I agree with both Karin and Joannes opinions on this matter.
My personal professional opinion is that there are no mandatory certifications in this field period.
I have expressed this frustration many times on this site.
Until or unless we have licensing or a specific policy or mandate that we must follow, we are at this point able to pick and choose as we see fit.
Take a look at ZUMBA, and Crossfit. These are huge money makers, nobody can stop them.