when she injured her knee. She was advised by her physical therapist to build her strength back up by stepping on and off an upside-down plastic milk crate ( tall). The crate was too high, so she used her 8-inch front porch step instead. After a few weeks of therapy, she noticed her increased fitness and realized this would be a good workout method for others. Working with Connie Collins Williams, Miller used prototypes made of plywood, and tried them out in an Atlanta Gold's Gym franchise, the location later called Sportslife. Working together, they developed 250 separate step-based movements. The program was aimed at men, the usual gym-goers at Gold's. These wooden prototype benches were very long: , with a choice of heights: 10, 11 and 12 inches. Small weights held in the hands could also be used. Fitness instructor Kathy Smith first experienced the Williams/Miller prototype step aerobics program during its early days, thinking "This is the most cutting-edge workout I’ve ever seen." Miller and Williams formed a company called Bench Blast in late 1988, making wooden steps from 6 to 12 inches high. They began to sell the benches and teach their style of step aerobics. The two split in 1989, with Miller leaving for Reebok. Miller's friend and Reebok shoe representative Kelly Watson saw the Bench Blast program, and recommended Miller visit Angel Martinez, Reebok's Director of Business Development. Martinez thought the step aerobics idea was good, and introduced Miller to Reebok CEO Paul Fireman who quickly gave the go-ahead to hire Miller and start a major product campaign. Reebok already had connections with many health clubs through their shoe promotions, and they were very interested in any new aerobics program which would attract male customers, since existing classes were about 90% women. Reebok commissioned physiology trials of the step exercise program, undertaken in 1989 by Doctors Lorna and Peter Francis at San Diego State University. The Francis study showed that 40 minutes of step aerobics was equivalent to running in terms of oxygen breathed and calories burnt, but the body stress was much lower, the same as normal walking. Lorna Francis also observed a Bench Blast training session in May 1989, remarking that it was an excellent overall exercise regimen for people without joint problems. Meanwhile, in New Jersey, fitness trainer Cathe Friedrich had been working with long wooden benches which were high. Up to