[justinator]

They do that by going slow - building up a base for most of their season, and peaking for maybe once - or twice in a year - sometimes a career. The time they take for speed work is a small percentage of their total training time. What you're seeing is not someone sprinting for 26 miles, what you're seeing is someone comfortable running at that speed, for 26 miles, because they've slowly built up the engine to allow that.

A 100 meter sprint is done well over 20 mph these days. If anything, it's a prime example how halving your speed can reap rewards when it comes to Going The Distance (endurance) - which works better in the long run? So many metaphors.

You can't sprint forever, and you don't get fast, by trying to beat your best time, in each run. Even if your discipline is truly sprinting, you still don't train by going fast all the time. A 100 meter sprinter works on various components of what it takes to run fast, and puts it all together, come race day. An elite 800 meter runner could have a program of 100 mile weeks - a lot of those are Long Slow Days.