FB Fit day two killer workout!

I've started FB Fit after just doing independent workout videos and I was really looking forward to today's workout. It's a 4/5 but it completely flawed me! I don't know whether I'm just having an off day but I was struggling after 10 minutes! Anybody else found this workout really challenging or is it just me?

https://www.fitnessblender.com/videos/cardio-hiit-workout-butt-thighs-abs-ultimate-workout-for-belly-fat-loss-no-equipment