Well, it's not for everyone, and I'm not going to claim it's a sign of either physical or mental health, but...
Last month I did a 600 km ride in 39 hours. That was about 235 miles the first day and 150 the second day, if I recall correctly, and that was a seriously hilly ride. In July I did a 1000 km loop around Lake Ontario; the first "day" (from 7:30 pm one day to 9 pm the next day) I rode 299 miles. That was quite flat, and obviously 25½ hours is more than a day. But yeah, people do distances like that.
Why, I can't tell you.
I would like to try it, but I can't get to a place where it would be feasible to attempt it. I think my neck couldn't take it. I would need a modern back to attempt it. Anyway I had a PX 10 that was to big a few years ago. 25" Frame and the guy that bought it was 5'6".
