Adam Meyer

Author: Expert reviewer:

November 30, 2022

Adam Meyer

By Adam Meyer

mbg Contributor

Adam Meyer is a health writer, certified holistic nutritionist, and 100 percent plant-based athlete. He graduated from the NutraPhoria School of Holistic Nutrition in 2019 and has since founded Pillars Nutrition. His work has been featured on EatingWell, Eat This Not That!, The Beet, Verywell Fit, The Healthy, Livestrong, Alive, Best Life and others.

Sarah Kostyukovsky, PT, DPT, OCS

Expert review by

Sarah Kostyukovsky, PT, DPT, OCS

Sarah Kostyukovsky, PT, DPT, OCS, is an orthopedic physical therapist who specializes in treating pelvic floor dysfunction and the perinatal population. She earned her B.S. from the University of Virginia and her Doctorate of Physical Therapy from Columbia University College of Physicians and Surgeons. She is co-founder of Flow Physiotherapy and the owner of Mom in Balance New York, which offers pregnancy and postpartum outdoor fitness classes in Manhattan and Brooklyn.

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November 30, 2022

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Proponents of the 12-3-30—a treadmill-based cardio workout—tout it as a simple way to burn calories, lose weight, and grow your glutes, all while boosting your fitness and cardiovascular health. But how effective is it really, and is it a good workout for everyone?

We spoke with personal trainers to learn all about the pros and cons of the 12-3-30 and snag expert tips on how to tailor the workout to your needs or find another one that’s a better fit.


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What is the 12-3-30 workout?

The name may sound confusing, but the 12-3-30 workout is straightforward. Each number represents a component of the workout: To do it, you increase the treadmill incline level to 12 percent, set the speed to 3 miles per hour (MPH), and walk for 30 minutes.

However, keep in mind these numbers are to be used as guidelines. If your treadmill incline doesn’t go up to 12 percent, or the speed is too fast or slow, you can adjust accordingly to suit your fitness level. The workout goal is to keep your heart rate elevated by walking at a moderate pace on an incline.

The 12-3-30 workout was created by social media influencer Lauren Giraldo in 2019 when she shared it as a YouTube video. However, it wasn’t until Giraldo posted the workout on TikTok and Instagram in 2020 that it exploded in popularity. Three years later, the original YouTube video has garnered over 1.5 million views and over 49,000 likes. 


The 12-3-30 workout, which first went viral on TikTok in 2020, requires setting your treadmill to a 12% incline and 3 MPH speed and walking for 30 minutes.


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What are the benefits?

What experts say:

While it’s easy to dismiss the 12-3-30 workout as another fleeting fitness trend, don’t knock it until you try it.

According to Giraldo, her treadmill routine has helped her shed 30 pounds (and keep it off for over two years) while gaining more confidence in the gym. Over 1,000 YouTube commenters have echoed her claims. They’ve also said the workout is much harder than it appears, has given them the motivation to go to the gym, and has helped them overcome gym intimidation.

While these benefits are merely anecdotal, experts back some of them up. Kate Meier, CPT, a certified personal trainer with Gym Garage Reviews, tells mindbodygreen that “Walking is a great, low-impact form of cardio that comes with the benefits of any cardiovascular exercise: improving your overall fitness, burning fat, and improving heart health.” Incline walking especially works the lower body, including the glutes, quads, and hamstrings, she adds.

“The 12-3-30 workout is a low-steady state cardio that benefits your cardiovascular system,” says Dan Johnston, CPT, a certified personal trainer and strength and conditioning coach. Steady-state cardio it’s a low-intensity exercise that you can do for a more extended period. Like other forms of cardio, it can also help you reduce stress.


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What the research says:

Science also reinforces the physical and mental health benefits of consistently walking at a moderate pace. Here’s how the 12-3-30 workout can benefit you.


It burns more calories than walking on flat ground.

While any type of cardio exercise will increase your daily energy expenditure, incline walking ramps up the intensity of your walk and elevates your heart rate into the fat-burning zone.

Though the number of calories you’ll burn walking on an incline depends on several factors—such as your age, size, and fitness level—a 2012 study published in the Journal of Biomechanics1 found that energy expenditure increased on average by 17 percent on a 5 percent incline and by 32 percent on a 10 percent incline.

Translation: For a 150-pound person, every one percent increase in incline burns roughly ten extra calories per mile than flat-surface walking. That means that doing the 12-3-30’s 12 percent incline, you’ll burn approximately twice as many calories than if you walked without an incline.


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It strengthens your lower body muscles.

Another benefit of incline walking is that it can activate several muscles in your lower body, including your glutes, hamstrings, and quads. Also, it can increase stability in your leg muscles2, which boosts joint health and mobility in your hips, knees, and ankles.

In addition, strengthening this muscle group in your back body (known as your posterior chain) can save your lower back and reduce injury risk.


It improves heart and cardiovascular health.


Fans of the 12-3-30 workout say that it has helped them lose weight and gain confidence at the gym. Science also shows that walking at a 12% incline can burn calories (about twice as many as you would walking on flat ground), strengthen your lower body, and improve cardiovascular health.


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What are the drawbacks?

Depending on your fitness goals, there may be a better workout for you than the 12-3-30. That’s because it doesn’t increase strength or improve flexibility, two key components for overall fitness.

Giraldo (the workout’s creator) claims to do the 12-3-30 five days a week with no other exercise. While this is good for cardiovascular health, it misses out on the many benefits of strength training and overall mobility. “Furthermore, the 12-3-30 could be too intense for people who haven’t done this type of exercise before,” says Johnston.

And while incline walking can strengthen your lower body, don’t rely on it as an effective exercise to significantly target your glutes. “The 12-3-30 can be a complementary form of cardio if your goal is to grow your glutes, but I would also include plenty of glute-centric resistance training exercise into your workouts,” advises Meier.

Johnston adds that people wanting to reap the benefits of low-impact steady-state cardio while putting on muscle and increasing flexibility should combine the 12-3-30 with a well-rounded strength training and flexibility program.

In addition, adding variety to your workout routine is essential for optimizing fitness. “Diversifying your fitness routine is a good idea to prevent burnout and overuse injuries,” Meier says.


While the 12-3-30 is a healthy cardio routine to do from time to time, it should be paired with other types of training. Doing it as your sole form of exercise (as it was initially shared on TikTok) could lead to injury, and it won’t necessarily build muscle or increase flexibility.

How to do the 12-3-30 properly.

Before lacing up your walking shoes and hopping on a treadmill, read these expert tips and cues from Johnston and Meier on how to do the 12-3-30 workout safely, while engaging the correct muscles:

  1. Maintain good posture by keeping your shoulders back, stabilizing your core, and having a neutral spine throughout the workout.
  2. Ensure your feet are landing beneath your shoulders as you walk to maintain a steady heel-to-toe gait.
  3. Avoid jumping straight into doing the 12-3-30 five days a week if you’re a beginner. Doing so may tax your muscles, joints, and nervous system and result in injury or burnout.
  4. Warm up before doing the 12-3-30 with five minutes of walking at an easy pace without an incline. Repeat this as a cool-down after completing the workout.

Other workouts that will give you the same results.

If you’re looking for other exercises to mix up your routine that deliver similar results as the 12-3-30, we got you covered. We asked Johnston and Meier for their top beginner-friendly exercises that can be done in under 30 minutes. Here’s what they had to say.

For a glute burn:

Incorporate lower-body resistance training exercises, such as lunges, squats, Romanian deadlifts, hip thrusts, split squats, and step-ups. These are excellent movements to help strengthen your glutes.

Here’s a sample circuit workout that you can do if you’re short on time:

For a cardio push on a machine:

Try this pyramid-style rowing machine workout that will activate muscles in your lower body while boosting cardiovascular fitness.

  • Two minutes of easy rowing to warm up
  • 30 seconds of hard rowing
  • 30 seconds of easy rowing
  • One minute of hard rowing
  • One minute of easy rowing
  • 90 seconds of hard rowing
  • 90 seconds of easy rowing
  • One minute of hard rowing
  • One minute of easy rowing
  • 30 seconds of hard rowing
  • 30 seconds of easy rowing
  • Repeat this pyramid twice for a 24-minute cardio workout that works the lower body as well as your heart.

For a high-intensity bodyweight workout:

This circuit workout will give you a solid glute burn while quickly elevating your heart rate. Perform each exercise continuously for 40 seconds, then rest for 20 seconds before moving on. Repeat the circuit three times with a one-minute break between rounds. 

For a workout that makes you forget you’re working out:

Aerobic activities like hiking, dancing, swimming, and biking are not only great for your cardiovascular health, but are also fun and engaging and can be done in group settings.


How many calories do you burn during 12-3-30?

Energy expenditure varies widely depending on your age, height, weight, metabolism, and fitness level. Meier says, “On average, the 12-3-30 will burn roughly 200 calories depending on a person’s weight and individual metabolism.” Also, remember that the more you do a specific workout, the more your body adapts to it. So as your fitness improves, you’ll need to increase the intensity (speed, incline) or the volume (time) of your 12-3-30 workouts to continue burning the same amount of calories. 

How much weight can you lose doing the 12-3-30?

Like energy expenditure, the amount of weight you can lose from the 12-3-30 depends heavily on your fitness level, age, weight, metabolism, and whether or not you’re eating in a caloric deficit. Generally, to lose one pound per week, you need to reduce your caloric intake by 3,500 calories weekly (roughly 500 calories per day). Ultimately, your nutrition will have more bearing on your weight than your workouts.

How many times a week should I do the 12-3-30?

The Centers for Disease Control and Prevention (CDC) recommends that healthy adults do a minimum 150 minutes of moderate-intensity aerobic exercise per week. Since the 12-3-30 falls within this category, it’s safe to do the workout five times per week to meet the minimum recommendation. However, fitness experts recommend mixing it up with other resistance and flexibility exercises to offset the cardio.

The takeaway.

The 12-3-30 treadmill workout is an effective way to increase aerobic fitness, burn calories, boost your mood, and improve your heart health while engaging muscles in your lower body. Combined with a healthy diet and calorie deficit, it can also promote healthy weight loss.

However, there’s no easy solution or magic pill for losing weight or getting fit. For optimal results, make sure you incorporate strength training and flexibility into your fitness routine on top of doing cardio workouts like the 12-3-30 a few times per week.