Reebok worked with fitness professional Gin Miller in the late 1980s to develop Step Reebok, based on Miller's wooden prototype step and her ideas for step aerobics. The Step was evaluated in physiology trials undertaken by Drs. Lorna and Peter Francis at San Diego State University. In August 1989 the Step was ready, made in molded plastic by Sports Step of Atlanta with Reebok's name on it, and by March 1990, the step aerobics classes were attracting media attention. Miller promoted Step Reebok in person, touring the U.S. and demonstrating it at exercise studios. Step aerobics became widely popular, helping the company sell many thousands of adjustable-height step devices, and millions of high-top shoes with ankle support. Step aerobics peaked in 1995 with 11.4 million people exercising in that style.