Pure Boost ZG Trainer ShoesEnergy returning training shoe to cushion workout stress.Strength and conditioning workouts demand agility. These men's training shoes feature energy-returning boostâ„¢ to absorb stress and impact. Their upper is made of textile and synthetic for soft, durable support.boost™'s energy-returning properties keep every step charged with an endless supply of light, fast energyTextile and synthetic upperGrippy rubber outsoleImported