Steel construction plyo boxes with durable non-skid rubber surfaces. Wide base and angled construction prevents tipping. Boxes are stackable for convenient storage.Plyo Steps are specially engineered tools for plyometric exercises. Plyometric exercises are based around having a muscle exert maximum force in as short a time as possible, rapidly stretching the muscle and then rapidly shortening it. Plyometric exercises were first introduced to western athletes by former U.S. Olympic long distance runner Fred Wilt. As opposed to American athletes at the time who prepared for races only with static stretching, Wilt noticed the highly competitive Russian runners execute jumps in their warm-ups prior to track and field events.As a result of the high intensity of plyometric exercises, it is important to always use the appropriate equipment when performing this training. Plyo Steps are designed with pyramid shaped bases to prevent toppling, and rubber tops to guard against slippage. According to the American Council on Exercise, properly executed plyometric exercise can improve muscle strength, increase vertical jump, and reduce the force of impact on joints. Athletes who train using Plyometric exercise can improve their acceleration, balance, agility, and bone density, all qualities that belong in your gym too.