Pausing your workout to take off your jacket isn't exactly an inconvenience, but Under Armour has still worked to solve that issue with the ColdGear Reactor Hybrid Lite Print Jacket ($106, originally $140). When your body temperature starts to rise, Under Armour's intelligent insulation will adapt to your activity level and let warmth out through its quilted front panels, so you can keep your jacket on, and keep working out.