;However, once you start increasing mileage, chances are you'll slow down to be able to complete the extra mileage.  Or at least that was my experience when I went from 35mpw to 50mpw.

 

 

I totally agree with this. As my mileage has gone up, I've added recovery paced runs for the first time. These are effortfully easy, in that I have to focus on going slowly. It's exactly the distinction LTH was making about easy v. recovery runs. Anyway, I think adding these have helped me to stay feeling fresh. I think you can definitely work to build your mileage, just make sure you're not adding mileage and intensity simultaneously by really speeding up your easy runs.