It's an infomercial mainstay and the punchline of many comedians' off-color jokes. But does the Shake Weight actually build muscles? The answer may not please those who already invested $20 for the women's version or $30 for the men's. While the shake weight may help define muscles in the arms, that's all it does. It won't burn fat like aerobic exercise would, so it doesn't let you off the hook on the treadmill. And while it may seem like the shake weight offers more bang for your fitness buck when it comes to dumbbell exercises, that's not the case. The range of motion isn't the same; in fact, the shake weight limits your range of motion, which won't give you optimal results if you're looking for toned arms. And that "dynamic inertia" claim the infomercial makes? Just jargon - all it boils down to is movement, and it applies to all resistance training.
The product claims different results for men and women; for men, it claims to increase muscle mass, while women get "lean muscle." But with a mere 6-minute program, these results would be a major stretch, regardless of your sex. And the 5-pound weight for women - 10 for men - isn't enough to increase muscle mass. The product's up-and-down motion may be a hazard as well. The shaking motion is unnatural and can lead to muscle spasms and injury, according to WebMD. And all of those "scientific studies" cited in the ads? Unfortunately, there are no peer-reviewed studies on the product. So the bottom line on the shake weight is not to give it a shake - you'll get better results by doing a full-body cardiovascular workout paired with resistance training.
