Lesson learnt from Sundown Marathon

I tried my best to keep pushing my body to go beyond its limit, which I find interesting and challenging. I did minimum training, so my body suffered quite badly during the later part of the run. But what I found surprising was that when I put in a short burst for a short stretch of say 200-300m, I actually find it easier then to slow jog. I kept doing so from about 27km onwards until the end of the run. I would say I put in at least 75 percent effort for this run, next time I must try to at least put in 90 percent effort. Overcoming the most difficult part of the race when you body is giving up, is also the most satisfying. I need to push my body more to cut down the time wasted walking, could cut my timing further.