The BodiRocker¡¯s innovative design delivers a 2-in-1 workout¡ªstrength training and core training, simultaneously. As you strength train your shoulders, chest and arms your core muscles are also engaged as you control the rocking motion of the BodiRocker. This means that during each rep, your upper body muscles are engaged while your core stabilizer muscles are activated. This 2-in-1 feature means that with each rep, you get double the results in half the time. Because the BodiRocker uses your balance to control the rocking motion, each and every repetition is intensified, engaging more muscle activity -- especially in your abs and back. You¡¯ll develop more lean muscle, burn more calories and see the difference as your trouble spots are transformed.From fun, easy exercises for beginners to muscle shredding workouts for athletes -- the BodiRocker adapts to your changing fitness level. Your BodiRocker System includes a free set of workout DVDs with over 30 exercises. Each features beginner to advanced workouts that you can do in just 10 minutes a day.The BodiRocker has a built-in balance meter which helps guide your balance during each rep so that you engage your core even more by maintaining proper form.Plus, multiple grip positions let you zero in on the muscles you want to target, while the cushioned handles provide additional support and comfort.