Tim Tebow has already gotten bigger. Now, according to TMZ, he's getting badder by taking up MMA training with the famed Gracie family. Rener Gracie tweeted a welcome to the New York Jets quarterback and later added that "He's a natural!" Tebow is among many NFL players to incorporate MMA workouts in their offseason routines. The Gracie family is legendary for its Brazilian jiu-jitsu prowess, the martial art is a self-defense system that focuses on ground-fighting and is known for enabling smaller combatants to ward off bigger foes with savvy use of leverage and technique. Source: USAToday