I really enjoyed this article and the comments. I am going to sound like a whinner, but I don't mean too. I was working 75 hour weeks this fall. I had a difficult time getting over 50 mile weeks. I am training for a marathon and I will run 20 mile runs inside those 50 mile weeks. It is the only way I can get a long run in. The positives of doing this is leg strength. I feel I have leg strength, but it is true during those weeks I had a difficult time getting quality speed in. Now I am at 60 miles and slowly working my way up. I am not a great runner. I finish in the top 10% at most races, but not major races. This is the way I get to challenge my body at the marathon distance and still try for PRs. I know it is not ideal, but still somewhat effective.
Again thank you for all the comments this has been really a great read.