Spenga has opened registration for founders memberships. Classes for founders began the week of April 5. A grand opening will be held May 1 at 2450 Cross Timbers Road, Ste. 130, Flower Mound.

The fitness concept focuses on cardio, high-intensity interval training and flexibility exercises in one-hour sessions, according to the company website. 214-513-5003. www.spenga.com