If there was a technique improvement that would enable you to run at the same heart rate but faster, would you want to know about it? Running economy, improving your technique, might help you improve your times. This might be it. It’s not new but you might not have heard about it. Here are some videos (a video playlist) that will inform you.
There are 6 videos embedded here. Mouse over the movie to see how to navigate to the others. Enjoy!
Although I have tried to limit videos to the subject matter, I do not control the content of these videos.