[chrisfosterelli]

They are actually much more similar than most people realize. However, people usually burn more calories total on cycling because it's easier to put longer time periods into cycling than it is for running.

Put another way, an average cyclist will find a 2 hour bike ride to be an average ride but an average runner will consider a 2 hour run to be quite long.

[Buldak]

As much as I enjoy cycling, I don't have anywhere near enough time to accommodate a bike regimen equivalent to my running regimen. To my mind, the only way cycling comes out ahead of running for most people is if (1) they have an usual amount of free time (e.g. enough to go on three hour rides every day), or (2) they're unable to run without injuring themselves.