The goal of training, in running, is to extend the duration of our top-end speed.

Ideally, a 10.00 100m runner would be able to run 20.00 for 200m and 40.00 for 400m. But the Current World-Record for 400m is 43.03, run by someone with 100m/200m PBs of 9.94 and 19.84…so what is the limiting factor? there is a 10.9% disparity between the 200m and 400m WR.

The same concept is applied to middle and long-distance running.

If a someone can run 50.00 in the 400m, they have the speed to run 800m in 1:40.00…but the WR is 1:40.91 set by a runner with a 400m PB of 45.50…there is a trend beginning to appear.

the WR for the 1500m is 3:26.00, so theoretically that runner has the ability to run 3k 6min and 52sec…but the fastest 3k of all-time is 7:20.67 (6.6% disparity). The same holds true for the 5k/10k World records of 12:37.35 and 26:17.53 (4% disparity)

What is the reason for this “inability” to carry these speeds over a longer distance???