The more slow runs you do the more mitochondria you develop.
But, Why is Mitochondrial development important?
Put very simply, Mitochondria produce energy for cells. In the presence of oxygen, mitochondria breakdown carbohydrate, fat, and protein into usable energy. Therefore, the more mitochondria you have, and the greater their density, the more energy you can generate during exercise, and hopefully the faster you will be able to run.
S0, by running slow you build up your body’s ability to produce more energy, so that when you run fast your body can meet the energy demands of running fast.
The best athletes in the world train light 90% of the time. Purposefully performing below their potential. Not pushing their limits. Morgan Housel, in his regular column compares the same about investing. The most important investing question is not, “What are the highest returns I can earn?” It’s, “What are the best returns I can sustain for the longest period of time?”
He adds further:
So many investors over the last five years have gone out of their way to maximize annual returns, squeezing every potential penny out of every opportunity they could find. The highest-risk investments, often fueled with leverage.
They did that because the opportunities were everywhere – everything seemed to go up, every asset, month after month.
It felt great. Always does.
But now I think we’ll see that a lot of, even the best investors were the equivalent of an athlete who pushed to 110% in every training session, and now they’re burnt out.
For a period of time they felt like champions. But over time they’ll be lapped by the guy who casually jogs each day way below his potential, who can sustain his training and build a body that can adapt and recover for the next day.
Remember the old age lesson: Slow and steady wins the race.
Don’t burn out soon.