ds, though what you say is true about faster runners... the notion of the 90s runner is still correct (seeing I came up then. Started running in 1992). It was commonplace that high school runners, perhaps the most important time for long-term elite development, were running 15-30 miles a week. In fact, I ran at a decent D1 school and I didn't know a single person who ran MORE than that in high school.Additionally, if I sampled 10 of those guys, I bet you 9 of them NEVER ran a tempo run. It was all intervals and racing with 3-4 mile recoveries.
The best guys who ran those 15-30 miles/week were 4:14-4:19 guys in the 1600 in hs and 9:15-9:30 guys in the 3200 (again... mind you know base and all intervals). These same guys then ran max 60 a week in college. Maybe a few got a little crazy by senior year and had some weeks in the 70s. They became low 4:00 guys and low 14:00 or just under guys in college.
These guys were no slower than some of the fastest guys now... but they were severely under trained during the 6 years where the body is producing more testosterone than at any other time in your life (thereby making recovery easier).
Now, high school runners run double or triple what we did in the 90s. They run tempo runs, building their lifetime base and aerobic capacity.
So maybe the elites of the 90s ran as much as the elites today, but their foundation was on straw, whereas someone like Rupp, Solinsky, Ritz, Hall, Webb, Derrick, Puskedra, etc have a foundation of solid concrete.
That is a huge difference.
Also, Rupp AVERAGED about 70 last year... but that included breaks and weeks of peaking where his mileage drops to 40 and 50. He was running about 120 last year at PEAK.
If you go through the duathlon.com link above, and calculate out what Kennedy's average yearly mileage looked like when he got up to 140, it was no more than 80. Does that mean Kennnedy runs "80 miles per week" or 140 miles per week? Really, neither. The best in the world know how to periodize very well, and have times well into the 100s and times at 0. Average mileage means nothing.