Backyard Ultra Belgium is a Backyard (6.7km loops) ultra marathon in Retie, Belgium. Elevation: 50m D+. Difficulty: challenging (Challenge Rating 35/100). DNF rate: 98%. Time limit: 100h. Surface: trail. Established 2018.
Backyard Ultra Belgium
Retie, Antwerp, Belgium
"The last person standing wins — 6.7km loops every hour until only one runner remains."
A backyard ultra in the Belgian forests — the devastating format where you run 6.7km every hour until you're the last one standing.
The Course
A backyard ultra format race where runners complete a 6.7km (4.167 mile) loop every hour, with the last person standing declared the winner. The flat Belgian forest course through Retie's pine woods is deceptively brutal — the format tests mental fortitude as much as physical endurance.
flat
backyard
1
Runner Experience
Loop-based format with continuous access to a central aid area between laps.
Warm, inclusive finish line with a strong community feel. Runners celebrate together regardless of finish time.
Race Day Weather
10°C
4° – 14°
80%
50%
Belgian autumn. Cool, often wet. Night temperatures can be cold. Multiple weather cycles over 24+ hours.
Stats & Records
2018
1
Entry
€60
March
months
Lore & Trivia
Belgium's backyard ultra brings the last-person-standing format to the Benelux countries. The event has grown rapidly as the backyard format sweeps across Europe, attracting runners from Belgium, the Netherlands, and northern France who are drawn to the egalitarian nature of the format. Belgian ultra running culture is small but passionate, and the backyard format — which requires no qualifying and rewards stubbornness over speed — fits the national character perfectly.
- ▸ By definition, there is exactly one finisher in every backyard ultra — the last person standing.
- ▸ Top backyard runners can go for 60+ hours, covering over 400km in 6.7km loops.
- ▸ The format was invented by Lazarus Lake, the same eccentric who created the Barkley Marathons.
- ▸ The simple format belies extraordinary mental and physical demands — the certainty of another loop breaks most runners.
- ▸ Established in 2018.
Belgian backyard runners bring the same stubborn determination to the loop that they bring to their beer and chocolate — absolute commitment.
Notable Editions
The 50-Hour Barrier
Belgian runners pushed past the 50-hour mark for the first time, demonstrating that the small country's backyard scene had genuine last-person-standing depth beyond the casual community level.
Compare with another race
Similar Races
16 MAY 2026
Centurion Backyard Ultra
Goring, United Kingdom
17 APR 2026
Sweden Backyard Ultra
Borås, Sweden
15 AUG 2026
Big's Backyard Ultra
Bell Buckle, United States
18 MAY 2026
6 Jours de France
Privas, France
Frequently Asked Questions
How long is Backyard Ultra Belgium? +
Backyard Ultra Belgium is a Backyard (6.7km loops) ultra with 50m of elevation gain on trail terrain.
How hard is Backyard Ultra Belgium? +
Backyard Ultra Belgium is rated challenging with a Challenge Rating of 35/100 (Moderate). The DNF rate is 98%. Runners have 100 hours to finish.
What is the weather like at Backyard Ultra Belgium? +
Average temperature is 10°C (range 4°C to 14°C) with 80% humidity and a 50% chance of rain. Belgian autumn. Cool, often wet. Night temperatures can be cold. Multiple weather cycles over 24+ hours.
Are crew and pacers allowed at Backyard Ultra Belgium? +
Crew access is allowed. Pacers are not allowed.
Are you the organizer? Claim this race
Stay in the loop
New races, course records, and stories from the trail — monthly