The Mistake Fitness Experts Say People Make With The 12-3-30 Treadmill Workout

While it’s easy to dismiss the 12-3-30 workout as another fleeting fitness trend, don’t knock it until you try it.

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 it’s 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.