What is it? An hour of hard-core strengthening and conditioning work.

What's needed? "A towel, a drink bottle and a positive attitude", according to the gym's website, which also mentions people leave "gasping for breath, sweating buckets, but loving every minute".

The experience: I sign a form to declare I understand that what I'm about to do is at my "own risk".

Dear God.

I suspect if I have a problem with this, I'd be told to go hard, or go home; this gym is for "tough mudders".

The Ludus Magnus School of Training is named after the largest of the gladiatorial arenas in Rome. Therefore, I'm going to have to find my inner gladiator.

So I prepare to get primal and do battle. I tell my editor I just hope to survive.

The arena awaits in Eden Terrace, close to K Rd. It's not posh, rather a real-deal gym with big weights, boxing bags and other kick-arse gear. The gym promotes the fact it has no fancy gimmick machines.

In a comical twist, the trainer taking the class is Pua Magasiva, who plays Vinnie Kruse, the joker nurse on Shortland Street. The actor, who has a certificate in personal training, is among several super-fit actors or sports stars among the trainers here. There's even a bloke with a military background.

There's a dozen in the class and there's almost as many gals as there are guys. Speaking of women, I spy some other Shorty stars, including Teuila Blakely (who plays Vasa Levi, the tough HoD of nursing) and her on-screen daughter Ula Levi (real name Frankie Adams).

Pua blows a whistle to kick-start the class. And then we all surrender to a menu of punishment that's scribbled on a giant blackboard.

We do circuit-like drills, over and over and then over and over again: push-ups, chin-ups and sprints. I clamber up ropes from a lie-down position after doing sprints in-between each climb. I heave big heavy bags on my shoulders and do repeat squats. Next I'm leaping up and down on to a knee-high wooden box and summoning strength that I didn't know I had.

At one point I hear a burly bloke whimper to a mate "I just can't do that again". He was talking about heaving his hulk up the top of a rope for the zillionth time. Of course I wriggled up there like a slick little snake ... Yeah right.

I pumped dumb-bells, pressed my own weight, lapped the car park outside more times than I can recall and I did pull-ups on a metal bar until my arms wobbled they were that wasted. I think I might have even growled ...

Pua barks orders for each drill, and runs around the class, constantly spurring everyone on. And it works. No one wants to be the wally not working hard.

He drops his whistle to do a few sets with each group. Alongside me, we load up our shoulders with heavy bags and do sets of squats, in between biffing our bags on to the concrete floor and leaping up high on to wooden boxes.

I know I look ludicrous. But I strangely lap up unleashing some brute force. It feels bloody brilliant.

Pua quips, "hard out aye!"

I nod and save my breath for abusing him later. He gives me a high five and remarks "beautiful!" What he means is I'm doing a beautiful job at thrashing my body. Because I can assure you no one looks pretty by the end of this battle. We're all among the ruins.

One of those sweaty stars, Teuila, who is very sweet by the way, confides the hardest part of the workout is actually turning up to it - "especially when you know what's going to happen!" she laughs. But she adds "it's just such a great workout".

She tells me I must be committed to my craft to be giving this my all.

Either that, or I'm a sucker for punishment, I suggest.

Pua yells "good work peeps!"

While surrounded by a trio of Shorty Street stars, I briefly wonder if I'm being "had" and I'm unsuspectingly playing a role as a sucker journalist on Shorty Street.

Except Pua's not laughing, he's yelling at us all to keep moving and work harder!

I ask another woman how she felt after her first session. Her reply: "I wasn't good mate."

At the finale, a room of sweat-drenched souls stretches before crawling out of there to recover.

That was a killer workout.

How much? Casual session $20, 12-concession card $200. Other options include a 12-month unlimited session pass at $34.95 weekly.

Worth it? Great workout for those who are up for the challenge. Cool vibe.

Try it: The Ludus Magnus School of Training is at 4 Glenside Cres, Eden Terrace, Auckland, ph 09 379 6803.

Rating: 10/10

- Herald on Sunday