Did 3x20ish (2 10min sections split by a min rest, Carillon +2 for TR people) averaging 90%, felt super easy, but my basement was also low 50's (my Garmin said 43 when I turned it on but I closed the window most of the way). Gonna see after a full week of the plan whether it's a little too easy and bump things up or just maintain the course, but first 2 workouts have felt great.