You can learn a lot from watching a lot of elite runners with a lot of high-speed cameras. And much of what you learn is a surprise. For instance, most elite runners are actually heel-strikers, which flies in the face of the popular belief that the best runners are forefoot strikers. Alex Hutchinson:
In the men’s marathon, the top four finishers, hailing from Kenya, Ethiopia, Tanzania, and Great Britain, were all heel strikers during all four laps of the race. … The claim that the best runners in the world land on their toes should be abandoned in the face of the new data.”
Excellent bias-confirming fodder for an update to my barefoot/minimalist running article. And there’s much more here: Lessons from Watching the World's Best Runners.