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⏵ Course guide · Tennessee ultra

Big’s Backyard Ultra Course Guide

Big’s is the one that started it all, the original backyard ultra on Laz Cantrell’s farm in Bell Buckle, Tennessee, and the world championship every other backyard race on earth is modeled on. There is no finish line. You run a 4.167 mile loop on the hour, every hour, until you are the last person standing. I will walk you through the loop and the format first, then give you a pacing and fueling plan built for a race that never tells you how far you are going. Free calculators along the way to dial in your own numbers.

⏵ At a glance

Big’s Backyard Ultra quick facts

Date
Saturday, October 17, 2026 (third Saturday in October)
Location
The Big Farm, Bell Buckle, Tennessee (Gary “Lazarus Lake” Cantrell’s land)
Format
Backyard / last person standing: a 4.167 mi loop on the hour, every hour
Distance
Open-ended; a full 24 hours of yards equals 100 miles, and it keeps going
Start
Near dawn (about 7:00 AM CT), a new yard on every hour after that
Cutoff
Per yard: finish the loop and be back in the corral before the next hourly start, or you are out
Surface
Wooded singletrack loop by day, a gravel/road out-and-back loop after dark
Field
Invite-only world championship (2026 is the team year; individual runs in odd years)

These facts come from UltraSignup, the official race site, and public records. The backyard format has no set distance, the entry is invite-only, and the start time and rules can shift year to year, so confirm the current specifics with the official race before you plan anything.

The loop and the format: where Big’s is won and lost

Forget elevation profiles and finish splits. At Big’s the course is the same 4.167 mile loop run over and over, and the race is really a contest of who can keep doing that the longest. The loop is wooded singletrack on the farm by day and a road out-and-back after dark. It is rolling, not mountainous. The hard part is the clock and your own head, not the hills.

The yard: 4.167 miles, on the hour, every hour

Here is the whole game. Every hour, on the bell, everyone starts the 4.167 mile loop together. You have 60 minutes to finish it and be back in the starting corral for the next bell. Run it in 50 minutes and you get 10 minutes to sit, eat, and deal with your feet. Run it in 58 and you get almost nothing, then you have to turn around and do it again. The math is the trap: 24 of these is 100 miles in a day, and the winner usually goes well past that into multiple days.

The smart move is to run each yard at a relaxed, repeatable effort and bank rest in the corral, not speed on the loop. Going faster does not get you a better finish, because there is no finish. It only buys you a few more minutes of sitting. The runners who last are the ones who treat the loop as a chore to do efficiently and protect every spare minute between laps.

Day loop vs night loop

During daylight the loop is wooded singletrack through the farm, with roots, leaves, and the kind of rolling terrain that is easy fresh and annoying on lap 30. After dark the course switches to a gravel and road out-and-back for safety, which is simpler footing but its own kind of lonely. You will run through at least one full night, usually more, so a reliable headlamp, backup batteries, and a system for the cold pre-dawn laps are not optional.

Treat the day-to-night and night-to-day transitions as their own checkpoints. Sunset is when the mood gets heavy and people start doing math they should not. Sunrise is when survivors get a second life. If you can grind through that first dark night still moving and still eating, you are in the real race.

The corral cutoff and the assist

There is exactly one rule that matters and it is brutal. Be in the corral when the bell rings, ready to go, or you are out. Finish the loop a few seconds late, or wander up to the line a few yards behind the start, and you get a DNF, no appeal. There are no intermediate cutoffs and no overall time limit because there is no set distance. Every hour is the cutoff.

The win condition is just as stark. The race ends when one runner completes a loop that nobody else finishes, and that person has to go run one final loop alone to make it official. The runner who drops one yard short, the de-facto runner-up, is recorded as the "assist." Everyone else is a DNF. It is the only race I know where second place and last place are written down the same way.

Pacing strategy for a race with no finish line

Pacing a backyard ultra is not about a goal time, because there is no goal distance. It is about picking a loop pace you can hold for days and protecting your rest. Run too fast and you burn yourself out chasing minutes that do not matter; run too slow and you have no buffer for a bad lap.

Pick a loop pace you can repeat half-asleep

The target is a loop time that leaves you real rest every hour without ever feeling hard. For a lot of runners that is a comfortable 50 to 55 minutes per 4.167 mile lap early on, which banks 5 to 10 minutes of corral time. Use a grade-adjusted pace to figure out what effort that actually is on the rolling loop, because the gentle climbs eat more time than they look like they should, and you want a pace that stays easy when you are sleep-deprived at 4 AM, not just when you are fresh on lap two.

The number-one mistake here is treating the loop like a race and sprinting it for ego. All that buys you is a slightly longer sit, at the cost of legs you will desperately want on day two. Run it boring. Boring is the whole strategy.

Know what a day actually costs you

Even though there is no finish line, it helps to plan in chunks: get to 24 yards (a 100 mile day), then re-set and go again. Use a race-time prediction off your real fitness to sanity-check what holding a given loop pace for a full day does to you, so you go in with a realistic picture of how deep you can push before sleep and fueling become the limiter instead of your legs.

A backyard ultra rewards stubbornness and management far more than raw speed. Reality-check your endurance against the format with an equivalent-effort estimate from a recent long race, then plan to be conservative early. The runner who is still calmly clicking off easy laps at sunrise on day two is almost never the one who looked fastest on Saturday afternoon.

⏵ Free tools to plan your yards

Fueling and the mental game over multiple days

A backyard ultra can stretch into two, three, or more days of running, so fueling is not a race-day plan, it is a way of life for as long as you are out there. The corral is your aid station, your kitchen, and your bedroom, and the runner who keeps eating and keeps their head together outlasts the one who is simply fitter.

Eat every single lap, even when you do not want to

Because the laps are short and the effort is easy, your stomach handles real food here better than in a flat-out race, and you should use that. Aim to take in a steady stream of carbohydrate every hour, often in the range of 150 to 300 calories per yard depending on your size, and lean on actual food (broth, rice, sandwiches, hot stuff at night) alongside gels and drink mix. The danger is not your gut. It is the slow drift into a calorie hole over many hours that you never climb out of, so eat on schedule from the very first lap, long before you feel like you need it.

Keep sodium and fluid steady the same way. You are not sweating buckets on an easy loop, but over days it adds up, so take electrolytes every lap and drink to thirst rather than overdoing it. Set your corral up so the right food is in your hand the second you finish, because by hour 20 you will not have the brainpower to make decisions.

The mental game is the actual race

This is where Big’s is truly won. The format is a slow grind designed to break your will, not your legs, and the lows come in waves, usually worst in the dark hours and again in that mid-afternoon slump on day two. The trick is to never make a quit decision while you are low. Get to the corral, sit down, eat something hot, deal with your feet, and tell yourself you only have to do one more lap. Then do that again. Shrinking the race down to the next single yard is how people go from 50 miles to 200.

Sleep is the wild card. Some runners nap for a few minutes in the corral on fast laps, some never sleep at all and ride it out. Figure out your own approach in training, protect your feet obsessively, and have a crew or a plan to drag you back to the line when your brain starts negotiating. The body can usually go a lot further than the mind wants to let it.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight and a multi-day backyard effort with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.

⏵ Train for it with Summit Line

Get a training plan built around YOUR fitness and the kind of relentless time-on-feet a backyard ultra demands. Summit Line reads your real training, builds the back-to-back long efforts and durability the format asks for, and rehearses your fueling so the yards become something you execute, not guess at.

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Big’s Backyard Ultra FAQ

How does Big’s Backyard Ultra work?

It is the original backyard ultra, a last-person-standing race. Every runner has to complete a 4.167 mile loop, and a new loop starts on the hour, every hour, kicked off by a bell. If you finish the loop fast you get the leftover minutes to eat, change, and rest before the next one, and if you finish slow you get almost nothing. The instant you cannot complete a loop in the hour, or you are not in the starting corral when the bell goes, you are done. There is no set distance and no finish line. It just keeps going, one yard at a time, until a single runner completes a loop that nobody else does.

How long is a loop, and how far do people run?

Each loop, called a yard, is 4.167 miles, which is 100 divided by 24. So a full day of running, 24 yards in 24 hours, comes out to exactly 100 miles. The thing is, the race does not stop at a day. It is normal at Big’s for the winner to go well past 100 miles into multiple days of running, and the course best is 108 yards, about 450 miles, set by Harvey Lewis in 2023. You do not pick your distance here. The competition picks it for you, because you keep going as long as someone else does.

How hard is Big’s Backyard Ultra?

It is brutal in a way that has almost nothing to do with the terrain. The loop itself is gentle rolling farm trail with no big climb, so the difficulty is the format, not the vert. You are running roughly a 4 mile loop over and over with no real break and no end in sight, your sleep gets shredded down to a few minutes an hour at best, and the mental weight of knowing you could be out there for days is the actual crux. Most people are not beaten by their legs. They are beaten by the math, the sleep loss, or the moment they decide to sit down and not get back up.

What is the cutoff at a backyard ultra?

The cutoff is simple and merciless: you have one hour to complete each 4.167 mile loop and be back in the starting corral before the next hourly bell. Miss the loop, or show up to the corral late by even a few yards, and you get a DNF on the spot. There are no intermediate cutoffs and no overall time limit, because there is no set distance. Every hour is its own cutoff, which is exactly what makes the race so relentless.

What is the course and weather like at Big’s Backyard Ultra?

The loop runs on wooded singletrack through Laz Cantrell’s farm in Bell Buckle, Tennessee during the day, then switches to a gravel and road out-and-back loop after dark for safety. It is rolling rather than mountainous, so do not expect a big climb, but the constant gentle up and down adds up over dozens of laps. Mid-October in Middle Tennessee can swing a lot: mild or warm days, cold nights, fog, dew, and rain are all in play, and you will run through at least one full night cycle, often more. Plan your gear for warm afternoons and cold, wet 3 AM laps.

How do you get into Big’s Backyard Ultra?

You do not just sign up. Big’s is the backyard world championship, and entry is by qualification only through the global satellite series. Runners earn a spot by winning a silver-ticket backyard event or ranking among the top at-large performers for their country, and the format alternates year to year between a team championship and an individual championship. If you want to run a backyard ultra without the qualification gate, look for one of the many satellite races worldwide that use Laz’s exact rules. They are the normal on-ramp, and a great place to learn the format before you ever chase Big’s.

This guide is independent and for planning only. The format, date, start time, course, and entry rules come from public sources and can change year to year, so confirm the current specifics with the official race before you register or run. The fueling and pacing advice is general and not medical advice.