What is the 12-3-30 Treadmill Workout and is it Worth the Hype?

When it comes to cardio, the treadmill doesn’t typically get a lot of love; that is, until a TikTok trend rolls around.

8 min read

Health & Wellness

What is the 12-3-30 Treadmill Workout and is it Worth the Hype?

When it comes to cardio, the treadmill doesn’t typically get a lot of love; that is, until a TikTok trend rolls around. From hot girl walks to walking backwards, treadmill workouts are finally getting their beat in the spotlight.

One treadmill trend that’s here to stay? The 12-3-30 treadmill workout.

Designed by social media influencer, Lauren Giraldo—who shared it first on YouTube in 2019 and again on TikTok in 2021—the workout has garnered nearly 12 million views and counting.

And for good reason. The 12-3-30 treadmill workout is refreshingly simple:

  • Set the incline to 12
  • Set the speed to 3 mph
  • Walk for 30 minutes

A quick Google search will yield an endless thread of reviews, praising the 12-3-30 treadmill workout as a great way to lose weight, boost fitness, and get excited about working out again. But is it? We dig in below.


What Are the Benefits of the 12-3-30 Treadmill Workout?

For Giraldo and her followers, the benefits of the 12-3-30 workout tie back to its simplicity. “I used to be intimidated by the gym and it wasn’t motivating,” she explained in her TikTok video. “But now I go. I do this one thing, and I can feel good about myself.”

Perhaps Giraldo’s biggest win was losing 30 pounds, but that isn’t how she sees it. “I obviously noticed the changes in my body, but I was most happy with the changes that I felt mentally,” she said. “I was proud of myself for getting on the treadmill and having my ‘me time’ for 30 minutes. I feel accomplished every time I do it.”

For those looking for a straightforward solution to getting more active, 12-3-30 might be the ticket. Here are some of the science-backed benefits of the 12-3-30 treadmill workout:

  • It’s low impact(1)
  • It builds lower body strength(2)
  • It helps improve cardiovascular fitness(3)
  • It burns a significant amount of calories; and thus, fat(4)
  • It strengthens bones(5)
  • It boosts balance and coordination(6)


Is 12-3-30 a Good Workout?

The 12-3-30 treadmill workout is a great workout, for the right person. What makes it good? First, according to the American Heart Association (AHA), moderate to vigorous cardiovascular training is key for reducing your risk of preventative disease like heart disease, stroke, type 2 diabetes, high blood pressure, dementia, and Alzheimer’s(7).

For most people, walking on an incline will land somewhere in that moderate to vigorous zone. If you find running boring or painful, incline walking presents a different way to get a similarly metabolically demanding workout without needing to hike up the speed. Plus, from a cardiovascular standpoint, you’ll be able to increase your heart rate much higher than walking on a flat surface alone.

Do it five times per week, which is what Giraldo recommends, and you’ll hit the AHA recommendations for cardiovascular exercise—which encourage adults to get a minimum of 150 minutes of moderate intensity activity or 75 minutes of vigorous intensity activity per week(7).


Is There a Downside to 12-3-30?

You must be in pretty decent shape to walk at the speed and incline of the 12-3-30 treadmill workout for 30 minutes straight. In fact, most people will need to work up to it (more on that below).

That’s because adding incline boosts the challenge on the large muscle groups of the backside of your body like your glutes and hamstrings. When you walk uphill, your muscles must work harder to overcome gravity.

One study found when compared to walking with no incline, walking on a grade of nine degrees resulted in a 635 percent increase in hamstring activation, and a 345 percent increase in gluteus maximus contraction(2). As the grade goes up, muscle activation goes up, too.

Incline walking also builds up strength in your core and intrinsic muscles of your feet and ankles—which will kick on to keep you balanced and stable as you climb.

The big but: building strength in these muscles takes time. Hop into this routine too fast, and tight muscles, aches and pains, and injuries could crop up. Which is why most people will need to work up to the full 30-minute session, let alone five days of it in a row.


Is 12-3-30 Good For Weight Loss?

Yes, the 12-3-30 treadmill workout can help with weight loss. Keep in mind, the best way to lose weight is through a well-rounded approach that includes consistent cardiovascular exercise, regular strength training (which can help shift your body composition from fat to lean muscle), a healthy and balanced diet, and a recovery routine.

Consistency to your exercise routine and diet is key for seeing weight loss results. If you aren't consistent, you can’t expect real change to occur (and that goes for the 12-3-30 treadmill workout, too).

However, if you are consistent— particularly to your workouts—keep an eye on recovery. Sleep at least seven hours a night, stretch and foam roll tight muscles, and fuel your body with nutrient-dense, whole foods that provide your body a variety of macro and micronutrients.


Is the 12-3-30 Treadmill Workout Safe?

For the most part, yes. But there are some considerations to keep in mind. The most important: don’t do it without first properly preparing your body for the challenge. The 12-3-30 treadmill workout is basically like going on a steep 30-minute hike. Multiply that by five days a week, and you’re putting a significant load on your muscles.

Your hamstrings and glutes will take on the brunt of that work, but your calves will work harder, too. To lift your leg higher, your hip flexors and quads will kick on. If you hop right into it, you can expect all of them to be sore (speaking from experience).

Walking properly, with good upright posture, and not relying on the handlebars will also require a great deal of core strength. If your core is weak, it’ll stress your lower back instead. If so, you may deal with some lower back soreness or pain.

All of these woes can be avoided by easing into it and equipping your body with exactly what it needs to crush the 12-3-30 workout. Find out exactly how to do it below.


How to Safely Try the 12-3-30 Treadmill Workout?

Ready to give it a shot? Great. Here are our top recommendations for working up to the 12-3-30 regimen.

  • If you’re new to fitness, start on flat ground. Make sure you can walk five days a week for 30 minutes on flat terrain before launching yourself into the 12-3-30 treadmill workout.
  • Gradually increase the incline. After that, try adding rolling inclines several times per week by alternating periods of incline with periods of flat walking. Then gradually incorporate longer and steeper inclines. For guidance try our Beginner Incline Treadmill Interval Workout to get started, our Intermediate class to level up, and our Advanced class to progress.
  • Listen to your body. Only graduate to longer or steeper inclines when you’ve mastered your current workout. A good rule of thumb is to increase by about 10 percent intensity week over week. But if you’re sore, don’t progress to the next level until it subsides.
  • Don’t hold onto the rails. When walking on an incline, try to mimic regular walking as much as possible. If you feel you do need to hold onto the rails to maintain your balance, decrease the incline until you feel confident to increase it without relying on the treadmill. Like any workout, your success should be defined by putting in real work by functionally moving your body. You’ll get a better workout doing something that’s challenging but possible than cheating your way there with the handrails.
  • Pay attention to form. As you walk, focus on bracing your core and engaging your obliques to keep your hips and trunk stable with each step. Keep your shoulders down and back and chest up to maintain good posture through your upper body and aim to keep your gaze straight forward rather than down. Instead of sticking your butt out, engage your glutes and try to keep your pelvis tucked and connected to your core to avoid putting excess pressure on the upper back. Swing your arms, they’ll help generate the momentum to power you upward.
  • Supplement with strength and stretching. Pair your routine with regular strength training and stretching. Both will help prepare your body for the challenge of incline walking and improve the results you see from your overall routine.
  • Switch it up as necessary. The best exercise is the one you will do on a regular basis. If the 12-3-30 treadmill workout isn’t right for you or you’re tired of it, mix it up with other activities to stay active. Download the SunnyFit® app for endless options at your fingertips.


Can You Do the 12-3-30 Workout Without a Treadmill

It’s easy to replicate the 12-3-30 workout on other cardio machines, so if you don’t have a treadmill, don’t sweat it. Read: there are endless ways to rack up the same metabolic demand needed to see results. Try the elliptical, rower, or cycle bike and tack on resistance instead of incline.

If you have an elliptical and you’re looking for a good way to ease into a 12-3-30 routine, try this 4-30-5 elliptical workout—which we designed to help you start a simple cardio routine that’s lower impact and more approachable for beginners.


1. Haggerty, M. et al, The Influence of Incline Walking on Joint Mechanics, 2014. https://www.sciencedirect.com/science/article/abs/pii/S0966636214000022 Accessed 8 January 2023.
2. Franz, J. et al, The Effects of Grade and Speed on Leg Muscle Activations During Walking, 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262943/ Accessed 8 January 2023.
3. Padulo, J. et al, A Paradigm of Uphill Running, 2013. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0069006 Accessed 8 January 2023.
4. Silder, A. et al, Predicting the Metabolic Cost of Incline Walking From Muscle Activity and Walking Mechanics, 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504736/ Accessed 8 January 2023.
5. Krall, E. et al, Walking is Related to Bone Density and Rates of Bone Loss, 1994. https://pubmed.ncbi.nlm.nih.gov/8304358/ Accessed 8 January 2023.
6. Ferraro, R. et al, Effects of an Inclined Walking Surface and Balance Abilities on Spatiotemporal Gait Parameters of Older Adults, 2012. https://www.researchgate.net/publication/225043578_Effects_of_an_Inclined_Walking_Surface_and_Balance_Abilities_on_Spatiotemporal_Gait_Parameters_of_Older_Adults Accessed 8 January 2023.
7. American Heart Association, American Heart Association Recommendations for Physical Activity in Adults and Kids, 2018. https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults Accessed 8 January 2023.


12-3-30 Treadmill Workout

12-3-30 Treadmill Workout


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I am so intrigued by this 12-3-30 workout but I have a manual treadmill that I believe only goes up to about 6%incline. I was wondering if you could tell me how I can alter the workout to fit this incline percentage. I can imagine it’s the same as if I doubled my time but I would love to hear your thoughts.
Thank you!