Tried and Tested: I tried the viral 12-3-30 workout for a month – here’s why the results surprised me

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  • Yes, really.

    Quick question: if you haven’t heard of the 12-3-30 workout, then where have you been? The workout – which went viral on TikTok after being coined by content creator Lauren Giraldo – shot to fame earlier this year and currently has 2.7 million likes and 12.6 million views.

    When it popped up on my feed, I was intrigued. The routine looked simple enough and involved walking on a treadmill at the gym for 30 minutes. I’m normally sceptical when it comes to celebrity workouts or online trends – I’d rather try routines or sweat sessions recommended by qualified professionals – but was keen to give this one a go.

    It sounded fun, and seeing as there are so many benefits to walking, I decided to try it out for a month. Keep scrolling for my take, and professional insight from PureGym personal trainers Josh Hardman and Laura Eaton.

    12-3-30 workout

    Ecommerce Writer Grace Lindsay doing the 12-3-30 workout at the gym

    What is the 12-3-30 workout?

    As above, the workout is quite simple – all you need is a good sports bra, a treadmill, and a good pair of running trainers. Ready? Giraldo explains that, from there, all you have to do is set your treadmill to an incline of twelve, change the speed to 3mph and walk for 30 minutes.

    Giraldo doesn’t warm up pre her session, but I made sure too – even a few minutes of dynamic stretches pre and post getting a sweat on can reduce your risk of injury, as per the NHS website.

    Speaking about the workout in her video, Giraldo explains that it’s the one workout that makes her enjoy the gym – hence why I was sold, as someone who often feels the same. “I used to be so intimidated by the gym and it wasn’t motivating. Now I go, I do this one thing and I can feel good about myself,” she shares.

    @laurengiraldoGame changer honestly♬ original sound – Lauren Giraldo

    How often did I do the 12-3-30 workout for?

    Good question. Over the course of the month, I aimed for two to three workouts a week – again, the amount the NHS advises working out a week.

    Giraldo says she aims for five days a week in her video, but I wanted to avoid overexercising. Not only would I have found five times a week difficult to fit into my work schedule, I also wanted to prioritise rest days to make sure my muscles had time to recover (no delayed onset muscle soreness, over here).

    How did I find the 12-3-30 workout?

    After trying it out for four weeks, I’ve got mixed feelings. Before starting out, I was silly enough to think that the workout would be easy. It’s walking, right? As someone who loves nothing more than a sweaty spin class or an intense HIIT workout, walking for 30 minutes sounded like a piece of cake. How wrong I was.

    Sure, for the first five to ten minutes it seemed pretty doable, but by the fifteen-minute mark, I was sweating just as much as I would during, say, a run or class.

    Just because it’s a form of low-impact cardio doesn’t mean it won’t be a hard workout – you’re actually walking on an incline for a pretty long time.

    Pros: I was certainly getting a sweat on and my heart rate up. Similarly, it was simple- sometimes, after a super busy day where all I wanted to do was switch off, I didn’t even have to think about my workout. All I had to do was jump on the treadmill for 30 minutes. Occasionally I listened to music, sometimes I watched a half an hour show on Netflix, and often I just walked.

    Cons: I started to find it quite difficult to do the same workout again and again for such a prolonged period of time. As mentioned above, I’m a big fan of HIIT workouts – they aren’t repetitive and so it’s hard to get bored, whereas at times with the 12-3-30 I found myself wanting to stop as I was just doing the same motion over and over again for half an hour.

    Overall, it’s definitely a workout I’ll keep doing, but I’d like to mix it up with weight training, gym classes and other forms of exercise, too. I’m all about keeping things exciting.

    What equipment do you need for 12-3-30?

    A good pair of trainers are key when it comes to this kind of workout. I only wore one pair for the whole month, and they were the Guide 15 trainers by Saucony.

    Not only did I love the colour for summer, but they literally made me feel like I was walking on air. As an Ecommerce Writer who tests products for a living, I’d recommend.

    Women’s Guide 15 Trainers, £130 | Saucony
    The redesigned Guide 15 delivers a comfort-first sensation that takes your run (or walk) to new heights. Built using softer cushioning and a pillowy sock liner, when I tested, I could feel that they were springier – they certainly have more foam and less weight than other trainers I’ve tried.

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    Alongside a good pair trainers, your best gym leggings and a supportive sports bra should do the trick. If you don’t fancy going to the gym, why not invest in a treadmill so you can try it at home?

    JTX Sprint-3 Electric Treadmill, was £639 now £599 | JTX Fitness
    This treadmill is small but mighty, ideal for home workouts. It comes with everything you need, from a a fully automatic incline, a 5” high-visibility backlit display to keep track of your workout and a tablet holder, MP3 sockets and speakers so you can listen to music.

    View Deal

    What are the benefits of 12-3-30?

    Although I personally found that this workout helped improve my fitness, as well as my mental health, I wanted to get a professional opinion on the benefits – because, after all, Giraldo isn’t a qualified PT (despite thousands jumping on the trend and trying her workout, myself included).

    Laura Eaton, a personal trainer from PureGym, shared that the 12-2-30 is a memorable programme as it requires minimum set up time and is short enough that most people could fit it easily into their day. “Most gyms will always have a treadmill free, which reduces your risk of not being able to get your workout in as others are using the equipment,” she adds. Similarly, she adds that you’ll reduce your risk of gym anxiety (more common than you’d think) if you walk into the gym with a plan.

    After doing it for a month, I definitely felt like my confidence in the gym had improved – I was comfortable in the space and felt like I could smash any workout there (within reason). But how can it affect your physical health?

    “Walking is a fantastic cardiovascular activity, and adding the incline will get your heart rate up, improving both your cardiovascular health and endurance,” Eaton explained. “This exercise is also much more gentle on the joints than running or jogging, making this an excellent choice for different age groups and fitness levels.”

    Is the 12-3-30 workout safe?

    Although it seems relatively simple, it’s always important to clarify that a workout is safe before trying it yourself. Eaton’s answer? As it’s largely low impact walking, it’s safe. But she does advise familiarising yourself with safety functions – like the emergency stop chord – pre-workout.

    Also, top tip: don’t hold onto the sides of the treadmill while you’re working out as you could injure yourself (plus it means your muscles are effectively cheating). If you feel that you need to do this, she encourages you to lower the incline slightly.

    Who should avoid doing the 12-3-30 workout?

    Do remember: while a workout may be safe, that doesn’t mean it’s suitable for everyone. We would always recommend checking in with your doctor or a personal trainer before trying out a new routine. It doesn’t need to cost the earth – just take five minutes next time you’re at your local gym to check in with the PT on shift. That’s what they’re hired for, after all.

    For the 12-3-30, both experts warned those with lower back pain or extremely tight calves to swerve. “Those also suffering from plantar fasciitis should avoid it, as the increased pressure on the feet can create small tears in the connective tissue,” adds Eaton.

    Are TikTok workout trends causing more harm than good?

    So, this particular TikTok trend was actually a sound workout – but that doesn’t mean all of them are. You’ve likely seen ridiculous workouts posted on social media all for the sake of likes – so, how do you sieve the ones worth your time from the ones that, well, aren’t?

    Good question-  and one I picked the PT’s brains about, too. While they said that these trends can be a positive, as they encourage people to get active and move more, a lot of them have been created by amateurs who have no formal training or qualifications.

    Similarly, they’re often solely focused on weight loss, rather than improving your fitness or maintaining your current health.

    Josh Hardman, a personal trainer from PureGym, said: “A lot of them are causing more harm than good – this one especially. There’s nothing special about this workout – doing the 12-3-30 workout is exactly the same as going for a walk outside, and the latter will probably be better for your mental health.”

    Eaton agrees, adding that her concern is that these videos can occasionally misinform viewers and make planning workouts seem confusing – conflicting views are rife on the platform. “The goal should be to make exercise accessible to everyone – you should work to find exercises that are challenging yet enjoyable, too.”

    We agree with both PT’s – while some workout trends online can be risky, working out in a way that works for you is best. Will you be giving it a go?

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