Get some balls

We are a society obsessed with multiples. We don't want one car, we want a fleet of them. We're not satisfied with just having a television in the living room, we want one in the kitchen, the bedrooms, and even the shower. We're not content with a person juggling three pins -- we won't be satisfied until there's five pins, two chainsaws, three tennis balls, and the entire Encyclopedia Britannica collection being tossed around in the air. And when it comes to sex ... well, you get the point. In many ways, this same obsession with multiples carries over into the fitness world, too.

That's why the perfect exercise for the numbers-obsessed exerciser is the Double Swiss Ball Stability Pose. Unlike other Swiss Ball exercises that only require the use of one ball, this fantastic builder of core strength uses two. To do it, lie face-down on two Swiss Balls. Keep your body straight, with your chest on the first ball and your knees and shins on the second ball. Now, depending on your current level of fitness, you may want to either place your palms on the floor, or grab onto the sides of the first ball with your forearms and hands. In case you were wondering, the latter is much more difficult than the former, although each will provide you with a great core workout.

Try to hold in this position for 20 seconds. As your core strength becomes greater, increase this amount of time by five-second increments. Then, once you're done, flip through the 8,000 songs on your iPod and find one that will help motivate you through a second set.