What Is the 12-3-30 Workout - and Does It Really Live Up to the Hype?

When I first heard about the 12-3-30 workout - a nickname for the viral 30-minute treadmill incline walk sweeping the internet - I was only mildly intrigued. I generally prefer walking in the quiet, hilly woods near my house with my dogs since it's a great workout and essential for my mental health. But when the weather doesn't cooperate, the 12-3-30 method seemed like the perfect indoor option. Not to mention, it's a constant trend on social media: videos detailing 12-3-30 results continue to rake up millions of views on TikTok alone. All you need to get in on the trend is a good treadmill and a little motivation.In essence, 12-3-30 is a simple (and walkable) alternative to high-intensity cardio, helping people stay consistent and motivated. Plus, the results speak for themselves. "It is way harder than it sounds, trust me, you'll be dripping sweat by the end," promises content creator Ava Vescovi after sharing her before and after transformation. Curious to see how well the treadmill incline workout holds up IRL, I decided to see what all the fuss is about.Experts Featured in This Article: Nicole Rodriguez, is a registered dietitian and NASM-certified personal trainer.What is the 12-3-30 Workout?12-3-30 is a 30-minute treadmill incline workout where the incline is set to 12 percent and the pace is set to three miles per hour. Yes, it's really that simple. Influencer Lauren Giraldo first introduced the 12-3-30 workout on YouTube in 2019, but it didn't become popular until Giraldo posted a TikTok about it in late 2020, crediting it for helping her lose 30 pounds and keep it off for two years. The workout has since gone viral, but it's also withstood the test of time. People all over social media are calling themselves "12-3-30 girlies," sharing their love for the workout, how they've modified it, and their own 12-3-30 results. From the outside looking in, it might seem like an unassuming cardio routine, but the simplicity of 12-3-30 has fostered a sense of community and helped the gym seem less intimidating for many. 12-3-30 Workout BenefitsSocial media users love 12-3-30 because it's straightforward - no interval timer or further instruction needed. It's a challenging yet low-impact workout that makes cardio a little less painful, and it comes with plenty of benefits. In fact, the 12-3-30 workout gets your heart rate up as much as a jog, without the additional impact on your joints, making it great for cardiovascular health. Additional research shows that this kind of incline walking may even help strengthen the knee joints.The steep, 12-percent incline makes your body work harder than walking on a flat surface, explains registered dietitian and NASM-certified personal trainer Nicole Rodriguez. This gets your heart rate up and places more demand on your body, forcing it to expend more energy. For example, a small 2012 study found that the metabolic cost (AKA calorie burn) of walking increased by 17 percent when set at a five-percent incline, and by 32 percent when set at a 10-percent incline when compared to walking on flat ground.The 12-3-30 workout also has muscle-building benefits: that same 2012 study found that incline walking increases activation in many lower body muscles. Specifically, walking on an incline strengthens your glutes, quadriceps, hamstrings, and calves more than walking on a flat surface.12-3-30 Workout RisksAll workouts come with some level of injury risk, and the 12-3-30 workout is no different. "I would deem this safe with physician's clearance," Rodriguez says. That said, if you're struggling with knee pain or injuries of any kind, this workout may not be right for you.To help prevent injury while incline walking, experts at Texas Health recommend keeping your posture in mind: stand up tall, engage your core, and avoid slumping forward or leaning your weight onto the handrails.The 2012 study found that adding an incline changes your walking gait, so your muscles may not be ready for this movement if it's completely new to you. If you're a beginner to steep incline workouts, you should ease into it to avoid injury or strain on your muscles. Doing too much too soon can put you at risk of an overuse injury (when tissue is damaged due to repetitive demand), according to the Hospital for Special Surgery. It's best to gradually build up the incline and speed at your own pace.12-3-30 Workout ResultsI decided to try the 12-3-30 workout for two weeks, doing the workout five times a week, per Giraldo's recommendation. I wanted to see how this incline workout compared to my usual HIIT workouts, running, and rowing. Could a walking workout really be as effective? Keep reading to hear about my 12-3-30 workout results.