I found this workout to be VERY challenging! I was SERIOUSLY huffing and puffing and my legs were fried! WOW! Since it was my first time doing it I hesitate to compare/contrast this workout with any other, but...I think it was tougher than Cardio Leg Blast! I haven't done LIHI Legs yet, and I still have Plyo HIIT #2 on my plate for today...but so far, HIIT Circuit LB has been the most challenging for me....