If you’ve ever been in a rut with your workout routine (let’s be honest who hasn’t), or if you’ve been inspired to try a new treadmill workout to mix it up, you may have heard of of the 12-3-30 workout. The 12-3-30 workout was coined nearly five years ago by health and beauty influencer, Lauren Giraldo. Giraldo posted the workout to her YouTube channel.

“I was out of shape and didn’t have a great relationship with fitness at the time,” Giraldo tells Runner’s World. “I found a lot of the fitness advice and workouts online were extremely overwhelming and impossible to stick with long-term.” At the gym, Giraldo found weights intimidating and gravitated toward the treadmill instead. Through trial and error, the 12-3-30 workout was born—and then it took off on social media, including TikTok.

At the gym, Giraldo found weights intimidating and gravitated toward the treadmill instead. Through trial and error, the 12-3-30 workout was born—and then it took off on social media, including TikTok.

While the hype for the 12-3-30 workout is real, can it truly benefit you as a runner? We asked Jess Mena D.P.T., C.SC.S., certified strength and conditioning specialist, and Brianna Bernard, certified personal trainer, to help us break it down.

What is the 12-3-30 workout?

The 12-3-30 workout is pretty straightforward: You set a treadmill to a 12-percent incline and 3.0 speed and walk for 30 minutes.

“I found 12 percent incline, 3 speed, for 30 minutes on a treadmill was easy enough for me to do frequently but still challenging enough for me to feel accomplished after,” Giraldo says. “It was what got me in the gym every day and set the foundation for my fitness and health journey.”

Setting the treadmill to a 12-percent incline forces your body to work a lot harder, says Mena. The 3.0 speed is an average walking speed and attainable for most folks, so this makes it a very beginner-friendly option.

Giraldo, who says she has never been a runner, loves the 12-3-30 workout because it’s a way for her to use a treadmill and feel like she’s getting more out of it than just walking.

Who should do the 12-3-30 workout?

If you are looking to start exercising, this is a great workout for beginners. You can even start at a lower incline or slower speed. Because walking on an incline builds strength in your glutes and hamstrings, it can serve as a stepping stone for strength training.

Anyone who wants to get in a solid cardio workout—experienced and novice runners alike—can do this workout, says Bernard.

For runners who dread the tread, the incline produces an increased heart rate, as well as greater posterior chain activation (think: glutes, quads, and hamstrings) as opposed to walking on a flat road, says Bernard. For experienced runners, this workout is a great option for a recovery or cross-training day.

What are the benefits of the 12-3-30 workout?

Giraldo still uses the 12-3-30 workout for cardio, and says over time, it gave her the confidence to try new things in the gym. So it can be helpful for building both cardiovascular endurance and confidence. Now, she incorporates weights after cardio some days.

Walking on an incline on a treadmill means you don’t have to drive somewhere to find hills, and if you have a treadmill in your home, it’s a great way to get a workout in without going to the gym.

Mena says the workout can be used as a way to increase stamina and endurance for long-distance runners. “It’s a nice way to force other muscles to work a little harder and in a different way,” Mena says.

If you typically run on a flat road, this workout can be a great way to prepare for the hills you might find on a race course. The incline helps build not just cardio endurance, but also muscular endurance, which will help you get through those final, sometimes grueling miles in a race or intense workout, says Bernard. Plus, it’s great for those who work a desk job.

When you’re short on time, Bernard also suggests breaking the workout into three 10-minute walks. Studies have shown that training for 30 minutes at the end of an eight-hour workday isn’t enough to counteract all of the sitting we do. “Therefore, we need to increase our movement throughout the day and the 12-3-30 is an easy fix for that,” Bernard says.

How often should you do the 12-3-30 workout?

Giraldo tries to do the workout every day.

“It’s become less of a workout and more of a lifestyle,” Giraldo says.“I use it as my ‘me time.’ I put on a YouTube video or my favorite Netflix show and tune out the world.”

For a novice, it’s best to ease into it by doing the workout just two times a week. Each week, add one day until you reach five-plus days, checking in with your body to see how it’s adjusting to the workout to avoid injury, says Mena.

Over time, your body will adapt to the 12-3-30 workout, so if you want to see change—increase your, build strength, or whatever your goal—you’ll eventually have to add a new stimulus like weight training or running to lead to greater change. But, if you’re looking to just move a little more or need simply want something new to add to your workout routine, the 12-3-30 could be a great way add more steps to your day.

Headshot of Jordan Smith
Jordan Smith
Digital Editor
Jordan Smith is a writer and editor with over 5 years of experience reporting on health and fitness news and trends. She is a published author, studying for her personal trainer certification, and over the past year became an unintentional Coronavirus expert. She has previously worked at Health, Inc., and 605 Magazine and was the editor-in-chief of her collegiate newspaper. Her love of all things outdoors came from growing up in the Black Hills of South Dakota.