80/20 Running: Run Stronger and Race Faster by Training Slower

by Matt Fitzgerald

The two most important variables in run training are volume (how much you run) and intensity (how fast you run). These two variables have been combined in every conceivable way over the past 150 years. There have been low volume/low intensity runners, high volume/low intensity runners, low volume/high intensity runners, and high volume/high intensity runners. Each of these general approaches has encompassed a full range of permutations. The particular high volume/low intensity combination of one hundred to 120 miles of running per week and 80 percent of total running time at low intensity was first tried by elite runners in the 1950s. By the late 1960s, it had driven virtually every other way of combining volume and intensity into extinction, and it remains in almost universal use by today’s elite runners.