THE RACE / THE FORMAT
One yard.
Every hour.
Until one remains.
One 4.167-mile loop (a yard) starts every hour on the hour. Finish in less than one hour, recover with the time left, then return for the next bell.
There is no preset finish time or distance.
NEW TO BACKYARD ULTRA?- FIRST YARD
- December 19, 2026 / 8:00 AM EST
- LOCATION
- Miami Marine Stadium / Virginia Key
- ENTRY
- 18+
THE HOURLY FORMAT
One hour.
Your time to reset.
Choose a finish time and see how much recovery remains before the next start. Everyone still in the race goes again on the hour.
Illustrative timing • 1 hour in 12 seconds
0 COMPLETED LOOPS0 MI COMPLETED
THE COURSE / VIRGINIA KEY
Back to
the Basin.
The planned course combines dirt trail with paved or concrete sections at Miami Marine Stadium / Virginia Key. The same course is planned for the entire race, including after dark.
All race activity takes place outdoors in the area surrounding Miami Marine Stadium, rather than inside the venue.
This illustration shows the planned setting. The final measured course map will be shared before race day.
Planned start / finish
Approximate area- 01
Enter the corral under your own power and be fully inside at the bell. Start with the field on the hour. Three whistles sound three minutes before the start, two whistles two minutes before, and one whistle one minute before.
- 02
No late starts. You cannot skip a yard and rejoin.
- 03
Complete every yard in less than one hour.
- 04
No personal aid during an active yard. Any shared on-course station, if offered, is self-service water or electrolytes only: fill your own bottle, with no personal handoffs or volunteer bottle filling. No on-course station is confirmed; basecamp aid is between yards.
- 05
No pacers or other non-competitors may accompany you.
- 06
There is no predetermined yard cap or finishing time.
- 07
The winner completes one more yard than every other runner. If two runners start a yard and only one finishes within the hour, that completed yard decides the race. No additional yard is run. If nobody completes one more yard than everyone else, there is no winner.
- 08
All other runners technically record DNF. Completed yards remain their official result.
YOUR DISTANCE
Count the returns.
Every completed loop adds to the same question: how far will you go?
Whole loops, 0–10,000.
Planning distance: 4 miles + 880 feet per loop. 24 loops = 100 miles. Outputs are rounded to three decimals; the draft GPX length is separate from this format distance.
CREW + SPECTATORS
Between
the bells.
Crew and spectators are welcome in designated areas. Crew may support runners between yards. Keep the active course, starting corral and emergency routes clear.
Detailed access, setup and overnight procedures will be included in the Athlete Guide.
MBU is mainly self-supported. Bring your own food, nutrition and personal supplies. Water and a limited supply of Näak drink mix will be provided. Final aid locations and procedures will be included in the Athlete Guide. Crew support is only permitted between yards. No specific on-course aid station is confirmed.
CREW + SUPPORT FAQPARTICIPATION
Solo, Duos and Teams of Four
You can run solo or choose an optional duo or team of four. Each runner registers and pays individually, follows the same Backyard Ultra rules and remains eligible for the individual result. Teams are not relays: everyone runs independently, and the team's score is the sum of all valid completed loops. Duos are ranked against duos and teams of four against teams of four. If one runner stops, their completed loops still count and teammates may continue. Existing registrants can join a team without paying again.
SOLO + TEAM FAQDECEMBER 19, 2026 / 8:00 AM EST
The first
start.
Read the full rules and prepare for repeated hourly starts before you enter.
Registration on RunSignup.