J.R. wrote:
I ran 3x 440 in 55 with much longer rests in my early 20's during a period when I wasn't running any distance, and therefore had very little endurance. I ran 52.5 or faster 25 times, 51.7 fastest, but barely broke 2 in the half.
After that I went back to distance running, ran many more miles and greatly improved all the distance events, but then could barely break 60 for 400 meters. At this time I would occasionally run 4x 440 with 5 minute rests but only in 65 seconds with the aim of running through them without expending any energy.
I did feel a conundrum with running my fastest distance times - while improving my speed for 800/mile - as they seemed to be contradictory to each other.
And what have you learned from this J.R.? I would hope that now you would know how you could have raced fast over a wide range of distances within a few weeks with the right training?