The other day I was riding a slight downhill, making a serious effort (not conversational!), and going quickly for me (over 20 mph). Then some ****** cruises by with maybe 4 mph in hand! (No, he undoubtedly was not a "******," he even said a friendly hello when he passed. It's just I was working so hard...)

But on a serious note, I noticed that my running took a nosedive around 50-55. I started cycling at 64, so I don't have much history to draw on there. In the subsequent 4+ years I have had my cycling performance affected by losing my initial insanity (4,700 miles in my first 7 months, riding with temperatures under 20), and 3 bouts of medical problems (prostate cancer & removal at 65, breast cancer & removal at 66, and then breaking my hip [while leading 70 riders] and getting it replaced. So even now my cycling history isn't too much help.

In general, I have gotten slower. I did two centuries in my fourth month, both 15.3 mph average on a somewhat hilly course. Most of my rides now are under 40 miles and under 15 mph. But I am still recovering from the new right hip and dealing with a left knee that needs replacement very soon. And I wonder if I were averaging 200 miles a week again if I would be just as "good" as I was that first year. But that's drivel.

The question I want to ask is if there are any decent studies on age and performance drop off. I am interested in general "rules," not those exceptional outlier cases. Although even articulating the question makes me realize that there is probably too much variability, and even that the overwhelming majority of cyclists and runners that are still active in their 60's are a pre-selected group. But I may as well ask.

Thanks.

PS - I am very lucky, I've had almost zero medical problems previously, no broken bones ever, etc. And I revel in the enjoyment I get from cycling (slowly) and my cycling groups. I even lead my own ride every year, but it's mostly older riders so my pace is not a problem.