The official world record for 100k is 6:13:33 which works out to be exactly 6:00 per mile.
To run a sub 6 hour 100k you need to run 5:47.6 per mile for the full 62.13 miles. The 50 mile world record is about 5:50 pace currently.
What would a normal training week look like for a guy who could be the first to break 6 hrs and what would they look like.
Here is my thoughts:
The guy would be about 5'5" to 5'8" with a small bone structure, narrow hips and a BMI in the 18.5 range. Very light and economical form.
He'd probably have a solid world class marathon background in the 2:09 to 2:11 range.
A typical training week might look like this:
Mon: 15-20k @ 6:00-6:30 pace
Tue: 30k @ 5:45-6:00 pace
Wed: 30k @ 5:45-6:00 pace
Thu: 20-30k Tempo @ 5:00-5:15 pace or 4-5 x 5k @ 5:00 pace
Fri: 30k @ 5:45-6:00 pace
Sat: 30k @ 5:45-6:00 pace
Sun: 60k @ 5:45-6:00 pace or 80k @ 6:00-6:30 pace
205-250k per week (127-155 miles)
Scary to even think about.
The key would be someone who is so efficient as to be able to constantly refuel at that type of pace. That pace would have to be a fairly comfortable type of training pace for him.
It would take someone with the current mileage and training pace of a Brian Sell and then slowly train them to extend their long runs and learn to refuel on those runs.
No world class marathoner is currently willing to do that as they can make far more money running marathons. But maybe one day a few of them will seek out this new challenge.