Copenhagen Backyard Ultra

Løbsbeskrivelse fra 2027

One loop. Every hour. Until only one runner is left.

We’re bringing the backyard ultra out of the countryside and into the city parks. CPHBYU27 is for everyone, you can come for a few laps or chase the 48 loops. There’s no finish line until there’s only 1 runner left.

Anyone can start:

The first loops feel easy. At around 9–10 minutes per km you have plenty of time, so beginners and elite runners start side by side. Some aim for 4 loops, a little over a half marathon. Others go for 24 loops, which is 100 miles. You set your own goal.

Practical Info:

Race Start: 10:00am on September 4th, 2027, CEST UTC+2 (Please be at the start corral for race briefing at 9:40)
Distance/loop: 6.7 km (1Yard = 6.706 km, the official backyard distance) x ∞
Time/loop: 60 minutes
Capacity: 600 runners
Age limit: 16+ (runners under 18 need written guardian consent sent to support@hourzero.dk)
Basecamp setup/Bib Pickup: Tiøren, Amager (Open for setup from September 3rd, 2027 14:00–20:00, and on the 4th from 07:00, CEST UTC+2)
Route: Basecamp is located at Tiøren and the loop/yard runs roughly along the Amager Strandpark coast – Link to Strava or Komoot can be found at hourzero.dk (route is subject to minor changes before the event)
Headlamp: Mandatory once it gets dark. Parts of the course have street lighting, but long stretches are dark.
At basecamp: Water station and toilets at basecamp. Bring your own food and race nutrition.
Timing: The timing chip is built into your bib. Wear it on the front and visible on every loop.
Tents and gazebos: Allowed, max 3×3 m per runner. Set up during basecamp opening hours.
Crew: No crew registration needed. Crew can support you between loops inside the crew zone.
Metro: Femøren station (M2) is a short walk from Tiøren.
Parking: Paid public only. Spaces are limited, so we recommend taking the metro or being dropped off.
Liability: Participation is at your own risk.

How it works: (official Backyard Ultra rules)

Every hour on the hour, a new loop starts. You run 6.7 km (6.706 km, the official backyard distance) and get back before the hour is up. Whatever time is left is yours to rest, eat and get ready for the next loop. When the next hour starts, you go again.
Every loop starts on the bell, for everyone at the same time. Signals sound 3, 2 and 1 minute before each start.

Your race is over if you:

don’t finish a loop within the hour
aren’t inside the start corral when the bell rings
leave the marked course or cut a corner
get help from anyone outside the race during a loop

Once you’re out, you can’t rejoin. Your result is the number of loops you completed. A partial loop doesn’t count.
Your crew can help you as much as you like between loops, but only inside the crew zone in the basecamp. On the course, you’re on your own: no pacers, no food or drink handed to you, and no poles.
Toilet breaks, food and gear changes all come out of your 60 minutes, so plan your time wisely.

How you win:

The last runner standing isn’t the winner yet. To win, you have to run one more full loop alone and finish it within the hour. If you don’t make it, nobody wins, and every runner gets a DNF (“Did Not Finish”).

The last runner to drop out before the winner gets the title of “assist”. Everyone else gets a DNF too. That’s the format.