The ‘Hardcore’ Exercise Class Responsible for Sydney Sweeney’s Toned Body…and Why Some Say It’s the Toughest Workout They’ve Ever Done

Actress Sydney Sweeney just revealed the secret to how she maintains her world-famous body.

She takes part in a hardcore, Pilates-inspired workout that travels across the country.

‘I love this place called SolidCore. It’s an intense full-body workout, but on a reformer, and it’s killing me. I love it,” the “Euphoria” actress shared WJ. Magazine.

SolidCore was founded in Washington DC in 2013 by Anne Mahlum, a former nonprofit worker turned entrepreneur. She created it to “redefine pilates core workouts.”

Sweeney entered popular culture with her role as Cassie Howard in HBO’s ‘Euphoria’

As of December 2023, they have expanded to over a hundred studios across America, from California to North Dakota to New York.

But it’s not cheap: individual lessons cost $43 and a six-month unlimited membership costs $367.94 per month.

The class takes place on a machine that Solidcore calls a “swetlana,” which is essentially a larger version of a Pilates reformer. This longer length makes certain movements more challenging.

You can adjust the strength and tension of the coils attached to different parts of the machine to create more or less resistance as you move through the different exercises in the class. Using these types of machines for resistance exercises is said to improve posture and balance and add extra tension to challenge the muscles.

But there are important differences between Solidcore and reformer Pilates.

Solidcore focuses more on building muscle and endurance, while Pilates encourages deep, slow breaths and gentler workouts.

The pace is also much faster – comparable to that of a spin class.

Newcomers are expected to come to class early to get acquainted with this machine, which may look like a torture device to beginners.

Once the 50-minute class starts, the lights dim and the music starts blaring, similar to cult-following spin classes like SoulCycle or Orangetheory.

As the music plays, the instructor calls out directions through headphones connected to the speaker system, guiding participants through a total of 25 different exercises – from planks to lunges, squats and biceps curls.

Solidcore classes take place on a machine called a 'sweatlana', increasing the challenge for your muscles

Solidcore classes take place on a machine called a ‘sweatlana’, increasing the challenge for your muscles

The instructors instruct participants to hold each position for extended periods of time while performing small, slow contractions or stretches, causing “muscle failure.”

This, the Solidcore team said, will help you build lean muscle endurance by stimulating slow twitch muscle fibers.

‘Slow-twitch muscle fibers are fatigue-resistant and are used for activities that require endurance. By gradually increasing the resistance on our Pilates-inspired reformer over time, muscles gradually become stronger,” they explain on their website.

For normal people, the lesson is designed to make you tremble.

Scientific literature does agree that to build slow-twitch muscles, people should do slow, endurance exercises muscle failure. For example, marathon runners often have very strong, slow muscles.

Sweeney is far from the first person to be ‘killed’ by this intense training.

‘I trembled with every step. Needless to say, SolidCore is no ordinary pilates,” the TikTok user shared in a video in which she shares her first experiences.

‘This is the hardest course I have ever taken in my life. I have never been so humbled,” said user Lavishlana another video.

In response, the official SolidCore account commented: ‘the vibrations mean it’s working!’.

I TRIED SOLIDCORE ONCE – AND I NEVER BEEN BACK

DailyMail.com wellness reporter Maiya Focht says the class was the most challenging workout she’s ever done…

I tried Solidcore one weekend, in November 2023, and within the first ten minutes of class I wanted to quit.

Having taken many Pilates classes in the past, I foolishly thought I could get through the class, so I didn’t prepare as well as I should have.

The ‘swetlana’ machine was more intimidating than a normal Pilates reformer, because of the confusing numbers and markings on the sides – which I later learned were supposed to tell you where to place your hands and feet.

The hardest part of the class was the plank sequence, which in my case was how we started and ended the class. Your legs are placed on a moving platform that you pull in and out while you hold your body in a plank position.

I started shaking quite violently when we got to the part of the workout devoted to lunges. The leg resting on the moving platform felt so unsteady that I was afraid I was going to fall off the machine, but I kept my balance.

The term “muscle failure” began to take on a lot of meaning at this point in the class. It felt like my muscles were giving out and I was losing control.

During the class, I would often look at the mirrored walls to see if other people taking the class were struggling with it as much as I was. In many cases, it seems that people were.

I felt absolutely euphoric when I was done. I felt like I had just survived a small death, and I was triumphantly sore for a week after class.

Therefore, I think it makes sense that the company does not recommend that newcomers take more than three classes per week.

I think I would go again, but I would have taken the time to stretch before class and would have been better hydrated.