Welcome! It is, indeed, a little harder to build the strenght and lose the fat in our 50s and 60s than it was in our 20s. BUT we're so much smarter now. We've got a little more patience and we (hopefully) know ourselves pretty well by now.
At least for me, back in my 20s if it didn't happen overnight, I quit (pretty much no matter what "it" was). Now I know that anything worth acquiring is worth working for. And since I have enough experience in actually acheiving goals over the years, I have the confidence to know that I can do whatever I set my mind to do.
So yup, age has its benefits too!