Material is crucial. While you may not require the most sweat-wicking fabrics (as you would for running and HIIT), comfort and a good stretch are key qualities for Pilates tops. Katz tells me she's a fan of tops with a "lightweight, stretchy, smooth and breathable texture." She continues, "soft is probably the biggest yes for me, I like to relate my outfits for Pilates as my 'comfy sports gear' but also the type of gear that makes me look slick, empowered, feel beautiful and able to breathe through my movement."