Anna Kournikova 'Biggest Loser'

Anna Kournikova 'Biggest Loser'Anna Kournikova 'Biggest Loser'. Anna Kournikova to Join 'Biggest Loser'.It looks like 'The Biggest Loser' might have found another new trainer. According to reports, tennis star Anna Kournikova will join the NBC fitness show next season.

Kournikova will join new trainers Cara Castronuova and Brett Hoebel as the show undergoes major changes in the wake of Jillian