When TikTok Is Your Trainer

Is The 12-3-30 Workout Actually Legit? We Asked The Experts

What the fitness pros have to say might surprise you.

Ariela Basson/Scary Mommy; Shutterstock, Getty Images
TikTok Trends Debunked

Squeezing in time for movement is tough even under the best circumstances, so when we spotted the "12-3-30" treadmill workout all over our feeds, we low-key rejoiced at the idea of sneaking in a solid full-body sweat session in just 30 minutes.

But is this trendy TikTok workout actually as good as it seems? Scary Mommy rounded up some fitness pros, who shared details on this seriously simple, easy-to-follow cardio routine and whether or not it's safe and effective.

What is the 12-3-30 workout?

Created by lifestyle influencer Lauren Giraldo, the 12-3-30 workout involves walking on the treadmill at three miles per hour for 30 minutes at a steep 12% incline. Sounds easy enough, right? Giraldo first shared it on her YouTube channel in 2019, but it didn't go viral on TikTok until 2020, seemingly when people were looking for new ways to move their bodies in lieu of shuttered studio classes.

Giraldo — who relatably calls herself "not a runner" — credits the accessible routine with helping her feel more comfortable in the gym, noting that she does it five times a week and calling it her "me" time. And while your idea of "me" time might involve lying horizontally on the couch in complete silence, she certainly makes the case for hitting the treadmill from time to time.

If the idea of walking for that long on such a sharp incline feels daunting, Giraldo can relate. As she told TODAY in 2020, "It was definitely a struggle at the beginning, and it took me a couple of months to really start to enjoy the workout. I found that just focusing on myself for 30 minutes a day was not only great for my body, but also great for my mentality. Now, it's something I look forward to doing every morning."

As with any type of exercise, form is crucial to prevent injury as you build strength and stamina. But is the 12-3-30 actually safe? And does it live up to the hype? Here's everything to know before you try it yourself.

Pros give 12-3-30 two thumbs up, with caution.

"Walking is an excellent method of exercise for almost everyone," says Jessica Maurer, director of operations and education at FIT4MOM and ACE-certified personal trainer. "Walking improves cardiac health, muscular structure, and posture while elevating mental well-being and mood." There's also a low barrier for entry since all you need are comfy clothes and shoes, and it's low-impact for those with sensitivities or who've recently recovered from injury, illness, or childbirth.

"Often, people plateau in their walking workouts due to time, limitations, or fitness levels, but incline walking is a great progression from walking on a flat surface to avoid this," says Maurer. "Increasing your walk's inclination requires more force, energy, and muscular movement to propel you forward, increasing your workout's intensity without involving more impact."

Beginners will want to work towards a full 12-3-30, adds Paizley Longino, CPT, CNC, and coach for STRIDE Fitness in Lubbock, TX. "Incline challenges so many different parts of your muscular and skeletal system, and straining or overworking muscles can lead to serious injury," she shares.

Focus on form and function.

Longino recommends starting and ending each session with dynamic stretches like side lunges and controlled leg swings, even if (and especially if!) your body is already accustomed to incline walking, hikes, or intense lower-body movement.

When you're ready to hit the treadmill, you must take care with your form to prevent injury, she adds. Avoid "leaning in" to the treadmill, and try not to put your weight on the handlebars, which will cause you to round your shoulders, adding strain to your neck and lower back.

"You should be walking as if you were outside climbing a hill, pumping your arms next to you," adds Maurer. "While walking on an incline, you will automatically pitch your torso and upper body forward, just as you would hiking. Maintaining strong posture during this workout is essential: keep your core engaged, shoulder blades rolled down and back, and chest lifted. This posture will help you avoid hunching your shoulders or craning your neck forward and will activate more of your glutes. It has also been shown to alleviate pain in the knee joints."

If you're working up to the 12-3-30 goal, Maurer has you covered. "Instead of cranking the incline to 12%, ensure you can walk for 30 minutes at zero incline first," she suggests. "If you cannot accomplish that task, make small adjustments by adding 1 or 2 minutes of additional walking to your workout. Once you can complete a 30-minute walk, you can slowly increase the incline per workout, but make sure to listen to your body. Experiment with 2 or 3 degrees to begin with and then increase by a few degrees weekly."

Longino also recommends trying it in two intervals of 15 minutes each in the morning and evening, noting that breaking it down into shorter walks can help you build up to a full 30 minutes in time.

Listen to your body.

As with any and all movement, listening to your body is crucial. "Remember, pain means no gain," says Maurer. "If you experience discomfort, lower the incline back down. If you must grip the treadmill handles to stay upright, you have gone too far and should reduce the incline back to a more comfortable degree."

While walking is gentle on muscles and joints, Maurer notes that "it's important to cross-train and diversify your activity. Doing the same workout that uses the same muscles in the same way every day will make you prone to boredom, injury, and plateaus."

So, go ahead. Lace up your sneakers, queue up your TV show, podcast, or playlist of choice, and give yourself 30 minutes on the treadmill. The to-do list can be tackled when you're done, promise.