Originally Posted by
Number400
Depends on how fast you ride. A walk is about 90 calories a mile. Biking that distance can burn almost no calories but if you go 20mph + or treat it like an interval the whole time, you can burn some serious calories pushing that kind of pace.
Pretty much impossible to burn 90kcal per mile on a bike for any length of time. A 200lb rider putting out around 320 watts to go 25mph will burn only about 1200kcal per hour, or 20kcal per minute, which is about 50kcal per mile. And 25mph is a very respectable pace for a one hour time trial, most people can't do it.
However, if you measure by time instead of distance, an hour spent walking will burn maybe 300 kcal. Very easy to burn more than that in an hour's cycling, 15 mph would do it even on totally flat terrain.