Quote:
Originally Posted by RobertSmalls
P&G on a bike might make sense at a walking pace, but if you P&G at higher heart rates, you're doing it wrong....
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That seems accurate, though walking pace for a bike is significantly faster than actual walking and likely much more efficient since you can coast and your legs balance each other out rather than lifting and dropping (and your whole body lifting a bit each step). So you *should* be able to cover a lot more ground and do it faster on a bicycle using only the effort of walking.
Edit, ok maybe that is too obvious
http://en.wikipedia.org/wiki/Bicycle_performance
"A human being traveling on a bicycle at low to medium speeds of around 10-15 mph (16–24 km/h), using only the power required to walk, is the most energy-efficient means of transport generally available. Air drag, which increases roughly with the square of speed,[4] requires increasingly higher power outputs relative to speed, power increasing with the cube of speed as power equals force times velocity. A bicycle in which the rider lies in a supine position is referred to as a recumbent bicycle or, if covered in an aerodynamic fairing to achieve very low air drag, as a streamliner.
Racing bicycles are light in weight, allow for free motion of the legs, keep the rider in a comfortably aerodynamic position, and feature high gear ratios and low rolling resistance.
On firm, flat, ground, a 70 kg person requires about 30 watts to walk at 5 km/h. That same person on a bicycle, on the same ground, with the same power output, can average 15 km/h, so energy expenditure in terms of kcal/(kg·km) is roughly one-third as much. Generally used figures are"