As many reps as possible...100% effort and exertion. Belleville's AMRAP TR501 athleticlly inspired trainer boot features an expanded TPU midsole which provides incredible shock absorption and energy return…up to 50% more than typical midsole compounds. The AMRAP trainer also features a strobel construction to enhance your flexibility and resiliency during grueling training events like rucking, road marching, and PT. In additon, the rubber outsole design is that of a training shoe, flat with multiple gripping surfaces, making it an ideal lightweight option for training, range, and garrison use.