BUILT FOR REAL CORE WORK — These therapy balls are the size PT clinics actually stock — the 9 inch pilates ball your therapist hands you for home protocols (also called a pilates ball 9 inch). Wedge it between your knees during bridge progressions,...

PICK YOUR SIZE FOR YOUR HEIGHT — 45 cm for kids and shorter PT users / 55 cm for 5'0"-5'5" / 65 cm for 5'6"-6'0" (most popular) / 75 cm for 6'1"-6'5" / 85 cm for 6'6"+. The workout ball is intentionally unstable, so...