Not to make matters even more technical than running should be, but I saw this article in runnersworld, and thought it was interesting. Years ago before reading this article, I realized I wasn't breathing enough when I was running, my breaths were too long going in and out. I wasn't getting enough oxygen to my muscles, once that happens you become tired and loss steam. Then I decided to take shorter breaths, which started to fuel my muscles more sufficiently. Just from breathing more and quicker, I got a bit faster and just noticed an overall better performance and efficiency with my running.
http://www.runnersworld.com/running...unnersWorld-_-Content-Training-_-RunningOnAir
http://www.runnersworld.com/running...unnersWorld-_-Content-Training-_-RunningOnAir