What is it? A combination of cardio and aerobic exercise, work with hand weights, stretching, ballet barre work, yoga and Pilates.
What's needed? Unrestrictive and comfortable clothing, water bottle, towel, yoga mat, bare feet.
The experience: Casey Green, wife of All Black and Blues player Ali Williams, is teaching the Body Beautiful class on the night I'm at the Abundance studios in Auckland city.
Wearing black leggings, a tangerine top and with her hair swept into a ponytail, she's dazzling. And so, too, is the sapphire and diamond ring weighing down her left hand.
She's more than beautiful, though; she's got brains. Body Beautiful is her creation.
Casey and Ali were in Santa Monica a few years ago (he was training) when she discovered a studio that offered ballet conditioning exercises for the public.
She became hooked on the graceful moves that transformed her body and it got her thinking ... She decided to infuse some of the moves with the best bits of other exercises she loves, such as Pilates, yoga and using free weights, and came up with Body Beautiful.
"I'll never be a ballerina, but I would like the grace and the body of one!" says Casey, explaining that Body Beautiful helps create "the dancer's body" of long, lean thighs, sculpted arms, taut buttocks and stellar abdominals. If you work at it, of course.
Well, she got me working all right - and the dozen other girls in the class.
We're in a pristine and cosy studio, surrounded by mirrors and ballet barres (handrails fixed to walls) and listening to contemporary music.
Outside, I watch rain pelt the pavements and workers scurry about under a dark night sky over Queen St.
Casey is at the front of the class, skin glowing and an absolute advertisement for her brand. She kicks off with an aerobic-style warm up.
We use 1kg weights in each hand that Casey warns "will become like bricks". And when this happens she sympathises: "I know you hate me right now!"
We're often instructed to do "tiny movements" to target specific muscles, which results in big pain. Think, tiny "pulse-like movements". I can't believe such little moves can smack the muscles with such punch.
When it gets to the barre work, I love being "girly", with poise. And as we get to the heel-raises-while-holding-the-barre moves I can't believe I'm wishing I'd donned at tutu as a child: It's fun!
Casey is often beside members in the class, quietly helping them with technique, while giving out constant instructions to the class for the next move.
Her speech is sprinkled with Body Beautiful lingo: Whenever she reminds us to lock in our abdominals, she calls it things like "the Body Beautiful tummy tuck".
When she asks us to lift our "seat", this is code for clench thy buttocks. And stomach crunches become "crunchies".
And when we are doing a particularly gruelling move, Casey promises "there's a reward coming soon", which is code for "a stretch will follow soon so suck it up and hang in there!"
We place large pliable balls between our legs in some exercises to target our "muffin tops" and even "back fat" gets blasted by squeezing on the ball and then doing abdominal work by shifting our legs from side to side.
Doing planks, ie, being on toes and elbows and holding in our middles, comes near the end, as does "massaging the muscles" by stretching with giant bands.
As the 50-minute workout ends, Casey says "thank you ladies" and encourages everyone to head home for a "healthy dinner".
Casey asks me "have you noticed you're not a sweaty mess?" I'm quite surprised to find that I'm not, but promise I worked hard! She boasts this is why it's an ideal workout for city workers who like to exercise in their lunch hour.
I tell her I thought the barre work was great fun and she lets me in on a secret: she's working on a new class that will boast even more of this.
I'm sure her clients will love it.
How much? Class rates at Abundance are $20 and an unlimited class membership is $29.50 weekly (which gives access to 44 classes across seven days weekly, including body beautiful, yoga and Pilates mat).
Worth it? Absolutely. What gal wouldn't want to look like a dancer?
Try it: The Auckland Abundance studio is at 203 Queen St, ph (09) 304 0764. They also have studios in Hamilton, Porirua and Thorndon.