Is Walking or Running a Better Calorie Burner?
I’ve heard that you burn 100 calories per mile no matter how you do it. But it seems that running would burn more calories.
Q. My registered dietitian insists that a 150-pound person will burn 100 calories per mile, regardless of whether they walk, run or crawl. The only difference, she says, is the time is takes to cover that mile. Intuitively, this does not seem right—running should burn more calories than walking, and walking should burn more calories than sauntering. You even wrote in one of your columns on metabolism that to burn more calories you should “do more cardio or do your cardio more intensely: walk faster, run, jump and climb.” What gives?
A. You are confusing two different concepts: how to burn a certain number of calories in a given time period versus how to burn more calories regardless of the time period.
“The bottom line is to not get too fixated on exact calorie numbers.”
Before I explain, keep in mind that all calorie figures are estimates. Numbers for calories in a given food or calories burned in a workout are not going to be exact. There are differences in an individual’s intensity, weight and body mass that may affect a calorie burn that are not taken into account unless measured in a laboratory metabolic chamber. And, with food, there may be a variety of factors with ingredients, ripeness, portion size and preparation that could affect calorie count. The bottom line is to not get too fixated on exact calorie numbers.
A hundred calories is a standard estimate for the energy required to move a body a mile by walking or running. A heavier body requires more energy (hence, a greater calorie burn) to move. Yet any size body can move with greater intensity to also burn more calories (either by speeding up, walking up a hill that requires more effort, etc.). Terrain and environmental conditions can affect intensity and speed.
The slower one moves, the lower their calorie burn. The flatter the surface (flat road vs. dirt hills) or the less resistance it provides (concrete path vs. sand or wind), the lower the calorie burn.
It generally takes an average person around 15 to 20 minutes to walk a mile, and 7 to 12 minutes to run or jog that distance. Walking a little more slowly, at a 20-minute-per-mile pace, will burn around five calories per minute. Running a mile might burn from 7 or 8 calories per minute up to 10 to 12, depending upon a person’s size and speed.
The classic textbook Exercise Physiology: Energy, Nutrition, and Human Performance provides energy expenditure estimates for a variety of activities based on body weight. According to the estimates, a 150-pound person will burn 3.6 calories per minute when walking 2 mph; 5 calories per minute when walking 3 mph; and 6.6 calories per minute when walking 4 mph. So the slowest walker would burn 108 calories walking a mile (3.6 x 30 minutes); the moderate-paced walker would burn 100 calories (5 x 20 minutes); and the fastest walker would burn around 99 calories (6.6 x 15). These numbers are in the 100-calories per-mile range.
To burn more calories in a workout, what I wrote holds true: “Do more cardio or do your cardio more intensely: walk faster, run, jump and climb.” Doing more cardio means adding 10 or 20 minutes to each workout (walking or running more than one mile), working out on more days per week (walking or running more miles per week), or both.
Working out more intensely burns more calories because you cover more ground in the same amount of time. So if you speed up from walking 2 mph to 4 mph, you go from burning around 3.6 calories per minute to around 6.6 calories per minute. Therefore, in 30 minutes of walking you could double your calorie burn simply by walking faster. Of course, you should be fit enough to safely push yourself to exercise at a higher intensity. Work up to harder and longer workouts gradually so that you don’t put any excess stress on your joints while you’re trying to increase the number of calories you burn.
Do you have a fitness or weight-loss question for Martica? Send e-mail to experts@microsoft.com. Please include Ask Martica in the subject line. Each of our experts responds to one question each week and the responses are posted on Mondays on MSN Health. We regret that we cannot provide a personalized response to every submission.
Martica Heaner, Ph.D., M.A., M.Ed., is a Manhattan-based exercise physiologist and nutritionist, and an award-winning fitness instructor and health writer. She has a Ph.D. in behavioral nutrition and physical activity from Columbia University, and is also a NASM-certified personal trainer. She has written hundreds of articles for publications such as
Self
,
Health
,
Prevention
,
The New York Times
and others. Martica is the author of eight books, including her latest,
Cross-Training for Dummies.
(Read her full bio.)
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Walking is such a purge of stress. I do a nine mile track in about 1 hour 48 minutes--at least five days a week. Somedays, I am even faster--depending on how cold the weather. Best of all, there is no pain--my legs are fatigued and wobbly, but there is no injury from the pounding on the road. At 52, I am more fit than people half my age. My 75 year old mother walks three miles a day--she is super-fit as well.
I encourage everyone to take a stroll. Go "take a hike"!
If you walk at 'x' speed for 'n' distance it takes you 't' time. If you run the SAME distance 'n' at twice the speed (which would be '2x', you burn calories faster but only for HALF the time. Therefore to burn the same number of calories in the run, you have to burn calories at twice the rate since you only have half the time to do it. According to the numbers above, you don't:
--2mph burns 3.6 calories per minute
--4mph burns 6.6 calories per minute, which is NOT twice the burn rate as 2mph.
One (possible) explanation for this is that you burn some calories just living (even sitting on the couch reading this!). Call it the Life Burn factor. (I just made that up, so if someone uses it, I want my royalty check each month! jk) That happens all the time. Breathing, digesting food, brain activity... normal bodily functions. So the exercise 'E' is an additional calorie-burning event that happens over and above the Life Burn 'LB'. So let's say our exercise calculation would be:
E + LB = CB (calorie burn)
If you are walking, 'EW' is the specific additional calories burned by walking 2mph that are over and above LB. 'ER' (no pun intended!) is the specific additional calories burned by running 4mph. Let's suggest that ER = 2EW, running 4mph burns twice the specific calories as walking. But our total caloric burn is not just the exercise but the exercise plus LB, a constant. Therefore, although the running exercise portion ER is twice the walking exercise portion EW, the calcation:
ER + LB is not twice EW + LB. So that's why the article says that running 4mph does not burn calories twice as fast as walking 2mph.
Even if running a mile at 4mph did burn the same amount as walking the mile at 2mph, the pounding on your joints is MUCH greater. However, the cardio workout is MUCH greater with running, so pick your poison. Running is WAY better cardio, but walking is WAY easier on the rest of the body.
I try to split the difference: I jog a half-mile or so to get my heart rate up (thus getting the cardio benefit), then I alternate walking a block, jogging a block, etc. My heart rate stays up during that walking block, so I still get the cardio benefit. This GREATLY reduces the pounding on my joints (I'm 51), but I still get the cardiovascular benefit of an elevated heart rate. Also, I can do this for a MUCH longer distance than I could by just running, and so the TIME that my heart rate stays elevated is much increased.
Will Bee, a runner-walker.
The idea that walking burns the same amount of calories as running is a happy myth, similar to Santa. It sounds good because walking is easier and it would make us all happier to believe it. Here is why it is wrong - burning calories is more than physics (work= distance X mass). Burning calories and fat is physiological (physics, biology, and chemistry) and has more to do with oxygen requirement. It takes more oxygen to run than walk and that is the simplest explanation I will give as a Ph.D. in biochemistry.
Recently I started a running program with a friend. We're both female, about 10 years apart in age, she's younger but out-weighs me by about 60 pounds. I am a pretty fit runner, she's just starting out. Twice a week we cover the same distance doing run/walk intervals. At the end, she's burned about 80-100 cal more than I have, but here's the thing... the amount of calories we each burn remain consistent to the distance. Running, walking, fit or unfit, it's all the same. I personally tend to burn 100 calories a mile, regardless of how I covered the mile. My buddy burns about 25% more.
The science does not backup the idea that calories burned over a given distance is a constant regardless of the time required to travel that distance. This is not true for humans or most machines and the differences can be quite significant (a 1000 horse power bughatti will use approx one third its power to achieve 300mph and every last horse to achieve 400mph). Running is less efficient that walking. The displacement is partially vertical, when you land the force required to lift your body again is exponentially larger than walking due to gravity, and when running near aerobic/anaerobic threshold, physiological and mechanical inefficiencies are introduced (not the mention the after burn mentioned by others). Studies show the difference to be as much as 40% more calories burned running vs. walking per unit of displacement with some interesting exceptions:
-speed walking 5mph burns a lot more calories per mile than jogging 5mph (due to inefficient "waddling" as this pace)
-walking VERY slow burns more calories per mile than walking at a comfortable pace (due to energy required to hold you muscles back).
If the difference was small, I wouldn't even question the article. But the difference is big and I think this belief is prevalent partially due to the fact that it makes exercise a lot easier. I lost 60lbs and during that loss, I tried different cardio exercises and my experiences back up the science.
I am a Ph.D. Physiologist-Endocrinologist and enjoy your lively discussions. Work=Weight x Distance; by definition. There is not a statistical difference in work done in running or walking a distance. Both also raise your BMR (Basal Metabolic Rate) for several hours after stopping work, again both are equal. Hormonal control of BMR is primarily by Thyroid Hormones and Insulin along with synergies from Adrenal (cortex and medulla) and to a lesser extent GH hormones.
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