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I've only ever done Pilates – here's what happened when I tried a 6-week HIIT challenge

I took on the F45 challenge to tone up and make new friends - these are my honest thoughts


Maisie Peppitt F45 6-week challenge
On 17 October 2023
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As a long-time advocate for Pilates and plods around the park, the F45 challenge had never been on my radar. Notorious for its intensity and rigorous pace, my clumsy nature and phobia of gym machinery has, until now, caused me to give gyms such as F45 a miss.

Instead, I’ve spent most of my twenties settling for slow runs or yoga in candle-lit studios. In other words, workouts that are gentler, easier and pose less of a risk of me impaling myself.

Walks and pilates are well within my comfort zone
Walks and pilates are well within my comfort zone

But as more of my friends and colleagues jumped aboard the F45 train, I couldn’t ignore their glowing complexions or the infectious enthusiasm for the concept. Meanwhile, after a chaotic year spent burning the candle at both ends, I was struggling to get back into a regular routine.

I found myself craving consistency, and despite oversleeping and avoiding exercise, I felt more tired than ever. So, I bit the bullet and signed up for the F45 Challenge – and here’s what I thought…

What is F45? 

Founded in Australia, F45 is a studio franchise that incorporates functional movements designed to target fat loss and help to build lean muscle mass.

From HIIT style cardio workouts to targeted strength training, or even a hybrid of both, there is a specific class to suit everyone’s abilities. On weekdays, the classes run for 45 minutes, and an hour-long on weekends.

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What is the F45 Challenge?

F45 offers challenges that last either two, six or eight weeks. Without wanting to be overly confident, I opted for the six week Challenge. Each Challenge gives you unlimited classes at your chosen studio, along with access to the Challenge App.

The F45 Challenge app allows you to track your progress
The F45 Challenge app allows you to track your progress

This app allows you to track your workouts, meals and goals. It also contains free home workouts and plenty of healthy recipes to choose from if you don’t have time to hit the studio.

The app helps to measure your progress through several body composition markers such as BMI, skeletal muscle mass and hydration levels. I found that clocking my workouts in the app helped me to keep track of how active I’d been that week. When I mapped out my goals with my trainer, I decided that dropping weight wouldn’t be my key goal - instead, I wanted to tone up.

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That’s the best part of this challenge - it can be tailored according to what you want. If you want to drop the pounds, cut out alcohol and train every day, the team is there to support you and make sure that you’re losing weight in a healthy way. If, like me, you’re more focused on feeling stronger and making healthier choices, that’s cool too.

What to expect from an F45 class

The horror stories of relentless squatting and militant circuit training had me feeling sick with nerves as I walked into my first session at the F45 studio in Peckham Rye. But as I packed my gym bag into one of the communal lockers, it wasn’t the heavy iron weights or the intimidating set of kettlebells that caught my attention.

Instead, it was how every member of the class strolled casually into the studio with a smile on their face, before striking up a conversation with one of the trainers. From complaining about their hangover to discussing their plans for the weekend, I felt instantly at ease by the upbeat atmosphere and level of familiarity.  

Each workout is a team effort. Every class is run by two trainers and has space for about 25 members. There are usually 12 exercise stations to complete within 45 minutes, but this can vary depending on the class. The trainers begin by demonstrating how to complete each exercise, before beginning a team warm up where you and another member are assigned a number. This number dictates which station you both start at, before making your way through the rest of the circuit.

My local F45 studio
My local F45 studio

I’m usually antisocial when I work out. But throughout the challenge, I completed classes whilst cackling with laughter on a rowing machine, exchanging the occasional word of encouragement, and even in comfortable silence - and each time, I’ve been grateful for the person next to me. You’ve got someone to remind you how to do each exercise, to cheer you on if you struggle, and to high-five you when you’re done. As cheesy as it sounds, making friends along the way ended up being my favourite part of the experience.

Once the circuit is complete, you can choose whether to stay for a five-minute cool down, or to head off. I cycled to and from my nearest studio, so I always stayed to catch my breath before tackling the journey home.

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F45 Six Week Diary

Week 1

Before my first class, I was worried I’d stick out like a sore thumb. I expected rows of shredded abs, frosty trainers and nimble attendees who knew the gym’s layout like the back of their hand - but I was pleasantly surprised to see that each class held a variety of people of all shapes and sizes.

For some, F45 is a big step towards changing their bodies. For others, it’s something we do most days to make us feel good, have a laugh and let off steam. Even the trainers reflect this attitude, and as I entered the gym I was instantly greeted by the bubbly manager, Jade, who talked me through the steps.

I started my journey with an InBody scan. Like most people, I always find checking my weight a dreaded process, but the team’s casual tone and positive attitude made it feel like no big deal. As I decided that my main focus would be to get stronger, rather than shed pounds, my diet would be less restrictive. After some helpful tips from my trainer on which foods would provide me with long-lasting energy to smash my workout goals, I felt pumped and ready to start.

Maisie Peppitt F45

As for the exercise, I made it through the first week with a fair amount of trembling legs and sore midweek muscles. I sheepishly opted for the lighter 4-5kg dumbbells and stumbled my way through the circuit.

 I made my fair share of mistakes, often heading to the wrong station by accident whilst having to take a few breaks to catch my breath. Each time I stumbled, I received a smile of encouragement from the trainers and my workout partner.

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Top tip: If you’re geographically challenged, like me, just follow your station buddy until you feel confident with the route.

By the end of the week, I’d definitely caught the F45 bug. I was hyped up on endorphins, elated from the team spirit and sore from the weight training - but eager for more.

Week 2

I have one word for you - ball slams. Otherwise known as my new favourite gym activity.

After a stressful day, there’s no better feeling than lifting one above your head and hurling it towards the ground. I discovered ball slams during a resistance-based class, and I’ll be booking the same class next week just to be able to do it again.

Anger management and physical exercise all rolled into one? Sign me up!

What I’m not so great at are the more traditional exercises such as push ups and pull ups, as my upper body strength is currently non-existent. But my struggle must have been noticeable, as the trainer showed me how to adjust the exercises to make them easier.

I felt a little embarrassed at first, but when I looked around the room to see everyone else huffing and puffing along with me, I realised that no one cares - and that was liberating.

Week 3

It might be psychological, but I think I can already feel a difference. Today, I realised I could run for the bus without tasting blood (probably something I should have addressed earlier in my life), my arms appear to be a little more toned, and I can even do one real push-up without collapsing onto my face.

And best of all, my sleep has drastically improved. I’ve always found it really difficult to drift off, which is partly due to not being able to switch off my thoughts, and partly because I can’t stay still. But after regularly attending F45 about four times a week, I found that I was falling asleep much more easily.

Week 4

There’s a flaw with the rule of exercising more and eating less to get fitter, and that’s because when you exercise more, you eat more.

Since starting this challenge, I’ve definitely found that my appetite has increased. This could also be down to a number of other factors such as my menstrual cycle and the weather becoming colder, but never-the-less, I’ve definitely been craving more food.

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And that’s not a bad thing. Since my appetite has increased, I’ve loved experimenting with some of the healthy recipes for light bites on the F45 app. When carrots and hummus won’t cut it, I love to whip up one of the F45 protein shakes. If I don’t have any protein powder, I substitute protein yoghurt from Skyr which makes it extra creamy. I often throw in all my supplements too, so it’s an efficient way to get all my vitamins in one delicious drink.

I also feel more inclined to opt for whole foods instead of the processed snacks I usually reach for. Small changes such as cutting out the syrups in my coffee, swapping white bread for seeded sourdough and bulking out my dinners with colourful vegetables soon became healthy habits that now just feel natural.

Avocado and egg on sourdough bread has become my go-to lunch
Avocado and egg on sourdough bread has become my go-to lunch

Week 5

I may have overdone it, slightly. One thing that I’d stress to anyone considering trying the challenge is as great as it is to go frequently, it’s equally as important to give yourself rest days. I turned up to a class called Mont Blanc, which is a workout designed to exercise all the muscles that a skier would use - think squatting, lunges and jumping.

It’s a pretty cardio intensive workout, and having worked out every day this week I probably should have skipped it - but with the end of the challenge in sight, I didn’t want to slack. So I gave it my best shot, and it wasn’t until I attempted a box jump and landed flat on my shins that I immediately regretted this decision. Nevertheless, the trainers were really supportive, and once they saw that I was okay, they gave me an optional exercise to do that would be a little less aggressive on my legs.

That’s the best thing about F45 - you can tailor it to fit your needs on the day. Now, excuse me while I ice my shins…

Week 6

After a restful weekend, I wanted to make sure I could make the most of my final week. My favourite class this week was Red Diamond, which is a resistance-based workout that aims to achieve muscle fatigue through exaggerated movement. While the circuit still left me hot and out of breath, there was something satisfying about pushing my body to limits that I hadn't even imagined before I started the challenge.

Maisie Peppitt F45

Machines that I would have once given a wide berth no longer intimidate me. I felt confident enough to push myself further, and I understood what my body was capable of doing. Most of all, I wasn’t nervous to ask for help anymore - and that’s a valuable lesson in itself!

The results of the F45 Challenge

So, did I actually see a change in my body? At the start of this process, I documented that while weight loss wasn’t a priority for me, I did want to tone up and get stronger. And at my final body scan after six weeks of training, I was thrilled to learn that I had achieved my goal.

Before I go into the details, I think it’s important to mention that this body scan is optional. Weight management can be triggering and the staff at F45 were very considerate about letting me choose whether or not I wanted to participate in the final scan.

So, here’s what I achieved! After six weeks of training, I actually gained 0.7kg in weight! If I’d been standing on the scales at home, I think I’d have assumed I’d made some mistakes along the way. But my trainer explained that muscle is heavier than fat, and pointed out that I’d also gained 0.4kg in skeletal muscle mass, and my body fat percentage had lowered by 0.2%.

F45 has made me more active in my daily life
I can feel the difference in my brain as well as my body

Overall, pretty tiny results. But do I feel fitter when I run for the bus? Yes. Do I feel more confident when I’m getting dressed in the morning? Definitely. Did I push my body further than I ever thought I could? Absolutely.

Most importantly - would I recommend F45 to a friend? You bet.

Check out the F45 website to find your nearest studio and book your first class, plus visit HELLO!'s Happiness Hub for more inspiring stories

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