What Certifications to Get?

hey all,

i’m considering going for certification as a personal trainer. currently live in canada, may spend a few years living in japan, but am primarily wondering what is the most usefull certification to work towards.

in general, i’m more interested in training athletes as opposed to your generic gym personal trainer. Can-fit Pro, CSCS, there are a ton of different ways to go. any advice would be greatly appreciated!