Kettlebells

What is it? An entire class dedicated to lifting kettlebells (cast-iron weights that look like cannonballs with handles).

What's needed? Gym gear, water, wrist wraps. Chalk provided.

The experience: This workout is inspired by Russian military training, which means it will help you to be kick-ass strong. That's why professional boxer (New Zealand champ in his weight division) Robert "The Butcher" Berridge uses them.

They've helped him nab 20 wins, and 16 of those via knock out. So says his trainer, Vasco Kovacevic, from Red Line Fitness in New Lynn.

It's taken me a fair bit of time to brave this gig. I'm just a mere mother and I was afraid hauling cast-iron weights about might break me or turn me bloke-like.

But I soon learn I shouldn't have been so wussy: females do these classes, too. In fact, it was a gorgeous woman who trained Vasco to use the bells - Anna Samson, a New Zealand Iron instructor, who trains kettlebell trainers countrywide.

She says there are even bridal bootcamps based around kettlebells, helping brides get buff before their big day. She also runs chick-only sessions called "KettleBelles" on Auckland's North Shore. She raves how the bells give an intense cardio strengthening workout that boosts the metabolism, makes you strong and sears fat.

Vasco reckons the only other exercise forms that burn as many calories include high-speed cross-country skiing and high-speed wood chopping. He warns me to prepare for a tough workout. I'm in a clean, well-fitted-out gym filled with weights, a boxing ring and boxing bags.

The music blares and for 45 minutes I'm at the mercy of a computer that drives this workout and counts down each lot of reps, with rests in between. The computer flashes green for go, accompanied by a blast from a horn, or flashes red for stop.

One movement I do a lot is called "The Snatch". Vasco likens it to how you might look when you start a lawnmower or, to be more precise, you fling a bell down low, between your legs and then above your head and flop the weight over the wrist in a fluid motion.

I also swing the weight, do lunges, a military press (pressing the bell above the head while keeping the elbows in tight), hand curls and an abdominal blast to try to get abs of steel with my ball of steel. I am using a 6kg bell, Berridge uses one weighing 24kg. I feel like He-Man or the Incredible Hulk in training and I'm constantly told to "go hard out".

Vasco drives my reps: "You're not sweating enough! Still!" he says.

"I am so sweating! It's just that it's a freezing day," I argue.

"Do more reps," he says. "You need to sweat."

"Can you not see my angry face?"

"Chalk up your hands more." (This wards off calluses.)

"Are calluses a sign I've worked out hard enough?"

"Actually, if you're working as hard out as you can, your hands should bleed."

Needless to say, this is bloody hard work.

How much? There are casual, weekly, monthly and yearly membership rates at Red Line Gym, including $10 casual entry and membership rates that start at $15 weekly.

Worth it? I'd envy the body of any gal who does this regularly. You just can't argue with the sculpting these mean cast-iron balls help carve up.

Try it: Red Line Fitness, 2171 Great North Rd, New Lynn, ph (09) 215 7024, info@redlinefitness.co.nz

Rating: 8/10.

Rachel wears: adidas by Stella McCartney: Stu Perf Tank $130; Run Nylon Jacket $300; Dorifera Feather shoes $250 - stockists ph (09) 523 5005, adidas.co.nz/stella/
Mambo Core Trackie $44.99, http://www.thewarehouse.co.nz/

- Herald on Sunday