The La Sportiva Primal Thermo Tight is built for winter trail running first, with enough warmth and range of motion to carry over to any high-paced cold-weather effort. An internal adjustable waistband locks in a customized fit that holds through technical terrain, so the tight stays put over roots and rock rather than just on a flat road. What Our Gearhead® Experts Are Saying:"I wore these on a rocky, snow-dusted trail loop and never had to adjust the waistband once, even scrambling over exposed sections. My legs stayed warm through the whole climb without the tight ever feeling like it was fighting the terrain."