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Steve Jobs claimed on video that a bicycling human is more efficient at locomotion than any other species can manage. He repeated it separately on video, and in writing. The quote is still oft repeated. A poster print run raised 5k USD on Kickstarter.

Here's a transcription:

I think one of the things that really separates us from the higher primates is that we’re tool builders. I read a study that measured the efficiency of locomotion for various species on the planet. The condor used the least amount of energy to move a kilometer. And humans came in with a rather unimpressive showing about a third of the way down the list. It was not too proud of a showing for the crown of creation.

That didn’t look so good. But then, somebody at Scientific American had the insight to test the efficiency of locomotion for a man on a bicycle. And a man on a bicycle completely blew the condor away, completely off the top of the chart. And that’s what a computer is to me. What a computer is to me, is it’s the most remarkable tool that we’ve ever come up with. It’s the equivalent of a bicycle for our minds.

Is a human on a bicycle really overwhelmingly more efficient at moving from place to place than any other species?

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Anko - inactive in protest
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  • The closest I could find to the source Jobs describes in the second video "[…]an article when I was about 12 years old, I think it might have been [in] *Scientific American*" is [this one](http://www.jstor.org/stable/27845576) published in *American Scientist* in 1975. He was 20 years old at the time though, and I haven't managed to digest their results yet. – Anko - inactive in protest Apr 19 '15 at 21:24
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    I would think you would need to define the conditions better. I have a hard time believing a human on a bicycle can beat a soaring bird in an area of thermals. – Loren Pechtel Apr 19 '15 at 22:02
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    @LorenPechtel It's indeed hard to define a "standard atmosphere", but I imagine it's in the spirit of the question for the birds to get no thermals, the bicycles no downhills, the fish no currents and the earthworms no landslides. – Anko - inactive in protest Apr 19 '15 at 22:08
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    Speed runs and the like are usually done over a loop to eliminate things like downhills & currents. However, the soaring bird can soar in a loop. (Or, for that matter, substitute "glider pilot" for "bird".) – Loren Pechtel Apr 19 '15 at 22:21
  • @NateEldredge The quote is "least amount of energy to move a kilometer", so it's the former, at least literally interpreted. Is energy per distance per mass a more standard definition? – Anko - inactive in protest Apr 20 '15 at 01:53
  • Oh, I guess I should read more carefully. I don't know that there's a standard definition; either would be interesting to consider. But you would think a very light animal might have an advantage. – Nate Eldredge Apr 20 '15 at 01:58
  • One might also ask whether the efficient bicycling is done on a paved road, or FTM even a prepared mountain bike trail. I don't know of actual measurements, but from personal experience smooth pavement is more efficient than trail, which in turn is much more efficient than cross-country (which can be darned near impossible). If this is the case, then you have to add the energy expended in building & maintaining the road. plus the energy expenditure of making the bike, to the total. – jamesqf Apr 20 '15 at 03:29
  • cycling on a smooth paved road is certainly more efficient than on anything soft or bumpy. If it's soft you'd be using energy to move bits of the ground around, and if its bumpy you'd be using energy to lift yourself over each bump and move bits of your body, tyres and bike around to absorb the movement. – bdsl Apr 20 '15 at 12:46
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    Well, to travel from UK to Africa, I'm quite sure birds are more efficients than cyclists... – TZDZ Apr 20 '15 at 13:19
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    Comparing the energy efficiency of human and animal locomotion, one should also perhaps include the energy used to provide the required nutrition. With our incredibly inefficient agricultural industry and nourishment distribution networks, even using a car may leave a smaller carbon footprint than riding a bike. The carbon footprint of a Big Mac (4kg) is equivalent to driving my car 45km. With the provided 495kcal of energy, I would probably only be able to ride about 20-30km on a bicycle. – Tor-Einar Jarnbjo Apr 20 '15 at 14:13
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    @Tor-Einar Jarnbjo: Of course the subset of the population whose diet consists completely of Big Macs is probably rather small. – jamesqf Apr 20 '15 at 18:49
  • @jamesqf: The Big Mac was just an arbitrary example, which most of us know and for which it is easy to find relatively reliable data. – Tor-Einar Jarnbjo Apr 20 '15 at 19:24
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    Wouldn't be surprising if humans on bicycles beat others in conditions **perfect for humans on bicycles**, that is flat, smooth roads. But make it sufficiently off-road and suddenly walking on all fours could easily become less demanding of energy. E.g. tall grass in an uneven field. So for a proper comparison, let's incorporate the energy cost of preparing the surface, too. – RomanSt Apr 20 '15 at 22:33
  • Given the Silicon Valley yuppie culture, I'd be very unsurprised if this were completely fabricated. Next up: Does eating enough granola grant immortality? – Parthian Shot Apr 21 '15 at 06:33
  • @Tor-EinarJarnbjo That's taking one of the least efficient human foodstuffs. If you compared the most efficient (maybe soya, couscous or quinoa from a large-scale mechanised farm?) the energy used per calorie gained ratio might well be better than a condor hunting. Interesting question... – user56reinstatemonica8 Apr 21 '15 at 11:05
  • You consider traveling only where there are roads? Or bicycling off-road... – GEdgar Apr 21 '15 at 19:03
  • @Tor-Einar Jarnbjo: The Big Mac diet may have available data, but OTOH it is far from representative. – jamesqf Apr 21 '15 at 19:21
  • @Tor-EinarJarnbjo - I'd like to know where you find this bread that has only 250kcal per kg, most bread has 2000 -3000 kcal/kg -- which would power a cyclist for around 40 miles (64 km). In comparison, a car that drives that distance on a gallon of gas will generate 20 lbs (9kg) of CO2. – Johnny Apr 21 '15 at 20:42

1 Answers1

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The quoted statement says "energy to move a kilometer".

On an "energy to move a kilometer" basis, the statement is definitely false.

Acccording to Dr. Karen Oberhauser, a tagged monarch butterfly has been confirmed to travel 265 miles in one day.

According to How Much Fuel Do Monarchs Burn? reporting Dr. David Gibo's research:

On 140 milligrams of fat a monarch butterfly has enough energy to continuously flap its wing flying for 44 hours and to soar or glide for 1040 hours!

So the butterfly is using at most 3 milligrams per hour.

For comparative human statistics, use this excercise calorie calculator

For a 110 pound (50kg) human:

bicycling 16-20 miles per hour 599 dietary calories (kilocalories) are used per hour. This corresponds to 67 grams (67,000 milligrams) fat per hour.

bicycling at an unspecific "greater than 20 mph" racing speed is 798 calories per hour. This corresponds to 89 grams (89,000 milligrams) fat per hour.

Humans use more than 1000 times as much energy per kilometer as monarch butterflies, even considering the record distance on a bicycle for a day is 521 miles, about twice the butterfly's record.

Note: although the quoted statement clearly says "energy to move a kilometer", and nowhere suggests that mass moved should be considered, another way to consider efficiency is

(energy used)/((mass of organism)(distance traveled))

On this basis, swimming animals have been found to be the most efficient animals.

enter image description here

All credit to Brad J. Gemmell, Passive energy recapture in jellyfish contributes to propulsive advantage over other metazoans Proceedings of the National Academy of Sciences of the USA volume 110 pages 17904–17909.

As reported in Eel migration to the Sargasso: remarkably high swimming efficiency and low energy costs, the eel is very efficient.

Particularly, its efficiency is calculated to be 0.5 kilojoules/kilometer/kg.

Let's compare this to a human bicycling.

I'll use a 50 kg human, 29 kph (18 mph), 599 kilocalories per hour.

599 kilocalories/hr is 2500 kilojoules/hr.

This corresponds to 86 kilojoules/kilometer.

Or 1.7 kilojoules/kilometer/kg

Eel is more efficient by a factor of 3.

(From the jellyfish article it can also been seen that a species of jellyfish has about the same efficiency of the eel. Large marine animals such as whales do not seem to have been considered.)

See also Swimming speed, respiration rate, and estimated cost of transport in adult killer whales, which shows that at an optimal speed of around 3 meters/second, killer whales have an efficiency of 0.78 kilojoules/kilometer/kg. Better than a human on a bicycle, but not quite as good as an eel.

According to Energy in Nature and Society: General Energetics of Complex Systems by Vaclav Smil, at page 103

for a 15-t gray whale is 0.4 J/m kg (if this exponent holds than a baleen whale would need [less than] 0.1 J/m kg)

See also Comparative analyses of animal-tracking data reveal ecological significance of endothermy in fishes which shows some sharks have efficiency in the 0.1-0.2 J/m kg range.

In conclusion, a human on a bicycle is NOT the most efficient. Whether the quote is analyzed literally on an "energy to move a kilometer" basis, or alternatively as energy per distance per mass of organism, there are more efficient species.

DavePhD
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    This is a good answer, but it would be improved by showing how many grams of fat are burnt during a bicycle ride, or even bicycle exercise, rather than cardio, over the period of an hour. Preferably on a flat surface to avoid bias. – Zibbobz Apr 21 '15 at 17:01
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    @Zibbobz even basal metabolism (just resting in bed) is 1500 calories per day for women, which corresponds to 7 grams fat per hour. The butterfly still would have that beat by a factor of 1000. http://www.ncbi.nlm.nih.gov/pubmed/528122 – DavePhD Apr 21 '15 at 17:18
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    It seems like a very strange measure of efficiency to not factor in the amount of mass moved. If one factors in mass moved, the human on a bicycle beats the butterfly by a large margin, assuming your estimate of 1000 times energy usage. – Muhd Apr 21 '15 at 19:46
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    @Muhd If we factor in mass, the eel or jellyfish would be most efficient, see http://jeb.biologists.org/content/208/7/1329.full#T1 and http://www.pnas.org/content/110/44/17904/F1.expansion.html – DavePhD Apr 21 '15 at 20:02
  • @DavePhD Please add that to the answer. – gerrit Apr 21 '15 at 23:36
  • @gerrit I'll add a note about that, but I want to check for information on whales first, and a related question http://skeptics.stackexchange.com/questions/26331/is-a-human-on-a-bike-more-efficient-than-a-fish-in-water?rq=1 (and good answer) that considered mass was closed. The quote in this question clearly does not mention mass. – DavePhD Apr 22 '15 at 10:28
  • Considering that the difference between a classical cyclist and the eel is only a factor 3, I wonder how close to the eel we get on recumbents and velomobiles, in particular recent ones designed for optimal aerodynamics. We might get really close. – gerrit Apr 22 '15 at 14:09
  • @gerrit yes, but for the baleen whale it seems to be more than a factor of 17. – DavePhD Apr 22 '15 at 14:15
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    @gerrit: You're forgetting, though, that those vehicles only travel efficiently on pre-prepared surfaces (roads &c). For a randomly chosen trip between two points (on land, of course), there's a pretty good chance the bike won't be able to do it at all. If you want to look at special cases, for water transport, or in certain areas like dry lake beds, a sailing craft is far more efficient than a cyclist, since it takes zero internal energy to move, and only a tiny amount to trim sails. – jamesqf Apr 22 '15 at 18:47
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    @jamesqf I'm fully aware that this downside of wheeled transport exists, which is probably why wheeled locomotion is not found much/at all in nature. I don't think that considering *external* energy such as wind leads to a fair comparison, though. If we allow external energy, a diving falcon, or any falling creature, wins by having an efficiency of ∞. – gerrit Apr 22 '15 at 18:56
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    @gerrit Additionally, there are [wheeled vehicles with sails](http://www.instructables.com/id/The-Sail-Bike-a-two-person-sailing-bicycle/) and even a somewhat controversial [wheeled vehicle with a propeller](https://en.wikipedia.org/wiki/Blackbird_%28land_yacht%29) that can travel faster than the wind that's pushing it. – Johnny Apr 22 '15 at 19:40
  • This talk about eels and whales . . . you are comparing apples and oranges. We can't swim well with a bike, and eels and whales would be completely helpless on land. The buoyancy of the material the creatures are made of skews the results as far as actual work by quite a bit. – J Sargent Jun 03 '16 at 14:35
  • I would be very interested to know how Kangaroo's compare with the above figures and graphs. – elmato Jun 04 '16 at 12:02
  • The source that Steve Jobs was quoting did have a graph that was using energy used per gram for a kilometer of movement. – Michael Richardson Mar 20 '19 at 15:00
  • @MichaelRichardson what source was he quoting? – DavePhD Mar 20 '19 at 18:22
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    The article I read that had the details was here: http://www.bikeboom.info/efficiency/ – Michael Richardson Mar 20 '19 at 18:24