Happy 30th birthday, Gisele Bundchen! This Brazilian superstar will turn 30 tomorrow. But she's not just a supermodel; she's also a superfit mom! How does Bundchen stay so fit? She credits her slim figure to water-based cardio routines, as well as kung-fu and yoga (Anusara is her favorite!).

But that's not all Bundchen does. She is also reportedly a big fan of the Dukan Diet a high-protein, low-fat, low-carb diet that includes four phases and is very popular in Europe.

See which other super fit celebrities have summer birthdays in this gallery from RADAR ONLINE!