Barbie and Ken Go to Pilates: Here's How the "Barbie" Cast Trained For the Movie

London-based personal trainer David Higgins has been working with Margot Robbie since about 2015, when she was first prepping for her role in "The Legend of Tarzan." The aesthetic of that move — that is, tousled, grungy, raw — is just about the antithesis of her of-the-moment starring role in "Barbie."

Still, to prep for the perfectly pink, manicured role of Barbie, Robbie went back to Higgins, this time asking him not only to train her, but also the entire cast — both the Barbies and the Kens. (She got the rec, in case you were curious, from none other than Samuel L. Jackson.)

What followed was just about as wholesome as it gets: the whole cast would turn up for workouts with Higgins during their summer shooting schedule in London, and it became like "a community," Higgins tells POPSUGAR. "It was a really collaborative, fun experience," he says, with even director Greta Gerwig and other producers coming in.

"The gym environment effectively fed into the film; it was fun and everyone was just up for a laugh and to feel good. It wasn't aesthetics," Higgins says. "I always find that the aesthetics come naturally when you're working out properly and you're looking after your diet, but it wasn't ever the focus. It was more of a team-building, community experience . . . it wasn't like the superhero movies that I usually work on, where [the goal] is very specific, like, let's create these superhero bodies. Barbie was more about: let's just feel good, and if you feel good, that's going to translate on camera."

If you had to guess what type of workouts would comprise the "Barbie" method of training, you might say . . . step aerobics? And that's not far off, considering Gerwig herself is a certified step-aerobics instructor. But the reality is even more obvious, considering it's the hottest workout right now: Pilates.

Higgins, who's also a physical therapist, has been marrying Pilates with traditional strength and conditioning training — in the world of fitness, a surprisingly unlikely pair — for about 20 years now. As a PT, he comes at exercise from a rehabilitation perspective. He realized he "really enjoyed the majority of what Pilates was about, which was control, engagement, and correct alignment," he says. But instead of going full-on Pilates, Higgins thought: "Why don't you learn how to do it all? And you can, because the body responds significantly well to diversity."

This hybrid approach forms the basis of the Barbie method — a name he hasn't personally given the workout style, but which seems fitting when referencing his training of the movie's cast — and it seems like a great method for anyone, life in plastic or otherwise. Here, peek behind the curtain at the Barbie cast's training sessions, and even try a workout for yourself.

In an interview with Fandango, Simu Liu (who plays a Ken) joked that while the Barbies got a sleepover to encourage cast bonding, the Kens just got daily workouts — but to be fair, the Barbies did, too. They just looked a little different.

The Kens did a more strength-forward program, and the Barbies focused on Pilates, with strength and conditioning peppered in, Higgins says.

Generally, the Barbies did four days of Pilates and two days of strength and conditioning work per week, whereas the Kens did the inverse: four days of strength and two days of Pilates, he says. "And recovery-wise, we had physiotherapy on standby and treatments the whole time," he says. In total, the cast trained with Higgins for 30-something weeks like this.

The cast came in with a variety of workout experience. "You have people who do come in who are generally fitness savvy and who I've worked with before, like Margot, and you have people who have obviously done it before, like Ryan, who knows what works for him and he brings his own sort of experience into the world. And then you have other people who know that they should do stuff, but are a bit scared about it and don't necessarily know what to do," he says.

But Higgins finds joy in helping people get past that. "It's nice to get somebody new who's not so confident and to teach them about their body and how it works and what's good for them and how they can see and feel results. And they walk away with a bit of an education as well as and confidence," he says. "I love going through that journey with everybody I work with."

Despite the "girls' club" reputation that Pilates has, Higgins says no cast member was a stranger to a Pilates reformer, including the Kens.

"These days, I find actors really do look after themselves and they've sort of experienced all kinds of different modalities, but everybody had done reformer Pilates before, and they all loved it," he says. "We had sessions with multiple reformers going at the same time, so everyone had their own reformer, just training together."

Trendiness aside, it's hard not to like reformer Pilates, because it leaves you feeling so good. "With Pilates, you just gently build the relationship, and then they become obsessed with coming in and feeling good, and it's like: yes, this is exactly what my body needs," Higgins says. "It just gives you that sense of, not just center, that grounded feeling, but it also gives your body's mobility back and strength as well . . . And then when you couple that with some strength and conditioning work, it's just the best combination for results."

For the "Barbie" cast, Higgins would start with a 10- to 15-minute core activation, including things like crunches, static holds, extension through the lower back, or oblique twisting. Then, he'd move onto fundamental glute exercises to activate those muscles, something like a side-lying leg press. The workout then progressed into a more functional movement like a static lunge, reverse lunge, or squat on the reformer, and then next came an upper-body exercise like a fly or kneeling extension for posture, and maybe a side leg series. Finally, the session would finish with some full-body exercises. The formula here was to first activate the core and glutes, then build to incorporate the whole body.

Higgins is a big believer in measuring a workout program's success with questions like, "How do you feel? What are you happy with? What do you want to improve upon? And then that translates into results anyway," he says. But he also loves traditional strength work for its easily quantifiable nature, which allows you to track progress easily. "You can say this is where you started and this is where you're ending," he says.

The strength and conditioning workouts he'd do with the Barbie cast followed a circuit-style format: that is, a selection of several exercises done in succession that target different muscles, which you repeat several times. He says his Barbie training sessions looked a little something like this:

If you're liking Higgins's style and you want to try it for yourself, you can check out his content on Instagram, where he shares helpful fitness advice and looks behind the scenes at his training with other celebs, including "Stranger Things"'s David Harbour and "Eternals"'s Kumail Nanjiani.

For follow-along workouts, stay tuned: Higgins is due to launch a new video series soon that'll let you live out all your Barbie-workout dreams.