Are the Practice Courts Making Sense?

Tennis is a form of training, but it's also the highest stress you'll ever encounter as an athlete. Novag dyokovitch retired several times in grand slams because his body, which is brak down now,. I'm sure he's practising on the core and in the off season and the gim and all that kind of stuff. But i think it's more the long term adaptations from being in those five set matches and in those ornaments that contributes more to his ability over the years - if that makes sense.