Lou Kenny is one of Australia's most in-demand models. She's 58 years old.

Lou Kenny is currently one of the most in-demand Australian models, but she’s far from an emerging talent.

The model-and-yoga-teacher caused a stir on the Melbourne Fashion Festival runway earlier this year, appears in the latest campaign for underwear brand Berlei and has just done a Vogue Australia shoot. Oh, and she’s 58 years old.

Starting her career when she was just 18 years old, Kenny jokes it’s only taken her “40 years to get into Vogue“.

Despite working in an industry commonly associated with youth, she says she's never felt discriminated against because of her age. In fact, it's the exact opposite.

"I find it actually works in my favour as I'm a bigger fish in a smaller pond and less people are doing it," she tells Mamamia.

"It's good, it's really good. I'm happy to be able to mold a shape of some sort of empowerment of women by working with brands such as Berlei who do their part for women such as with their Chrissy Amphlett bra [which gives 100 per cent of the proceeds to Breast Cancer Network Australia]."

While women of every age require underwear, lingerie advertising in particular tends to alienate the majority of women by using younger models.

Listen: Christie Brinkley says she's battling ageism with this cover shot. Post continues after audio.

Kenny acknowledges the significance of her inclusion in the campaign but plays down the hype, saying ultimately it just makes sense.

"It's in my mind everyday that underwear is dictated on a certain level and what you can and can't wear," she says.

"You don't see very much of women over 40 and 50 [but] I like nice underwear. And you can dress in anything you like, we as consumers have the power."

It's a move Berlei Marketing Manager Zoe Hayes says the brand is really focusing on.

"We were elated to work with Lou for our AW17 Campaign. We recognise and share the desire of Australian women to see more diversity in advertising and want women to feel positive as a result of interacting with our brand," she says.

"And while this is a great first step, in SS17, in celebration of our 100years, we intend to up the ante on inclusivity and diversity in our marketing imagery, and also in the way we design our product. We can’t wait to share the next step with you.”

Kenny was studying social work when she started working as a swimwear model for a well-known swimwear company in 1978.

"I did that for a number of years and then on their product nights where they would sell to David Jones and Myer they would bring professional models and I was there as the fit model and then they put me in the show," she says.

One of my first jobs! #oldnews #model #oldschool #newspaper #rewind #melbourne

A post shared by Lou Kenny (@lou_f_kenny) on Mar 23, 2017 at 3:38am PDT

After impressing, Kenny was signed with an agent. In just a month, she'd landed her first commercial - with L'Oreal.

She says she had a lot to learn in the early days.

"I turned up for the job in February and was quite tanned and with two girls who were paler and I was told to stay in the hotel all day to let it fade! Sometimes having a tan is not a good thing," she says. That kickstarted it all.

In the '80s, Kenny was doing everything, including runway, print and commercial in Australia as well as a stint in Europe.

"I only did two seasons overseas, just before I had children [now aged 26 and 27]. I also choreographed for [department store] George's and Country Road and did some styling when I was pregnant and couldn't model," she says.

"I always thought one day I'd give it [modelling overseas] another crack, so here I am as an empty nester!"

Kenny retrained in her forties to be a yoga teacher, which she has been doing for 14 years and has spent the last three years in London.

Afternoon sun ☀️ ????

A post shared by Lou Kenny (@lou_f_kenny) on Apr 12, 2017 at 12:31am PDT

Forty years on, she says the industry is "so different but so much the same".

"It is much the same but I'm very different," she tells Mamamia.

"I'm a lot more appreciative and a lot more prepared, because success is preparation and opportunity. I've been preparing for a long time.

"When I was younger, I sort of took it for granted because you don't have to do so much. When you get older you have to keep fit, keep up."

Her secret, she says, is simple - yoga.

Yoga everyday :) #yoga #yogaeveryday #loveyoga

A post shared by Lou Kenny (@lou_f_kenny) on Apr 9, 2017 at 4:55pm PDT

"For me, it's about keeping yourself in good tone. I'm a yoga teacher and I really enjoy maintaining the body as well. It's just a way of life."

"I feel better about my body all the time. I'm a lot fitter than I used to be. Since I've been travelling I do so much walking, I've got used to it, my legs got stronger and paid dividends."

Kenny does yoga four to five times a week minimum, usually doing an hour or more a day.

"You can do it as you go, I do it on the train too as you can do minimal stuff in a seated position. I'm really good at doing it on the aeroplane too."

With decades of experience, Kenny says she still learns plenty from the younger models she works with.

"I like to watch their attitude in the rehearsal and their communication skills [on social media] and we all work as a team. It felt really solid at fashion week," she says.

@vamff @voguerunway walking for VAMFF vogue show last week @giant_mgmt #vamff #vamff2017 #runway #model

A post shared by Lou Kenny (@lou_f_kenny) on Mar 20, 2017 at 4:54pm PDT

"They are more laid back [now], there's not the fuss about hair and makeup. In the '80s there was so much makeup and everything had to be perfect. In these runways, hair and makeup were deliberately different and more catered to as a person rather than clone. I'd like to think that's across the board, it's now more about individuality."

When it comes to her own personal style, the 58 year old values feeling "pretty relaxed".

"I need to feel I can do handstand in. Yes, I can do handstands! And cartwheels and all that stuff," she says.

"If I'm going out at night, I like denim jackets. When I teach yoga at festival, I need to dress up - when I did Acid Yoga I wore a Puffa white tradesman jacket and put a silver bikini over the top. I have some silly things it's so fun to dress up."

Shooting for Vogue Australia #vogueaustralia @limbthelabel - jumpsuit! Perfect for travelling.

A post shared by Lou Kenny (@lou_f_kenny) on May 3, 2017 at 1:17am PDT

With age has come self-acceptance, too.

"I'm happier than I've ever been," she says. As for "feeling" like what society expects a 58 year old women to be? Not at all.

"If you look at all the advertising [of that age], I'm outside . I feel totally ageless. It's just about being yourself and it's about what you don't do rather than what you do."