Demi Lovato has just recently shown interest in having a fight in MMA. She is taking training seriously and TMZ Sports recently shot a video of Lovato and Sylvester Stallone sparring in boxing.
Sylvester Stallone may not have an actual boxing background, but he did train a lot for his movies. He is extremely knowledgable when it comes to the sport and he has a deep passion about it. Lovato may not be training full time with Stallone, but he certainly could share quite a few pointers with her.