I've heard many commentators touch on this...
The difference between a player born with a little talent - Sharapova
The difference between a natural born athlete - Venus, Mauresmo, etc.
Natural born athletes have bodies and natural innate ability in a multitude of sports. Both Venus and Mauresmo said they were good in other sports and are built very athletically. Strong frame, etc. They could play several other sports and succeed.
Sharapova is just a model with a little talent.