This may be well-known to fans of player pianos, but I finally
discovered how to make one of my players pump easier.  As the pumping
unit folds out, I place a small block of wood (thickness of 3/4")
under each foot that rests on the carpet.  This has made for a more
comfortable (flatter) angle of the pedals and so tires the ankles less.

I'd guess that anyone, whether they have plush carpeting or bare floor,
might benefit from experimenting with the angle at which the pedals
rest, with a view to making for easier pumping.

Tom Sendall