“Performance enhancement” is usually a problematic claim, because it’s commonly based on sloppy extrapolation from recovery effects (which are themselves often a bit sketchy). Even what genuinely helps people who are sick or broke is not necessarily going to do anything for fit, healthy people. Or vice versa. (Simple example: compression bandaging for swelling. Unambiguously handy in recovery … but useless if you’re not swollen!) Rehabilitation and performance enhancement are just different things. On the one hand, they are the same process with different starting points. On the other hand, how much value the body can extract from an input is generally proportionate to need. A glass of water is more important to a man dying of thirst, and novel sensation is more neurologically useful to an injured person than a healthy Olympian.