80/20 Rule — the easy to hard intensity ratio when it comes to training sessions, has been well publicized. Seiler believes easy days should be truly easy, meaning walking the hills may be mandatory. If the easy days are easy, then the hard days are hard. He espouses a fidelity to training models with little, if any, in-between efforts; that means no middle-of-the-road intensity. And his observations come straight from Norway. “… They know what gets you...