I think that the MOST important thing I have discovered in my new-found running "career" - which has now logged 1300 klms since January 2014 -- is giving myself permission to do whatever I want !!! Run however I want!!
I initially started to simply "exercise" because I was getting old and fat - and could see my contemporaries losing their ability to even walk. So I started out with the goal to be able to walk for 5Klms and the impossible dream was to be able to run 1 KLm. I have now exceeded these goals by a margin beyond my wildest imagination. But this means that I now have nothing to prove - even to myself - so all I really want to do now is to continue running forever. BUT - the word "running" now means for me whatever I decide it is -- not from somebody else's definition. I know an oldish man (74YO) who categorically refuses to walk at anytime during his weekly 5K parkruns - but it is plain to see that he is hurting himself by the way he runs ( too fast at the beginning, poor form as he runs and getting worse as the run proceeds). He WILL NOT accept my advice to stop to smell the roses along the way!! So now - I leave him to his choice