I ran almost 65 miles a week on average this summer, while the previous 3 summers I've never done more than 50. I did the 1 tempo run every 2 weeks, 1 long run a week, 5-6 easy runs a week, etc.
Exactly a year before I started doing more than 60 mpw, I was at a 17:14 for 5k. Now? it's gotten slower at 17:23 (which happens to be my PR for this season)... why is this???