Courtney Dauwalter drinks a beer after the Tahoe 200 ultramarathon. Photograph: Max Whittaker/The New York Times

At 1.40 in the morning, running through the woods near Lake Tahoe, Courtney Dauwalter began hallucinating. She saw live puppets playing on a swing se(...)

A while ago, I was standing at the office tea point when a colleague who had heard I was a runner asked me if I did ultramarathons – the term for any (...)