What is the 12-3-30 Workout?
12-3-30 is a 30-minute treadmill incline workout where the incline is set to 12 percent and the pace is set to three miles per hour. Yes, it's really that simple. Influencer Lauren Giraldo first introduced the 12-3-30 workout on YouTube in 2019, but it didn't become popular until Giraldo posted a TikTok about it in late 2020, crediting it for helping her lose 30 pounds and keep it off for two years.
The workout has since gone viral, but it's also withstood the test of time. People all over social media are calling themselves "12-3-30 girlies," sharing their love for the workout, how they've modified it, and their own 12-3-30 results. From the outside looking in, it might seem like an unassuming cardio routine, but the simplicity of 12-3-30 has fostered a sense of community and helped the gym seem less intimidating for many.
12-3-30 Workout Benefits
Social media users love 12-3-30 because it's straightforward — no interval timer or further instruction needed. It's a challenging yet low-impact workout that makes cardio a little less painful, and it comes with plenty of benefits. In fact, the 12-3-30 workout gets your heart rate up as much as a jog, without the additional impact on your joints, making it great for cardiovascular health. Additional research shows that this kind of incline walking may even help strengthen the knee joints.
The steep, 12-percent incline makes your body work harder than walking on a flat surface, explains registered dietitian and personal trainer Nicole Rodriguez. This gets your heart rate up and places more demand on your body, forcing it to expend more energy. For example, a small 2012 study found that the metabolic cost (AKA calorie burn) of walking increased by 17 percent when set at a five-percent incline, and by 32 percent when set at a 10-percent incline when compared to walking on flat ground.
The 12-3-30 workout also has muscle-building benefits: that same 2012 study found that incline walking increases activation in many lower body muscles. Specifically, walking on an incline strengthens your glutes, quadriceps, hamstrings, and calves more than walking on a flat surface.
12-3-30 Workout Risks
All workouts come with some level of injury risk, and the 12-3-30 workout is no different. "I would deem this safe with physician's clearance," Rodriguez says. That said, if you're struggling with knee pain or injuries of any kind, this workout may not be right for you.
To help prevent injury while incline walking, experts at Texas Health recommend keeping your posture in mind: stand up tall, engage your core, and avoid slumping forward or leaning your weight onto the handrails.
The 2012 study found that adding an incline changes your walking gait, so your muscles may not be ready for this movement if it's completely new to you. If you're a beginner to steep incline workouts, you should ease into it to avoid injury or strain on your muscles. Doing too much too soon can put you at risk of an overuse injury (when tissue is damaged due to repetitive demand), according to the Hospital for Special Surgery. It's best to gradually build up the incline and speed at your own pace.
12-3-30 Workout Results
I decided to try the 12-3-30 workout for two weeks, doing the workout five times a week, per Giraldo's recommendation. I wanted to see how this incline workout compared to my usual HIIT workouts, running, and rowing. Could a walking workout really be as effective? Keep reading to hear about my 12-3-30 workout before and after results.
My 12-3-30 Workout Warmup
Getty | Emilija Manevska
My 12-3-30 Workout Warmup
Before trying the 12-3-30 workout, I had been rowing 10,000 meters regularly (which takes about an hour). I didn't want to lose my rowing endurance completely, so I cut my rowing workout in half (5,000 meters). I did my rowing before 12-3-30, which helped warm up my lower back, glutes, and hamstrings for the steep 12 percent incline. After getting off the rower, I did a couple minutes of stretching before warming up on the actual treadmill.
I started with no incline at a pace of 2.0 mph for a few minutes, then I increased the incline to 12 for a few minutes (still walking at 2.0 mph), before officially beginning the 12-3-30 workout.
Even if you're not going to do something like rowing beforehand, it's a good idea to do a full-body warmup before hopping on the treadmill. Then spend a few minutes walking on flat ground before gradually increasing the incline to 12 percent.
What Is the 12-3-30 Workout Like?
PS Photography | Jenny Sugar
What Is the 12-3-30 Workout Like?
When I tried the 12-3-30 workout, I'd already been rowing five to six times a week, and before that, I was used to running, strength training, and walking my dogs in the woods. Frankly, I thought this walking workout would be easy.
I was so wrong. The first day, my heart rate increased much higher than it does when I'm rowing or running (as reported by my Apple Watch). Walking on an incline actually felt harder than running on a flat surface, because I couldn't just use momentum to bounce off the balls of my feet to keep my pace. There were several minutes when I had to hold on to the treadmill handles, and I even had to hop off a couple of times because my calves were getting so tired. It was humbling to get my butt kicked by a walking workout that I assumed would be easy. By the third day, I was able to walk without stopping, but on the fourth day, I had to stop just short of 30 minutes because my foot started to hurt. (This is exactly why Rodriguez recommends talking it slow at first!) I talked to my physical therapist, who told me to make sure I wasn't heel-striking (stepping and landing on my heel instead of the ball of my foot).
I took two days off to rest and then finished the week without any foot pain. The following week, I did the 12-3-30 workout four days in a row, rested for one day, then did two more days of the workout. After my foot started to hurt again on day four, I switched to my most supportive running sneakers, took more time to warm up with actual walking, and was more mindful about how my feet landed with each step. Taking a few extra minutes to stretch my calves and feet after the workout also helped.
By the second week, the 12-3-30 workout was still feeling intense, but in a fun way. I loved how I could swing my arms harder to elevate my heart rate or hold the handles if I wanted to tone down the intensity. I also appreciated how meditative the movement was, seeing as I could leave the treadmill settings the same for the entire workout.
During 12-3-30, I also noticed that setting the pace to 3.0 mph forced me to maintain that speed. This made it so that my heart rate range was about 20 BPM (beats per minute) higher than my usual rowing, where I'm in charge of my own pace.
How Many Calories Does the 12-3-30 Workout Burn?
PS Photography | Jenny Sugar
How Many Calories Does the 12-3-30 Workout Burn?
Warning: some things discussed in this slide may be triggering to those with a history of disordered eating or compulsive exercise.
Everyone's body is different, so the number of calories you burn during the 12-3-30 workout may vary. However, when I did the 12-3-30 workout, the treadmill readout said I burned about 195 calories. But I also tracked each workout over the two weeks with my Apple Watch, which said I burned between 210 and 230 total calories each time. For context, I usually burn around 205 calories during a moderate 30-minute rowing workout. Likewise, a 30-minute outdoor run burns about 240 calories, and a chill 30-minute walk around the block burns about 140 calories.
It's important to remember that the benefits of exercise go far beyond burning calories. While a lot of people come to the 12-3-30 workout for weight-loss, I'm here to say 12-3-30 is also a great way to feel stronger and get the endorphins flowing.
12-3-30 Before and After
Getty | martin-dm
12-3-30 Before and After
Over the course of the two weeks, I started to notice results from the 12-3-30 workout. For starters, doing this walking workout definitely inspired me to use my treadmill desk a little more. Just like my outdoor walks, I loved the meditative aspect of walking at a consistent pace without having to think about it too much.
I also noticed that walking on a 12 percent incline really targeted my glutes and hamstrings. The 12-3-30 workout also made me feel stronger overall, which I noticed when walking hills in the woods by my house, backcountry skiing, pulling my kids up a hill in a sled, or when doing dumbbell squats and lunges.
Who knew a simple walking workout would have so many benefits? Considering my 12-3-30 results, I'll definitely continue to throw the workout into my weekly fitness plan to keep my muscles guessing.
— Additional reporting by Lauren Mazzo and Chandler Plante
Chandler Plante is an assistant editor for PS Health & Fitness. Previously, she worked as an editorial assistant for People magazine and contributed to Ladygunn, Millie, and Bustle Digital Group. In her free time, she overshares on the internet, creating content about chronic illness, beauty, and disability.
Lauren Mazzo was the senior fitness editor at PS. She is a certified personal trainer and fitness nutrition specialist through the American Council on Exercise. Prior to joining PS, she worked for six years as a writer and editor for Shape Magazine covering health, fitness, nutrition, mental health, sex and relationships, beauty, and astrology.
Jenny Sugar is a former PS staff writer. She reports on all things fitness, but especially loves CrossFit and yoga.
WalkingTreadmillWorkoutsTreadmill WorkoutsCardio WorkoutsHome WorkoutsEditor ExperimentsTikTok
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