I also love that machine along with all the machines for the lower body. (seated calf raise, adductor and abductor machine, hamstring curl, hack squat, etc.) in terms of a substitute exercise for the leg press machine I have read many many times it is the step ups on a tall step (12, 14 or 16 inches depending on how tall you are). With the exception of S&H: Legs and Shoulders, Cathe does that exercise in the remaining lower body workouts she has released. This is also the core exercise of the workouts by The Firm.