personal trainer - coming out ?

i don’t really have to come out to people super explicitly since i’m lucky enough to pass a majority of the time, so this is new.

i’m planning on getting a personal trainer and i don’t really know how to approach the situation. obviously, him knowing i’m trans is kind of important as i’m just a few weeks on testosterone and plays a part in body composition and whatnot. i’m thinking about prefacing the conversation with “do you know what trans people are” but am looking for other ways to go about it.

any advice/ways to approach this less awkwardly so i don’t get misgendered or looked at weird?