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What To Know Before You Try This Viral 12-3-30 TikTok Treadmill Workout

In the last year, TikTok has brought on a whole mess of viral tips, tricks and trends to improve how we make pasta (the feta one is really that good, try it), how we clean and even how we work and workout from home. So don’t be surprised if your “For You” page serves up some other fitness game-changers, including the latest one: The 12-3-30 Treadmill Workout.

The workout comes from influencer Lauren Giraldo, who shared it first in 2019 and later on TikTok. Inspired by her own trial and error experiments, Giraldo says she discovered that using the maximum incline her gym’s treadmill would allow (12) at a speed she felt comfortable with (3 mph) for a low-key length of time she’d been recommended by a reliable source (30 minutes, courtesy of grandma) gave her the workout her body needed to keep feeling good.


@laurengiraldoGame changer honestly♬ original sound – Lauren Giraldo

“I’m not a runner, and running on the treadmill was not working for me,” Giraldo said in an interview with earlier this year. “I started playing around with the settings and, at the time, my gym’s treadmill had 12 incline as the max. The three miles per hour felt right, like walking, and my grandma had always told me that 30 minutes of exercise a day was all you needed.”

The appeal of this to the TikTok masses? It’s simple, it’s easy to remember and crams a bit more punch than some standard 15 minutes of walking workouts.

“I used to be so intimidated by the gym and it wasn’t motivating,” Giraldo said in her TikTok video (that has now been liked 2.7 million times). “But now I go, I do this one thing, and I can feel good about myself.”

Will this workout work for you? It depends.

The efficacy of walking for fitness is something we’ve known about for years — but, as with any workout, there are right and wrong ways to go about it. When done right, walking for fitness can, per the Mayo Clinic help a person “maintain a healthy weight; Prevent or manage various conditions including heart disease, high blood pressure and type 2 diabetes [and] Strengthen your bones and muscles Improve your mood Improve your balance and coordination.”

But it’s also good to remember that form counts (both for making sure you get the most out of your 30 minutes and to prevent injury) — and some experts have weighed in on this viral trend to note that walking at an incline and maintaining good form can be deceptively challenging.

Dr. Dennis Cardone, osteopathic sports medicine specialist and chief of primary care sports medicine at NYU Langone Health, told TODAY that he wouldn’t recommend this workout for someone new to walking for fitness and definitely not as an every day routine — especially if they find themselves struggling to reach the 30 minute mark without becoming out of breath.

“If someone is working that hard with this workout and they are a 20-something, young and healthy, and they are struggling, you see it was a pretty significant workout. It’s just too much too soon and it should really have a recovery day as well,” Cardone said. “It certainly adds more stress to a workout in the sense that people are getting more of a workout in a shorter period of time; the muscles are working harder…The problem is people don’t think that walking is a stressor. They think ‘what’s the big deal using an incline? I’m only walking.’ But it really is a big stressor: low back, hamstring, Achilles tendon, knee, plantar fascia … these are the areas where we see some significant injury related to inclining a treadmill. As a general observation, anytime anybody begins or changes a workout or adds something like an incline, they have to follow the rule to do it slowly, otherwise they are certainly at significant risk for an overuse injury.”

So depending on your fitness level and experience with walking at inclines, this steep incline/moderate speed walking workout could totally fit for your body and your workout needs (provided you are mindful of overuse and practice good post-workout recovery care). But, given the steep incline (we’re talking uphill, baby!) and the moderate pace, it’s probably not every beginner’s Low Intesity Steady State (LISS) workout dream.

But, it’s important to remember that everyone’s body is different — and, if you’re new to fitness walking, running or getting back into a regular cardio routine you’ll want to build up to this particular setting combo (start out walking flat on the ground and improve your form, core strength before you introduce any kind of incline).

If you’re looking for new ideas to change-up your daily workout routine or inject a bit more of a challenge if you’re a fitness walking pro, 12-30-3 may be for you. But don’t worry about matching up with these exact numbers or going step-for-step with an influencer whose body is used to a particular kind of workout. If it doesn’t feel good or right for your body, re-work to find something that does! It’s always better to be inspired than intimidated.

And just in case these videos have inspired you to go looking for your own treadmill, here’s a few beginner’s options that we love.

Our mission at SheKnows is to empower and inspire women, and we only feature products we think you’ll love as much as we do. Please note that if you purchase something by clicking on a link within this story, we may receive a small commission of the sale. 

MaxKare Electric Folding Treadmill Auto Incline Running Machine

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With options between 0-12 percent incline and a max speed of 8.5 mph, this is one treadmill that can rise to your needs as you develop your skills as a fitness walker and runner.

MaxKare Folding Treadmill

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Another less expensive option (clocking in under $400), this treadmill from MaxKare features a 17-inch wide tread belt, speeds capping at 8.5 mph and three manual inclines. It also has an LCD screen built in to help track data for speed, time, calories, distance and heart rate.

Fitness Avenue Treadmill

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Another folding option from Fitness Avenue, this treadmill is small and easy to store away when you’re not using it (for those afraid of having another workout accessory turn into a coat rack). It can reach up to 7.5 mph and has three levels of manual incline (not quite 12, but that might be better suited for a beginner anyway).

Fitness Avenue Treadmill $529.99 on

And before you go, check out some of our other favorite home gym equipment:


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