FOR: Medium and high impact workouts at the gym, studio, or outdoors. Walking the dog, chasing the kids, training for a Spartan, living life! FEEL: Lightweight polyester is stretchy and breathable. FEATURES:Thumbholes keep your sleeves in place. Easy-access zipper pockets to stash your essentials. FIT: Runs large, we recommend sizing down if you want a fitted look. Kari (left) and Amy (right) typically wear an XS. Kari is wearing XXS and Amy is wearing XS here.