When not training, I think about training.
Recently, I was wondering about the limits of what's possible. The winner of the last Self-Transcedence 3100 Mile (no, that's not a typo: 5000 km.) averaged 72 miles per day. Not for the benefit of the runners, but for logistical reasons, they're only allowed to run for 15.5 hours per day; it's hard to get people to volunteer to count laps all night for one night, much less 6-10 weeks! What if they were given all the time they wanted? Well, the record for running across the US (also about 3100 miles) is about 72 miles per day. I remember Cottrell saying at the time that he averaged 80 per day until he hit the Rocky Mountains. That seems to be about the limit.
In 6 day races, the winner is usually the one who sleeps the least. Yiannis Kouros (he of the 188.61 miles in one day - chew on that for a bit... 7 marathons, each in 3:20-3:25, back-to-back, plus 5 miles IN ONE DAY), besides being the world's best at almost all ultra distances, also sleeps the least, reportedly as little as 4 hours in 6 days. He's run 635, 635, 639 and finally 644 miles in 6 days, and unofficially did 658 in one of trans-Australia runs. Only 12 other men have run over 600 in 6 days, 6 of those before 1900, when it was a big money proposition.
If you look for the US record, it depends upon where you look. The USATF lists George Gardiner (who?) as best, with 524 miles. Search further and you find Stu Mittleman did 577.75. Search further still and you find in 1888, James Cathcart did 621 (and Patrick Fitzgerald 610 and Daniel Herty 605 about the same time). The record is a little nebulous.
The early guys ran as hard as they could as long as they could. Charles Rowley did his first 100 miles at 8 min./mile (13:26) and then slowed to 10 min./mile for the next 60; he thought he could do over 700, but fell ill. What if they ran more evenly?
I found Mittleman's splits. They add up to 571 miles, rather than 577.75 (later, I found out it was a different race; he broke 570 twice). He did 105 the first day, then 90-95 on days 2,3 and 6. On day 4, he only did 86, but on day 5 did 103. I think this indicates even pacing and that the anomaly in days 4 and 5 are because two rest periods were in day 4, none in day 5. This works out to only 2.5 hours of rest per day after the first day.
How does one train to do such things?
Working at the car wash
12 hours ago