Tried an experiment today and ran with Bill and Joann at Rancho San Antonio. From the beginning the pace, which was easy for them, was a bit fast for me, but I was able to hang with them for 55 minutes before I finally decided to back off and run in by myself. The pace was around 9:40 which age grades to low 7 pace at age 30. It wasn't anything to brag about but the course was all hilly trails.
Bill tells me it's 7 miles total. It took me just under 68 minutes.
It was a moment of truth. Bill runs in the 20 minute range for 5k and Joann runs in the 22's. No wonder I can't run those times anymore. Not sure whether it makes sense, but I might have to experience more days like this if I want to run faster.
The tempo running I've been doing definitely helped. I was never in oxygen debt. But it wasn't an easy run. It reminded me of first training with John and Jake back in late 1975. Back then it took me running with them every other day for a year to get used to a faster tempo. Then I could run with them every day.