On page 132 of the book you write “by increasing the challenge level of the harder sessions to a reasonable limit”… what is meant by this and how does someone increase the challenge level? Does that just mean doing the workout at the high end of the zone, or does that mean substituting a harder workout? Or does it mean something else?
I think we’ve found the editor for our next book. 29,000 copies sold and only now is it being truly appreciated and scrutinized. Actually, are you my editor? (Is that you, Rene?)
Seriously, these are great questions and add huge value to the Forums. I appreciate them!
What I meant there was executing the workouts at the top end of the range. There is a big difference between 4×8 minutes at low Zone 3 and 4×8 minutes at high Zone 3. So, if you find that you are executing all intervals at the high end of Zone 3, 4, and 5 then the only way to add volume is to add more duration (more workouts).