Most Energy Efficient Transport

Charting out the most energy efficient mode of transportation

Did you ever wonder, what animal has the most energy efficient movement? Is it a fish swimming the water? A bird or insect flying in the sky? Or animals walking across the land? Interestingly, this famous chart that was first published in the 1970s, also includes the human transportation systems.

Energy efficient transport is defined by how much energy is needed to transport one gram of the animal by one kilometre. The higher on the vertical y-axis, the less energy efficient. On the horizontal x-axis, the weight of the animal is plotted. The higher the weight, the further the right on the scale.

The graph is colour-coded for the different types of transportation modes, namely purple (swimmers), blue (flyers), pink (walkers/runners), and yellow (vehicles). The results are plotted below and also found on this link from the Scientific American magazine: https://www.scientificamerican.com/article/a-human-on-a-bicycle-is-among-the-most-efficient-forms-of-travel-in-the/

Interestingly, the least energy efficient of the animals plotted are mice, which consume almost 50 calories/gram/km. Small insects like fruit flies, flies and bees, are significantly more efficient at 13 calories/gram/km. And other bigger flying creatures like humming birds and sea gulls, are even more energy efficient at 4 and 1.3 calories/gram/km, respectively. Humans are even more efficient at 0.7 calories/gram/km. Not surprisingly, horses are even more energy efficient, namely at 0.52 calories/gram/km. Also not surprising is the fact that fish, that float weightlessly in the water, fall in the energy efficient spectrum of the chart, namely at 0.4 calories/gram/km for salmon. The most efficient mode of transport, however, is a human-made vehicle. No, not car at 0.85 calories/gram/km or a modern commercial jet plane at 0.58 calories/gram/km, but rather the mode of transport that many of us learn how to ride as kids: The bicycle! A human on bicycle has an energy consumption of just 0.14 calories/gram/km. No wonder, the bicycle design has virtually not changed since 1880s, as it is already a super energy efficient mode of transport!

Bicycle versus other modes of transportation

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A SIDE NOTE: Boost for bicycling infrastructure in Kuala Lumpur?

In recent months, it's been encouraging to see a couple of cover stories in The Star Metro newspaper section making the case for more bicycling in Kuala Lumpur.

24 Oct 2025 | Re-establish shared bicycle and motorbike lane along the KL Federal Highway

4 Nov 2025 | Establish green bicycle corridors in Kuala Lumpur

However, realities on the ground in Kuala Lumpur are that that only very few people currently commute by with the most energy efficient transportation mode: The bicycle. In a World that needs to decarbonise, this needs to change. Moreover, bicycles help to reduce traffic congestion and improve health by making people exercise in their daily routine. In the hot humid tropics pedal-assisted electric bicycles allow people to bicycle without sweating. Refer to below bicycle collage, showing how I (Gregers) get around in Kuala Lumpur as well as a great bicycle quote:

"The World has three major problems: Climate Change, Congestion and the Obesity Epidemic. The bicycle is the answer to all three of them". Quote by Dan E. Jørgensen, Member of the Danish Parliament

References:

• The main graphic "A Classic Graphic Reveals Nature’s Most Efficient Traveler" from the Scientific American magazine: https://www.scientificamerican.com/article/a-human-on-a-bicycle-is-among-the-most-efficient-forms-of-travel-in-the/

• Cranking Up Call to Reclaim Bike Lane, The Star Metro cover story, 24 Oct 2025: https://www.thestar.com.my/metro/metro-news/2025/10/24/cranking-up-call-to-reclaim-bike-lane

• Bike Commute Malaysia (BCMY), and NGO that promotes low carbon mobility

  by advocating for safe and equitable street design for all in Malaysia: https://bikecommute.my/