An Exploratory Study Comparing the Metabolic Responses between the 12-3-30 Treadmill Workout and Self-Paced Treadmill Running

Abstract

The fitness movement in the United States has evolved substantially since its emergence in the late 20th century, with social media platforms like YouTube and TikTok now playing a pivotal role in disseminating fitness programs and associated claims. One program that has gained considerable popularity is the 12-3-30 treadmill workout (12-3-30), which involves walking at a 12% grade at 3 mph for 30 minutes. Despite widespread claims about its effectiveness in burning fat and calories, there is a lack of peer-reviewed scientific studies evaluating these claims. The present study investigated metabolic responses to 12-3-30 compared to self-paced treadmill running, with both sessions matched for total energy expenditure. Sixteen participants (7 female, 9 male) completed both sessions in a controlled laboratory setting, where metabolic data were collected using a metabolic analyzer. The measures recorded were completion time, total energy expenditure, energy expenditure rate, and substrate utilization (percentage of carbohydrate [%CHO] and fat [%FAT]). The results showed that, when matched for total energy expenditure, 12-3-30 had a significantly longer completion time, lower energy expenditure rate, higher %FAT, and lower %CHO than self-paced running. While 12-3-30 may be less time efficient than self-paced running for expending energy, it may be more advantageous for individuals aiming to increase fat utilization. The present study enhances our understanding of the metabolic demands associated with a trending fitness program and highlights the importance of scientifically evaluating such programs to provide evidence-based recommendations.

Keywords: Aerobic exercise; exercise intensity; fitness influencers; incline walking; metabolic cost; submaximal exercise.