When you combine Merino wool with TENCEL Lyocell fibers, you get a performance fabric with a number of comfort-inducing benefits, including softness that feels great next to skin, odor resistance and moisture management for when the sweat starts to pour, and temperature regulation for when you take it up a notch. Best layered under shorts or pants, Smartwools Mens Intraknit Active Base Layer Bottom is the purpose-built staple that will help you stay comfortable and feel dry, even during the most challenging of activities.