Zach Bitter shatters 100-mile world record at Six Days in the Dome

American ultrarunner and Wisconsin native Zach Bitter has unofficially broken another 100-mile world record. He finished 100 miles in 11:19:13 at the Six Days in the Dome event in Wisconsin, beating the previous record held by Russian athlete Oleg Kharitonov at 11:28:03.

Zach Bitter sets unofficial new 100-mile world record of 11:19:18 at the Six Days in the Dome event in Wisconsin. (Previous: 11:28:03, Oleg Kharitonov, 2002) https://t.co/YVW2q9Fszy

— iRunFar (@iRunFar) August 25, 2019

RELATED: Zach Bitter breaks 100-mile trail world record

The event takes place on an indoor track, and is designed to provide the ideal space for elite runners to break 24-hour, 48-hour and six-day world records.

Canadian ultrarunner Dave Proctor also bettered his own national 48-hour record at the event (unofficially), after covering 362.65 kilometres. (His previous record, set last year in Arizona, was 358.16 kilometres.) Proctor was targetting the Canadian 6-day record. (According to the Association of Canadian Ultrarunners, the Open 6-day record of 870.25K was set by David Bennett in 1981, and the M45 6-day record of 805.99K was set by Michel Careau in 1988.)

Zach Bitter ran 11:19:13 to break the WR in the 100 mile, then ran 105.15 in the 12-hour and broke his own record!! @AltraRunning @iRunFar @zbitter pic.twitter.com/IfuUUZ7P9E

— TRACI FALBO (@FALBOTRACI) August 25, 2019

Bitter’s time means that he ran four consecutive sub-3 hour marathons. His official finish time for the 12-hour event is 11:58:32, and in that time he traveled 104.88 miles, which reportedly also breaks his previous 12-hour world record by three miles.

In November 2018, Bitter also broke the trail 100-mile world record at the Tunnel Hill 100-mile race in Vienna, Illinois in 12:08:36. The course is on smooth wide rail trail and has less than 600 metres of elevation change. In 2015 he ran 100 miles at the Desert Solstice 24-hour race in 11:40:55, which was the American 100-mile record before today.

Results from the event can be found here. Six Days in the Dome continues through August 31.

RELATED: Camille Herron breaks 24-hour WR and US 100-mile record at Desert Solstice