One of the big debates in endurance sports these days is about “training intensity distribution,” which is a fancy term for how much of your training time you spend going easy, medium, or hard. The dominant paradigm is the polarized distribution, which calls for a lot of easy running, a little bit of hard running, and not much in the middle. But there are various other viewpoints, including the currently fashionable Norwegian training, which puts a heavy emphasis on medium efforts.
One way of exploring which training distribution is best is to look at the training diaries of the best endurance athletes in the world. That’s how the concept of polarized training was born, and it’s why Norwegian training is rising in popularity. Of course, this isn’t as reliable as a randomized trial. Maybe most elite athletes train in a certain way because it’s popular, not because it’s objectively better than the alternatives. And even if we figure out the best way for elites to train, it’s not clear that those insights will apply to the rest of us.
Another option to assess training intensity is to look at…
