Even if it's just training, you still need to be careful. No sense in letting yourself get hurt just because you know they wouldn't hurt you badly.

[Another gesture, this one to Xion's head. She saw that headbutt, after all, and has had experience in dealing with hurt teens.]

We're a lot more fragile than they are, and sometimes they forget that even when they don't mean to. You always need to be on guard even if it's training.