Now consider this. The stairs are actually the easy part of this section of the routine. The tougher part is doing reps of exercises such as squats and lunges, with a 10kg bag of weight over my shoulders.
The idea is to do as many reps as possible, while my buddy for the day (Charlotte, a chick in the film and TV industry) climbs the stairs. We take turns to do the reps and stairs, until we reach 60-reps of each exercise.
Welcome to the "60s Club," says Janelle, who prides herself in designing "challenging" workouts, rather than what she calls "fluffy" programmes.
She also likes her workouts for just gals, "so they feel comfortable". This means you can talk about your muffin top or things like cramps and boobs and no bloke will flinch.
And there's no worry about some dude falling over themselves trying catch your attention while you're, um, trying to catch your breath, too.
I'll 'fess up now that when Janelle first asked me along to a session I said "thanks, count me in!"
Then I checked out her class timetable and panicked: It's for early-birds and I'm not a morning person; rather a blurry-eyed grumpy beast who will only morph into a semi-functional human being after a serious caffeine injection.
But I figured it was about time I checked out the world of those who exercise before work.
And on the day I'm here, more than a dozen women show.
The session overlooks Western Park, but the workout is no walk through it. After all, the company's website boasts "Bodyrox - Extreme Results". And I know you don't get extreme results by twiddling your thumbs. I've tried that.
But Janelle does promise on her website that she's a good sort and won't be a "nasty drill sergeant" who pushes anyone so they pass out or throw up.
We kicked off the session by jogging about a bit and doing some warm-up exercises. But within no time, we were into quick sprints around cones, hauling weights on our shoulders and then hitting that stairway to hell.
The buddy-up system for the 60s club is social, plus it's actually sneakily motivating - there's no way you want to dither about on those stairs because you don't want to leave your poor buddy to wilt doing non-stop exercise reps.
Janelle meanwhile is looking out for correct technique and spurring us all along to keep going. She also knows her girls' goals and makes some push themselves even harder for the results they want.
At the end of the session we do some stretches and Janelle asks us each to rate today's torment, I mean session, out of ten. Most people rate around the 9s for intensity and reveal what they liked most.
I give it a 9 out of 10 and rave about the motivating buddy system. I don't think anyone said they loved those stairs, funnily enough - but I reckon you'd get heavenly legs if you hit them regularly. They'd be effective.
Janelle looks happy hearing everyone felt challenged during this session. After all, she knows what it's like to be challenged herself. She was once 95kg, but she worked hard ("slowly and painfully," she tells me) to shed a staggering 30kg. And now this sassy and smart cookie is inspiring others to reach for their goals too.
How much? Different plans are available including $15 a week for three sessions weekly.
Worth it? Great workout in the fresh air - plus there's an indoor option if it's raining. There's even another instructor who takes boxing each week which keeps the workouts interesting. One bonus to the mostly early workout timetable is that there are fewer people about to see you in a sweaty mess.
Try it: Bodyrox group training sessions are at Western Park (in the city) and Onewa Domain (on the North Shore).
Rating: 9/10