I'm an engineer by training and nature. I read an article
comparing the efficiency of locomotion of various species.
The condor was the most efficient getting from point A to
point B. The human was somewhere in lower half, maybe about a
third of the way up the list. However, if you give the human
a bicycle, he is the most efficient of all species. If my
memory is correct, we still haven't ever developed any device that
is more efficient. That is why I love the bicycle. I
ride everywhere, all year long.