I have been wondering the same thing! I've been running every other day, without taking the extra day off. That has me at the middle of "week 8", but in reality I've only been running for just over 6 weeks. It's worked out fine for me, but I might consider taking that extra day off (skip a day between runs, skip an extra day between "weeks") as the runs are getting longer.... The best advice I've gotten is the "listen to your body" advice!