Smartwool PhD HyFi Training Beanie ($32, Smartwool.com)
Wool is a favorite material for winter training garments for a number of reasons, and the PhD HyFi beanie takes full advantage of these. Wool exhibits excellent temperature-regulation characteristics, enabling it to keep you comfortable during the first steps out the door and after fully warming up. The PhD HyFi beanie felt consistently warm and comfortable and never caused the tester to overheat. An added bonus of wool is that it does not retain any odor, so you might even get an extra run or two in before you’ll need to put this piece of clothing in the wash. The liner is 100 percent merino wool, while the two outer shells are a mix of merino and synthetic materials to enhance the fit and feel of the beanie. One-size-fits-most worked well for our tester yet might not work for all athletes. The beanie is cut with a higher forehead and lower ear, which covers the ears nicely and while sitting high enough on the forehead to fit sunglasses.