Is Running a More Efficient Way to Travel Than Walking?

It shows that in contrast to most animals, the efficiency curve of humans for running speeds is extremely flat, ie, we are about equally efficient at many different speeds, while the kind of game that we hunted was not.

The discrepancy allowed us to find a speed where we could exhaust the animal after 10-30km (as I understand) provided we were also excellent trackers.

https://www.nature.com/articles/nature03052.epdf?sharing_tok...

I hike a lot and started running races in alpine territory (e.g. this one [1]) about a decade ago and think if you take into account fatigue (mental, muscle, tendons) and exposure to the elements (sun, rain, wind, snow), a light running pace can definitely make you arrive at your destination less exhausted than walking the same distance, given that you can move confidently in the given terrain.

So it is a multi-dimensional optimization problem (as opposed to only optimizing for energy expenditure) and very dependent on how comfortably you can move at the given velocities.

[1] https://www.youtube.com/watch?v=o-12ghcODMM

From my experience of roughly analysing this a couple of years ago when I was losing quite a lot of weight, I drew two main conclusions:

* Calories used is a function of total distance travelled and your weight, your speed isn't really that significant a factor.

* Walking rather than running uses about 80% of the calories for the same distance compared to running. It seems to be based on the mechanics of changing gait. If you at walking speed (google MAF - maximum aerobic fitness for more info), you use more calories than just walking.

While these would seem to be opposite to the conclusions in the article, it's worth noting that the MET value is a function of calories over time, not calories over distance. The faster you're moving, the more calories you're using and the greater the distance you're covering, and they roughly cancel out.

I also found it interesting that running slowly and/or walking is better for losing weight as running faster primarily uses glycogen (and makes you hungry), and running slowly primarily uses fat. This doesn't really affect energy efficiency, per se, but fat is a more efficient energy storage source, so this might be relevant in answering the posed question. But in any case, if you want to lose weight, walking is significantly more useful than running as you can generally sustain the activity over a longer period of time, and with less stress on your body.

That gives you a hair over 13 min time on a 3000m run. When I was in the (Norwegian) military, that time would get you a 7 out of 9 score for males, and 8 (or 9) out of 9 score for females on a physical test. Pretty solid score.

It would also almost give you a sub 3 hour marathon.

You'd be a pretty capable runner if you can keep a steady 7 min mile, for the sake of running efficiently!

It's what makes us such terrifying hunters... prey can outrun us but then when they invariably have to stop to recover, we eventually just turn up and they have to keep running again.

So, any activity where you're cranking the ol' powerhouse up to 120% and going for a run is going to incur a cost, both in terms of energy consumption (which, as the post demonstrates, is slightly more efficient than a fast-paced walk), but then also the resultant metabolic waste which needs to be eliminated, which is a process that takes place during recovery in the 24hrs or so after you've completed your "efficient" 7-minute mile, and I don't believe the article takes this into account.

I watched an interesting video recently (I think it was Kurzgesagt?) that talks about the illusion of high-intensity activity vs low-intensity but longer-duration activity.

  1 MET = 4184 J/(kg hr),

  1 MET = 1.162 m^2/s^3

Seemingly an elite athlete must have been tracked because almost nobody(considering the whole population) can run the given top-end pace for a sustained amount of time (More that 100metres).

I was hoping for more from the article, or at least that it was called 'calorically More efficient'.

I seem to remember reading as a kid that this happened first in some Victorian bet (I would have read this in one of my dad’s kid’s books from the 1930s).

This was also a plot device in a Larry Niven short story (one of the Draco’s Tavern stories).

It doesn't seem that our body sees running as a method of travel, given our inability to regenerate cartilage and due the dehydration through cooling, it sounds more like a momentarily needed resource for survival.

That works out to a 3:03 marathon time. That's years of work to become so efficient.

I'm a little bummed that the article doesn't touch on how can maintain that pace for x amount of miles, since plainly: only people who have trained very carefully have a chance. So that running speed is off the table.

Stick to walking.

`kcal/kg/h = kcal/(kgh)`

The actual computations in the article are unaffected.

These guys need to get with the program and use metric units. For example, the cycling world uses watts per kilogram (W/kg) to quantify an athlete's output. This is the correct unit to use.

To help with this, note that 1 MET ≈ 1.162 W/kg.

You could slice this a million ways to tease out many different efficiencies.