The workout includes two 8-minute sets of 15/15 intervals. After a 10-minute warm-up, you will complete the first set of 8 rounds of 15 seconds in Zone 5 and 15 seconds in Zone 2. You will have 8 minutes of recovery before repeating the same intervals for the second set.
Finish the workout with a 10-minute cool down.
This workout is generally considered to be more difficult than 30/30 intervals as you are changing intensity more frequently.