Originally Posted by tacojohn

You have to consciously do this, at least at the beginning (I've never tried to ingrain it as a habit though).

... but for running, you should be inhaling for two strides, exhaling for two strides. It's not necessarily good for maximum effort, but once you set a good rythym as habit, and it's a rythym which supplies your body with lots of oxygen, you'll fall into naturally when you ride, and feel more comfortable when you're in it. And because most people have inefficient rythyms, when you set a good one it will feel like you're much fitter than you are.