I would recommend doing a gentle warm up before hand. The instructor doesn't inspire as she spends a lot of time walking about talking and not actually doing the exercises. Only Anna does modifications which are quite low level and I feel there could be another level in between Anna's and everyone else's especially as there were lots of people there, eg: standard burpees instead of diamond burpees. I did however get really sweaty and have a good workout.
This is at the high end of an intermediate workout. Lots of burpee style drills and a really good one for the upper arms, core and heart rate. You gotta be pretty fit to take on this one.
Incredible! This workout has had the highest calorie burn for me so far in the 30-minute range by a long shot! It got me so energized and into it that I snapped two hair ties trying to keep my hair out of my face!