what? that's not even a real question for school or SAT... but 46 days, 8 hours, and 36 minutes set by a running shoe salesman named Frank Giannino Jr. on October 17, 1980. That's the record but here's my average estimate. If someone ran without sleeping at an average of 5 miles per hour, it would take 536 hours to run across from coast to coast. but that's without sleep or eating or resting or changing shoes. so you have to factor in about 14 hours for each day for those essentials