True performance fabric certified without chemicals, finally! I have been working out in natural fiber clothing for several years which is both heavy and hot because it stays wet and prevents our body from cooling naturally through sweat evaporation. Not the case with aktiiv fabrics. They felt cool the moment I put them on. Also felt cool while I was working out in 95 degree sunny temps. Allowed for sweat to wick and evaporate as expected to keep body cool. Not compressive but stays put. 5'7", 28" waist, 40" hips/glutes; purchased size 8. A bit short for my 34" inseam...wish they had tall girl options. Can't wait for aktiiv to design more athletic clothing options like skirts and tennis dresses *hint hint*