Shake Weight

The Shake Weight’s biggest selling point is a phrase called “Dynamic Inertia”, which means that as you hold the dumbbell, spring loaded weights inside each end move back and forth thereby increasing the resistance. In addition, the website states that using the weight will work the biceps, triceps, shoulders, and chest. It also claims that it has scientifically proven results, takes only 6 minutes per day, activates up to 300% more muscle than using conventional dumbbells and that the 2.5 weight was specifically designed for women.