Not a good idea where I play. We already have enough problems keeping non-squash related activities out of our courts. We have had baseball teams use them for indoor batting practice - wearing cleats no less! - as well as soccer players and people doing weight training with plates that have been dropped and broken floor boards. Presently there are cross-fit types who use our courts to toss around weighted balls - 25 to 45 pounds - and have already damaged the walls/floors as a result. They also don't wear court shoes and the floors are constantly scuffed and dirty when they leave. I understand the value of this exercise, but would strongly advise against using the squash courts as an area to perform them. Instead, find a proper cross-fit area that has reinforced walls to do this type of exercise and leave the squash courts for actual racquet drills and games.