Former tennis ace-turned-model Anna Kournikova has signed on to put heavyweights through their paces in the new season of hit reality show "The Biggest Loser."
 
The stunner, who is singer Enrique Iglesias' longtime girlfriend, will be one of the show's trainers, according to X17Online.com.
 
Kournikova will reportedly join fitness experts Cara Castronuova and Brett Hoebel on the program.

Click Here For More Anna Kournikova Pictures