Men's Boost Jacket

Stretch polyesterspandex panels down the sides and under the arms dump heat when youre working hard uphill, and the mechanical stretch ripstop nylon body blocks the wind to keep you warm when you turn around to head downhill in a cool alpine breeze. Thumb loops and finger loops keep the sleeves down, and a rear pocket holds your energy gel or bar and turns into a stuff pocket when you need to de layer.