Бег по правилу 80/20: Тренируйтесь медленнее, чтобы соревноваться быстрее

The 80/20 approach challenges traditional fast-paced training, so I'm curious what motivated the author to emphasize this method and how it became central to the book.

The book presents a lot of research—did it change how others approach their training or confirm what they felt worked for them?

With so much research out there, I wonder what led to the selection of specific studies and how they shaped the training advice.