American runner Zach Bitter sets 100-mile world record with 6:48 pace

Stadium red plastic track
American runner Zach Bitter broke the 100-mile world record on Saturday. (Getty)

American long-distance runner Zach Bitter set the 100-mile world record on Saturday at the Six Days in the Dome event in Milwaukee with a time of 11:19:13.

And seemingly not having enough at that point, the 33-year-old ran for another 40 minutes to re-set his own 12-hour distance world record at 104.8 miles.

Bitter already had the top American time for 100 miles, when he ran a 11:40:55 in his second-ever 100-mile event in 2013. And for the last six years, he's trained to top Russian runner Oleg Kharitonov's 2002 world mark, which he bested by nearly 11 minutes.

“It was a huge weight off my shoulders,” Bitter told “It’s been a huge part of my training for six years, so when I got through it, it was like finally putting the last puzzle piece together.”

Bitter needed a 6:47 pace to top Kharitonov's record and was feeling good around the halfway mark, but his 50-mile mark of 5:40:38 initially seemed problematic. If he added his usual positive split of 10 to 20 minutes, he may not have topped the 11:28:03 mark he needed.

“Around 50 miles, I wasn’t super confident that I could double back on that,” Bitter said. “I had a few good laps after that, and when I got to the distance of my longest long run, I got into a really good headspace. It was the mental break I needed to stop thinking about the last dozens of miles as a 100-miler, and think of it as something I do on the weekends.”

Amazingly, Bitter actually carried a negative split, as he ran the second half of the race two minutes and three seconds faster than he ran the first half.

Once he set the first world record, he kept it going to take the 12-hour record, topping his own 2013 mark of 101.8 miles. He slowed down considerably at the end, but an 8:03 mile pace after that long is nothing to scoff at.

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