After 13 days of running, how about a blog full of 13 running related numbers?
13 = number of days run so far this month
10 = number of days run in the dark
2 = pairs of running shoes I own
4.5 = average number of miles I run per day
8.1 = longest daily mileage run so far this month
1 = number of dogs that I often take running
2 = number of legs I have
18 = number of runs left this month
1 = number of marathons completed
16 = number of half-marathons completed
10 = running shoe size
8.1 = number of miles run today
59.57 = number of Janathon miles so far