摘要：Muscular strength is an important component of physical fitness and can be improved by using free weights (i.e. barbells, dumbbells), weight machines, elastic bands, or body weight exercises (Stone et al., 2000). A new product in the exercise marketplace which is advertised to increase strength is the Shake Weight®. The Shake Weight® is a dumbbell shaped fitness device, sold by Fitness IQ (Vista, California). There is a 2.5 lb (1.13 kg) version for women and a 5 lb (2.27 kg) version for men. While gripping the Shake Weight® with one or both hands, users vigorously shake the weight back and forth. Springs on both ends allow the weight to move back and forth, creating a resistance which the manufacturer calls “dynamic inertia”. The Shake Weight® claims to build definition, size, and strength in less time than traditional weights, with the muscle purportedly contracting up to 240 times per minute (www.shakeweight.com). The purpose of this study was to determine the degree of muscle activation when using the Shake Weight® compared to traditional dumbbell exercises.
