Can I Study Making Gains?

Hello folks,

Since I received a refusal of a firm today where I could have been paid for studying (It’s a kind of dual education system where you study 3 month and then work 3 month, while getting paid the whole time), I am wondering, if there isn’t a study or apprenticeship about working out and/or the nutrition part.
I know that there are different studys like trophology but, if I am honest, I just only to work with athletes.

I am 18 and from Germany. I am capable of speaking English (international B2 level) and a little bit French (It has been much better a few years ago). I will finisch school this year.

So, if anybody has got an idea or suggestions, please tell me.