It seems gimmicky, but the TRX Suspension Trainer ($190, trxtraining.com) is the real deal. The design is why-didn’t-I-think-of-that-simple (an adjustable nylon strap with handles on either end and an anchor point in the middle), but it is perhaps the most versatile piece of equipment I’ve encountered. Attach it to a door frame with a door-anchor accessory (sold separately), and then choose from literally hundreds of body-weight exercises, every one of which activates your core. You can also use it to build strength, power, balance, flexibility and even anaerobic endurance.
My first thought upon seeing Power Systems VersaSteps ($45 for six, power-systems.com) was that a Bosu had a litter of puppies. Just like a Bosu, these mini-discs are flat on one side and rounded on the other, providing a progression of unstable surfaces to challenge your balance and core stability. Unlike the Bosu, they stuff into a little bag and fit under your couch. Arrange them in a pattern for jumping exercises, place them underfoot during squats and lunges, or use your fitness-smarts to create other balance drills.
If you have high ceilings, just get a jump rope. But if your house isn’t Yao Ming–compatible, opt for a Power Systems Airope ($35 per set, power-systems.com). Essentially two weighted jump rope handles, the Airope simulates the motion and resistance of jump roping—excellent for skiers—without the ceiling-scraping action.
The kettlebell craze is here to stay. But good luck doing a Turkish get-up (the mother of all kettlebell exercises) with the same size bell you need for kettlebell swings. Get more for your moolah with an adjustable kettlebell. The best design I’ve found is the Stamina Adjustable Kettle Versa-Bell ($250, staminaproducts.com). It retains the shape of traditional kettlebells, and uses a locking pin to adjust among six weights, from 16 to 36 pounds. If you need a lighter load, try the Weider Ultimate PowerBell ($199, getpowerbell.com), which offers six weight options, from 5 to 20 pounds. The shape is a little clunky, and you’ll need wrist guards to protect your arms, but for the money and space you save, it’s worth risking an occasional bruise.