I bought the R1 pullover hoodie last winter because I was freezing on my late-night winter runs (0-20 degrees). I pair this fleece with a wicking base layer, some wool socks, and running tights, and I can do six miles and stay warm. This fleece vents well and wicks moisture so even if I misjudge the weather and get a little warm, I don't overheat. This jacket is a must-have for cross-country ski trips and mountains climbs as well. It is the outer layer for high activity, and it is the mid-layer for hanging around summits and campsites.