In an interview with Gary Cohen, Benji Durden said he did much of his running on a loop that took three minutes to run. He'd go for as long as three hours on that loop. There was a thread here a few years ago about Lionel Ortega who did pretty much all of his running on the track at the U of New Mexico. I believe that malmo chipped in and said he'd do as many as 180 miles a week there. There are advantages to staying in the same place. It's really tough to get lost.