Have you tried the 12-3-30 treadmill workout challenge that has taken TikTok by storm, racking up more than 14 million views? If not, you’re about to see why fitness lovers can’t stop talking about it. This low-impact, fat-burning treadmill craze is shaking up the cardio world — and it might just make running feel a little overrated.
Here’s the scoop: the 12-3-30 method is simple but intense. Walk at a 12% incline, three miles per hour, for 30 minutes. No sprints, no jumping jacks, just a steady climb that gets your heart pumping and your legs burning.
But can walking on an incline really beat running? Science says… maybe.
What the Research Found
A peer-reviewed study in the International Journal of Exercise Science put 16 healthy young adults to the test. Participants completed two workouts: a 12-3-30 session and a treadmill run at a pace they could sustain for 20–25 minutes. Both workouts were calibrated to burn the same total calories, ensuring a fair comparison.
Running burned calories faster — roughly 13 calories per minute versus 10 calories per minute for 12-3-30. Certified personal trainer Maelee Wells Sutton explains, “It’s no shocker that higher-intensity cardio burns calories faster.”
Here’s the kicker: while running relies more heavily on carbs, 12-3-30 tapped into more fat for fuel — about 41% of energy came from fat compared to 33% during running. So if your goal is to prioritize fat burning without punishing your joints, this incline walk might actually give running a run for its money.
Who Should Try It
The study participants were already exercising at least three times a week, so the results may vary for beginners. Sutton adds, “We can’t draw conclusions about how less active individuals may respond, which is a big chunk of the population.”
Even so, the 12-3-30 method offers clear perks:
- Low impact: kinder on knees and joints than running.
- Beginner-friendly: less intimidating than high-speed sprints.
- Fat-focused: encourages the body to burn fat for energy.
If pounding the pavement isn’t your thing, walking on an incline is a strong alternative that still delivers results.
Running vs. 12-3-30: Which Should You Pick?
If you’re short on time and want to burn calories fast, running wins. But if you want a joint-friendly, fat-burning workout that’s easy to stick with, the 12-3-30 treadmill challenge is worth trying. The golden rule? Consistency beats intensity.
Sutton advises, “Pick a workout you actually enjoy. If you love 12-3-30 and hate running, stick with the incline walk. Doing it consistently will get you farther than forcing a workout you dread.”
Bottom Line
Fitness trends like the 12-3-30 challenge are fun, viral, and backed by some science — but they’re not magic. Focus on what you enjoy, what works for your body, and what you can do consistently. Your results will thank you.
