You don't need a gym or even a running track to build your cardio fitness. Just a few flights of stairs can do the trick, if you have a good plan to work from. These routines from Fallout Fitness fit the bill. Photo via VisualHunt.
For example, in your first week of stair climbing, you'll sprint up the steps for 60 seconds, and then recover with two minutes of easier paced stair walking. By the end of the eight week program, you'll be sprinting for 90 seconds and resting for just one minute.
For a well rounded endurance program, combine these stair workouts with Fallout Fitness's other endurance programs: Either the sprint-based cycling or running workouts, or the program of steady fast walks and slow jogs.
Whether you're outrunning zombies or just building your heart and lungs for better health, check out the link below for all of their cardio endurance programs.
Cardio Zero to Cardio Hero [Fallout Fitness]