I started on a fitness kick last summer, and this game helped a lot:

https://www.zombiesrungame.com

Get started now, and boost your stamina for when Zombie Apocalypse comes out!

Don't run, you'll only die tired

Don't run, you'll only die tired

Snicker. I don't have to be faster than the zombies, just be faster than you.

I don't have to do either, I just have to be the one releasing the zombies in the first place.