For whatever reason I found myself thinking about my 5K time (regression) over the past 30+ years. Here are my humble times over the years:
30 - 15:18
40 - 16:47
50 - 18:19
60 - 19:53
I seemed to have consistently slowed down about 1:3x every ten years. I quit any type of hard training at age 51, opting to just run 10 mile a day at whatever pace felt good that day. My body couldn't take the rigors of race pace intervals anymore and I couldn't get enough sleep to sufficiently recover. Now I'm 61, still doing my ten miles a day, albeit at a slower pace than the past. Most days my average pace is 7:30~ish, sometime a little faster, sometimes a little slower. I can still pull off a 4-5 mile tempo run under 7:00 pace maybe once every 3 weeks when all the planets align.
So what sort of time regression have other long time older runners experienced?