At 65, I'm still a strong rider. What about the future?

This is froma New Times article a few years ago, about aging and exercise, where scientists studied people who were in shape in their later years:

"There was...a drop-off in leg muscle strength around age 60 in both men and women. They weren’t as strong as the 50-year-olds, but the differential was not huge, and little additional decline followed. The 70 and 80-year-old athletes were about as strong as those in their 60s." (http://tinyurl.com/c2ovrbl)

I'm about 6 feet and about 172 pounds. When I was in my 20s, I was about 155 wiry pounds. I raced a few times, just so I could say I did it. Back in the day, few could beat me up a steep grade. While I'm slower now I'm still pretty fast. I can out sprint a lot of younger riders who are in very good shape on the flats. Very few people my age are faster than me on the uphill (although I am a lot slower uphill than I used to be).

And I'm still climbing up extremely steep grades in the Santa Monica Mountains, north of my home, e.g. 20%+ grades (for short distances), and plenty of 14% grades that go on and on and on.

The thought that I could be, if I just keep riding, about as strong in my 70s and 80s as I am in my 60s, is encouraging.