There's a reason the soft medicine ball is so key to CrossFit: Simply tossing it against the wall and catching it is hard work for all your muscle groups. But the best part of having a large, soft ball is that you can throw it around – and slam it. "Take a 20-pound ball over your head and slam it into the ground 20 times," says Rast. "You're getting a cardio workout, building strength in your abs, arms, legs, and shoulders, and blowing off steam." [$90; xtrainingequipment.com]
DO THIS: Basic slams. Hold the ball high overhead, extend, slam it to the ground, and catch the rebound. Repeat 20 times.
• Wall balls. From a squat position, thrust up and throw the ball about 10 feet up the wall. Catch and repeat.
• Ab throws. Lying with arms extended, holding the ball behind your head, sit up and throw it against a wall. Catch and repeat.
• Elevated push-ups. With the ball under one hand and your other hand flat on the ground, do a push-up.
• Extension passes. Lying on your stomach with your legs and arms lifted off the ground, roll the ball back and forth from hand to hand.