I just finished a 18.433km running that lasted about 1hh:30mm:25ss !
It's my long run for the week and feeling it a bit. I think it is just in my head though. I forget to have my usual pre work out that is stacked with a lot of caffeine and it kinda gets me moving as a result.
So many times during my run I felt like I should have stopped or cut it short but kept going only to keep the same pace I have been for the previous four weeks...so it seems it was definitely all in my head.