Runners often swear by the 80/20 rule for organizing their training—but this is no relation to the Pareto principle of the same name. Let’s talk about where the 80/20 idea comes from, how to implement it, and when it is and isn’t a good idea to train this way.
What is the 80/20 rule for running?
Briefly, it’s the idea that 80% of your running should be low intensity, and only 20% at medium or high intensity. Recreational runners (like you and me) often run closer to a 50/50 split.