The folks that came up with this are brilliant: ZOMBIES, RUN! (A running game & audio adventure for iOS/Android by Six to Start and Naomi Alderman). As they say:
Zombies, Run! is an ultra-immersive game for the iPhone, iPod Touch, and Android where you help rebuild civilisation after a zombie apocalypse. By going out and running in the real world, you can collect medicine, ammo, batteries, and spare parts that you can use to build up and expand your base – all while getting orders, clues, and story through your headphones.
If you find your running routine is getting stale, this could be the perfect way to reinvigorate it. I haven’t tried this yet, but I am thinking about it, especially for winter, when running becomes that much more challenging.