80/20 Running - by Matt Fitzgerald


80/20 Running - by Matt Fitzgerald

Read: 2022-03-06

Recommend: 4/10

At the beginning of this year, one of my Ph.D. advisors sent me a Harvard Business Review article called When Lower Intensity Leads to Higher Results by Harsha V. Misra. Harsha generalized the idea of low-intensity training to other areas of life like research and sales. Then a few months later, a running buddy of mine recommended this book to me. I skip quite a bit in the book since it gets repetitive after a point. But I get the idea of the benefit of training at a low intensity for 80% of the time and a hard intensity for the other 20%.


Here are some text that I highlighted in the book:

  1. Do 80 percent of your running at low intensity and the other 20 percent at moderate to high intensity.

  2. The boundary between low intensity and moderate intensity, according to Seiler, falls at the ventilatory threshold, which is the intensity level at which the breathing rate abruptly deepens. This threshold is slightly below the more familiar lactate threshold, which you can think of as the highest running intensity at which you can talk comfortably. In well-trained runners, the ventilatory threshold typically falls between 77 percent and 79 percent of maximum heart rate.

  3. Mo Farah started his career at seventy miles per week and moved up to 120 miles.

  4. Research has shown that high-intensity exercise increases the contraction force, or power, of the heart muscle more effectively than does low-intensity exercise.

  5. prolonged running at low intensity, the muscles release large amounts of a cell signaling compound called interleukin-6 (IL-6), which contributes to fatigue. Well-trained runners produce less IL-6, and this is one reason they are more fatigue resistant.

  6. In contrast, low-intensity, high-volume training teaches the mind to accept that it might as well make peace with its suffering because it won’t end anytime soon.

  7. inducing fatigue in the body through exercise triggers adaptations that make the body more resistant to fatigue in the future.

  8. The three most practical measures of running intensity are perceived effort, heart rate, and pace.

  9. Heart rate monitoring is especially useful in low-intensity runs.

  10. Heart rate monitoring is less useful in high-intensity runs. The reason has to do with a phenomenon called cardiac lag.

  11. If currently you run only three or four times per week, set a goal to run six or seven times per week. According to the World Health Organization, daily aerobic exercise is required for maximum all-around health. Once you’re consistently running six or seven times per week, a sensible next step is to increase the average duration of your runs to one hour.

  12. The marathon distance is, in my opinion, a bit longer than humans were meant to race on foot. This is proven by the fact that about 75 percent of the participants in any given marathon, including elite runners, hit the wall in the last several miles and slow down precipitously. The corresponding number in half marathons is only 8 percent.