According to the website, the F45 Challenge is:

‘A guided 45-day program focused on your personal fitness and performance progress through F45’s team training and goal-targeted nutrition. The 45 Day Challenge is designed to provide you with the core knowledge and application of a sustainable healthy lifestyle while improving your overall health and wellness.

The F45 community is here to support you over this 45-day journey, so get excited about setting personalised goals, building connections, and discovering your capacity through this fitness & wellness transformation. A few things to look forward to:

• Functional training from world-class trainers
• Daily customised meal plans with auto-generated shopping lists
• Macro-balanced recipes including mainstream, vegan and vegetarian options
• Fitness tracking, progress monitoring and nutrition guidance

F45 Challenges are comprehensive training and nutrition programs that you can approach as ferociously or casually as you wish. They used to be two, six or eight weeks long – I did six weeks – but now they are 45 days long.

At the time of my Challenge, signing up gets you unlimited classes at the gym and access to the Challenge app, which has free home workouts and thousands of healthy recipes.

The Challenge is book-ended by getting two InBody scans, which measure your progress in several body composition markers such as BMI, skeletal muscle mass, and hydration levels. You also get the added benefit of community encouragement – F45 gyms around the world are on the same schedule, so you’re all in this together. *Cue High School Musical soundtrack.*

The ‘F’ in F45 stands for ‘functional fitness‘, meaning movements that support you in your daily life. And the “45” is for 45 minutes, the length of the weekday classes. Saturday and Sunday classes are an hour. Sessions involve uber-fast-paced HIIT and circuits, alternating between cardio and strength days.

You can tailor your approach: on the hard-core, more intimidating end, my trainer says that someone in great health and peak fitness might cut booze entirely, train five days a week, follow the meal plan, and calorie-count for the most dramatic results. But on the gentler end of the spectrum, some folks are just looking to gradually reintroduce healthy habits in an uplifting community space, and get moving again. Both approaches are welcome, and besides, it can be dangerous to try to do too much, too fast.

I decide my approach will be somewhere in the middle: I commit to doing four gym classes per week, and to pay closer attention to what I’m eating and drinking during the Challenge; rather than any purposeful calorie restriction.

So, what are F45 classes *actually* like? I’m going to be honest: F45 is hard, especially if you’re new. But hard in a satisfying way, and not impossible. There’s a reason it’s so popular. In my head, I imagined everyone who goes to look like a ripped G.I. Joe doll. But that’s not the case at all; classes are full of different body types and fitness levels. My studio seems to attract a 50/50 ratio of men and women, and while maybe 60% of folks seem to be keen fitness buffs, the other 40% are just there to get some exercise.

There are plenty of people who go to lose weight or improve their fitness. Not everyone can quite do all the moves, myself included. Lots of us are there muddling through, taking breaks, doing our sweaty best. I’ve got to give a shoutout to the trainers – I was never once yelled at, humiliated, or pushed beyond my capabilities. (Something I dread in bootcamp style classes). They’re all super friendly, and they’ll happily provide a modification if you need one, or just let you get on with it.

Every day I walk into the gym, the floor is laid out with entirely different equipment: battle ropes, stationary bikes, sled pushes, kettlebells, step boxes, balance balls. *Gulps.* But you don’t have to be an expert. At every class, all exercises are explained and demonstrated before a brief warmup. The instructors circle the room the whole time too, answering questions and giving form correction tips. It might feel like a lot to take in, but don’t worry – handy screens at the front of the room play videos demonstrating each move, so you don’t have to remember it all.

Training is always different – they mix and match a staggering 5,000 different exercises into 45 classes, so you will never be bored. And you’re typically only doing an exercise for less than a minute, so if you hate it or just can’t do it, you’ll be on to the next in a flash. PS: the cool down guided stretches are only for a few minutes, so I’d suggest stretching more outside the studio or when you get home.

This is the weekly lineup:

I found the training to be the perfect blend of cardio and resistance, and everyone in the classes was able to modify the intensity to their ability.

Week 1

Time for my InBody scan. I briefly stand on what looks like a fancy bathroom scale and it prints out my body composition stats. A trainer points out some markers that I should aim to lower for optimal health (visceral fat on my midsection was one of them). I’m in agreement with all of her advice, and nothing she says surprises me. I found it interesting, and it didn’t bother me.

Fair warning, though: a friend (at a different studio) told me she found the scan upsetting because she’d gained weight, so she started to veer towards extreme eating and exercise habits. It’s never worth compromising your mental health, so if you think the scan could upset you or trigger any risky behaviours (such as disordered eating), it’s best to opt out. The total picture of our health is about so many different things beyond numbers, including how we feel mentally.

I made it through my first class, albeit with some extra breaks and modifications, and timidly choosing all of the lightest weights on offer. I was *stunned* at how fast it moves. You do an exercise for 45 seconds at a station, and then have just 15 seconds to get to the next one – barely enough time to pick up your water bottle. But I left feeling high on endorphins, and proud of myself for showing up. I got a bit confused with the pod formations in one class, but later realised I could follow my station buddy around if I got lost. Ideal. I completed four classes in the week and had major DOMS – my body was definitely in shock.

Week 2

I have never really lifted weights before, and am surprised to discover that, by week two, I actually love it. Resistance classes quickly replace running as my go-to form of stress-busting exercise. Arse-y email at work? Go to a lunchtime weights class, and suddenly things are back in perspective.

One strength training exercise involves hanging from some TRX ropes and attempting to lift your body up. The trainer walks by, and I simply hang there like a comedy sack of potatoes. I physically cannot lift myself. But, onwards. I remind myself that no one cares. The beauty of F45 classes is that everyone’s doing different moves, so everyone is focused on themselves, not you.

Week 3

I have come to accept that no one *ever* leaves F45 classes looking cute. It’s sweaty business, people. Back sweat, upper lip sweat, ass sweat. There is no room for vanity here, helped by the fact that no F45 studios have any mirrors – which I adore. I leave every session red-faced and bedraggled, but always glad I’ve gone. By this point, I’m feeling chuffed to be lifting slightly heavier weights.

Week 4

Every week I typically look forward to an hourlong Saturday or Sunday sesh before brunch, but this week I attempt to go while I’m on my period. Huge mistake. I find it utterly exhausting and too much. After only half an hour, I’m feeling unable to go on, and so I just leave early. I vow in future not to go to any of the cardio or hybrid sessions when I’m on my cycle; my body just needs something more restorative at that time of the month. Outside of that day, I am still loving the endorphin after-glow that each class brings, and my sleep is blessedly, dramatically better. Hallelujah.

Week 5

My mum is in London, over visiting from America. We’re staying in a hotel in a different neighbourhood, so I’m nowhere near my F45 studio. We’ve got a packed schedule and this is precious time together, so I always knew I’d skip classes this week. We’re logging an insane daily step count, though, so I still feel like I’m keeping my activity levels well up. I’d started to feel a little knee pain anyway, so I decide the break is good.

Week 6

It’s the home stretch, and I can’t quite believe I’ve made it this far. Summertime means people are out boozing on every spare scrap of sunny pavement in the city. It takes an iron will not to join them every night and keep up my four classes a week. But I tell myself I’m laying the foundation for long-term better habits. I’m amazed that I’m not bored of it yet; it’s still “me-time” in my day I look forward to.

I checked my calendar, and during the dates of my Challenge, I had: a hen do, a wedding, a friend reunion, multiple work dinners, and a week of hosting my mum. I momentarily considered not doing it at all, because it seemed like it would be impossible to monitor what I ate. But…when would feel like a “good time” to do this? Probably never, honestly. The next challenge was months away, so I just decided to go for it, however imperfectly.

So my food goals were this: to eat home-cooked nutritious meals as much as possible, to reduce my alcohol intake, and to choose lower-calorie booze when I did drink. I opted not to calorie restrict, and I didn’t follow the F45 meal plan, though I did flick through the recipes for inspiration. To be honest, I’m not the fastest or most confident cook, and have never calorie counted before, so trying to start all these new things on top of reintroducing exercise felt like too much at once. I just did what I could with my schedule.

A note on booze: one trainer said that while of course staying off the sauce would help give the most dramatic Challenge results, she acknowledged that it’s summertime, and we’re making up for precious lost pandemic time where we couldn’t mingle. She said that if having a cider in the sunshine with friends is what you’re craving, then to go for it and enjoy it. Besides, a moderate approach is also more sustainable in the long run for most people, she pointed out.

According to the brand, the F45 Challenge is “a nutrition and training program focused on holistic wellbeing,” designed to “help members transform their lives.” I’d agree with that. Here are the benefits I noticed:

• First and foremost, my confidence shot back up. I was proud of myself for having the courage to show up to something I found intimidating, and then stick with it. I was now a Person Who Goes to the Gym, and someone who chooses to prioritise my health more. Feels good.

• My sleep drastically improved. Fast-paced early evening classes especially helped to knock me out. My toxic trait is scrolling in my phone in bed, but some nights, I was asleep before I could tap onto the next Reel.

• I automatically started paying closer attention to what I put in my body. The whole “food as fuel” thing (ugh, sorry) proved to be true, and I was naturally reaching for nutritious whole foods a lot more. I found it hard to eat too much stodgy crap if I knew I had a gruelling workout to get through later. And no one wants to do cardio on a hangover. So pursuing a balanced diet came more naturally.

• I became stronger and able to lift more weight, which is super satisfying.

• I noticed more definition in my upper body, and my hips, back, and stomach got more toned.

• It improved my mental strength. The exercise was stress-busting, and the classes have an uplifting vibe to them. I walked out of every session feeling tired, but euphoric, and that’s pretty addictive, TBH.

According to the website, the training app is available to download at no cost. ‘However, to be a part of the Challenge in-studio experience you will need to contact your local F45 studio to discuss pricing options. To find your local F45 Studio go to: https://f45training.com/find-a-studio‘

At the time of writing, it’s free for existing F45 members, but a six-week Challenge at my London studio is £399 if you’re new. The price varies studio to studio, and it’s often much cheaper outside of major cities.