Originally Posted by WildVolley
You can't tell by looking at someone's physique.
With all the running the players do on the court, I'm guessing their legs and heart are in good enough shape to do the times I mentioned if they're also lightweight enough. Nadal would probably be too bulky to pull it off.
"Everybody wants to know what I'm on. What am I on? I'm on the court 6 hours a day, busting my a**. What are YOU on?" ~ Roger Federer, 05/29/2006