Well, I've begun the dreaded week 6. Today's interval runs didn't seem too bad (although I think the program had an evil plan to time my runs exactly with the onset of the uphill portions). I was also pleased at how quickly I recovered during the walks. I'm just a bit sore (muscles, tendons, and ligaments), but I don't feel it's anything worth worrying over. I even had enough left over to push slightly at the end of the last run interval (1.94km run and 1.45km walked). I'm pleased.