I have a bootcamp and as of now I only train adults. I want to be able to train older minors too. I believe there are many that desire to train. I simply do not know the rules when it comes liability for adolescents.
I have nothing more to add to Ariadne’s answer. Just make sure their parents or legal guardians understand what they are signing and they are agree to the terms and the conditions you have included in the waiver.