The Nike Pro HyperWarm Aeroloft Men's Long-Sleeve Training Top balances performance insulation with performance breathability for optimal warmth and comfort during your toughest cold-weather workouts. Targeted Insulation Lightweight, durable insulation provides warmth right where you need it, without limiting mobility. Targeted Ventilation Nike's warmest top is also among the most breathable: strategically placed thermal mesh helps keep you dry and comfortable when your workout heats up. Improved Visibility During dawn or dusk workouts, reflective details on the arms help you stand out in low light.