1 week (eg from Mon-Sun). Add the total mileage you run.
eg.
Mon-4km,
Tue, 6km,
Wed, Rest,
Thurs, 8km
Fri, Rest
Sat,8km
Sun, Rest
Total mileage for 1 week = 26km
Next week, you should not run more than 10% of 26km. that means max
you can run next week = 26+2.6=28.6km
U next to increase the mileage progressively, so as not to hurt ur
body and allow it to adapt slowly. 
