The New York City Ballet workout used to only be a book, then it was a DVD, and now it's available on YouTube for FREE! I always wanted to buy the book, but was too cheap, so I held off. Now that it's on YouTube, I've been doing the workout at home and was surprised by how much it got my heart rate up and felt like a great workout. I also taught it to my dancers in their ballet class - they liked it and were sweating, red-faced, and out of breath. For a teacher, that's success!
Here it starts with Part 1. There are 9 parts in all, and seems to be over an hour. Quite long, but I do the first couple of parts to get some cardio, stretch, and do abs. The voice-over is rather strange, but it makes it feel like you're in a ballet master class. See what you think!