Here's an interesting race concept...

[nadra's babydaddy]

http://shastatrailruns.com/4mph-challenge/

The 4mph challenge.  You run 6 mile loops averaging 4mph or faster.  Fixed start at the beginning of each loop every 90 minutes (i.e. if you average 10mm and take an hour, you get 30 minutes to rest).  Keep going until you quit or take longer than 90 minutes to complete a loop.

WHOSIN???

[merigayle]

There is an ultra called the Back Yard Ultra put on by the guy who is the RD for Barkley. It is a 4 mile loop. Every hour you have one hour to complete the loop. This goes on until one man is standing.