One 4.167-mile yard. Every hour. Until one remains.

Maybe it is two yards. Maybe four. Farther than you have ever gone. Through the night. Fifty miles. One hundred. The final yard.

Everyone starts the same yard under the same rules. What you come to find out is personal.

Complete one 4.167-mile yard in less than one hour. Use the time left to eat, rest and reset. Be inside the starting corral and start again at the next hourly bell.

There are no late starts or skipped yards. The race is open-ended. One runner must complete one more yard than everyone else to win. All other runners technically record a DNF, with completed yards preserved as their official result.

You do not need previous Backyard Ultra experience. First-time distance seekers and runners competing for the final yard share one course and one set of rules.

Miami Marine Stadium / Virginia Key.

Water, concrete, mangroves and the Basin Trail. The planned course combines dirt trail with paved or concrete sections and returns runners to the same race village every hour. The setting changes with daylight, darkness and sunrise.

Every runner starts the same yard under the same rules.

• Complete each 4.167-mile yard in less than one hour.
• Be inside the starting corral and start with the field at the bell. No late starts or skipped yards.
• No personal aid during a yard. No pacers or non-competitor accompaniment.
• The winner must complete one more yard than everyone else. All other runners technically record a DNF, with completed yards as their official result.

Read the complete rules

First Backyard? Read the FAQ

Register for Miami Backyard Ultra

December 19, 2026 / 8:00 AM EST. Limited to 500 runners.

Race at Miami Marine Stadium / Virginia Key. Parking, packet pickup, basecamp, crew access and final aid procedures are being finalized and will be published in the Athlete Guide before race weekend.

MBU plans to provide common race aid including water, ice and hydration support. Personal crew assistance is only permitted between yards in the designated support area.

Participant award details coming soon.

Read all event details

Provisional course reference. The final measured course map and nighttime instructions will be published before race day.