What's the deal with 12/3/30?

A viral workout challenge that actually has roots in science, and one of the only TikTok trends that I'll recommend!

The concept is simple- walk on a treadmill at 12% incline, at a speed of 3 mph, for 30 minutes a day to lose fat. It seems almost too good to be true, which might be why it's one of the biggest fitness trends on social media. This *can* definitely work, and here's why- for many people, this speed and incline is a perfect "light to moderate" cardiovascular output, or a 4-6/10 on a 1-10 effort scale.

This means your heart rate will be sitting in that "Zone 2" sweet spot, somewhere around 70% of your maximum heart rate. You'll be breathing quickly, but should still be able to chat with your friend on the treadmill next to you, and should be able to continue on well past the trend's 30 minute suggested timeline if you wanted to. So what's so special about this "Zone 2"? Zone 2 effort levels are where the body gets really good at burning fat for energy, not just during the exercise itself, but as a long term adaption. It's also the best zone to improve mitochondrial health, which in term promotes metabolic function- in other words, your heart and body will work better, metrics such as resting heart rate and calories burned at rest will improve, you'll decrease your risk of cardiovascular disease, and you'll live longer. So why did I say it *can* definitely work? Remember that when it comes to weight loss, your food intake will be the main driver in helping you lose weight, while exercise is there to help you keep it off, and keep your body healthy and thriving. It's very easy to cancel out the calorie burn of 12/3/30 with just a few extra snacks throughout the day. So is 12/3/30 right for you? It absolutely can be, especially on your off days or recovery days between strength training sessions, or to be done after a strength training workout. 30 minutes is by no means the maximum amount of time you need to do; however, I would try to make 20-30 minutes the minimum amount of time spent walking.

In addition, if you find that 12% incline and/or 3 miles per hour is more than a "6/10" on the effort scale, just decrease either or both- they are just arbitrary suggestions, not magic numbers. Work with what feels best for you!