I'm 52, my two daughters are grown.
I would have to say that I do way more now every day than I did when I was in my 20's. I do more work, more play, more chores and things to keep track of. But in my 20's it FELT like I was impossibly busy. I do more now but it does not feel as out of control or hectic because I have gotten better at managing my time more efficiently and suffling things and prioritizing stuff. Stuff that might have taken me 4 hours to do in my 20's now might take 2 hours.
I also am better able to say "no" to certain things without guilt, and better able to back off on some things so I can concentrate on other things. Just all around better at getting things done and planning my life and schedule, moving things around. Also definitely better at balancing work and play- if you are able to play too you feel less overwhelmed.

I don't plan on slowing down until my body forces me to- hopefully not until my 80's! (knock on steel)