no wasted energy, only more gains. Ua rush uses a mineral-infused fabric to take the energy you give off when you work and reflect it back into your muscles, increasing blood flow and helping them work harder. mineral-embedded material that absorbs and releases body energy to improve your endurance.ultra-soft, breathable and stretchy coldgear fabric that provides absolute freedom of movement and exceptional warmthoffset half-zip front closure for easy layering and a modern lookbuilt-in thumb loops to retain heat and keep sleeves in placecelliant technology 84 % polyester/16 % elastane