Work your abs, hip flexers, quads, and shoulders with this Pilates exercise. Learn how to use a stability ball for bent knee leg extensions in this free exercise video about Pilates ball workouts. Expert: Jeri Ryan Bio: Jeri Ryan is the owner of Pilates Pure N Simple. She was certified as a Pilates instructor through Core Conditioning Physical Therapy in Studio City, California. Filmmaker: Christian Munoz-Donoso


damn it’s hard!
Believe it or not this really does work to strengthen the abs.