Forgive me if this has been asked a million times before, but why does high mileage make you faster?

Exquisite Corpse wrote:

It was definitely a metaphor that I picked up somewhere, though I don't recall where. Definitely stuck with me though, primarily as a way of highlighting how one type of work affects another, but has diminishing returns as you move away from that type of effort.

To girlfriend: I think you've aptly picked up on an important point of the metaphor, as well: That when you're new to it, no matter where on the tube you squeeze, the tube is going to produce. Once you've been at it for years, it really starts to matter where you squeeze, for how long, and how quickly you move from the base of the tube and back.

You got it from Hadd's approach to distance running that was posted here about 5 years ago.

several reasons:

1. every movement of your body is done first by your primary mover muscles. once these are fatigued, your brain will start firing secondary movers that typically aren't used to produce that movement and are less efficient at it than your primaries. through repeated and prolonged stimulus (i.e. long distance), those muscles become more efficient at performing movements for which they are not primary movers. the long term implication of this is that by running long distance, you will extend the point at which both your primary and secondary muscles are exhausted. it is the fundamenttal point of endurance.

2. aerobic stress causes your body to build more red blood cells and vascularize the stressed muscles

3. you have slow twitch, fast twitch, and muscle fibers in the middle. most of this is genetic. however, training will nudge those middle fibers to function more like one of the others, depending on the stimulus

Stating the science of it isn't even necessary.

The more miles you run, the longer and faster your tempo/strength workouts will be. So when you get to more race-specific workouts, they will be faster and longer as well. What is complicated?

when my mileage (esp in the fall buildup) went from about 30 miles a week my senior year in high school to about 80 or so my freshman year in college; I actually got slower, speedwise. I could run a 400 in 51 in high school, just messing around. The next year, the best i could do was 52 but the big difference was strength; the ability to carry a faster pace, over the course of any race. so, it was 'speed' through 'strength'.