• Pilates is buzzy, but Hailey Bieber, among its most famous fans, said it's "a little over."
• Bieber said that "really good" Pilates teachers who care about form are now hard to find.
• Business Insider's Kim Schewitz grew up around Pilates, and agrees with Bieber.

Hailey Bieber, the Gen Z tastemaker and founder of the billion-dollar skincare brand Rhode, thinks Pilates "might be a little over."

"I love Pilates, I really do. But I think it's become a little bit of a fad, and it's really hard to find really good teachers that care about form," the 29-year old, who is thought to have practiced Pilates since 2017, told Time in an interview clip shared on May 6.

Like Bieber, I have a long history with Pilates, and think she's right that it has become faddy.

My mom is a Pilates teacher with 1,445 hours of training, who opened a studio in our London home in 2011 when I was 13. Growing up, I overheard cues like "aaand engage your core" over breakfast.

She enrolled me in a teen Pilates class, which I took for two years, and I restarted reformer (where exercises are done on a leather bed attached to weighted springs, rather than a mat) as an adult in 2024. The two classes I typically do each week have helped me feel stronger and much more aware of how I move in space.

The way I understand it, Pilates is a low-impact form of resistance training that uses controlled, precise movements to strengthen the core and the deep muscles that stabilize our joints. It teaches us how to stand, sit, lie, twist, and move using the correct muscles, and helps build the strength to use them at the right time. For a balanced workout routine, experts recommend complementing this type of movement with cardio and more intense forms of strength training.

When I was a teen, I saw Pilates as quite clinical and rehabilitative. Back then, it wasn't being sold on TikTok as a shortcut to the "skinny and toned" Victoria's Secret model physique that is known as the "Pilates princess" body, which has replaced the jacked look of "muscle mommies" as the aspirational body type du jour.

But this TikTokified, matching Alo set, matcha latte-drinking version of Pilates is just a cultural stereotype. It's not particularly reflective of traditional Pilates principles, which the gymnast Joseph Pilates developed in the 1920s to rehabilitate injured or bed-bound World War I prisoners.

"Pilates is for everyone. Athletes, beginners, people recovering from injuries, or anyone who wants to feel stronger and more physically connected," Heather Andersen, a Pilates teacher with 20 years of experience and the founder of New York Pilates, a boutique studio with eight locations across New York City and The Hamptons, told me via email.

"The real magic of Pilates is that it teaches people how to use their bodies well, and that carries into everything you do," she said.

I asked my mom, Alison Ashton, who is 60 and attends almost daily classes, her thoughts on the Pilates boom. "Some other modalities have hijacked the Pilates reformer to just do some fitness exercises," she said.

Pilates is based on six core principles: breath, centering, concentration, control, precision, and flow. "If you're not adhering to all those principles, then really, you're not doing Pilates," she said.

'Pilates' is being used loosely

In 2025, Pilates was the most booked workout on ClassPass globally, with bookings increasing by 66% compared to 2024 . Andersen is excited that Pilates has become so popular, but said that the industry's biggest challenge right now is quality control.

Venture capitalists and investors who have jumped on the lucrative Pilates bandwagon, which, combined with yoga, is worth $19.2 billion in the US, only care about expansion and profit, she said. "Rapid growth always comes with challenges around quality and education."

There is also growing confusion between authentic Pilates and what Andersen calls "Pilates-inspired fitness." Some studios are using reformers and branding their classes as Pilates, while prioritizing intensity, speed, or heavy repetitions over form or technique, she said.

"The word 'Pilates' is being used very loosely," Andersen added. "Just because a class uses a reformer-like machine or includes core exercises doesn't mean it's teaching the Pilates method."

My mom agreed that it has been brilliant to see more people discover Pilates, but she's noticed "gaps" in how some classes are taught. "I'm seeing people just going through the motions. I'm not seeing the deeper control," she said. "At the end of the day, Pilates is a mindful practice, and you have to be in your body, and your mind has to connect to those muscles."

A good Pilates teacher understands how the body works

There is no official governing body for Pilates, but to qualify for third-party accreditation from the respected US-based National Pilates Certification Program, candidates must complete 450 hours of practice, observation, teaching, and studying.

However, lots of mat Pilates training courses are only 40 to 60 hours, and while they are intended to be the beginning of a much longer educational path, you can technically call yourself a Pilates instructor once you've completed one.

This simply isn't enough time to develop the deep understanding of the anatomy and biomechanics required to teach Pilates, said Andersen, who completed a 600-hour comprehensive Pilates certification in 2009.

An adequately trained teacher should understand not just how to teach the exercises, she said, but how the body works, how people compensate when their form is incorrect, where injuries happen, and how to safely help students improve over time.

"You can learn choreography in a weekend. You cannot learn movement mastery in a weekend," she said.

How to find a good Pilates instructor

It takes time and consistency to truly reap the benefits of Pilates, but a great teacher can change how you move through everyday life, Andersen said. "They develop an eye, almost like X-ray vision, to see how your bones are moving and how your muscles are driving them," she said.

These are the qualities you should look for in a Pilates instructor:

• Ask where they trained and how many hours of education they completed. Andersen recommends looking for at least a 400-hour comprehensive certification with a strong focus on anatomy, alignment, and hands-on instruction.
• Pay attention to how you feel after the class. A great instructor should make you feel more connected to your body, not just exhausted, Andersen said.
• Look for a teacher who gives lots of instructions and encourages you to focus on your alignment and engaging your stabilizing muscles, my mom said.
• You want a teacher who observes your form and gives corrections, she said.
• In a balanced class, you should be moving your body in lots of different directions. Think: "Are we doing forward stuff? Are we doing stuff that's taking us to the side? Are we doing stuff that's twisting? Are we doing stuff that's bending our spine backward?" my mom said.

If you want some trusty mom advice, the key is to go slow and focus on learning the fundamentals first. Once you know how to move your body in the correct alignment, you can build the strength, stability, and maybe even the muscle tone you might be looking for.

"If you rush it, and you don't fully understand what it's all about, then yes, you will be doing Pilates, but you won't be doing it on a deep level. You won't be doing it mindfully. You won't be doing it correctly," my mom said.