How the format works
A backyard ultra runs on one rule: a 4.167 mile loop, called a yard, starts at the top of every hour. Finish the loop before the hour expires and you may start the next one. Miss the start, or fail to finish in time, and you are out. The race has no finish line; it continues until only one runner completes a yard alone. That runner wins. Everyone else, regardless of how many yards they covered, records a DNF. The odd loop length is deliberate: 4.167 miles times 24 yards is exactly 100.008 miles, so a runner who survives a full day has covered 100 miles in 24 hours.
The pace and rest tradeoff
Every backyard decision reduces to one exchange: running a yard faster buys more rest before the next start, but the speed itself costs energy you will want twelve hours later. Run a 45 minute yard and you sit for 15 minutes; jog a 55 minute yard and you get 5. Most experienced runners settle between 45 and 52 minute yards in the early hours, fast enough to earn a usable rest window, slow enough that the effort stays conversational. The calculator above shows exactly what each target buys you: the pace per mile and per kilometer the yard requires, and the minutes of rest it returns.
Worked example: planning 50 minute yards
Say you plan 50 minute yards. The calculator shows that a 50 minute yard demands a 12:00 per mile average across the 4.167 mile loop and earns 10 minutes of rest before the next start. That window is enough to eat something real, refill bottles, and sit briefly. Now slow to 55 minute yards. The pace relaxes to about 13:12 per mile, which feels easier lap by lap, but the rest shrinks to 5 minutes, which stops covering shoe changes and real food. The gap between those two plans looks small on paper and decides races in practice: the runner with a workable hourly routine outlasts the runner who is merely still moving.
Strategy notes from the ultra world
- Bank nothing. The format punishes speed held too long. A 40 minute yard in hour three earns rest you cannot store and spends legs you cannot replace.
- Rest is a skill. Eat first, sit second, and never lie down early. Runners who nap in the opening hours almost never see the night through.
- Night yards decide most races. Practice running at odd hours and keep the between-lap routine automatic so a foggy brain at 3am has nothing to figure out.
- The survival floor of about 14:24 per mile is theoretical. You cannot use the whole hour and still make the next start, so build your plan around 45 to 52 minute yards and treat anything near the hour as an emergency, not a strategy.
Related tools and guides
For a first-person view of what preparing for this format actually looks like, read the site author's account of training for his fifth backyard ultra around a job and kids. To translate a yard target into splits and speeds, use the pace calculator. The time on feet calculator helps estimate long training efforts on trail terrain, and the ultra fueling planner turns your projected hours on course into an hourly carb, fluid, and sodium plan.
Frequently asked questions
What is a good yard time for a first backyard ultra?
Somewhere between 48 and 52 minutes. That is roughly 11:30 to 12:30 per mile with walk breaks included, which feels almost embarrassingly easy in the first hours, and that is the point. A 50 minute yard earns you 10 minutes every hour to eat, change socks, and sit down, and it leaves enough margin that a rough patch does not immediately threaten the next start.
How far do backyard ultra races actually go?
Local events are often decided somewhere between 20 and 40 yards, but at the top end the format keeps stretching. The world record has passed 100 yards, which is more than 400 miles at one loop every hour for over four days. The distance is open ended by design: the race only stops when one runner is left.
What pace should I train at for a backyard ultra?
Train mostly at or slower than your planned yard pace, which for most runners means easy aerobic running in the 11 to 13 minute per mile range with deliberate walk breaks. There is no speed requirement in this format, so long runs, time on feet, and brisk walking practice matter far more than tempo work. Rehearse the exact run-walk rhythm you plan to use on race day.
How do people eat during a backyard ultra?
In the rest window, mostly. Runners come off the loop, eat real food first while standing, then sit for whatever minutes remain. Small, frequent portions beat big meals: broth, rice, potatoes, sandwiches cut into quarters. Many runners also carry a gel or chews on the loop for the night yards when appetite fades. Practicing your hourly eating routine in training matters as much as the running.
What happens if two runners both finish the last yard?
The race is not over. If more than one runner finishes a yard, everyone lines up for the next hour and the race continues until only one runner completes a yard that nobody else finishes. If the final two both quit or both time out on the same yard, there is no winner: this is the assist rule in action, since the runner-up exists to push the winner onward. Every finisher except the winner records a DNF.
Is walking allowed in a backyard ultra?
Yes, and every experienced backyard runner walks on purpose. The only requirement is completing the 4.167 mile loop before the hour expires. A steady walk of about 14 minutes per mile technically covers the distance, though it leaves no margin. Most runners blend running and walking to hit 45 to 52 minute yards while keeping their heart rate low.