We run all week, but only on Fridays do we run a really long run, increasing our distance.
Using this weeks schedule for example, on Friday we ran 13km. Saturday-night/Sunday we ran 10km, Monday night we will run 11km (working more on speed), Wednesday 11km again, then Friday we are scheduled to run 15km.
I would have thought that all week long we are slightly increasing the distance and achieving 15km by Friday. But that is not the case. I do not really understand how it works, but it seems we are solidifying our base at 11km all week, strengthening our bodies to have that as our standard, and the on Friday pushing ourselves to increase that.
Then next week we stabilize our base at the 11-12 range and then move up on Friday to 17km (then the week long runs are no longer even close to the Friday runs.
So I do not understand how the weekday runs prepare us for the increase in distance on the Friday runs.
I guess the real push is from Friday to Friday, with the weekday runs just keeping our base, and improving our speed.
Once you have run 11km, your next barrier is higher. You don't need to keep slowly incrementing upwards - just push yourself a little bit and you can make the jump.
There must be some mussar in that. Keep pushing yourself past your last limit. Strengthen your base, but always push your limits.