Liz Neporent is a diet and fitness expert and co-author of "The Fat-Free Truth." She regularly appears on national TV programs and is the president of Wellness 360, a New-York based wellness provider. You can also follow her on Twitter @lizzyfit.

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Have you ever seen that OK Go! Video, Here it Goes Again, where four guys do an amazingly-choreographed dance routine skipping between eight treadmills? Very entertaining. Am I the only one, or was it just a matter of time before someone came up with the bright idea to turn this thing into a workout?

The other day my friend and top fitness pro Terri Walsh sent me a link to Tracy Anderson's treadmill dancing video exercise routine. Anderson is the latest Hollywood "it" trainer. As Walsh puts it, "Fitness gurus come, and fitness gurus go, but one who trains Madonna and Gwyneth Paltrow, our patron saints of enlightened blonde fabulousness -- must be the guru-iest of them all no? THEY think she's got something, so she must be good, right?"

Um, not so much. At least not from what I see here. I watched the entire 20-minute video in abject horror. I haven't seen anything this scary or unsafe in exercise since I witnessed someone sitting on top of a stability ball accidentally launch a Kettle Bell into a mirror. Normally, I try not to be such a hater – if you can't say something nice, blah, blah, blah – but once I heard Anderson utter the words "women shouldn't ever lift anything heavier than 5 pounds" -- game on, baby!

The workout starts out on a stopped treadmill with a series of sweeping leg swings borrowed from the world of dance. There is none of the instruction on technique that is so important in dance, and which makes dance so effective. I immediately began to feel concern for anyone with hip or knee issues. The rest of the workout is done while the treadmill belt is moving and consists of skipping, sashays side to side in shuttle-run fashion with the front leg turned out, some run-run-jump-hops pulling the knee towards the chest, and then on to full on-jete leaps. Again, no real instruction at any point. And worse: No mention ever of recommended speed or grade! As I watched this mess, all I could think of was someone who admires Madonna's cut physique leaping onto the treadmill with gusto -- and then being ejected off the back like a popcorn kernel out of a hot pan.

Anderson clearly has dance training and looks good doing the moves. But she can't actually explain what's happening with the body. She often does not correctly identify which muscles initiate the movements. Many of the positions she uses are compromising to the knee, back and hips. And, as Walsh points out, Anderson wears Nike Shox to do the workout, a super bouncy shoe which amplifies the bounce of the treadmill and thus impact to the joints. Unless you are already a trained dancer who is very practiced in technique and body awareness (like say, Madonna), I believe there is a good chance you will be injured doing this routine.

My 2 cents: Just so I am perfectly clear about my opinion here: I think this workout is dangerous for the average person. Some trainer-guru programs are good -- Jillian Michaels, anyone? But this is not one of them. I can only pray Anderson does not come across the Afro Ninja YouTube clip. I shutter to think what she would do with that!

Now it's time for your 2 cents: Has anyone tried this workout? Anyone want to defend it? Anyone like to try a decent workout? Be the fifth person to tweet me today, and I'll send you a copy of Jessica Smith's brand new 10 Minute Solution: Belly, Butt and Thigh Blasters, complete with its own exercise band.

Here, exercise DVDs you should be buying.