The purpose of a belt is to increase intra-abdominal pressure, which provides added back support. Pushing your stomach against the belt creates an internal force that acts on the anterior side of your spine, acting to stabilize your entire body for a solid foundation during exercise. This translates into more energy being directed to moving the load and less to maintaining body position.
A nylon belt like the Harbinger Weightlifting Belt with Flexible Ultra-light Foam Core, 5-Inch provides sufficient support for those difficult lifts while being easy on the wallet. The velcro band makes strapping the belt on and off a breeze. Perfect for the casual lifter who is not weightlifting competitively.