“Walking is the best form of exercise you can do,” says Dr Elroy Aguiar, an assistant professor of exercise science at The University of Alabama.
“It’s easily accessible, with a low barrier to entry in terms of cost, equipment and skill requirements. The vast majority of the population can easily get outside and go for a walk; that’s why we say walking is the best recommendation for exercise.”
But, as with anything simple and successful, the internet has found a way to complicate it. Enter the 12-3-30 method – walking on a treadmill with its incline set to 12, at 3mph, for 30 minutes.
Influencer Lauren Giraldo brought the method into the mainstream, claiming it helped her lose 30lb (just over 13.5kg). Now this “cardio hack” has racked up millions of views on Tiktok, with top videos promising rapid weight loss and a “toned” physique.
As a fitness writer who’s ever-sceptical of anything that sounds too good to be true, I decided to give it a go for myself, and see how it compared to simply walking 10,000 steps a day sans-treadmill – which is something I’ve enjoyed doing for years with no complaints.
How to do the 12-3-30 workout
If you want to try the 12-3-30 trend, all you need is a treadmill and a spare 30 minutes. Set the treadmill’s incline to 12, bump the speed up to 3mph (or 4.8kph if, like me, your treadmill of choice only operates in the metric system) then walk for 30 minutes. You can do this in the gym, or using your treadmill at home.
My thoughts on the 12-3-30 workout
There’s logic behind the 12-3-30 workout. The treadmill offers a more controlled environment than a regular walk, so you can dictate variables like the gradient and pace.
“What you’re doing by increasing the incline is increasing the intensity of the activity,” Dr Aguiar explains. “Incline walking is much more difficult, so it’s going to increase oxygen cost, heart rate and energy expenditure.”
This can improve your cardiovascular fitness. Paired with an appropriate diet, it can also aid weight loss, increasing energy expenditure to create a calorie deficit. But there’s no magic formula to it, you’re just moving more, and some Tiktok videos may overstate its effectiveness on the fat loss front – consistency and time are the real secret ingredients if this is your goal.
Trying the 12-3-30 workout for myself, I wound up far sweatier than I expected; I was essentially walking up a fairly steep hill for 30 minutes. The time went fairly quickly, and compared to a run it didn’t take nearly as much preparation or motivation to get started. These are all plus-points, supporting its reputation as a “cardio hack”. However, I still took umbrage with some elements.
Firstly, I found it a bit boring. I was facing a blank gym wall for the full half hour and, although I roped a friend in to join me for a chat, I’d still rather head to an actual hill for a more stimulating walk.
It also doesn’t include any sort of progression. The workout will keep burning calories, sure, but if you want to see continued improvements in your fitness then you need to gradually make your training more challenging over time by upping various variables – in the case of a treadmill, the main ones are speed, gradient and time.
My other main qualm is that this workout keeps you cooped up inside. As someone who works from home most days, I’d rather use this time to head outdoors and reap the many benefits of doing so.
“Ideally, it’s good to get outside because there are other benefits – interacting with your environment, sun exposure, those sorts of things,” Dr Aguiar tells me.
Read more: I walked 10,000 steps with a weighted backpack every day for a week – here are five reasons I’m not stopping
My thoughts on walking 10,000 steps a day
Walking 10,000 steps per day has become a popular fitness goal thanks to fitness trackers making it their default target. But the figure really stems from a 1960s Japanese pedometer called the Manpo-Kei or “10,000 steps metre”. In other words, it’s rooted in marketing, not science.
The actual amount you need to walk each day to see most health benefits is more like 8,000 steps, studies have shown. However, I’ve found walking 10,000 steps a day works for me, and I’ve been doing it for years.
Getting on my feet and out of the house boosts my mood and helps my body feel looser after a day at my desk. I can squeeze extra steps in throughout the day with a lunchtime wander or stroll to the shops, and I enjoy it, often exploring new places or meeting friends for an on-the-go catch-up. For me, an ever-changing natural environment is far more engaging than a blank gym wall too.
Research supports my feel-good theory, with a study published in the Scientific Reports journal finding that spending at least 120 minutes per week in nature is “associated with good health and wellbeing”.
But there are some drawbacks to this practice too. Without a treadmill belt forcing you to walk fairly fast, it’s easy to let your pace drop while out for a walk. And Dr Aguiar’s research suggests that walking speed could be linked to the health benefits on offer from getting your steps in.
“The recommendation from our studies has shown that, if you walk at a cadence of about 100 steps per minute, that’s equivalent to what’s called ‘moderate intensity’,” he explains. “All of the research in this area suggests that most of the benefits accumulate at a moderate or higher intensity.”
Read more: You only need three moves and one dumbbell for the best abs workout at home, according to a top trainer
The verdict: 12-3-30 workout vs 10,000 steps a day
Both the 12-3-30 workout and walking 10,000 steps a day have pros and cons. However, the mental and physical benefits of both far outweigh any drawbacks.
Personally, I found walking 10,000 steps a day was the better option by far, leaving me feeling far better than spending 30 minutes staring at a treadmill screen. However, there will be people out there who prefer the structure and tangibility of the 12-3-30 method.
Which brings us to the deciding factors: enjoyment and accessibility. Which one are you able to do regularly, and which one is fun enough to keep you coming back for more?
“I’m not going to dissuade anyone from doing any sort of exercise,” Dr Aguiar says. “Whether people choose to exercise inside on a treadmill or outside by walking around a park, there are benefits to both. And if people are enjoying doing the 12-3-30 trend, good on them.”
In short, adding some extra movement into your routine is rarely a bad thing. If you find something that works for you then it’s well worth sticking with it, rather than flitting between the ever-flowing stream of fitness fads that dominates social media.
As Giraldo says in her initial video on the topic: “I used to be so intimidated by the gym and it wasn’t motivating. But now I go and do this one thing and I can feel good about myself… I look forward to it, it’s my me-time.”
Read more: Adam Peaty reveals the training and mindset shift that got him to Paris 2024 – and what he plans to do next