Coaching Advice

Last night I took the train with one of our members who is quite an experienced runner, but new to track work-outs. She wanted to know how fast to run her track repeats, and how to decide on targets for certain distances in races. I told her about the-10-second rule (or 4-second-rule for track races), and about Toni Nett and Frank Horwill. I will now try to give a few hints to all of you who are not quite sure how to set target paces for certain work-outs.
Almost 50 years ago Toni Nett published in his book Der Lauf (Berlin. Verlag Bartels und Wernitz, 1960) thumbrules to calculate possible personal records for common distances. The possible personal bests are calculated based on known performances on the next shorter distance. Manfred Steffny extended Toni Nett's rules to cover the marathon and the 100 km. He found these rules surprisingly accurate when comparing personal bests of hundreds of runners of different levels from beginner to world champion. Here is the list of these thumbrules as given in Manfred Steffny's book Marathontraining (Mainz, Verlag Dr. Hanns Krach, 1984, 5. ed.):
1500 m = 800 m x 2
3000 m = 1500 m x 2 + 20 sec
5000 m = ((3000 m + 20 sec) x 5)/3
10000 m = 5000 m x 2 + 1 min
marathon = 10000 m x 5 - 10 min
100 km = marathon x 3 (for each minute the marathon time is faster than 3 hours, you should subtract one minute from the final 100 km time).
(from: http://jeltsch.org/running)