We spoke with personal trainers to learn all about the pros and cons of the 12-3-30 and snag expert tips on how to tailor the workout to your needs or find another one that’s a better fit. However, keep in mind these numbers are to be used as guidelines. If your treadmill incline doesn’t go up to 12%, or the speed is too fast or slow, you can adjust accordingly to suit your fitness level. The workout goal is to keep your heart rate elevated by walking at a moderate pace on an incline. The 12-3-30 workout was created by social media influencer Lauren Giraldo in 2019 when she shared it as a YouTube video. However, it wasn’t until Giraldo posted the workout on TikTok and Instagram in 2020 that it exploded in popularity. Three years later, the original YouTube video has garnered over 1.5 million views and over 49,000 likes. According to Giraldo, her treadmill routine has helped her shed 30 pounds (and keep it off for over two years) while gaining more confidence in the gym. Over 1,000 YouTube commenters have echoed her claims. They’ve also said the workout is much harder than it appears, has given them the motivation to go to the gym, and has helped them overcome gym intimidation. While these benefits are merely anecdotal, experts back some of them up. Kate Meier, CPT, a certified personal trainer with Gym Garage Reviews, tells mindbodygreen that “Walking is a great, low-impact form of cardio that comes with the benefits of any cardiovascular exercise: improving your overall fitness, burning fat, and improving heart health.” Incline walking especially works the lower body, including the glutes, quads, and hamstrings, she adds. “The 12-3-30 workout is a low steady-state cardio that benefits your cardiovascular system,” says Dan Johnston, CPT, a certified personal trainer and strength and conditioning coach. Steady-state cardio is a low-intensity exercise that you can do for a more extended period. Like other forms of cardio, it can also help you reduce stress. Though the number of calories you’ll burn walking on an incline depends on several factors—such as your age, size, and fitness level—a 2012 study published in the Journal of Biomechanics1 found that energy expenditure increased on average by 17% on a 5% incline and by 32% on a 10% incline. Translation: For a 150-pound person, every 1% increase in incline burns roughly 10 extra calories per mile over flat-surface walking. That means that doing the 12-3-30’s 12% incline, you’ll burn approximately twice as many calories as if you walked without an incline. In addition, strengthening this muscle group in your back body (known as your posterior chain) can save your lower back and reduce injury risk. Having a healthy heart is critical for several aspects of overall well-being4. For example, excellent cardiovascular health can help prevent chronic diseases5 such as heart disease, diabetes, and obesity; reduce blood pressure6; control blood sugar response7; aid in stress management8; and combat mental health disorders like depression and anxiety. Giraldo (the workout’s creator) claims to do the 12-3-30 five days a week with no other exercise. While this is good for cardiovascular health, it misses out on the many benefits of strength training and overall mobility. “Furthermore, the 12-3-30 could be too intense for people who haven’t done this type of exercise before,” says Johnston. And while incline walking can strengthen your lower body, don’t rely on it as an effective exercise to significantly target your glutes. “The 12-3-30 can be a complementary form of cardio if your goal is to grow your glutes, but I would also include plenty of glute-centric resistance training exercise into your workouts,” advises Meier. Johnston adds that people wanting to reap the benefits of low-impact steady-state cardio while putting on muscle and increasing flexibility should combine the 12-3-30 with a well-rounded strength training and flexibility program. In addition, adding variety to your workout routine is essential for optimizing fitness. “Diversifying your fitness routine is a good idea to prevent burnout and overuse injuries,” Meier says. Here’s a sample circuit workout that you can do if you’re short on time: However, there’s no easy solution or magic pill for losing weight or getting fit. For optimal results, make sure you incorporate strength training and flexibility into your fitness routine on top of doing cardio workouts like the 12-3-30 a few times per week. Adam lives in British Columbia, Canada, with his wife, two kids and an Australian shepherd. That’s where you can find him running mountain trails, working out in his home gym, or writing in a coffee shop.
