I have always noticed that most training programmes on the Internet ( regardless of distance) go something like this . Three levels of programme -
Beginner -- running to finish
Intermediate -- running to improve time/performance of previous race
Advanced -- - accomplished competitive runner -- competing for even faster times.
OK - so I am a Beginner - Running to Finish - But I have already now finished a 5k race, 10K race and HM. I don't want to improve my 'times' - what I want to do is to run the distances easier/stronger.
I can now, after 2 years , run the 5K distance at will -- sometimes fast (for me, sometimes slow -- but the 5K no longer holds any fear for me.
But 10K - and 21K are a different matter - I have "experienced" them both once. But now I want to conquer them -- forget times/pace , I just want to be able to run them strongly and easily.
I am guessing that what I need to do is just to run - more and more - longer and longer - at a slow pace.