Are calories burned while walking/running independent of speed?

We all know running burns more calories than walking and now the trend is to jog then walk in 60 second cycles. But I started thinking that calorie burning is a function of distance3 only. Lets say running burns 3X more calories per hour than walking but it is also 3X faster. Then after I complete a mile, I’ve burned the same number of calories.

Is that accurate or am I missing something?

According to this, it’s not just a function of distance. You burn about twice as many net calories per mile running vs. walking. (0.63 x weight per mile for running, and 0.30 x weight for walking. “Net” calories means calories burnt over your basal metabolic rate.)

If you could slow down a running person to a walking speed, you would see there’s a lot more wasted motion, which translates to extra calorie burn. It’s not that you’re going faster that’s burning the calories, but all that extra motion that it takes to go faster.

The different types of motion (walking, jogging, running) do each burn more calories per mile than the other. But within a given motion type, speed doesn’t make much difference. So if you’re walking slow or walking fast, you’re burning about the same number of calories per mile. The same with running. If you run slow or fast, your calories per mile is about the same. The difference is that you’re burning the calories faster.

However, the calories you burn after the activity are dependent on the speed. The harder you push, the more calories you’ll burn afterwards. It’s called the Post Exercise Calorie Expenditure. If you push hard, your body spends more calories replacing energy, repairing damage, and preparing your body for more activity.

The PECE will be different for how you do your exercise. It will be lowest if you walk the whole way, a bit higher if you alternate walking/jogging, and the most if you jog the whole way. The bulk of the calories will be burned in the exercise itself and the PECE will be some bonus calories.

That’s a great link! And they are right that people tend to think in terms of gross rather than net calorie while net is what matters. The simple fact is that walking at reasonable speeds is very energy efficient and running not so much so.

filmore, pulykamell’s link claims something different re the “within a given motion type, speed doesn’t make much difference …” claim that you made. Cecil also disagrees in this old column on the issue:

Your point about the burn after exercise is spot on. Those interested in more though might find it easier using the phrase “Excess post-exercise oxygen consumption” (EPOC).

I read somewhere that calories burned when running really don’t change much with speed. However it does change quite a bit with walking. I guess the extreme is race walking where they certainly don’t look to be very efficient.

I’m a cyclist and calories burned there certainly go up with speed. However aerodynamic drag is a big factor in cycling.

I would think efficiency is highly dependent on running style. A competitive runner looks very different from a casual jogger. The upper body of a competitive runner does not bounce around. It’s very still. But the body of a casual jogger is flopping all around and their gait may be poor. You can see this if you watch a marathon. The leaders hardly look like they they are exerting themselves, but the people at the back of the pack are struggling even though they are at twice the pace.

I could believe that a trained runner might be more efficient, but I doubt that a casual runner would be more efficient running than walking. It seems they are taking their inefficiencies and making them more inefficient.

Not speed but heart rate - speed is just a function of power to weight ratio.

i.e. the fitter/leaner you are, the fewer cals you burn.

Heart rate monitor - calibrated to your vitals - is an excellent measure.

Running is essentially jumping from foot to foot.
Walking is pushing your body up and over so it pivots on the ankle of the planted foot.
(And both involve swinging the free foot forward)

Two different actions.
It’s somewhat evident that jumping takes more calories than pushing/pivoting.
However, the amount of work done at any speed would likely be close to the same, until you get to where you are pushing the limits of muscle speed.

Nah–the extreme is not moving at all. I’m just standing here and I’m burning infinity calories per mile.

That’s funny. I’m a cyclist too, and I burn more calories during the slowest part of my rides and the least during the fastest.
OK, just kidding here. The slowest part of my rides is going up steep hills and the fastest is going down them. You obviously were talking about riding faster or slower on a consistent slope.

If you don’t have a heart rate monitor, you can pretty much judge how many calories you’re burning based on your breathing. The more calories you burn, the heavier your breathing gets. And in order to get the Post Exercise Calorie Burn mentioned above, you have to exercise at about 70% max for about 45 minutes or more. 70% max is breathing heavy enough that you can’t carry on a conversation.

Most people are not in good enough shape to exercise that much, which is why exercise doesn’t help them lose weight very much. Note that following the recommended 30 minutes of moderate exercise 3 or more days a week is totally useless for losing weight or even getting in shape. I doubt if it really helps maintain heart health all that much.

Where is this walking/running taking place - on soft sand or a treadmill? I would think that would also have some bearing on the efficiency.

Someone had to bring treadmills into it.

Nah, it’s not that bad. Excess post oxygen consumption (EPOC) does only significantly occur at minimal intensity but reviews (pdf) place it at 50 to 60% of VO2 max (higher EPOC with higher intensity) and then fairly steeply increasing with intensity and linearly increasing with duration.

That said we are not talking about a huge amount of calories … but higher intensity does bring other benefits as well.

As for your personal doubt that 30 minutes a day of moderate intensity exercise does much to maintain heart health … what do you base those doubts on? Because when the CDC, the American Heart Association, and the American College of Sports Medicine all review all the evidence they find the evidence very convincing (and not just for heart health but for overall health and mortality rates): the biggest difference is between those doing no exercise and those hitting that minimum. Further increase brings further health gains to be sure.

From the NIH - Short Bouts of Brisk Exercise May Help Cut Obesity Risk

Indeed, I have to at every possible moment. What can I say, it’s an illness! I’ll shortly be starting up a Foundation for other sufferers :smiley: