Oh, of course I had to buy this as I really like Chalene's HiiT workouts. So Turbo Fire Greatest HiiTs total workout time is 20:42. The workout contains a warm up, 4 HiiT drills, and a cool down. The warm up and first drill is from HiiT 15. The second drill is from HiiT 20. The third drill and cool down is from HiiT 25. The fourth drill is from HiiT 30. Drill 1 is 34 seconds. Drill 2 is 46 seconds Drill 3 is 55 seconds Drill 4 is 61 seconds Each drill is repeated twice. The Turbo Fire logo flashes and is used to transition the workout from drill to drill. Other than that, Greatest HiiTs is pretty much the same as the other HiiT workouts. Chalene marks the drill and then she does it. I don't mind the compilation and I like having another HiiT workout. I just wish they would have combine all the HiiT drills from all 4 workouts for a super duper HiiT workout - maybe doing each drill once to keep the workout shorter. Although as they already have a 15, 20, 25 & 30 minute worko...