You wouldn't think there were really many features you could pack into a set of arm warmers. Then, of course, Asics had to come along with its Thermopolis LT Arm Warmers and blow that theory out of the water. Made with Asics' exclusive Thermopolis LT fabric, these sleeves are just chock full of useful innovations. Asics added thumbholes for more coverage on those frigid mornings, as well as silicone along the inside of the cuff to help keep the whole thing in place. Since neither you nor Asics always knows just when the running urge will hit you, a reflective logo adds a touch of visibility. To top it all off, a pocket on the top of the hand holds a key or card so you don't have to worry about getting back into your house at the end of your run.