Plenty of people who care about zones and total intensity do a low intensity session with a high intensity kicker. I got the idea from Prof. San Millan: https:

Plenty of people who care about zones and total intensity do a low intensity session with a high intensity kicker. I got the idea from Prof. San Millan: https://peterattiamd.com/inigosanmillan/ https://peterattiamd.com/inigosanmillan/