Chances are you’ve come across the “12-3-30 workout” on social media, or maybe you’ve caught a glimpse of someone doing it at your local gym. Created by social media influencer Lauren Giraldo, what’s now known as the 12-3-30 workout method has swept across the internet and made its way onto treadmills everywhere, with fans of this specific exercise format praising its ability to boost endurance, get them sweaty, and increase cardiovascular fitness, among many other benefits, without raising the treadmill speed above 3 miles per hour. We asked fitness experts for the scoop on how to do this workout, its health benefits, and whether it’s safe for anyone to add to their exercise rotation.
What Is the 12-3-30 Workout?
Health and beauty influencer Lauren Giraldo introduced TikTok to her 12-3-30 workout in 2020. It’s a walking treadmill workout where you set the machine at an incline of 12 percent, leave the speed at 3 mph, and walk—or really, hike—for 30 minutes.
12-3-30 is categorized as a low-intensity steady state cardio workout (LISS), says Charlee Atkins, certified strength and conditioning specialist and founder of Le Sweat. But there’s nothing easy about this low-impact, high-rigor workout. Walking uphill at that speed and for that long requires a lot of endurance and will really get your heart rate up.
Trust me. The first few times I attempted this trendy workout setting, I found myself more out of breath than I’ve ever had on a run. This is probably because “it can be classified as a full body workout,” says Lauren Leavell, certified personal trainer, group fitness instructor, and owner of online fitness company Leavell Up. “For most people, it’s getting them into a cardio zone for their workout. So they’re getting in their steps and cardio, which is beneficial