A consistant item on this blog has been the debate over running singles versus doubles. I've run through the analysis from a scientific standpoint and a practical standpoint a couple of times. Recently, I wrote an article on the subject for Running Times that integrated everything together that many of you will hopefully find interesting. My conclusion is that there is a time and place for each, you just have to know when each is needed. That's another reason why we can't get into dogmatic statements like I believe in singles or I'm a high mileage (or low mileage) coach. The truth is if you want to be a good athlete or coach, you have to be highly adaptable and be able to use multiple ideas.