  In a six-day footrace, competitors accumulate as much distance as possible on
foot over 144 consecutive hours by circumambulating a loop course. Now an
obscure event on the fringe of ultra running and contested by amateurs, six-day
races and the associated sport of pedestrianism used to be a lucrative
professional athletic endeavor. Indeed, pedestrianism was the most popular
spectator sport in America c. 1874-c. 1881. We analyzed data from 277 six-day
races spanning 37 years in the post-pedestrianism era (1981-2018). Men
outnumber women 3:1 in six-day race participation. The men's (women's) six-day
world record is 644.2 (549.1) miles and the top 4% achieve 500 (450) miles.
Adopting the forecasting model of Godsey (2012), we predict a 53% (21%)
probability that the men's (women's) world record will be broken within the
next decade.
