Famed BJJ Coach Says Joaquim Valente's His Hero For Vacationing W/ Gisele

Brazilian jiujitsu coach Joaquim Valente is a hero in the BJJ community -- but it's got nothing to do with kimuras and omoplatas -- it's because ... GISELE!!

TMZ Sports ran into Rigan Machado, a well-known BJJ coach who counts Keanu Reeves and Ashton Kutcher amongst his celeb clientele, at Toast in Beverly Hills on Thursday, and we asked about Valente, the world's most high-profile martial artist.

"He's my hero! My hero now," Rigan joked.

Of course, Valente is currently with the former supermodel and her two kids, Ben and Vivian, in Costa Rica.

Our Gisele sources say Joaquim is there to act as a teacher for the kids while they're away ... he's acting as a sort of jiujitsu gym teacher.

But, many people aren't buying the explanation -- despite people close to Bündchen adamantly denying there's anything romantic going on -- the rumors have persisted.

Joaquim and Gisele have known each other for over a year ... and even appeared in a magazine spread together.