How do I support my 16-year old?

Please advise me on how to support my 16-year-old daughter. She recently asked to get involved in MMA — Mixed Martial Arts — like, cage fighting. She says she wants the physical fitness and self-defense skills, as well as the positive character influence and self-discipline that comes through martial arts. I fully support all those reasons and I respect a lot of martial arts, but MMA seems a different ball game. Professional women MMA fighters look nothing like who my daughter is right now. The thought of seeing someone hit and kick my daughter in a cage is shredding my heart. Is this a no answer I have to accept and support her through MMA? Thanks for your thoughts.