The company claims "six minutes with a Shake Weight burns as much muscle energy as 42 with a standard dumbbell." How it works: "dynamic inertia," whereby shaking the oversized plastic dumbbell with short, rapid movements force your muscles to tighten (submaximal isometric contraction). Holding the weight with one or two hands, or engaging in different motions targets the biceps, chest or triceps.

Needless to say, we were skeptical of the ultimate wonder weight. After familiarizing ourselves with the fine print — i.e., "Keep the Shake Weight at least 6 inches away from your face" — it was time for the instructional DVD. On its own, the 6-minute routine demo starring a glistening, shirtless personal trainer was almost amusing enough to warrant the weight's hefty price tag.

In practice, however, the "workout" wasn't terribly satisfying. We'll admit you do feel reasonable tension in your muscles. However, jerking this 5-pounder only got our max heart rate up to 114, which pales in comparison to a standard weightlifting session, let alone back-to-back sets of push-ups. More importantly, after a few days of use, our muscles didn't feel nearly as sore as they do from weightlifting. And, as everyone knows: no pain, no gain.

WIRED You can tell people you actually have one, or better yet, show them. Comes with a DVD (also, excellent for entertaining). Getting your roommate to go halvesies on it means you're only down $15 (cheaper than a gym membership).

TIRED People visiting your dorm room might see you actually have one. Shake Weight won't balance end-on-end (our weight tipped over and almost broke a shaving mirror). Doesn't compare to a legit regime of weightlifting, push-ups or pull-ups.

• Manufacturer: Shake Weight
• Price: $30

Authors: Steven Leckart

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