The Fanny Lifter would be fine for leg presses, but it's too light and easily moved for any cardio, especially the type of cardio Cathe is doing. It would be far too easy to kick it out of the way. Also, if you look on the Fanny Lifter, it has a warning not to leap or jump on it. It's not made for that kind of action. (Though it does make a good laptop table, which is what I use it for!)