Two Schools of Thought

“There are two schools of thought,” the college coach said to me seven years ago, as I watched the 800-meter runners run 200-meter reps on the track at 800-meter PR pace in November. She was referring to how to train middle distance and distance runners — with lots of speed training or lots of endurance training. “You’re right,” I responded, “the right school of thought and the wrong school of thought.”    

I spent this morning watching seventh and eighth graders in a cross country race in southern California. One of the parents invited me to watch the race and talk to her and some other parents about how to train their talented kids. And I heard the same story I’ve heard hundreds of times before: The coaches subscribe to the wrong school of thought.

People always tell me that they like my candid, direct way of stating things, that I’m very good at simplifying the science so that everyone can understand. And so, as Albert Einstein used to say, I will make things as simple as I can but no simpler: The single biggest factor in your long-term running success is the amount of running you do, not the intensity, and if you do a lot of high-intensity interval training, especially at a young age, you will sacrifice your aerobic development and retard your progress as a runner. 

One of the main goals of training is to increase the pace at which you can run aerobically, before oxygen-independent (anaerobic) metabolism begins to play a significant role. Because when the pace starts to become anaerobic, fatigue is imminent and you will slow down. So, the faster you can run before that happens, the faster you will run a race.   

You cannot keep getting faster by hammering more and more interval workouts. This is true for a variety of reasons, not the least of which is that the anaerobic side is limited (you can only increase speed by so much) and constantly pulling the pH of your muscles down with anaerobic workouts (a condition called acidosis) negatively affects muscle function. In contrast, the aerobic side is virtually unlimited, at least up to the point that your genetics will allow for further adaptation.  

If you have kids, or if you run yourself, the best way to train, especially in the developmental years, is to take a methodical approach, focusing on the aerobic training, increasing how much running you can handle each year, and sprinkling in just enough speedwork to improve speed and create a peak in performance. You can improve speed from aerobic strength; doing it the other way around by trying to improve speed first doesn’t work. You’ll get faster more quickly that way, but your long-term development will get flushed in the toilet. It’s amazing to me how many coaches still don’t understand that, including that college coach I had the conversation with seven years ago.

For distance runners, the volume of training induces the biological signal for adaptation and dictates the performance capacity. And in order to accomplish a large training volume, the runner must perform most of the running at a relatively slow pace, and then by doing quality aerobic work.

Aerobic running develops many physiological and biochemical traits:

1) It increases total blood volume.

2) It increases the number of red blood cells and the amount of hemoglobin contained within them, giving your blood vessels a greater oxygen-carrying capability.

3) It creates a larger spider web of capillaries around your muscle fibers, enhancing oxygen delivery to your muscles by shortening the diffusion distance from capillaries to mitochondria. Think of a highway system — you want lots of highways traversing your muscle fibers so that when oxygen takes an exit, it has only a short distance to travel to arrive at the mitochondria.

4) It increases the volume of mitochondria in slow-twitch muscle fibers, where aerobic metabolism takes place. 

5) It increases aerobic enzyme activity, which enhances the speed at which the chemical reactions of metabolism occur. 

6) It enhances neuromuscular coordination, improving running economy, the oxygen cost of running at submaximal speeds.

7) All of the above improves VO₂max, the maximum volume of oxygen your muscles can consume per minute. 

The more aerobically fit runners are, the more they will ultimately get from their subsequent speedwork. Since recovery is an aerobic process, being more aerobically fit enables runners to recover faster during the rest intervals of interval workouts (which enables them to run more reps) and in the days following a workout (which enables them to do fast workouts more often when it is the right time to do them).

As I wrote about in a previous blog, the best 800-meter runners and milers in the world run a lot of miles each week, because even a race that short requires a large aerobic engine (i.e., a high VO₂max) and is more aerobic than anaerobic.

Seven years after my conversation with the college coach about the two schools of thought, and the cross country team is still near the bottom of the conference. Perhaps one day, if she truly cares about her athletes, she’ll go back to school.