If High Intensity Interval Training (HIIT) did not exist we'd have to invent it to help superheroes train. The Superhero HIIT workout therefore pulls very few punches. It will push your VO2 Max and speed of recovery time to the limit. The only reason this is not a difficulty Level 5 workout is because superheroes can just do this kind of thing so to them it's only a Level 4.
Extra Credit: 1 minute rest between sets.