner Workout

Catching up with your BFF is fun. Kicking each other's patootie? Even better!

That's the beauty of our buddy routine: You'll not only spend time together, but you'll also work out way harder than if you were going through the motions solo. "You push yourself more than you would on your own. You can't flake," notes Barry Jay, a cofounder of Barry's Bootcamp, home to one of the most body-morphing workouts around, and a big fan of partner pair-ups. But don't expect to be dishing about last night's date: Jay and fellow Barry's Bootcamp trainer Astrid McGuire created a fun but fierce head-to-toe routine that delivers fast results. You'll shed fat and sculpt firm muscles while moving back and forth nonstop between strength exercises and cardio bursts.

What you'll need: a 5- to 10-pound dumbbell and a medicine ball (use the weight instead of the ball in a pinch). Warm up for five minutes on a treadmill at an easy pace, jog in place, do low step-ups, or jog around the block. Then do one set of each of the following moves in any order, changing it up every time. Rest only as necessary, and after every third move do a cardio interval (see "Cardio Blasts," slide 11). If time allows and you're feeling supermotivated, add in a few more rounds of strength moves and cardio bursts. Follow the plan consistently four days a week while keeping an eye on your calories, and you and your chum will be admiring each other's sleek physiques in just three weeks.