Why is cycling more efficient than walking?

Cycling is the most efficient form of human-powered propulsion with 98.6 percent of the cyclist’s pedal effort used to spin the wheels, while those who walk/jog are only 65 percent efficient, and waste over a 1/3 of their energy to non-movement functions.

• Running is even more inefficient than walking. At the same energy expenditure (caloric burn) cycling is 5 times more efficient than running on flat surfaces with a still wind.

walking inefficiencies

The average human walking speed is 3 mph (5 kph). While humans can maintain this pace for hours, the walking movement is very wasteful and inefficient, with over 1/3 of our energy being wasted to non-forward propulsion effects, such as:

• Every step the knee of the grounded leg bends and flexes

• Spine bends

• The body is constantly being lowered and raised during striding

• The hips twist

• Arms move forward and backwards

• Swinging motion of the non-ground leg absorbs energy when the foot strikes the ground

cycling & what makes it efficient

• Riding in a position that maximizes calories

• The bicycle acts as a lever, which multiplies the distance our feet travel around the bottom bracket, turning each pedal stroke into a much greater distance

• Bicycles can coast along a smooth surface with relatively little resistance to motion. This is a great contrast with walking and running, where there is always an energetic interaction with the terrain

uphill bike riding & inefficiencies

During uphill cycling, speeds generally slow to such an extent that aerodynamic drag is no longer a factor. The most significant forces are gravity and the rider’s mass plus that of the bike.

• Studies show that walking is more efficient than cycling once a 2-3% gradient has been reached.

• Cycling up a 10% gradients results in 800% more energy expended than cycling on a smooth flat surface.

• Mass of the rider, the bike, gravity and height gained all factor in to how much energy is required to pedal up a specific hill. Once a 2% grade is reached, even when pedaling in the lowest gear, it is still more efficient to walk.

Biking vs walking & headwinds

Headwinds impede both cyclists and walkers but to differing degrees. The cyclist will notice headwinds more than the walker. 

For example, if a cyclist and walker are both walking into a 10 mph (16 kph) headwind and exerting the same amount of effort:

• The cyclist will lose about 75% of their speed

• The walker only loses about 35% of their speed

With a tailwind or downhill, however, the cyclist is aided by orders of magnitudes compared to the walker.

Can bicycles get even more efficient?

Yes, even though 98.6% of the rider’s pedal effort is utilized to spin the wheels, the aerodynamics can be greatly improved. 

A real-life example is a recumbent bicycle.

In 1938, the Union Cycliste Internationale, the governing body for competitive cycling events, banned recumbent bikes from most competitions because they had an unfair advantage……they’re too efficient.

Today, even the speed record for a bike is held by a recumbent bicyclist.

How much more efficient is a recumbent bike compared to a road bike?

This is a really hard question to answer, as there are so many different types and styles of recumbent bikes. However, 15 to 30 percent lower aero drag is normal for most commercially available recumbent bikes.

Jesse (Director of Pedal Chile) lives in Chile’s Patagonia. Jesse has a Master of Science in Health & Human Performance and a Bachelor of Science in Kinesiology. Hobbies: Mountain biking, snowboarding, reading, writing, and researching all bicycle-related topics.

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Sources:

1. Burgess, S., et al. “A Comparison of the Efficiency of the Bicycle with Analogous Systems in Nature.” International Journal of Design & Nature and Ecodynamics, vol. 6, no. 2, 27 June 2011, pp. 97–108.

2. David Gordon Wilson. Bicycling Science. Cambridge (Massachusetts), Mit Press, 2004.

3. Glaskin, M. (2018). Cycling Science.

4. Hirsch, Rebecca. Science Lab: Motion and Forces. New York, Cherry Lake Publishing, 2011.

5. Langford, B.C., Cherry, C.R., Bassett, D.R., Fitzhugh, E.C. and Dhakal, N. (2017). Comparing physical activity of pedal-assist electric bikes with walking and conventional bicycles. Journal of Transport & Health, 6, pp.463–473

6. Too, Danny. “Biomechanics of Cycling and Factors Affecting Performance.” Sports Medicine, vol. 10, no. 5, Nov. 1990, pp. 286–302.