Forget the TB12 Method ... Rob Gronkowski clearly needs to come out with his own fitness line -- 'cause Camille Kostek says he's the reason for her smokin' hot bod!!
The Sports Illustrated Swimsuit model -- who joined Harvey and Charles on "TMZ Live" -- says she's been training with the Patriots tight end ... and credits his workouts for gettin' her magazine ready this fall.
"I'm doing the same workouts [as him]," Camille says ... "Maybe not the same weight, but I'll do just as many reps and he'll push me until I can't go anymore."
Soo ... what's the RG87 Method's secret? Camille tells us the New England superstar LOVES resistance bands!!
If you wanna see the results of Gronk's training program firsthand ... Kostek's gonna be on the beach in Miami for a charity celeb soccer match this Saturday.
In case you can't make that ... no worries -- we've gotchya covered here!