An exercise system includes a platform, a set of ankle holders connected to the platform by resistance (e.g., elastic) bands, and a leg support. A user can sit on the platform with her back supported by a back support (or fully reclined with her head/neck supported by a headrest) and with her legs supported by the leg support. After attaching the ankle holders to her ankles, the user can perform leg extensions as part of a cardiovascular and resistance workout. The leg support can be constructed so as to compress during each leg extension, thereby reducing knee strain and minimizing the potential for injury.