Recognizing that world record holders in distance running (800m through ultras) have unique genetic advantages that training alone cannot replace for the rest of us, which coaches and/or sport science researchers do you think deserve the most credit for helping advance distance running training methods for those genetically gifted world record holders? By "advance distance running training methods", I am thinking of evidence of improvement for the greatest distance running successes. Having read Emil Zatopek's biography, I can no longer see Arthur Lydiard & Percy Cerutty as being as original as they claimed they were. Cerutty literally met with Zatopek, then used a lot of his ideas as if he had thought of them, and Lydiard was a relentless self-promoter who used a lot of ideas before the 1960 Olympics which Zatopek had used to success in 1948. Reindel & Gerschler developed interval training in the 1930's. Lydiard's ideas did not carry over to the marathon as well as they applied to 800-5000m training because his repeat distances were too short. He also needed to blend elements of future training periods in with current ones to ease the transition and prevent injury.
Here is a resource to get start providing some perspective. Whatever you do as an athlete and as a coach in distance running, you can always learn more from other coaches' approaches as well as from your own experiences, and it is important to remember that the same methods of trainign do not necessarily provide the best results for two different athletes.