This is an excerpt from Daniels' Running Formula-4th Edition by Jack Tupper Daniels.
Many coaches and young (even some not so young) runners have told me they enjoy achieving higher and higher levels of performance based on VDOT values. It has become somewhat common for me to hear, “Our cross country team has a top five who all have a VDOT over 50,” which would mean they have a top five who have all broken 20 minutes in a 5K race. Some can say they have a top five all with a 60 VDOT or higher (17:03 5K or faster).
What I have done to make this a little more interesting for young runners is to calculate comparative VDOT values for male and female runners, with basic increments of about five VDOT values per performance category. Table 5.4 shows how male and female runners can be compared over 10 performance levels at several distances. So now a coach could say, “We have seven level-6 girls on our team,” or “We have seven level-6 guys on our team,” and so on. Naturally, having a bunch of level-7 or level-8 runners would be quite an achievement; there are probably not many level-9 runners on the same team, and level-10 types are few and far between.
My most recent calculations are associated with comparing performances over a wide range of ages, based on research done on young runners up through runners in their 70s. Naturally, to go a little beyond the ages at which I have done tests, I have extrapolated from the ages that are known, estimating that the rate of performance drop is fairly consistent over the full range of ages.