A guide from The Wasatch Yard
What Is a Backyard Ultra?
A backyard ultra is a last-runner-standing race. Everyone starts the same 4.167-mile loop together at the top of every hour. There is no set distance. The race ends when one runner completes one more loop than everyone else.
Four rules make the whole sport
- One loop per hour. Every runner starts the same loop together at the top of every hour, signalled by a whistle or bell.
- Finish inside the hour. Whatever time is left over is your rest. There is no other rest.
- Be at the line for the next start. Missing a start ends your race, no matter how strong you feel.
- Complete the loop under your own power. No pacers on course, no shortcuts, no outside assistance out on the loop.
The rules are easy to understand and hard to obey at three in the morning on your seventeenth lap.
Why every backyard loop is 4.167 miles
4.167 miles is 6.706 kilometres. Run it once an hour for 24 hours and you have covered exactly 100 miles. The odd number makes a full day of racing land on exactly 100 miles.
Because the loop is standardised, lap counts travel. Nineteen laps at a race in Utah means the same thing as nineteen laps at a race in Belgium, which is what lets backyard results be compared and ranked worldwide. A lap is often called a yard, and finishing 24 of them is a 100-mile day.
Courses differ in surface and climb, so some yards are harder than others. The clock does not care. You still have sixty minutes.
Miles, or 6.706 kilometres.
Miles in exactly one day of racing.
Minutes to run it and get back to the line.
Only the last runner standing is credited with a finish.
One winner, and everyone else is a DNF
A backyard ultra needs two things to finish: a last runner standing, and an assist. The assist is the runner who goes out for one more loop and does not complete it, or who cannot start at all. Their exit is what allows the remaining runner to win by completing that loop alone.
The winner is the only person in the field recorded as a finisher. Every other runner takes a DNF against their name, whether they ran two laps or thirty-nine. It looks harsh written down, and it is the reason the racing stays honest deep into the night: there is no consolation placing to settle for.
If nobody is willing or able to start the next loop, the race ends with no winner at all. Those laps still count in the records as the field's shared result.
How runners actually last
Backyard racing rewards patience much more than speed. The clock resets whether you were fast or slow.
- Pick a lap time and hold it. Most runners settle somewhere around 48 to 54 minutes early on. Faster than that burns your legs to buy rest you do not yet need.
- Protect the transition. The rest window is where races are lost. Have your food, layers, and shoes laid out so you are eating within a minute of finishing.
- Eat before you are hungry, drink before you are thirsty. Once you are behind on either, you do not catch up inside a 10-minute window.
- Respect the night. Temperatures drop, footing gets harder to read, and the hours between 2 and 6 AM knock out more runners than the terrain does.
- Do not sit down without a plan. Sitting is fine. Sitting with no one to tell you when to stand up is how races end.
- Have a number, then ignore it. Aiming for 24 laps is useful right up until lap 25, and the runner who came without a ceiling usually wins.
Training for repeated efforts
Training for a backyard ultra looks different from training for a 50K or a 100-miler. You are preparing to start again, over and over, on someone else's schedule.
Practise the hourly format
The single most useful session is a backyard simulation: run a 4-mile loop, come back, eat, change something, and go again on the hour. Three or four repeats teach you more about your own transitions than a long run ever will.
Get comfortable at night
Run in the dark, with the headlamp you plan to race in, on terrain you cannot see perfectly. Learn how much slower you actually move and plan your lap times around that reality.
Rehearse your fuelling
Whatever you plan to eat at hour 14, eat it during training at hour 4 when you are already tired. Race day is not the time to find out that a gel you like fresh is unbearable late.
Train the boring part
Back-to-back medium days build the specific durability this format asks for far better than a single heroic weekend effort.
What to bring to your first backyard
You return to the same spot every hour, so bring more than you think you need. It costs you nothing to leave it in the box.
- Two headlamps, plus spare batteries, so a dead light is never what ends your race.
- More layers than the forecast suggests: a warm mid-layer, a wind shell, gloves, and a hat.
- At least two pairs of shoes and several pairs of socks.
- Food you already know you can eat when tired, including something savoury and something warm.
- A chair, a blanket, and a way to stay out of the wind between laps.
- Anti-chafe, sunscreen, and basic foot care that you use before you need it.
- A written plan your crew can read out loud when you have stopped thinking clearly.
Backyard ultra vocabulary
- Yard
- One 4.167-mile loop. Runners talk about lasting "19 yards" the way road runners talk about a finishing time.
- Corral
- The staging area where runners gather in the last few minutes before each hourly start.
- Assist
- The runner who goes out for the final loop and does not finish it, allowing the last runner standing to win.
- Last runner standing
- The winner: the only runner to complete a loop that nobody else completed. The only official finisher of the race.
- DNF
- Did not finish. In this format, everyone except the winner takes one, regardless of lap count.
- Crew
- The people who feed you, dress you, and get you back to the line between laps. They work between laps and are not allowed on course.
- Backyard
- The format itself. It started in 2011 with Big's Backyard Ultra, held on Gary "Lazarus Lake" Cantrell's own property in Bell Buckle, Tennessee, and named after his dog. Every backyard race since has used the same loop distance and the same last-runner-standing rule.
Common backyard ultra questions
How far is a backyard ultra loop?
4.167 miles, or 6.706 kilometres. That distance repeated every hour for 24 hours comes to exactly 100 miles, which is why every backyard ultra in the world uses it.
What happens if you finish a lap early?
Nothing, except that you get more rest. Finishing in 45 minutes gives you 15 minutes before the next start. Finishing in 55 minutes gives you 5. There is no credit for a fast lap beyond the recovery time it buys you.
How does a backyard ultra end?
It ends when one runner completes a loop that no other runner finishes. That runner is the winner and is the only person credited with a finish. Everyone else in the field is recorded as a DNF, no matter how many laps they ran.
How do you train for a backyard ultra?
Train for repeated efforts rather than one long push. Practise running a loop, stopping, eating, and starting again on a schedule. Run at night with the headlamp you plan to race in, eat the food you plan to race on, and get used to being on your feet again after sitting down.
Do you need a crew?
No, but it helps a lot. The rest window between laps is short, and a crew who can hand you food, swap your layers, and tell you when to stand up removes decisions from a tired brain.
Is a backyard ultra a good first ultramarathon?
It is one of the friendliest ways in. You are never far from your gear, you can stop at the end of any hour, and the distance is entirely up to you. Ten laps is a 41-mile day.
Run a backyard ultra in Park City, Utah
The Wasatch Yard runs the standard 4.167-mile loop through Round Valley, starting at 6:00 PM on Friday, October 23, 2026. Evening start, crew area at the line, and a course that is honest without being brutal.