Last year, we applauded Blake Lively when she asked fans not to celebrate her post-baby body in her latest film The Shallows, admitting she'd rather people celebrate the fact women give birth to the 'incredible miracle that life has to offer' rather than having a 'Victoria's Secret ready' body weeks into motherhood.

However, after watching the American horror film, which sees the 29-year-old play a surfer who is attacked by a great white shark, we couldn't help but want to know the secret behind her toned physique and rock-hard abs, a mere eight-months after giving birth to her first child, James.

I mean, come on. Her body is marvelous. We can celebrate that a little bit, right?

Ryan Reynolds and Blake Lively | ELLE UKpinterest
Getty Images

After filming, the Gossip Girl actress revealed she attained her athletic body after cutting out soy and gluten from her diet before shooting the film, but now her stunt double has explained just how hard it is to get a body like Blake's.

And no, it sadly doesn't involve a packet of caramel bites and a handful Doritos.

Blake Lively on red carpet | ELLE UKpinterest
Getty Images

Body double and world junior professional surfer Isabella Nichols, who played the actress' body double in the shark attack survival film, shot on Australia's Lord Howe Island, told myBody+Soul how she maintains her self-proclaimed 'pretty gnarly' fitness regime.

She surfs at least two times a day

Yes, a day.

'Sometimes, two to three times a day. I'll try to be in the water for four or three hours, depending on what I have on. But if it's good I stay out for six or seven hours,' she told the publication.

instagramView full post on Instagram

An average session at the gym lasts an hour-and-a-half

'Every day I drive to the gym that's half an hour away for a specific session. These days, the girl on tour have a lot of power, so it doesn't look as good if you're not as strong.

'At the moment my focus is on improving my lower body strength – so we're doing loads of squats and lunges. I go to the gym for an hour and a half, five or six days a week, and have a day or two for rest and recovery,' she admits.

Forget the treadmill

Describing a typical training session, Nichols reveals she likes to mix up her exercise regime.

'We're doing lots of legs sessions – squats, lunges. One day, it's body mobility – twists, gymnastics and stretching. We might do the odd cardio session on the rower, though paddling and surfing is really my cardio,' she says.

'I don't use a treadmill at all. Leading into events, we focus on fast twitch movement sessions – jumping and plyometrics, to get your muscles firing and responding,' she adds.

Her diet is as healthy as you'd imagine it to be

'Breakfast: Eggs and avocado on toast or cereal with fruit

Morning snack: Banana or berries

Lunch: Sandwich melt with ham, avocado, cheese, egg and onion

Dinner: Tuna bowl with brown rice and avocado, or steak and veg (I eat red meat four times a week for energy).'

Fueling is key

Before a surfing competition, Nicols admits she'll 'knock back something like a banana, muesli bar or yoghurt. But staying hydrated is the main thing'.

She dislikes one of our favorite foods

Icecream. I don't like it.

Positive thinking is key

'I'm still trying to work on the best way, but keeping a healthy mind. I like to practice reinforced positive thinking and make sure I let myself have time off to listen to music and read a book,' she concluded.

*Puts down the cookie dough ice cream and picks up a 1kg dumbbell*

Headshot of Katie O'Malley
Katie O'Malley
Site Director

Katie O'Malley is the Site Director on ELLE UK. On a daily basis you’ll find Katie managing all digital workflow, editing site, video and newsletter content, liaising with commercial and sales teams on new partnerships and deals (eg Nike, Tiffany & Co., Cartier etc), implementing new digital strategies and compiling in-depth data traffic, SEO and ecomm reports. In addition to appearing on the radio and on TV, as well as interviewing everyone from Oprah Winfrey to Rishi Sunak PM, Katie enjoys writing about lifestyle, culture, wellness, fitness, fashion, and more.