What is the 12-3-30 workout? Fitness experts explain how to do the walking for weight loss routine

The 12-3-30 workout was made famous by social media star Lauren Giraldo

Woman doing the 12-3-30 workout on treadmill in the gym
(Image credit: Getty Images)

The 12-3-30 workout was made famous by influencer Lauren Giraldo as a simple treadmill workout that's highly effective for fat loss, as well as being a great alternative to running for anyone looking to build their cardiovascular fitness. 

Social media star Lauren became a fitness sensation after sharing this 30-minute treadmill routine online - and it couldn't be easier to recreate at home or at the gym. The key principle of the 12-3-30 fitness routine, which originally appeared on TikTok, is swapping treadmill running for incline walking. 

Lauren Giraldo (opens in new tab)rose to fame as an actress in her teens, but the vlogger really started making waves in the fitness world after sharing exercise videos online. The star's 12-3-30 TikTok video was a viral hit, shared by more than 2.7 million people, with followers raving about the results. Talking about the workout online, Lauren says, "I used to be so intimidated by the gym, and it wasn’t motivating. But now I go and do this one thing, and I can feel good about myself." 

The 12-3-30 workout is a great plan for anyone who wants to start walking for weight loss or try walking as a workout. But is it really worth all the hype and why is this exercise so effective? We asked the fitness experts about the benefits of the 12-3-30 workout and how to get the most out of it. 

What is the 12-3-30 workout?

The 12-3-30 workout by Lauren Giraldo is a very simple concept. Lace up your trainers, hop on a treadmill, adjust your gradient/incline to 12 and speed to 3mph, and set a timer for 30 minutes on your pick of the best Fitbits or on the treadmill machine. 

You'll then walk for 30 minutes at the same incline and speed. During that time you can listen to your favorite podcast, watch a Netflix show, or tune into an audiobook as your stroll. If you want to give it a try, all you'll need is access to a treadmill, a spare half an hour, and a pair of the best running shoes to get started.

To do the Lauren Giraldo treadmill workout you should: 

  1. Warm-up with a brisk walk for five minutes 
  2. Turn the incline on the treadmill to 12
  3. Turn the speed to 3 mph (4.8kmph)
  4. Walk for 30 minutes
  5. Cool down with five minutes walking on the treadmill at 0 incline 

Unlike HIIT treadmill workouts, there are no intervals or changes of pace. You move at one speed at one incline level for the whole workout. While it may not be easy for many people, especially after the first 10 minutes, three miles per hour is an average walking pace on a flat surface, so it an achievable goal for most. Although, of course, it all depends on what level of fitness you start with. Lauren herself gradually worked up to a full 30 minutes but she took frequent breaks at the beginning.

Watch how to do Lauren's treadmill workout: 

Why the 12-3-30 method is great for women of all ages

Lauren Giraldo is only in her 20s, but the 12-3-30 workout is also a must-try for anyone embarking on a new journey into fitness. In the walking vs running debate, we're often reminded that running can be tough on joints. As we age, we naturally lose bone density, but doing the 12-3-30 workout and strengthening your muscles and bones can combat this natural loss and reduce the risk of osteoporosis without putting pressure on joints in the way that running does. 

If you're returning to exercise after some time away, it's a great strength training workout for building up your fitness levels again. You can start at a lower gradient and pace to take things at a speed that feels comfortable for you to begin with, or make it harder for yourself by adding ankle weights and take it up a notch. 

Plus, for those who normally aren't fans of cardio-based workouts like running or spinning because of the intense 'out of breath' feeling, walking on a treadmill at an incline could be a great fitness solution. The 12-3-workout is a form of LISS cardio, which means you're going for longer at a slower pace. Much like swimming or Nordic walking, it's a gentler way to get your heart rate up and improve your cardiovascular health.

How to start the Lauren Giraldo treadmill workout

To get started, you could reduce the incline to 3 or 4 and challenge yourself to hold the pace for as long as possible. Then, when you feel ready to do so, build up your time and gradient as you get fitter and stronger. The speed at which you progress will be different for everyone, so don’t compare yourself - work at the level that’s right for you. It should feel challenging, but not so much so that you don’t want to do it again. 

It's also important to maintain good form as you walk. Engage your core, keep your shoulders back and your head up. Always look straight ahead, rather than down at your feet on the treadmill. 

Health Editor Grace Walsh doing the 12-3-30 workout at the gym

(Image credit: Grace Walsh / Future)

If you're new to treadmill workouts and find the gradient or speed daunting, adjusting the intensity is a good idea. "Adapt the gradients and paces for your level and consider breaking the 30 minutes up into intervals with short rests, and building up to 30 minutes over four to six weeks if you're a total beginner,” suggests athletics coach Tom Craggs (opens in new tab)

Walking coach and author of Walk Off Weight (opens in new tab), Michele Stanton, agrees. She tells woman&home: "Your muscles work harder as you increase the incline, so starting at a high incline without acclimating your body could leave you feeling sore or even injured. A high include stretches the calf which tends to be tight for a lot of people."

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

1. It builds fitness and stamina

It is certainly a good workout for building fitness. "The treadmill isn't all about running. Power walking on the flat or even hills can provide a great workout, often with less impact on joints," says Craggs. "A 30-minute walk with a high gradient such as 12% working at a strong steady intensity will certainly get your heart rate up, be a test for your posture and work your core muscles with a good ab workout - and you will also have to engage and drive with your glute muscles to maintain your position on the treadmill belt."

2. It aids weight loss

For those looking to walk for weight loss, the 12-3-30 workout offers so many benefits. Firstly, unlike running or more intense cardio activities, you could do this every day thanks to the joint-friendly movement and slower pace. This means you'll be burning more calories over time and it's mostly about calories in versus calories out when you first start losing weight. Reducing the number of calories you consume while burning more - through low-impact workouts like these - will put you in a calorie deficit for weight loss

The 12-3-30 workout could help you lose weight even if you just do it once a week. One of the top reasons many people stop working out is boredom, a study by the University of Konstanz (opens in new tab) highlights. If you're doing other forms of exercise doing the week and you're looking for something to spice things up a little by the weekend, this workout could be just the thing. 

3. It helps you lose belly fat

If you want to know how to lose belly fat, Lauren Giraldo's treadmill workout could be the answer - alongside changing your diet. While it's not possible to spot-reduce fat, by doing the 12-3-30 workout three times a week you can really improve your cardiovascular fitness and burn calories, alongside working your core and glutes. Walking uphill also has a strength training element that will help to build muscle. 

You will also use your back muscles more than you might expect, which can help build strength in this often-neglected area. Though, for the same reason, anyone who suffers from upper and lower back pain should be careful when walking at this incline continuously for 30 minutes. 

4. It improves heart health

Experts from the Mayo Clinic (opens in new tab) credit aerobic exercise as having a key role in helping to keep your heart healthy. It will not only lower your blood pressure and heart rate, reducing your risk of heart disease, but it will help pump blood more efficiently around the body.

The 12-3-30 workout is a great aerobic exercise. It will get you breathing and your heart rate up as you walk at a brisk pace on the incline but, as mentioned, it will also be kind to joints because of its low impact nature. 

12-3-30 verdict - is it worth the hype? 

Yes, walking is great for your overall health and by doing the 12-3-30 workout, which adds an incline, you'll be forced to work a little harder - activating more muscles in your body and pushing your cardiovascular system harder. Although 3mph may be an average walking pace on flat ground, with the incline it will certainly get your heart rate up and you’ll likely break out in a sweat. 

That being said, a good exercise program should involve variety. Using the same muscles every day in the same workout can grow mentally stale after a while and while the 12-3-30 workout is a good introduction to strength training, you'll need a little more than this to truly reap the benefits. If you really enjoy the 12-3-30, it's a good idea to mix it up with easy weightlifting exercises and other forms of cardio at the gym, such as the bike or elliptical machine.

As Stanton points out, “Your posture may suffer if you push yourself hard from the beginning, especially if your core isn't strong, and this can lead to back pain. You'll get better results from exercise if you do it consistently, so building up gradually is a better approach to creating a long-term exercise habit and getting the results you desire.”

Grace Walsh
Health Editor

A digital health journalist with over five years experience writing and editing for UK publications, Grace has covered the world of health and wellbeing extensively for Cosmopolitan, The i Paper and more.

She started her career writing about the complexities of sex and relationships, before combining personal hobbies with professional and writing about fitness. Everything from the best protein powder to sleep technology, the latest health trend to nutrition essentials, Grace has a huge spectrum of interests in the wellness sphere. Having reported on the coronavirus pandemic since the very first swab, she now also counts public health among them.

With contributions from