Arm yourself against the weather with the Under Armour Reactor Run Long Sleeve Top. Its lightweight fabric has a unique hex-shaped pattern that traps some warmth but still breathes as you run.

Stretch-mesh panels under the arms and across the shoulders for strategic ventilation

Four-way stretch construction moves in every direction

Material wicks sweat and dries fast

Anti-odor technology prevents the growth of odor-causing microbes

Reflective logos for greater visibility on low-light runs

Fitted fit

95% polyester/5% spandex