If you’ve been on TikTok, you’ve likely heard of the 12-3-30 workout. It’s a viral treadmill workout that social media users claim has completely transformed their fitness routines and bodies. But does it live up to the hype? We tried it for a week to find out.
Fitness fads come and go (think: Crossfit or hot pilates), but there’s one workout that has stood the test of time: walking. In fact, walking saw a major resurgence in popularity in light of the pandemic, as gyms closed down and at-home equipment became extremely difficult to get. And it doesn’t seem to be going anywhere any time soon.
But there’s more to this form of exercise than convenience. Walking has some serious health benefits, according to experts. Studies have found that walking can ease depressive symptoms, combat cognitive decline, and can help with weight loss.
It’s no surprise, then, that walking workouts have been trending all over TikTok. One workout, in particular, has gotten everyone’s attention: The 12-3-30 workout. All you need is walking shoes, a treadmill, and an awesome workout playlist.
I tried the 12-3-30 treadmill workout for a week to see if it really lives up to the hype. Plus, I spoke to personal trainers about why there’s more to this workout than meets the eye.
What Is the 12-3-30 Workout?
TikTok’s 12-3-30 workout is a walking workout based on the treadmill. To do the workout, set the treadmill to an incline of 12 and a speed of three and walk for 30 minutes. Sounds simple right? But that high incline makes it tougher than it sounds.
Emmy Cook, NASM-certified personal trainer, says given the intensity of the workout, weight loss is a possible outcome of trying it. “Increasing your daily movement can put you in a caloric deficit, which helps promote weight and fat loss,” she says. “As always, consistency matters.”
My Experience Doing the 12-3-30 Workout for 7 Days
I’m not going to lie: When I first heard about this challenge, I was skeptical. Just 30 minutes of walking didn’t seem like it could be as effective as intense HIIT cardio classes or running miles and miles on end. (And spoiler alert: It may not be, but that doesn’t mean that walking shouldn’t be part of your exercise routine, or is a good starting point.) As a former swimmer, I’m used to workouts taking a long time (think: two to three hours), so 30 minutes didn’t seem like enough time to get a good workout in.
But I was wrong. Despite hiking regularly and walking 10,000 steps a day, I found myself struggling with this workout initially. My legs were burning during the first few sessions, and I found myself constantly checking the clock hoping the 30 minutes were up.
I did it every day for seven days straight, which Gray says is perfectly fine. “Depending on your ability level and injuries, this workout can absolutely be done every day,” she says. “However, if someone is newer to fitness, it might be a shock to the system, so starting out with three days a week and allowing recovery days in between will be helpful to keep them consistent as their body adapts to this new way of training.” After about two weeks, reevaluate to see if anything needs to be decreased or increased.
If you’ve already got an established gym routine (specifically resistance training or weightlifting), Cook says you can also tack this on—just leave it until the end. “I think 12-3-30 is a perfect way to end a weightlifting workout a few times a week to get in some heart-healthy cardio and accelerate fat loss if that’s your goal,” she says.
My 12-3-30 Results
To be completely honest, the first two workouts were tougher than I expected. I was out of breath and the back of my legs were burning. (That 12 percent incline is no joke!).
After the fact, the back of my legs were noticeably sore after the first few workouts, but that went away as the week continued. Throughout the week, I learned that recovery is a big part of staying on top of this workout. I made sure I got plenty of rest, stayed hydrated throughout the day, and fueled my body with protein, carbs, and veggies. (To make sure I was getting enough protein in, I followed up my workouts with a smoothie using HUM Nutrition’s Core Strength is a plant-based protein powder made with 20 grams of protein and 22 amino acids to promote lean muscle mass.)
It worked: I really do feel a difference after one week of 12-3-30. The biggest change? A noticeable improvement in my endurance. I’m able to keep my breathing under control the entire time, and that burning sensation in the back of my legs has subsided into something milder. The 30-minute time frame seems completely doable—I no longer wish for the time to speed by. In fact, I’ve started to look forward to my 30-minute strut on the treadmill.
I noticed this improvement outside of the gym, too. On my hikes, I wasn’t getting out of breath as easily, and I was able to keep my heart rate and breathing steady. Plus, I felt like my legs weren’t getting as tired as quickly on the steep parts of the trails.
I normally walk outside for exercise to reap the myriad of benefits of being out in nature (such as increased creativity and decreased stress). I missed out on those benefits with this treadmill workout, but you could easily do a similar walking workout outside. Just try to walk uphill for as much of it as possible. While I personally prefer being outside to being in a gym, I think this popular workout is worth a trip indoors.
After just seven days, I didn’t see the jaw-dropping physical transformation so many TikTokers have. One week simply isn’t enough time to see a huge difference in your body. But my legs did look a little more toned, and they felt stronger as the week went on.
Personally, I don’t think 30 minutes would be enough for me after a couple more weeks, so I would try adding more time or adding in different kinds of workouts (such as weight lifting, HIIT, or yoga) to add on to all the benefits of my trusty 12-3-30. That said, this workout has tons of benefits.
Health Benefits of the 12-3-30 Workout
It’s Low Intensity
One of the best parts of this viral workout is that it’s an approachable way to introduce exercise into your routine, whether you’re a beginner or just getting back to exercise after a hiatus. “Low-intensity cardio is an important part of a well-rounded workout regimen, and has a lot of benefits relating to heart health, improved mobility, and potential fat loss if that is part of your goal,“ Cook says.
It’s Easy on Your Joints
The low-impact nature of the workout is great especially if you’re worried about getting hurt. Walking has a much lower risk of injury than interval workout classes or straight-up running. That means walking is a form of exercise that can work for almost anyone—no matter age, fitness experience, or past injury. In fact, it’s a great option for those who have injured their knees in the past (like me), or if you have a condition like arthritis.
It Improves Your Endurance
The workout involved 30 minutes of cardio, which means it’ll help to improve your overall endurance too. “It’s great for improving cardiovascular and muscular endurance due to the amount of time at a steady state,” explains Danielle Gray, NASM-certified personal trainer and founder of Train Like A Gymnast.
It Increases Your Strength
Yes, you can get stronger walking on the treadmill. Gray says this is a great option for strengthening all kinds of muscles. “It not only strengthens your muscles with the incline, but it also works the stabilizer muscles that keep you balanced,” she says.
It Improves Your Workout Consistency
The biggest key to any fitness routine is consistency. Gray says one of the best parts of this workout is that it only requires 30 minutes of the day. “The 12-3-30 workout is great for busy people who know that the workout will only take them 30 minutes of their time so they have a goal to reach within a certain amount of time,” she says. “It also can help improve mental toughness by forcing you to be resilient and commit to the entire workout.”
I particularly loved how approachable this workout was. On days I really didn’t want to go to the gym, I told myself all I had to do was walk for 30 minutes. When I was done, my heart was pounding, I was sweating, and I felt so much better. Elle Woods was right: Exercise really does make you happy. And doing a form of exercise you enjoy and that is sustainable (like walking for 30 minutes) is key to remaining consistent with it.
Are There Any Risks Involved in the 12-3-30 Workout?
As with any workout, there are risks of injury involved (although they are much lower than other kinds of exercise). “The risks I see for trying the 12-3-30 workout would be that no workout is a one size fits all: Everything is dependent on certain factors to ensure someone is safe,” Gray says. For example, if someone has a knee issue, the incline might exacerbate or irritate an injury. Additionally, Gray says if someone is on blood pressure medication and shouldn’t get their heart rate above a certain level, they should proceed with caution.
“Make sure you are always cleared by a medical professional for the kind of exercise you want to try, especially trends on TikTok,” Gray says. “Social media influencers are not doctors. Some are, but not even certified personal trainers like myself are medical professionals.”
So, what’s the fix? Adjusting the workout to fit your personal needs, Cook says. “If you end up feeling joint stiffness or other joint pain, knock down the incline and speed,” she says. “It should feel challenging, but manageable enough that if you were to participate in a conversation with someone while walking, you’d feel fairly out of breath but could still keep chatting comfortably enough.”
The Takeaway
The overall consensus? This workout works. It’s great for beginners and die-hard gym rats alike—and it’s something you can actually fit into your schedule (even on your busy days). It even gets the sign-off from personal trainers: “I’m generally not a fan of viral workouts, but 12-3-30 makes it onto my list as a reasonable and achievable workout to incorporate into your week as much as is enjoyable to you,” Cook says.
Plus, it’s so much fun. Don’t believe me? Grab your headphones, push play on your music, and try it out.
