Sports Ultramarathon runner Zach Bitter breaks 100-mile treadmill world record at home in Phoenix May 17, 2020Arizona RepublicComments Off on Ultramarathon runner Zach Bitter breaks 100-mile treadmill world record at home in Phoenix For Zach Bitter, 100-mile treadmill world records are made to be broken within one year. He ran the distance at a pace of 7:17 per mile.