The Smartwool Active Fleece Wind 1/2-Zip Top pairs a windproof front panel with a non-PFC DWR finish, so a headwind on a cold run doesn't cut straight through the fabric. A four-way stretch knit keeps a soft merino blend against the skin for warmth, while a recycled synthetic layer faces outward to take on the wind and weather. The result is a fleece built to hold heat in without trapping it, even when the workout gets exposed. What Our Gearhead(R) Experts Are Saying:"I run into a headwind most cold mornings, and this is the first fleece where I stop noticing the front of my chest going cold halfway through. The back stays breathable enough that I'm not overheating by the turnaround."