In today’s episode, you are going to learn why running a mile burns more calories than walking a mile. Plus, you'll learn how to burn more calories in your own exercise, even if you’re not a runner.
In “Does Running Or Walking Burn More Calories?” I introduce a question my exercise physiology professor posed to my class when I was studying exercise physiology at University of Idaho. He asked: if a person runs one mile, do they burn more calories than if they had walked that one mile? Technically, the answer is no. According to physics, if all you're moving is your body weight, and you're traveling by foot, you burn the same amount of calories getting from point A to point B, no matter how fast you get there.
However, the true answer is actually more complex. And in today’s episode, you are going to learn why running a mile burns more calories than walking a mile, and how you can use this to burn more calories in your own exercise, even if you’re not a runner.
Excess Post-Exercise Oxygen Consumption (EPOC)
To understand why running burns more calories than walking that same distance, you need to know about something called excess post-exercise oxygen consumption (EPOC). When you run, you consume more oxygen than when you walk because you’re moving more muscles at greater contractions and faster paces when you run, and this means that after you finish running, your body has to pay back that oxygen “debt” by consuming more calories for several minutes or hours after you finish running. That is a "metabolic-boosting" effect that exercise scientists call excess post-exercise oxygen consumption or EPOC (incidentally, the hormonal fat-burning response to running is also greater compared to the hormonal fat-burning effect of walking). So while both walking and running burn the same amount of calories during the actual exercise, running continues to burn far more calories after you're done!
A recent study at San Diego State University entitled “Comparison of measured vs. predicted energy expenditure during 2h of work and rest” looked into exactly how much more energy you burn when you account for EPOC. The purpose of the study was to compare the predicted caloric cost of two hours of exercise and post-exercise time to the actual caloric cost of that exercise.
In the study, ten subjects performed 2 hours of exercise on a treadmill using six different work to rest cycles:
1) 3.0 mph,1.7% grade; 30 min rest, 30 min work
2) 3.5 mph, 3.8% grade; 20 min work, 40 min rest
3) 3.0 mph,1.7% grade; 30 min work, 30 min rest
4) 2.5 mph, 1% grade; 40 min work, 20 min rest
5) 2.0 mph, 1% grade; 50 min work, 10 min rest
6) 1.5 mph, 1.7% grade; 60 min work, 0 min rest
The measured calorie burn for protocols 1 and 6 were not significantly different than predicted. But for protocols 2 through 5, the measured calorie burn was significantly greater than predicted—about 7-15% higher than what would be predicted from metabolic equations found in exercise science manuals! In addition, the measured resting calorie burn was significantly higher than the predicted values by 24-46% for protocols 2 through 5.