How Does walking lose weight?

You can move this to another subforum if you like, but To me it seems like a genuine general question so I put it here.

I have reasonable understanding that you lose weight by burning more calories than you consume, and that you can burn calories fast by doing something that increases your heart rate quite a lot, or that tears muscle tissue (and you burn calories while the body repairs it over time)

But how does your body burn calories when it’s doing something very easy, that doesn’t [seem to] increase the heart rate much at all?

I do quite a lot of walking and initially I saw weight come off… but as I do even more walking the weight loss seems to be slower now… or maybe I’m just expecting too much too fast.

So what are the ‘mechanics’ of weight loss through normal muscle usage (e.g. walking) Say I walk for 3 hours every other day (with terrain being about 30% flat, 60% slight hill, 10% steep hill - steep enough to get a marked heart rate increase)

Or to be more accurate… divide each hill percentage between up and down… since the starting points are the same.

30% up light hill, 30% down light hill, 5% up steep hill 5% down steep hill 30% straight.
Does going down a hill burn more calories than walking straight (since you are making effort to halt your weight against gravity)

Moving your body requires an expenditure of energy, which burns calories. Simple as that. With respect to hills, I’m not sure about downhill vs. flat, but if you go downhill and want to return to where you started from at some point you go back up, and that will burn more calories.

ETA:For the “mechanics

It doesn’t matter how hard you work, as long as you burn more calories than you consume, you will lose weight. If you go from a regiment of “not walking” to one where you walk more, you are burning more calories and will lose weight. Yes, higher heart rates, muscle tearing and rebuilding, etc… can make you burn more, and lose weight faster (in theory*), but as long as calries out > calories in, the pounds go away.
*Of course, the added fatigue, strain, and nutrients needed for harder workouts also means you’re more likely to replace a lot of what you burned afterwards because of how thirsty and hungry you feel. At least, that’s true for me. I’ll go work out for a couple hours then feel like eating a giant steak.

Your body is constantly ‘burning Calories’ just to stay alive. Everyone has a basal metabolic rate (here is a good calculator). So if I sit on my couch watching TV all day. I will still burn about 1700kcal. As long as I eat less than that (Ha!), I will lose weight.

Any additional physical activity will increase the amount of Calories that you burn each day.

As you’ve noted: Cal in < Cal out = weight loss.

You’ve just hit a plateau. Welcome to the club. :smiley:

Also, it’s interesting to note that burn about the same number of calories walking as you do running. So walking faster won’t help you lose weight faster.

Hints here for walking on hills. And they’re not kidding about the “moderation” thing: I gave myself a nifty case of Achilles tendonitis by over-enthusiastic marching up a hill at the park every day.

Work (energy expended) equals force (weight) times distance.

It doesn’t matter how high your heart rate is.

Are you speaking as an engineering student or as a physiologist here?

But a higher heart rate means at least your heart is burning more energy, doesn’t it?

I never quite understood the thinking behind that. From the linked site:

I guess the same calories for walking/running idea makes sense if you structure your exercise solely around distance, but aside from bragging rights (I X for Y miles every day!) aren’t most people/programs based on time spent exercising? Taking the same braggart above, someone who runs for X hours per day is going to burn much more than someone who walks the equivalent amount of time. Maybe this is obvious, maybe I’m an oddity who thinks of exercise in time units, or maybe I missed some nuance – but the pronouncement still strikes me as somehow ‘off.’

The main cause of burned calories during exercise is generating waste heat. Some calories are also expended in an elevated metabolic rate afterwards, especially for aerobic exercise. A heart rate increase correlates to, but does not cause, calorie burning.

Any activity burns more calories than sitting on your ass, including walking. You do enough walking, you’ll burn plenty of calories.

Work is not energy expended. If I push like crazy on a brick wall for an hour, that’s force times zero distance. I’ve done zero work but will have expended a lot of energy.

Generally I have found that if I am walking I am not eating and thus lose weight. Unless of course I am walking to the ice cream shoppe.

[QUOTE=Duck Duck Goose]
Also, it’s interesting to note that burn about the same number of calories walking as you do running. So walking faster won’t help you lose weight faster.

That is not at all the conclusion I come to when I read that article. From the article:

A runner and a fast walker, both at a speed of 12 minutes per mile or 5 miles per hour, achieve the exact same 8 MET. Their calories per mile and calories per hour are identical. Walking at various speeds burns between 2 to 8 MET. Running at various speeds burns 8 to 18 MET

If they are both at a speed of 12 miles per hour, depending on your definition, they are either both walking or both running. You are not comparing running to walking. Of course they are burning the same amount of calories - they are doing the same thing.
The last two statements in that paragraph, I think, prove that running burns more calories.
“Walking at various speeds burns between 2 to 8 MET.”
So the average walker burns 5 MET.
“Running at various speeds burns 8 to 18 MET.”
So the average runner burns 13 MET.

I conclude that running burns more calories. Am I missing something?

Hmmm… could it be that the difference is in the gait, not the speed? Kind of like comparing the breast stroke to a butterfly?

12 minutes per mile, or 5 MPH according to the original quote. You can run or walk at that pace (but it’s a very fast walk).

The Master Speaks.

You also have to realize that when you run your body has to work harder to move it. You walk with both feet on the ground at the same time in a fairly lateral manner. When you run, there is only on foot on the ground at a time, and you move more vertically then you do when you walk. It takes extra energy to push off from one foot to the other, thus burning more calories.

Not quite. Heat is generated as a result of oxidative phosphorylation, or the process of converting calories (from sugar, fat, protein, alcohol, etc.) into ATP.

As far as I can tell, the main mechanism behind weight loss is conversion of those metabolic intermediates to CO2 + water, both of which are exhaled (for the most part). So while your heart rate may not increase all that much, pay attention to the depth and frequency of your breaths. Depending on how hard you are working, one or both should increase.

The more I learned about this, the more I started to shy away from the concept of calories in < calories out. While by and large this is true, there are any number of scenarios where the efficiency of the cellular machinery can affect the energy generated from the same number of calories.

That’s what it is. Walking means at least one foot is on the ground at all times; running, both feet leave the ground. A fast walker can pass very slow runners but they’re still using different gaits.

If you’re running up a hill or some stairs, don’t you have to expend the same amount of energy as it would take to lift your entire body that same height?

And going down a hill you should reduce how much energy you are personally putting into it, since you don’t want to put your foot down with the same force as you were using going up. You’d break an ankle or something!