training zones

How to Go Easy (and Why): An Introduction to the Polarized Training Model

I grew up playing soccer. Every practice was hard. “No pain, no gain,” and all of that. By tenth grade, I was burned out and quit.  I started rock climbing. Every day at the crag was about pushing your limits. This was before indoor gyms or any concept of training other than doing as many pull ups as possible. I plateaued, got frustrated, and quit.  Then I had a go at running. I read some...