Roger MrBlack.  I got a better one than that though.  
I was injured in January of 2001 (itb syndrome).  My friend at work asked me to run a mini-marathon with him in April.  Exactly 4 weeks before the half-marathon, I began training.  At the beginning of the training, I was doing 15 miles per week with a long run of 6 miles.  Three weeks later, I was doing 45 miles per week, with a long run of 14 miles.  My time was 1 hour 30 minutes for the mini.
After work tonight, I will dig out my running books and articles and post some evidence.