We're sorry, but online registration is not allowed for this activity. Group Exercise classes, Yoga & Pilates and personal training are available for full members of the facility. Please contact us during regular business hours for registration information. This mat work class focuses on the body's core stability. Enhance your control, stability, coordination, endurance, balance, strength and flexibility. This is a prerecorded class taught by a YMCA instructor that airs on-site at the branch. Category Exercise, Health and Wellness Location Aerobics Studio at West Chester Branch Instructor Jackie C.