In what way?
Physically, what else? Have you seen the state of guys like Djokovic and Nadal towards the end of 5 set matches that get intense?
Somehow doubt Sharapova and Williams etc are going to be able to slug it out for 4+ hours in tough conditions, seeing as Sharapova complains of fatigue after 2 or 3 back to back 3 set matches and she's one of the best in the women's game.