I did this yesterday. It’s a staple in my cross-training rotation. It’s intended to build core strength, but it’s a pretty decent aerobic workout if you do it fast enough and keep your pulse up. It was developed by a doctor who just happens to be a marathoner and triathlete too.
I recommend watching the videos to get your form down so you’re doing the exercises correctly. When I first started doing this, someone posted a PDF in the comments that just has them as a list. For the short term memory/Dorie crowd (that’s me) it helps to refer to it so you get your reps and times right. If anyone wants a copy, let me know – I don’t see it any more at the link.
A word of advice: don’t pick the heaviest barbell you can lift. I usually do this with 10 or 12 pounders. What can I say – I’m no Arnold Schwarzenegger.