A Backyard Ultra is an endurance race unlike any other.

The format is simple: runners complete a 4.167-mile loop every hour, on the hour. Finish the loop in less than an hour, and the remaining time can be used to rest, eat, recover, or prepare for the next lap. When the next hour begins, everyone returns to the starting corral and heads out again.

The race continues until only one runner remains.

Twenty-four laps equals 100 miles, but one of the things that makes a Backyard Ultra unique is that there is no predetermined finish line. Every runner arrives with a different goal. For some, success means completing a single lap. Others may be chasing a marathon, a 50K, 100 miles, or simply seeing how far they can go.

A Brief History of the Backyard Ultra

The Backyard Ultra format was created by Lazarus Lake, the race director best known for creating the legendary Barkley Marathons.

The first Backyard Ultra was held in 2011 at Laz's farm in rural Tennessee and became known as the Big Dog's Backyard Ultra. The race introduced a completely new concept to endurance running: instead of racing toward a fixed finish line, participants would continue running hourly loops until only one runner remained.

What began as a small, unconventional event has grown into a worldwide movement. Today, Backyard Ultras are held across the globe, culminating in an international championship where national teams compete in the same last-runner-standing format. Records that once seemed impossible continue to be broken, yet the appeal of the format remains remarkably simple: one more lap.

How Does It Work?

Every hour follows the same cycle:

1. The starting bell rings.

2. Runners complete a 4.167-mile loop.

3. Any time remaining in the hour becomes recovery time.

4. The next loop begins precisely on the hour.

Runners who are unable to complete a loop within the allotted hour are eliminated. The final runner to successfully complete a solo lap is declared the winner.

The simplicity of the format creates a challenge that is as much mental as it is physical.

Why Are Backyard Ultras So Popular?

Backyard Ultras have become one of the fastest-growing formats in endurance running because they offer something different from traditional races.

Every participant shares the same schedule. The fastest runners and the slowest runners begin each lap together. Throughout the day and night, runners experience the same course, the same weather, the same aid station, and the same challenge.

The format also removes many of the barriers that come with longer races. There are no complicated pacing plans, no concerns about missing aid stations, and no need to carry hours of supplies. Every hour provides a fresh start and another opportunity to continue.

The result is an atmosphere that is both competitive and supportive. Every participant is pursuing a different goal, but everyone is facing the same question:

Can one more lap be completed?

More Than a Race

At first glance, a Backyard Ultra looks like a running event. In reality, it often becomes something more.

As the hours pass, the challenge shifts beyond pace and fitness. Success depends on patience, consistency, problem-solving, nutrition, recovery, and the ability to keep moving forward when things become difficult.

Many runners discover that the most memorable moments are not the fastest laps, but the moments when continuing requires determination, resilience, and grit.

The race has a way of reducing a seemingly impossible challenge into a simple task: complete the lap in front of you.

Why the Sisu Project Hosts a Backyard Ultra

The Finnish word sisu describes perseverance, courage, resilience, and the determination to continue despite adversity.

Those qualities are at the heart of every Backyard Ultra.

The Sisu Project exists to create opportunities for exploration, growth, community, and personal challenge. The Backyard Ultra format provides a unique environment where participants can test their limits, support one another, and discover what is possible through consistent effort and determination.

Whether the goal is one lap, a personal distance record, or the final lap of the event, every participant has an opportunity to discover their own version of sisu.

Is a Backyard Ultra Right for You?

Backyard Ultras are often more accessible than they appear.

Participants range from experienced ultrarunners to runners attempting their first running event. The hourly format naturally encourages pacing, breaks the challenge into manageable pieces, and allows each runner to define success on their own terms.

Whether the goal is to complete a couple yards (laps), reach a new distance milestone, spend a day on the trails with friends, or simply explore personal limits, the Backyard Ultra offers a challenge that can be shaped by each individual participant.

Find Your Sisu

The Sisu Backyard Ultra is an invitation to explore your limits, embrace uncertainty, and discover what happens when you keep showing up for one more lap.

The distance is unknown.

The finish line is uncertain.

The opportunity for growth is limitless.