You don’t become a delicate wilting flower, if you work to mantain it and eat well. Keep hitting the dhal and the gym, do some running or whatever floats your boat and you’ll still be more than capable moving around the world. It just requires a bit more effort, but then that’s kinda typical for trans folk anyway :)
I’m in my 30s, transitioned in my early 20s. I’m not the strongest I’ve been but definitely the fittest. I may not look amazing but I can throw a brick at anyone who points that out and book it before the cops show up ;)