This is a cool human interest story but I have no idea why it’s at the top of HN. A random ultramarathon not planning for a woman winning just isn’t that surprising or interesting.
If it stays at the top of HN front page, it means that it's relevant for the community. HN is about curiosity and conversations, interesting threads create value so people can learn by spending some time here. In my case, it was the comment of michaelt: https://news.ycombinator.com/item?id=20745614