As you longtime readers know, I'm not young, I'm not muscular and I'm not thin.
What I am is motivated to work on my shortcomings. [I'm not tall, either.]
One of the ways I get and stay motivated is by reading what fitness bloggers have to say, and there's nothing I can say that tops this one from Skwigg.
I'm not where she is; I may never get there. But I can move myself in that direction: wanting to be healthy and fit instead of just looking like it.
Go. Read. Now. You'll be inspired.