I'm 64 and my goal is 5 times a week, with the other 2 days as rest. Distances have ranged from a 10 mile quick ride up to 107 miles today doing a century, but generally 20-30 miles most days although I keep wanting to get a 50 miler in during the week. I would do more but there is the time factor even though I've retired. There are still other things that I do during the day. But the funny thing is that before I retired I was able to get about 150 miles/week in because I commuted 20 miles about 3 times a week. Those miles added up, and then I'd do a 50 miler on the weekend and fill in the rest.

It is hard to use average speed as any kind of indicator as the stopping/starting gets in the way even if your computer auto-pauses. My average HR today was 135, with a peak of 171. In the last few weeks I've had my HR peak over 190 on some climbs. I usually slow it down when I see that.