What Our Gearhead(R) Experts Are Saying:"I've worn this through plenty of early morning runs when the temperature hasn't quite committed to spring yet, and the venting on the back keeps me from overheating once I get moving. It packs down small enough to stuff in the zip pocket and carry once I warm up."Cold air has a way of talking runners out of lacing up, but the Weather Insulated Jacket makes that first mile out the door a lot easier to commit to. It holds heat in through the coldest stretch of the run, then lets it go once the pace picks up and the body starts generating its own warmth. On ThermaTec insulation sits across the front and back where it matters most, while overlapped panels vent excess heat before things get sticky underneath. A durable water repellent coating shrugs off light rain or snow, and when the jacket's not needed anymore, it folds down into its own zip pocket with a loop to clip it wherever's convenient.