The Viral Pilates by Izzy Challenge is Known as One of the Toughest—I Tried It for 25 Days, and My Core Strength Has Skyrocketed

You don’t need to scroll far on YouTube to stumble across a Pilates workout. From classical mat routines to hybrid sessions that blend yoga and strength training, there’s something to be found on the platform for everyone. It’s why when one instructor’s name keeps popping up across social media, my curiosity as a health writer kicks in.

That’s exactly what happened with Izzy Samuel, the Perth-based Pilates instructor whose workouts have taken over TikTok and YouTube. Since launching her channel in late 2024, she’s already amassed over half a million subscribers, thanks, in large part, to her signature 25-day challenge, which combines traditional Pilates principles with resistance training over a series of twenty-five daily 25-minute workouts.

And while here at Marie Claire UK, we’re immediately sceptical of anything that claims to be a "quick fix" (particularly when it comes to our health), Izzy’s approach doesn’t seem to be that. The daily workouts included in the challenge might be short, but she makes it clear that they’re designed to kickstart a habit that should continue long beyond the end of the series.

And in fact, growing research backs this idea of "exercise snacking", (brief, regular bursts of movement repeated over time), as more sustainable and effective than sporadic, intense sessions, both for enjoyment and overall training volume.

So, with my studio membership on pause, I set out to put Izzy’s now-infamous 25-day challenge to the test, to see whether it would live up to its online hype.

For my thoughts, keep scrolling. And if you’re looking for more Pilates content, we’ve got guides to the best Pilates exercises for beginners, plus the best Pilates moves for building strength at home. While you’re there, why not take a look at how I got on when I tried the equally viral Move with Nicole Pilates workouts every day for a week.

Pilates By Izzy Workouts are Famed for Being some of the Toughest YouTube Has to Offer - I Tried Them for a Week

What is the Pilates by Izzy 25-day challenge?

The concept of Izzy’s challenge is simple: 25 days of contemporary Pilates workouts, with each daily session clocking in at around 25 minutes. And whilst this may sound manageable, the Pilates by Izzy 25-day challenge has earned a reputation for being one of the toughest at-home Pilates workouts out there, with creators on TikTok raving about the strength gains they’ve seen in just a few weeks.

Unlike classical Pilates, which adheres to a fixed 34-move sequence, Izzy’s classes are more contemporary, says Ally Barron, Pilates Instructor and Founder of Align by Ally. “Izzy uses a wide range of equipment with different paces and strength-based focuses, which you wouldn’t find in a traditional mat Pilates class.”

Jo-Leigh Morris, Pilates Instructor and Founder of Aether Spaces, agrees, explaining that “Izzy infuses Pilates with barre, strength, and functional fitness, which adds creativity and variety to her classes.”

Why have Pilates by Izzy classes gone so viral?

With so many online fitness classes out there, what is it about Izzy’s 25-day challenge that’s made it such a hit?

According to Pilates instructor Harriet Adams, it’s a mix of Izzy’s presence and her programming. “Izzy mixes classic movements with more dynamic layering, which keeps each day fresh and interesting - something which is so important when you’re doing a multi-day challenge,” she explains. “Couple that with Izzy’s approachable energy and clear instruction, and the challenge is both motivating and easy to follow.”

Morris agrees. “The format hits a sweet spot: 25 days feels long enough to build consistency but not so long that it becomes overwhelming. The 25-minute sessions fit easily into busy schedules, and the addition of light weights makes the workouts feel effective and results-driven even in a short time frame. On top of that, Izzy’s personality means she creates a space where people feel comfortable, supported, and excited to return each day. It’s a clever combination of accessibility, variety, and energy that keeps people engaged.”

For Barron, it’s the unfiltered social media buzz that’s really driven the challenge’s virality. “People were seeing and sharing real results and experiences after completing the workouts, which helped to fuel a changing narrative around Pilates. In the past, people have thought of Pilates as a slower, low-resistance workout for women, but the challenge provided evidence that Pilates can generate a true burn for anyone, even from home.”

What are the benefits of the Pilates by Izzy 25-day challenge?

Take one look at TikTok and you'll find no shortage of testimonies from creators sharing the changes they’ve seen in strength, energy, and body composition after completing Izzy’s 25-day challenge. But what do the experts think makes the programme so effective?

1. It breeds consistency

With research showing that just sixteen sessions of Pilates are enough to improve postural alignment and core strength, it’s no wonder that Morris cites consistency as the biggest benefit to Izzy’s 25-day challenge.“Consistency is the greatest benefit any Pilates challenge can provide - at the end of Izzy’s 25-day Pilates challenge, people are feeling stronger, more confident, and start seeing results that motivate them to keep going. That’s the most important thing.”

2. It’s accessible

Morris also highlights the programme’s accessibility. “25 to 30 minutes is both manageable and sustainable, lowering the barrier to entry while still delivering results. That’s why Izzy’s challenge works so well: the 25-minute sessions fit easily into busy schedules whilst still being effective enough to challenge the body.”

“There’s also the at-home element, which is a total game-changer,” adds Adams. “With no timetables to juggle,” (or fee attached), “you can fit it into your day whenever it works for you.”

3. It's packed with variety

“Izzy’s style adapts the Pilates method for today’s fitness world with more variety and creativity,” says Morris, a sentiment echoed by Barron: “Introducing something new and innovative each day keeps you motivated and engaged, especially when using a variety of different apparatus.”

4. It delivers results

“Pilates is about precision, control, and really activating the right muscles,” says Adams. “Izzy’s tempo and cues are spot on for this, which makes her classes great for anyone wanting to build confidence, strength and muscle tone outside of the studio.”

Barron agrees. “I myself have just completed the 25-day challenge, and I couldn’t fault it,” she says. “I absolutely loved the innovation, the cues, the movements and the burn, all elements I use to inspire my own teaching.”

Who is the Pilates by Izzy 25-day challenge best for?

There’s been some debate on social media about whether Izzy’s 25-day challenge is suitable for beginners, with some suggesting the intensity of the workouts makes it better suited to more experienced movers. So, I put the question to the experts.

"Online classes are generally best for people who already have an understanding of Pilates, because form cannot be corrected online,” says Barron, who recommends the Pilates by Izzy challenge to those at an intermediate or advanced level in their practice.

Morris agrees, reminding us that “anyone with an injury should approach with caution, as the classes don’t always provide modifications.” That said, she sees huge value in the programme for “women who are short on time, want to train at home, and are looking to either start or re-establish a fitness routine,” adding that it’s especially good “for those who want to feel stronger and more consistent without needing to dedicate hours each day.”

I Committed to the Pilates by Izzy 25-Day Challenge Every Day for 25 Days. And My Core? Well, She’s in Bits

Days 1-12

Leggings on. Playlist cued. Hand weights at the ready. It’s day one of the Pilates by Izzy 25-Day Challenge.

“Hi, my girls,” Izzy greets me through the screen in her distinctive Aussie accent. It’s a promising start - I don’t know what’s in the water over there, but in my experience, no Pilates class burns like those led by an Australian instructor.

I have to say, I’m nervous. Each session might only run 25–30 minutes, but if TikTok is to be believed, I’m in for a serious burn. Day one is billed as a full-body Pilates x Strength class using 2kg hand weights, and from the first few minutes, it’s clear this isn’t your standard mat Pilates. Where many traditional programmes focus on bodyweight movements, Izzy’s approach blends classical Pilates foundations with dynamic resistance work - just as the experts said.

We start with mobility, then move straight into a weighted crunch series, with variations to target your obliques, lower and upper abs. At six minutes in, I’m almost embarrassed to admit how badly I’m flagging. I thought myself to be quite experienced in Pilates, but the pace of Izzy’s class is relentless, the sequencing smooth, and there’s a distinct lack of rest between sets.

It’s hard, but not miserable, because Izzy’s energy is infectious. She’s warm and motivating, her instructions sharp, and her cues easy to follow. Modifications are offered, and she reminds you often to pause when you need to, which makes a big difference when you're wobbling through your third set of glute pulses.

So, despite the burn, when day two rolls around - a “booty & ab burn” using a yoga block - I’m genuinely excited to roll out the mat again. The class delivers exactly what it promises, and while I have to pause for water more than once, I make it through.

From days three to seven, I return to the mat daily, my DOMS (delayed onset muscle soreness) deepening with each session. There's a clear emphasis on the core throughout, but the sessions vary enough to keep things interesting and provide a bit of respite for your muscle groups by rotating through upper body, full body and lower-body burnouts.

On day ten, I’m faced with a 35-minute full-body Power Pilates workout, using a resistance band and the familiar hand weights. It’s the biggest test of strength so far, but I’m feeling noticeably stronger and more stable in my core than I was on day one, which feels like remarkable progress in such a short space of time.

At the halfway point, I’m a full convert. Izzy’s classes rival any studio I’ve been to (minus the buzz of a packed room), and her energy is a huge part of why I keep showing up. Physically, my glutes are in a near-permanent state of burn, my core feels more engaged throughout the day, and even my posture has shifted.

Days 13-25

This is where the challenge steps up, and things get interesting.

Days 13 to 16 each clock in at 35 minutes (which is the longest the sessions go), and by day 16, I’m feeling it. The sessions may be short, but the intensity makes them anything but easy. My legs feel heavier when I’m out running, and I’m definitely more fatigued than I usually am after Pilates.

By the final week, I’m actually reluctant for it to end. While it’s not a programme I’d recommend to total beginners, for anyone familiar with Pilates or functional strength work, it’s one of the most effective home workouts I’ve tried.

Where I dreaded the full-body sessions at the beginning of the challenge, by the end of the three weeks, I found myself enjoying them more than any other workout. The deep burn in my core and glutes never seems to get easier, but there’s no doubt that I’ve become stronger in the last three weeks.

Day 24 brings a standing Pilates routine - something less common in Izzy’s library. It’s here I notice other improvements, not just to my strength, but also to my balance and mobility: single-leg movements feel steadier, I’m more flexible, and there’s far less wobbling around the room.

It’s rare that I’m lost for words, but Izzy’s classes are that good. I do miss the studio buzz and community element, but in terms of structure, energy and results, it’s hard to fault. That said, it’s not a beginner workout, and I’d recommend taking the time to build up with instructors such as Move with Nicole to build foundational strength and technique before jumping into this. But for those looking for a no-nonsense, time-efficient, seriously challenging home routine, Pilates by Izzy delivers.

And yes, I’ll be bookmarking more of her classes and slotting them into my weekly routine. My glutes wouldn’t have it any other way.

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