What Is a Backyard Ultra?

The Short Answer

The backyard ultra is the simplest and most ruthless format in ultrarunning. One loop. One hour. Last person standing wins. Read our complete guide for the full breakdown of rules, records, and history.

The Math

Why It's Exploding in Popularity

The format is brilliantly accessible: anyone can run one loop. The loop distance (6.7 km) is manageable for any runner. What makes it hard is repetition, uncertainty, and the psychological weight of knowing you can't quit and rejoin. It's chess, not checkers. Ready to train? See our training guide and race strategy articles.

The Rules That Matter

The rule set is intentionally simple. Every runner starts the same loop at the top of every hour. If you finish in 45 minutes, you get 15 minutes to eat, change layers, use the bathroom, or sit down. If you finish in 59 minutes, you get almost no reset time. You cannot start early, bank time, skip a loop, or rejoin after missing the bell.

The winner must complete one more loop than every other runner. If all remaining runners stop after the same loop, there is no winner. That single rule creates the distinctive pressure of the format: you are not racing a distance, you are racing the willingness to answer the next start.

What First-Timers Should Know

Backyard ultras are beginner-friendly in one sense and brutally honest in another. The first loop is approachable, but the format exposes weak routines quickly. Shoes, food, lighting, and base-camp setup all matter because you repeat the same process every hour.

For a first backyard ultra, do not obsess over total loops. Build a clean hourly routine: finish calmly, eat immediately, change what needs changing, and arrive at the start corral with time to spare. A runner with a reliable routine often lasts longer than a faster runner who wastes the rest window.