The 12-3-30 treadmill workout gained popularity a few years ago, when influencer Lauren Giraldo credited it with helping her lose 30 pounds. If you’ve been living under a fitness rock, so to speak, the workout involves setting your treadmill to an incline of 12%, at a speed of 3 miles per hour, and walking for 30 minutes. I tried it for a month, and found it to be a great, low-impact workout, but as a marathon runner, it couldn’t replace the joy I get from a slow, steady run outdoors.
Fast forward a few years, and researchers have looked into the workout and how it compares to running. It turns out Giraldo wasn’t wrong — according to the study, published in the Journal of Exercise Science, the incline treadmill workout burned more fat than running did.
