As Seen on TV: Do Shake Weights and Other Gadgets Work?
Can you shake, push, or rock your way to a better body? The makers of the newest fitness products would have you believe you can. But science doesn't always back their claims.
The claim: The Shake Weight promises dramatic results in just six minutes a day. First, shake the 2.5-pound plastic dumbbell. Then perform a traditional strength-training move. The result? Toned and defined chest, arms, and shoulders.
The theory: Vibrations from the device make the muscles work harder during exercise, building strength and power.
The research: Most studies of vibration training have been done using whole-body platforms. These may build muscle strength and power under a trainer's guidance. But the Shake Weight is difficult to use properly, according to the American Council on Exercise. It's also too light to strengthen muscles, and the directions call for too few reps.
Try instead: For better muscle definition, try dynamic workouts that tone your whole body, like jumping rope or dancing.
Shape-Ups and other shoes
The claim: So-called toning shoes—like Skechers Shape-Ups and Reebok EasyTone— claim to strengthen your calves and hamstrings, burn more calories, improve your posture, and reduce joint stress and pain.
The theory: The rounded soles create an unstable surface, challenging your feet and legs.
The research: A study by researchers at the American Council on Exercise found no differences in heart rate or calorie burn with toning vs. regular shoes. You may use different muscles in these shoes than you would in regular shoes, which could improve balance. But each brand is different. What works for one person may cause injury to others, such as people with poor balance or with joint or tendon problems.
Try instead: To amp up your walking routine, carry hand weights. To tone your legs and butt, try squats.
The claim: The Perfect Push-Up promises to strengthen your upper body in 10 workouts or less.
The theory: These handgrips rotate with your arm's natural movement while you do a push-up. This supposedly strengthens your chest, arms, back, and abs while reducing joint strain.
The bottom line: Overall, push-ups are an effective move. But one study, in the Journal of Strength and Conditioning Research, didn't show muscles working harder with the handgrips. The instability may actually trigger wrist strain and increase the risk for injury.
Try instead: Start your push-ups on the floor or any stable surface. Move your hands closer together to target triceps and shoulders.