Which is more efficient riding a bicycle or walking?

But suppose the bike weighs 100 lb or a 50 lb or less.

but which uses the least energy on a level surface, riding a bicycle or walking the same distance?

At what point does it become more efficient to ride the bicycle, if at all, than to walk.

If you speed up to walking a mile in 13 minutes or less, you will be burning more calories per mile. But for most beginning walkers, it is best to increase the distance before working on speed. A simple rule of thumb is 100 calories per mile for a 180 pound person.

How many calories do you burn riding a bike for 1 mile?
Light Cycling. Bicycling 10 to 11.9 mph is regarded as a “light effort” by the Wisconsin Department of Health. When you bicycle 10 to 11.9 mph, you burn about 47 calories per mile if you weigh 190 pounds, about 38 calories per mile if you're 155 pounds and about 32 calories per mile if you're 130 pounds.

Notice that I'm not trying to burn the most energy but the least energy.

So if your bike weighs 200 lb it's still much easier to ride a bicycle for a mile than it is to walk, right?

Nobody seems to take the weight of the bicycle into account.

Everyone talks about bicycle weight. It consumes our discussions. Magazine reviews make it clear that if the very lightest parts are not chosen, if it is not as light as possible, the bicycle being examined is suspect. Light weight has become the sine qua non of a good bicycle. A light bicycle is a good bicycle, without any further discussion of its other merits or qualities.

If we look at overall efficiency, should we consider the issue of securing the bike when not in use? If one lives in a second floor walk up apartment, the energy and general hassle of carrying it up one flight of stairs might make a short walk look pretty good, even if it's made of unobtanium and weighs less that fifteen pounds.

Which is more efficient riding a bicycle or walking?

What freaking bike weighs 200 pounds?!

Man on a bicycle can go three or four times faster than the pedestrian, but uses five times less energy in the process. He carries one gram of his weight over a kilometer of flat road at an expense of only 0.15 calories. The bicycle is the perfect transducer to match man’s metabolic energy to the impedance of locomotion. Equipped with this tool, man outstrips the efficiency of not only all machines but all other animals as well.

Bicycles let people move with greater speed without taking up significant amounts of scarce space, energy, or time. They can spend fewer hours on each mile and still travel more miles in a year. They can get the benefit of technological breakthroughs without putting undue claims on the schedules, energy, or space of others. They become masters of their own movements without blocking those of their fellows. Their new tool creates only those demands which it can also satisfy. Every increase in motorized speed creates new demands on space and time. The use of the bicycle is self-limiting. It allows people to create a new relationship between their life-space and their life-time, between their territory and the pulse of their being, without destroying their inherited balance. The advantages of modern self-powered traffic are obvious, and ignored.”