If anyone is interested in a great sweat, definitely do this one.  I have used this one a number of times while traveling because it is a bodyweight only session. Here's my moment to share progress as well...it's been a while (maybe 6 or 8 months?) since I last did it.  This morning I never had to stop on the power planks.  Before I would always hit a point where I needed to stop and rest before the 30 seconds was up, and today I did all the sets without stopping and rebounding from plank to pike the whole time!  Like Jenny says in this one, this exercise is the hardest one for me.  I was so excited that this seemed much easier than I had remembered (easy being relative, not eeaassyyy, but easier than before).  Still a great shred, I was drenched at the end of the session.  This was great to show progress for me and so much fun to do!  Highly recommend it for this week!  Wanted to share so that others can realize that you will see progress if you are consistent, I promise!