Turn-around point

　　Last year next month, I was around at the finish of the Ehime Marathon for something different from the marathon and I saw lots of runners passing the finish line after their long run of 42.195km. Their faces looked tired and exhausted, but looked proud at the finish at the same time. I didn't know the route of the marathon and I wondered how far they ran. Some of them looked far older than I and fatter than I. I thought, chances were not bad that I could finish the marathon. It was my cue to do the marathon.
　　I had some advice from one of my friends who had a hobby of jogging, about a training plan for beginners. As a result, I started with some rapid walking at the end of last February. I have jogged in the night of weekdays and in the daytime of weekends, and eventually joined two road races of 10km and a half-marathon.
　　Today, I tried to run all the way of the Ehime Marathon to estimate my physical strength. To complete the race, I have to keep it in mind that a high pace during the early part of the race will lead to a drop-out in the latter half. At last after a year's struggle, I reached the turn-around point of the Ehime Marathon, the farthermost point from the start, the answer to the question which I had muttered last year at the finish point of the Ehime Marathon.

http://kumo.typepad.jp/marathon/Marathon_Training.html

(Vocabulary)
turn-around point（マラソンの）折り返し点
sb's cue to do ～するきっかけ