They need to be light and stretchy to let you move, and have a liner to keep you cool and dry.Features:- Ultra-light, stretch-woven fabric for totally unrestricted movement- Built-in Iso-Chill mesh compression shorts disperse body heat, making it feel cool to the touch- 4-way stretch material moves better in every direction- Material wicks sweat & dries really fast- Updated, expandable center-back pocket is water-resistant & keeps your phone secure, with no bouncing- Encased elastic waistband with external drawcord- Reflective details for low-light runs- Pockets: Yes- Fitted: Streamlined fit that's not too tight or too looseSpecifications:- Outer shorts: 100% Polyester- Liner shorts: 90% Nylon/10% ElastaneCare:- Machine wash cold with like colors- Use only non-chlorine bleach when needed- Tumble dry low- Do not iron- Do not use softeners- Do not dry clean