I can't run outdoors anymore and I'm avoiding the treadmill like the plague so I've taken to running stairs. It's a great cardio and strength training workout, and like running, you're using your entire body to get you up those steps. It's not a total substitute for running but it's better than sitting on my couch.
Running stairs is like using the stair-stepper machine at the gym without the enticing bars on each side. Back in the day, when I went to a gym, I'd ALWAYS find myself holding on for dear life on those machines. Doing so decreases the intensity of the workout and the amount of calories you are burning.
Here's what I do:
I started by running five sets (up and down) of five flights of stairs. The first couple of times, it hurt, my chest was burning and I was tired but it does get easier. I am now at seven sets of the same five flights. The goal is to do 8 sets in 15 minutes.
I've yet to run down the stairs. Typically, I run up as fast as I can and use going down the stairs as a way to catch my breath. I believe in safety first and its easy to fall down a flight of stairs. In the near future, I'll work on walking faster but I'm staying away from running.
I do this twice a week.
Use your arms just like you do when running on a track or on the street. Keep them at your side and away from the railings. They will help propel you forward.
Step on your toes. Try to spend the least amount of time possible on a step. This means your whole foot shouldn't touch the step. You should be "kissing" it with your toes and moving on.
Breathe. As you approach another flight of stairs, its easy to take a deep breath and hope that it will be over soon. Avoid that as much as you can. Keep a steady pace in your breathing.
Be creative. I'm running straight up the stairs and back down. Some people hop up, walk briskly side-to-side like a lunge, or skip every other step. It's a long winter so changing it up will make a big difference.