I'm a good example of one that let age get to me. I got so slow and weak that I couldn't even aim my 12 gauge to take a shot. I started going to a weight trainer and he started me off with no weights at all, just some mobility exercises. And even that was work. But I've kept it up and I'm finally working out with 10 pound weights. He increases me by 2 1/2 pounds just about every other session. I can sure see the difference now but believe me it's work. So it can be done. I darn sure can't say it's fun either but definitely doable.
Do things as if your life depends on it. It COULD!
American Legion Rider