Bushwalk Australia

Just read this in WIRED on the most efficient speed in walking/jogging.

https://www.wired.com/2016/09/whats-ide ... ve-energy/


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Hahaha, that explains why I so often overtake unfit joggers when I'm just walking normally

I'm a physicist and bit shocked at that lol. Air resistance doesn't matter if you're walking unless there's strong winds. Also my biggest concern is he didn't included any model regarding the heart rate. Basically when he says "I am going to say that a human uses energy at a constant rate." it all falls appart. He says walking very slow isn't good as breathing/thinking/blinking then takes more energy relative to the walking. I don't believe that's true. What is true is that walking really slowly makes you do short steps that aren't efficient compared to longer steps, that's all. The most amount energy you spend is lifting your legs, so there's an optimal steplength. Nothing to do with breathing or blinking. He assumes the energy required to walk/run is propotional to 1/s with s the length of the stride, there's no way that's true. Also, an elderly woman is recommended to have an intake of 1500 kCal per day (not Cal)... So his 500 is ridiculous, you need at least 3 times that when no exercising at all. It's so messy it makes me angry lol.

Hallu wrote:It's so messy it makes me angry lol.

A first attempt is always better than nothing. It often spurs others into doing something better. The perfect is the enemy of the good.

ribuck wrote:

Hallu wrote:It's so messy it makes me angry lol.

A first attempt is always better than nothing. It often spurs others into doing something better. The perfect is the enemy of the good.

Except when someone reads it on the internet and thinks it makes sense and starts quoting it.

I've seen studies on walking and running based on measured oxygen consumption.
Running uses a roughly constant amount of energy per distance covered except at low speeds (under about 6-8km/hr) when it becomes inefficient to run. This is because there is energy conserved in the muscles by the bounding action that does not function well by running at low speeds.
Walking has a more U-shaped curved where it is inefficient at both low and high speeds and the optimum walking speed depends a lot on the individual, but is commonly 4-6km/hr. When given a free choice most people walk very close to the speed at which they have minimum oxygen consumption per km. The optimum walking speed is lower if you are carrying a pack.

Hallu, calm down. These are just of interest and for talking points. Don't take it too seriously or your O2 consumption will go up exponentially... Not good.

Still, the number is in the 1st order range. I'd be more worried if it came up with 1km/h.

Hallu wrote:What is true is that walking really slowly makes you do short steps that aren't efficient compared to longer steps, that's all. The most amount energy you spend is lifting your legs, so there's an optimal steplength.

Interesting.
My normal stride length is actually rather long given my height, and slow walking is more a matter of slower steps than shorter ones - except on the reeeeeaally steep bits, of course. Trying to walk with shorter steps doesn't work - it's as though my body has an maximum number of steps it's happy to make in a given time, and exceeding that shags it out. Hadn't thought about it in terms of where the energy is used, but that makes sense.

Interesting.

I had a physio appointment for insoles a couple of years ago. I was walking on the treadmill while the camera was taking a movie of my foot pronation etc. The Physio was saying my long strides were less energy efficient than a shorter stride. I can understand that over striding would waste your energy but walking at a happy pace and stride should be pretty efficient?

Also, a pace of 4.46km/h might be fine on the flat for some, but what about ups and downs, and what about the length of your legs? It all seems a bit over averaged to be a useful number to me.

Looking at my recorded walks (6,526km not including long distance walks) all in the Adelaide hills, (not flat most are 2-300m elevation and descent), my average walk pace is around 11-12 minutes per kilometer, so 5.00 to 5.45km/h. I carry a light 3-4kg pack everytime.

My hip to floor distance is 1080mm I think that is of more significance than anything else for a reasonably fit walker. A fit and flexible walker like nnw would have longer strides than average for their height.

photohiker wrote: A fit and flexible walker like nnw ...

*snorfle*

Once upon a time, mate. But these days? The average geriatric slug gives me a good run for my money.

photohiker wrote:Interesting.
...
Also, a pace of 4.46km/h might be fine on the flat for some, but what about ups and downs, and what about the length of your legs? It all seems a bit over averaged to be a useful number to me.

Obviously the result was based on numerous assumptions over an uncomplicated basic terrain. As Hallu pointed out, take it with a grain of salt. Don't get to accurate on it.

Realistically, with enough walking, most of us probably have found the most efficient and sustainable pace naturally.


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Well energy efficiency isn't a problem for us modern humans anyway... We have plenty of food available to us... It's actually better to increase your heart rate when walking so it's actually a sport and not just a way of going from A to B, it's healthier. For example, Nordic walking is NOT energy efficient at all. You waste a lot of energy using your arms and having a longer stride but you go faster and get fitter. It was the whole purpose of this, getting somewhere fast. Energy efficiency isn't a concern unless you're in survival mode or doing a marathon. Don't have energy anymore ? Just pause and eat.

NNW if you're frustrated with senior walkers, don't go in the French Alps. You'll always meet one that's been doing this his whole life and that can outpace any fit kid =) It's one of the reasons I start walking at 7-8 am, so I won't be frustrated by people overtaking me.