Run, Don’t Walk – The Truth About Walking Versus Running
By Rick Morris
A line has been drawn in the sand. We are squaring off – choosing up sides. A major battle is beginning. Well….maybe not. But there is a debate going on in the world of exercise concerning walking vs running. For years fitness enthusiasts have believed that walking and running burned the same number of calories per mile. This old school thinking says no matter what speed we move, we are expending around 100 calories per mile when moving over level ground. If you crawled 1 mile you used up 100 calories. Did you just sprint a mile? You still burned 100 calories. We believed this because it is what we have been told for years and years. Since we have been told this for so long it must be correct, right? Not necessarily.
The study of exercise and human movement is just like any other science. It is a work in progress. We are always discovering new information that makes some accepted beliefs outdated. Don’t forget we used to think the world was flat. Aristotle dispelled the myth of a flat earth. This confusion over calories can be blamed on Sir Isaac Newton. It is Newtonian physics that shows it takes a specific amount of energy to move a specific mass a certain distance. In other words, physics tells us that it takes the same number of calories to move your body one mile no matter how fast you are moving.
According to science, the old school is correct. But wait… not so fast. The new school proponents believe that running burns more calories per mile than walking. A recent study seems to support the new school train of thought. Researchers at Syracuse University conducted a study in December of 2004 for the purpose of comparing the energy expenditure of walking and running with equations that predict energy expenditure. As a part of that study the researchers needed to determine whether differences exist in energy expenditure of walking versus running.
The researchers measured the calorie burn of 12 male and 12 female subjects as they both ran and walked for 1600 meters on a track and a treadmill. Each subject ran at one specific pace and walked at one specific pace. The scientists, headed by Jill A. Kanaley, PhD in the Department of Exercise Science, found that the women expended about 105 calories while running versus only 74 when walking. The men had similar results of 124 calories when running compared with just 88 calories burned while walking. (Med Sci Sports Exerc.2004 Dec;36(12):2128-34).
That seems like a big difference, but it is actually even larger. To get the true number of calories burned from exercise, you must subtract the calories you would have consumed at rest. After taking away those “resting” calories, the net calorie burn for the women was 91 running versus 43 walking. For the men the net calories burned was 105 running versus 52 walking. So, in reality, the subjects were burning more than twice the calories when running versus walking.
It would be nice if the answer to the calorie confusion question was that easy. But let’s take a closer look at this study. The subjects in this investigation walked and ran at only one pace. They walked at 1.41 meters per second and ran at 2.82 meters per second. At those specific paces, the subjects did average twice the calorie burn while running. But does that result hold up at all walking and running paces?
Another study showed that it does not. This study was conducted by the Washington University School of Medicine for the purpose of investigating the energy expenditure and perceived exertion levels of walking and running at various speeds. The subjects each walked for 5 minutes at various paces ranging from 4 to 10.4 kilometers per hour and ran for 5 minutes at paces from 7.2 to 10.4 kilometers per hour. This study concluded that walking burns more calories than running at speeds greater than 8 kilometers per hour (5 miles per hour). The study also showed that walking felt harder than running at speeds over 5 miles per hour. (J Sports Med Phys Fitness. 2000 Dec;40(4):297-302).
So, who is right? Does the old school thinking still hold up or is the new school correct? The answer is that both are right! Before you get mad at me for giving you a non-answer, please read on. Generally speaking, running does burn more calories than walking. Why is that? That is a very good question with a fairly simple answer. When we walk or run, each stride results in some impact force as our lead foot strikes the ground.
The mechanics of running and walking are very different. When walking we always have one foot on the ground. Our body weight is always supported. Each stride results in a force equaling our body weight being applied to our leg muscles. If you weigh 150 lbs. each stride places about 150 pounds of load on your leg. Running is very different. When running you are completely airborne between foot plants. When your lead foot comes down, it is absorbing more than your body weight due to the effects of gravity.
The force placed on your leg muscles with each running stride will vary depending upon how fast you are running. When you run faster your stride becomes longer. A longer stride equals more force with each stride. The impact for each stride will vary from 1.5 times to over 4 times your body weight, depending upon your speed. It requires many more calories to absorb these much higher impact forces and to propel yourself with the next stride.
In most cases running burns more calories than walking, but when walking at increasing paces you eventually reach a point at which the walking becomes more difficult than running. That point is called the preferred walk-run transition speed (PTS). It is at this point that walking begins to burn more calories than running. The study from Washington University showed that this point occurs at approximately 5 MPH. However, this will vary slightly depending upon your fitness level and how efficient you are at walking and running.
One of the predictors of running performance is running economy. This is simply a measure of how efficient you are at running. If two runners of equal fitness levels were running a race, the runner that is the most efficient will win. That is because a more efficient runner is able to run faster with less effort. Running with less effort means you are burning fewer calories. A more efficient runner would probably reach the walk-run transition speed at slower speeds than a less efficient runner.
The bottom line is that the number of calories burned during walking and running is not a static number. It is a dynamic measure that will increase as your speed and effort level increases. Each of us will have a preferred walk-run transition speed (PTS). Running at speeds slower than your PTS will feel harder and will burn more calories than walking. Walking at speeds faster than your PTS will feel harder and will burn more calories than running. The average PTS is about 5 MPH but your individual PTS will depend upon your fitness level and your walking/running efficiency. Your calorie burn per mile will increase as you accelerate at speeds faster than your PTS.
As you can see, the answer to the question of calorie confusion is that both sides are correct. There is a point at which the calorie burn per mile of walking versus running is equal. There is also a level at which walking burns more calories per mile than running. But, at speeds of 5 MPH or faster, running will burn more calories per mile than walking. It is very difficult to estimate your exact level of calorie burn per mile without expensive laboratory analysis. In order to simplify things you will always get a fairly close estimate of your calorie burn by using the old accepted equation of 100 calories per mile. It will not be exact, but it will be close and easy.
1000 Calorie – Fat Burning Workout
Here is a great workout that will burn off those excessive holiday pounds. This workout incorporates hill training to increase your calorie and fat burn. This workout is designed for the treadmill but you can also do this workout on the roads or trail if you have the appropriate hilly terrain to run on.
- Set the treadmill elevation at 1 percent and run for one mile at your easy pace.
- Increase the elevation to 2 percent and run for one mile at your easy pace.
- Increase the elevation to 4 percent and run for one mile at your easy pace.
- Increase the elevation to 5 percent and run for one mile at your easy pace.
- Decrease the elevation to 2 percent and run for one mile at your easy pace.
- Increase the elevation to 6 percent and run for ½ mile at your easy pace.
- Increase the elevation to 7 percent and run for ½ mile at your easy pace.
- Decrease the elevation to 2 percent and run for 1 mile at your easy pace.
Total Workout Mileage – 7
Approximate Calories Burned – 1045