This is a great all-rounder workout. It starts with an easy warm-up followed by 10 minutes at the top of zone 2, straight into five intervals of 30 on, 30 off, and working through multiple zones. After fully recovering from the first block, you get into the main set. The main part of this workout is four intervals of 60 on, 60 off between zone 2 and zone 5. The final block is eight intervals of 20 seconds on and 40 seconds off.