A few ways:

* I run a 5K over lunch or after work 2-3 days a week. Very good for clearing my head when working on something tricky. Also fantastic for getting through audiobooks!

* If it's a nice, quiet weekend and friends are free, we often go on a hike somewhere outside the city.

* If it's a nice, quiet weekend and friends aren't free, I'll go on a bike ride somewhere in the city.

* Every now and again I'll go bouldering with friends, or maybe swimming.

* Finally, I walk a lot, because I live in London. You rack up a lot of steps just getting places here.