That sounds a lot and it has been often dismissed, but a couple of years ago I did find the original study by the US Army that stated something along those lines.
This from a more recent study :
The perceived exertion was shown to be greatly dependent on the oxygen uptake. From the results a regression formula was calculated predicting the oxygen uptake depending on the mass of the footwear, walking speed and body mass. It was concluded that the mass of footwear resulted in an increase in the energy expenditure which was a factor 1.9–4.7 times greater than that of a kilogram of body mass, depending on sex and walking speed.http://www.springerlink.com/content/u18032vm25770745/
Note the recumbent bike in the "studio" pics. Aarn builds and races those too.
Same thing there. People laugh at them till they try one...
(I have a trike)
Recumbents have been banned by the cycling federation since 1930, because they are faster.. (less energy expenditure)
Currently the highest speed attained (on flat ground) is 135 KMPH , try doing that on a standard bike.
The point here is that Aarn is not stuck on conventional thinking .
http://en.wikipedia.org/wiki/Recumbent_bicycleFranco