Off topic. I can't help but wonder why astronauts on board the ISS wear sneakers. They aren't wearing gloves, and don't you mostly move with your hands in zero G? Why wear shoes and socks at all?
Specifically while doing this exercise, I imagine that the additional padding and weight spreading is more comfortable than doing so barefoot, since the goal is to create lifting force between the floor under your your feet and the cable via your hands. I also imagine that many astronauts do frequently "kick off" objects and walls to start their propulsion/movement around the space station.
More generally - I often wear socks and slippers around the house while otherwise half dressed, because my toes get cold. Warm feet is a luxury.
I guess the problem remains that the legs still don't need to lift the body weight.
For example in a barbell squat, your shoulders lift the bar, but your legs lift that weight plus your bodyweight. In space, bodyweight is not a factor so your legs only have the same load as the shoulders. So upper body / shoulder might end up being the limiting factor, not giving the legs the same amount of load they would under gravity.
That could be solved via a vest that you wear, that has additional cables pulling with a force of the bodyweight. That way you could also do pull ups with your bodyweight.