Peter Attia structures his cardio week with Zone 2 training on Tuesdays, Thursdays, and Saturdays, and VO2 max training on Sundays, preceded by Zone 2.

“my zone 5 workout which i really only do once a week is three minutes of zone two with one minute at vo2 max because i know what my vo2 max is i know how to convert it into mets which is vo2 max divided by 3.5 and the stairmaster allows you to work in watts and mets so basically i'm doing three minutes at my zone two and then i go one minute at what my vo2 max is which truthfully is quite difficult to hold your vo2 max for one minute and then right back to three my recovery is then the three minutes at zone two and so that four minute pattern i just repeat for 20 to 30 minutes and i usually do that on the tail end of a zone two workout”

“Tuesday is zone two followed by dedicated hour of stability. Thursday is a repeat of Tuesday. Saturday is zone 2 in the morning... Sunday is zone 2 followed by V2 max.”

“80% of that time is zone 2 and 20% of that time is V2 max.”

“Peter’s 80% zone 2 / 20% VO2 max training protocol”