Fitting a walk into a busy life can be challenging, so I suggest walking rather driving to work or to run errands as often as you can - in other words, think of walking as alternative transportation.
If the only way you could read an email was to run a mile first, the urge would quickly die. Human beings constantly do subconscious effort/reward calculations. Tapping a screen is the easiest of physical tasks.
Just the attempt to learn a [new] language is like running different software through the brain.
