Benefits And How To Do It Effectively

Whether you’re looking for a new salad recipe, genius hack, trendy dance, or new abs routine, TikTok has the answer with an endless stream of viral videos. One trendy workout continues to top the charts: the 12-3-30 workout.

The simple treadmill workout was originally created by social media star and actress Lauren Giraldo. She came up with the routine entirely by accident playing around with treadmill settings, but she loved it and so did everyone who saw it on TikTok. Her own 12-3-30 workout results, a 30-pound weight loss and extra gym motivation, were certainly impressive.

Meet the experts:

Haley Gott, CPT, is a certified personal trainer and dance coach.

Gail McGhie, CPT, is a certified personal trainer and founder of Gail McGhie Fitness.

April Gatlin, CPT, is a certified personal trainer and coach for STRIDE Fitness.

The training plan only has three “rules” to follow, but don’t mistake the simplicity for ease. The 12-3-30 workout is intense. The killer sweat session supposedly burns hundreds of cals in under an hour and has even helped some users lose weight. Others say the 30-minute workout is a great way to gain strength, boost cardio endurance, and build bone density.

This content is imported from poll. You may be able to find the same content in another format, or you may be able to find more information, at their web site.

But is it too good to be true? Can the 12-3-30 treadmill workout actually do all that? WH has all your answers, straight from three personal trainers. Read on as they unpack the risks and potential benefits of the 12-3-30 workout and how realistic those results really are. Here’s everything you need to know before lacing up and hopping on the treadmill.

The 12-3-30 Workout Routine

First, set the treadmill to an incline of 12, and set the speed to 3 mph. Then, walk for 30 minutes—that’s really all there is to it! Users also recommend doing the workout five days a week.

12 3 30 workout treadmill

Christine Giordano

Is 12-3-30 a good workout?

Yes, walking on an incline is a great workout. “When walking on a treadmill with an incline, the posterior muscles are recruited,” says April Gatlin, CPT, a certified personal trainer and coach for STRIDE Fitness. It’s a form of resistance training, and you’re building strength in your glutes, hamstrings, back, and core muscles, she adds. All of those muscles are continually engaged to keep you moving. There’s no coasting.

On top of that, the speed adds more difficulty. Perhaps the 3 mph doesn’t sound that fast, but combined with the incline it definitely is. All those muscles above are now working at a deeper capacity, Gatlin explains. Your heart rate will also rise since you’re working harder to move at a quicker pace, she adds. “If you’re consistent, over time the body will adjust to the quicker speed and the heart rate will be more comfortable as the body has adapted to a ‘new normal’ working capacity.”

If you can hit five 12-3-30 workouts a week, which is what Giraldo suggests, you’ll meet the recommendations from the U.S. Department of Health and Human Services Physical Activity Guidelines, which recommend adults to get at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity a week.

All that said, you don’t want to overdo it, and five days a week might be a little over the top if your physical fitness isn’t already pretty high. Doing the 12-3-30 method for two or three days a week, when combined with other types of training, is plenty, according to both Gott and McGhie.

On non-12-3-30 workout days, there are awesome complementary modalities. Interval training, weight training, or even swimming workouts are great options, according to McGhie. Look for exercises in the lateral plane (side-to-side motion), she says, since the treadmill only pushes your body to do one type of forward motion.

Benefits Of The 12-3-30 Workout

  1. Gain strength. For starters, the 12-3-30 treadmill routine is a banger of a lower-body workout, says Haley Gott, CPT, a certified personal trainer. “It’s a great way to activate multiple muscle groups in your legs.” Your quads, hamstrings, glutes, and calves are all firing.
  2. Boost cardiovascular health. If your current cardio routine needs a shake-up, the 12-3-30 workout could be a helpful addition to build endurance and boost cardiovascular health, says Gott. Walking on an incline increases your heart rate, and research shows this helps maintain a healthy heart and blood pressure.
  3. Burn calories. If you’re looking to torch calories, Gott confirms those claims that the method burns hundreds of calories are true. One 12-3-30 workout sesh can burn anywhere between 400 and 800 cals to be specific. The exact number will vary depending on your current activity level.
  4. Support your immune system. Exercise in general, including this workout, can help support your immune system and improve your sleep, says Gail McGhie, founder of Gail McGhie Fitness. Studies also show that physical exercise can reduce the risk of inflammation and stimulate cellular immunity.
  5. Reduce injury. The workout itself is tough, but unlike running, this routine puts less stress on the bones, ligaments, and tendons, says Gatlin. “With 12-3-30, or any higher intensity incline walking, there is one foot soundly planted on the ground at one time, making the body more stable and the risk of injury lower,” she explains.
  6. Build bone density. Incline walking is a weight-bearing exercise, so with the resistance the body creates, you naturally strengthen your bone density, says Gatlin. Exercise slows bone loss, according to research, so it’s a win-win.

Can the 12-3-30 workout lead to weight loss?

Possibly, Gott says, although she stresses that any weight loss from doing the 12-3-30 workout would vary from person to person. (It’s also important to note that weight loss mostly requires eating healthy foods in a calorie deficit.)

“Everyone’s heart rates are different,” Gott adds, “so, ultimately, if you’re trying to lose fat, then you should be paying attention to your personal heart-rate zones.” Heart-rate zones represent how fast your heart should beat during different kinds of exercise for the most efficient workout. (You can find out how to calculate yours here if you’re curious about this type of training style!)

Are there any potential risks of trying the 12-3-30 workout?

The 12-3-30 workout isn’t for everyone. “Walking on a steep incline can really aggravate your lower back,” Gott notes. “So paying attention to your posture is really important.” Maintaining proper posture requires strong core engagement, too.

Because the incline is cranked up so high and a treadmill is a flat surface, it actually isn’t a low-impact workout, McGhie. “It really stresses the body,” she says.

That means the 12-3-30 workout could lead to injuries for anyone with hip, knee, or ankle issues. “If you have those issues, or you experience low back pain, you should start this workout at a lower incline,” McGhie says. “You can still challenge your cardio and your legs at a lower incline.” You can always work your way up from there.

Plus, if you have a history of shin splints, this training plan may not be for you, says Gatlin. “To combat shin splints, ensure the body is properly warmed prior to starting the workout and wear the proper type of footwear specific to your gait and stride,” she explains.

And, it’s important to pay attention to your body as you walk. “When we start to get tired, our bodies will naturally start to compensate,” Gott says. As you get tired, your body might start relying on other muscles to help you power through (like your lower back muscles, Gott explains). She says this can cause discomfort or a change in your stride.

“You don’t even notice it, but when you’re tired, your body just does its own thing,” she adds. So, if you’re feeling any aches and pains beyond your usual post-workout tiredness, consider lowering the treadmill’s incline, taking a break, or stretching your muscles out.

No matter what, Gott always encourages stretching after a routine like this. “Because you’re exhausting your legs for 30 minutes in the same exact fashion, a deep stretch afterwards is really important,” she says. She recommends focusing on your hip flexors by moving through some lunges and static stretches.

How To Do The 12-3-30 Workout Safely

This workout is in-tense, but there are great modifications to keep it safe and effective at all levels.

If you’re new to this training method (or fitness in general), aim for two to three 12-3-30 workouts a week, Gatlin suggests. Start at 3 mph and a lower incline. Then, gradually add one percent incline each week as your body adjusts to the added resistance. Once you build strength and cardio endurance, you can up your game and try four or five times per week, if you want.

If you have a solid fitness foundation (previous cardio and strength training experience), you can dive in to the official 12-3-30 workout as is, says Gatlin. Some TikTok users recommend doing the 12-3-30 workout five times a week.

At all levels, proper treadmill form is also key for staying safe and maximizing the benefits, Gatlin says.

Treadmill Form Tips

  • Relax shoulders and hands.
  • Keep shoulders rolled back.
  • Hold head steady with chin parallel to the treadmill.
  • Avoid leaning backwards to maintain upright posture.
  • Don’t hold the rails.

If at any point you feel like you’re falling behind on the treadmill unless you grab the rails, that’s a sign to lower the incline. Holding the rails nixes any effect of the incline, which TBH, is the essence of the workout, and breaks proper form which can lead to injury, explains Gatlin.

You may be wondering, how should I feel during and after the workout? In general, “You should feel like you are working hard during the 30 minutes,” says Gatlin. “Your heart will be pumping, the glutes and hamstrings will be activated, and you will be breathing in a challenging manner.”

You may also notice some soreness in the following 24 to 48 hours after your workout, says Gatlin. This is normal and actually a good thing. It’s a sign your body is adapting, and after a few weeks of consistency, you’ll notice major strength gains and improve cardio endurance, she adds.

In case you’re looking for a reason not to try 12-3-30, I gotchu. “I don’t think there’s anything wrong with this workout,” Gott adds. “But, it is very repetitive and it’s very steep.”

Bottom line: The 12-3-30 workout can be an effective low-impact cardio and resistance workout. “Anything that gets people moving is a great thing,” McGhie points out—just remember to go into it gradually.

Headshot of Andi Breitowich

Andi Breitowich is a Chicago-based writer and graduate student at Northwestern Medill. She’s a mass consumer of social media and cares about women’s rights, holistic wellness, and non-stigmatizing reproductive care. As a former collegiate pole vaulter, she has a love for all things fitness and is currently obsessed with Peloton Tread workouts and hot yoga.  

Related posts