What’s the 12-3-30 Workout and Why Is Everyone (Still) Obsessed? I Tried It to Find Out

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), and I’d do that before this walking workout. I found it helped to warm up my lower back, glutes, and hamstrings for the steep 12 percent incline. After getting off the rower, since I was already warmed up, I did a couple of minutes of stretching before getting on the treadmill.

Then I’d hop on the treadmill and warm up a little. I’d walk with no incline at a pace of 2.0 mph for a few minutes, then I’d increase the incline to 12 for a few minutes, and then I’d officially start 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 before gradually increasing the incline to 12 percent.

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 a few times a week. So, frankly, I thought this walking workout would be really 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), which made me realize I could push myself harder for both. 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 was able to finish off 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 loved how I could set the treadmill and just forget it, allowing this to be a very meditative form of movement.

I noticed that when doing these walking workouts, setting the pace to 3.0 mph forced me to keep that speed up. When I’m rowing, I’m in charge of keeping my pace, and on the Apple Watch, I could see that my heart rate range was about 20 BPM (beats per minute) lower than during the 12-3-30 workouts.

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 will vary from my experience. 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 noted that I burned a range between 210 and 230 total calories each time. For comparison, for me, a 30-minute rowing workout at a moderate pace burns around 205 calories, a 30-minute outdoor run burns about 240 calories, and a 30-minute, chill-paced outdoor walk around the block burns about 140 calories.

It’s important to remember that workouts are important for so much more than burning calories. Exercise imparts so many benefits for your physical and mental health that make it an invaluable part of living a healthy lifestyle. While a lot of people come to the 12-3-30 workout because of its touted weight-loss benefits and because they’re curious how many calories the 12-3-30 workout burns, it’s also helpful to remember how strong it makes your legs and heart, and how wonderful the endorphins feel.

Over the course of the two weeks, I definitely started to notice results from the 12-3-30 workout. Doing this walking workout inspired me to use my treadmill desk a little more. And because of the freezing temps in Vermont (where I live), I wasn’t doing any outdoor walks, so the 12-3-30 workout also felt like a good replacement for that activity. And just like my outdoor walks, I loved the meditative aspect of walking at a consistent pace without having to think about it.

I also noticed that walking on a 12 percent incline really targeted my glutes and hamstrings. Rowing also majorly works those muscles, so I was shocked to notice my legs and glutes felt stronger after incorporating the 12-3-30 workout into my routine. 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 this 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.