How a backyard ultra works
Each loop is called a yard. It is exactly 4 miles 880 feet, or 6.7056 km, so that 24 of them make 100 miles in a day. Every yard starts exactly an hour after the last. Warnings come three, two and one minute before, and at Big's Laz then rings a cowbell. Everyone has to be inside the starting corral and leave on the bell. Late starts are not allowed.
Whatever time is left when you finish the loop is yours to eat, sleep or change shoes before the next bell. Finish a yard in more than an hour, or fail to start one, and you are out. The last runner to complete a yard after everyone else has stopped wins. The runner who stops last before the winner is called the assist.
If nobody can complete one more yard than everyone else, there is no winner. That happened in Belgium's team races in 2022, at 101 yards, and 2024, at 110.
The rules on the loop
- You may leave the course only to use the toilet.
- Nobody else may run with you, including runners who have already dropped.
- No personal aid on the loop. Crews help only between yards.
- No artificial aids, including trekking poles.
- Slower runners must let faster ones pass.
Day loop and night loop at Big's
At Big's the course changes with the light. For 11 hours runners use a trail loop with about 450 feet of climbing. For the 13 night hours they switch to an out-and-back on the road past Laz's house, with about 90 feet. Most runners find the night loop easier.
How far is a backyard ultra?
As far as the last runner goes. Type a number of yards to see the distance and the time on the course.
One yard is 4.1667 miles (6.7056 km), started on the hour.
Distance covered
100 mi
160.9 km after 1 day on the course.
Common milestones
| Yards | Miles | Kilometres | Time on course |
|---|---|---|---|
| 12 | 50 | 80.5 | 12 hours |
| 24 | 100 | 160.9 | 1 day |
| 36 | 150 | 241.4 | 1 day 12 hours |
| 48 | 200 | 321.9 | 2 days |
| 72 | 300 | 482.8 | 3 days |
| 100 | 416.7 | 670.6 | 4 days 4 hours |
How to get to Big's
You cannot enter Big's directly. Since 2020 the championship has alternated between two formats, and each has its own route in.
Odd years: the Individual World Championship
The individual race is held at Big's in odd years, next from 16 October 2027. The field is 75: the top 50 national champions from the previous year's team championship, plus 25 at-large places for the best performances anywhere in a two-year window. For 2027 that window runs from 16 August 2025 to 15 August 2027.
Even years: the World Team Championship
In even years every nation runs its own race at the same moment, and teams of up to 15 score the total yards of all their runners. Team USA runs at Big's. It is made up of six Silver Ticket winners from assigned US races and the nine best at-large performers, and is open to US citizens and permanent residents.
Getting started
The usual way in is through one of the hundreds of affiliated backyard races around the world. Results from affiliated races count towards national teams and individual qualification. The official calendar listed more than 700 affiliated races in October 2026.
Records
The backyard world record is 119 yards, about 496 miles, set by Phil Gore of Australia at the Dead Cow Gully Backyard Ultra in June 2025, with Sam Harvey of New Zealand as assist on 118. A claim of 123 laps from a Russian race in June 2026 was declared void by Laz, because video showed other people on the course.
At Big's, Phil Gore holds the course record of 114 yards from 2025. Britain's Sarah Perry set the women's world record of 95 yards in the same race.
| Record | Runner | Time | Year |
|---|---|---|---|
| Backyard world record | Phil Gore (Australia) | 119 yards | 2025 |
| Women's world record | Sarah Perry (UK) | 95 yards | 2025 |
| Big's course record | Phil Gore (Australia) | 114 yards | 2025 |
| Team USA race at Big's | Scott Snell (USA) | 88 yards | 2024 |
Source: official race website, checked 19 October 2026.
How the record has grown
| Yards | Runner | Race and year |
|---|---|---|
| 68 | Johan Steene | Big's, 2018 |
| 85 | Harvey Lewis | Big's, 2021 |
| 101 | Merijn Geerts and Ivo Steyaert (no winner) | Belgium team race, 2022 |
| 108 | Harvey Lewis | Big's, 2023 |
| 116 | Łukasz Wróbel | Legends Backyard, Belgium, 2025 |
| 119 | Phil Gore | Dead Cow Gully, Australia, 2025 |
Recent races at Big's
| Year | Race | Winner | Yards | Assist |
|---|---|---|---|---|
| 2025 | Individual World Championship | Phil Gore (Australia) | 114 (475 mi) | Ivo Steyaert, 113 |
| 2024 | Team USA race | Scott Snell (USA) | 88 (367 mi) | Megan Eckert, 87 |
| 2023 | Individual World Championship | Harvey Lewis (USA) | 108 (450 mi) | Ihor Verys, 107 |
| 2022 | Team USA race | Piotr Chadovich (USA) | 76 (317 mi) | Harvey Lewis, 75 |
| 2021 | Individual World Championship | Harvey Lewis (USA) | 85 (354 mi) | Chris Roberts, 84 |
2025: the longest race yet at Big's
Phil Gore won with 114 yards, after Ivo Steyaert of Belgium stopped at 113. Gore ran his loops about six minutes faster than the rest of the top four, which over the race added up to roughly 12 extra hours of rest. Harvey Lewis and Jon Noll both reached 111, a US record, and Sarah Perry's 95 broke the women's world record.
2026: the team championship
The 2026 World Team Championship started at 7:00 a.m. Central time on 17 October, with 69 nations starting together. When we checked on 19 October, after 52 yards, 12 of the 15 Americans at Big's were still running and Japan led the team standings. Results are provisional until the organisers confirm them, and we will add them here.
Team champions
- 2020: Belgium, 574 yards.
- 2022: USA, 860 yards.
- 2024: Belgium, a record 1,147 yards.
History
Laz Cantrell, who also created the Barkley Marathons, launched Big's in 2011 because he wanted a race that rewarded mental toughness rather than speed. It is named after his dog, Big. For its first decade it was a single race in Tennessee. Maggie Guterl became the first woman to win, with 60 yards in 2019.
In 2020 the pandemic pushed the championship into national satellite races, which became the team championship. The format has since spread around the world: the official site counted more than 700 affiliated races in 82 countries, and 55,000 athletes in the past year. Laz says nobody is more surprised than he is.
What it takes
Speed matters less than you might think. In 2025 the top 25 runners at Big's averaged about 50 minutes 50 seconds per loop, leaving around nine minutes each hour. The skill is in using that gap: eating, managing feet and snatching sleep in a few minutes at a time, for days.
Runners set up a tent or chair next to the corral, with their crew, food and kit close by. Laz has called the race half running, half poker, because nobody knows how long anyone else can last.
How to watch
The races are streamed on the Backyard Ultra Channel on YouTube. In individual years live results are on RaceResult, and in team years the official dashboard updates the team and runner standings about once a minute.
Questions people ask
How far is a yard at Big's Backyard Ultra?
4 miles 880 feet, which is 4.1667 miles or 6.7056 km. Twenty-four yards make 100 miles.
How long does Big's Backyard Ultra last?
Until only one runner can complete a yard. The individual championships lasted 85 hours in 2021, 108 in 2023 and 114 in 2025.
What is the Big's Backyard Ultra record?
114 yards, 475 miles, by Phil Gore in 2025.
What is the backyard ultra world record?
119 yards, about 496 miles, by Phil Gore at Dead Cow Gully in Australia in June 2025.
What is the women's backyard ultra record?
95 yards, by Sarah Perry of the UK at Big's in 2025.
How do you get into Big's Backyard Ultra?
By qualifying. In odd years the field is the top 50 national champions plus 25 at-large runners. In even years Team USA runs at Big's, selected through Silver Ticket races and at-large results.
Is Big's held every year?
Yes. The Individual World Championship is in odd years and the World Team Championship in even years.
What happens if the last two runners stop on the same yard?
There is no winner. That happened in Belgium's team races in 2022 and 2024.
Are trekking poles allowed in a backyard ultra?
No. The rules ban artificial aids, including poles.
Where can I watch Big's?
On the Backyard Ultra Channel on YouTube, with live results on the official dashboard.
Sources
Rules, qualifying and records come from the official Big's Backyard Ultra site and RaceResult, checked on 19 October 2026, with BBC Sport, Trail Runner and iRunFar for history and race analysis. The 2026 team championship was still running when we checked, so its results are not included yet. Running for Good Ultra is independent and has no connection with the race.
- Big's Backyard Ultra: official site checked 19 October 2026
- Big's Backyard Ultra: rules checked 19 October 2026
- Big's Backyard Ultra: 2027 roster and qualifying checked 19 October 2026
- Big's Backyard Ultra: road to Big's checked 19 October 2026
- Big's Backyard Ultra: Team USA race checked 19 October 2026
- Big's Backyard Ultra: national record holders checked 19 October 2026
- Big's Backyard Ultra: affiliation and tickets checked 19 October 2026
- Big's Backyard Ultra: race calendar checked 19 October 2026
- 2026 World Team Championship dashboard checked 19 October 2026
- RaceResult: 2025 results checked 19 October 2026
- RaceResult: 2024 results checked 19 October 2026
- RaceResult: 2023 results checked 19 October 2026
- Big's Backyard Ultra: 2023 championship checked 19 October 2026
- Big's Backyard Ultra: 2022 team championship checked 19 October 2026
- iRunFar: 2021 Big's results checked 19 October 2026
- iRunFar: 2025 Big's pace analysis checked 19 October 2026
- BBC Sport: the backyard ultra checked 19 October 2026
- Trail Runner: a race with no end checked 19 October 2026
- Athletics Weekly: Sarah Perry's world record checked 19 October 2026
- Marathon Handbook: 2026 records voided checked 19 October 2026
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