Backyard ultra


The backyard ultra or last one standing is a form of ultramarathon race where competitors must consecutively run the distance of in less than one hour. The distance of each loop is equal to 100 miles divided by 24 hours, or 1/24th of 100 miles, so that a competitor would run 100 miles for a full day of competition. They must repeat this every hour until only one person completes a full lap - the last one standing.
The backyard ultra format has gained a reputation for its grueling and unpredictable nature, as well as the camaraderie among participants. Challenges include sleep deprivation, exhaustion, and varying weather conditions.

History

Backyard ultras are the invention of Gary "Lazarus Lake" Cantrell, who is also one of the founders and race directors of the Barkley Marathons.
The original backyard ultra is Big's Backyard Ultra, which is held on Cantrell's property in Bell Buckle, Tennessee, and is named after his dog. First held in 2011, today Big's is an invitational race where the top competitors participate based on wins in a bracket of the various American and international backyard ultras.

Description

A backyard ultra consists of repeated one-hour laps. Each lap begins on the hour and must be completed within that hour. The distance of each lap is set at, a figure derived to ensure that completing one lap every hour for 24 hours results in exactly covered in a single day.
The event continues until a single runner completes a lap alone; that runner is declared the winner and the sole official finisher, while all other competitors are recorded as "DNF". If no competitor manages to complete one more lap than the others, the race ends with no winner and all competitors listed as DNF. The competitor who completes the second-most laps is commonly referred to as the "assist".
Rules are strictly enforced across local and championship events; runners must be in the starting corral at the bell, may not receive aid on the course, and cannot leave the course except for restrooms.

Global growth and impact

Since its inception, the backyard ultra format has grown into a global phenomenon. By 2023, events were being held in over 70 countries under an international framework that feeds into a World Championship. Media outlets have noted the format's rapid rise in popularity, attributing it to its accessibility and the "existential" nature of a race with no defined finish line.
The format has also been adapted for virtual events, notably gaining traction during the COVID-19 pandemic when travel was restricted. Beyond the sport itself, the format has drawn attention for its psychological depth; coverage in The New York Times highlighted how the grueling, repetitive nature of the event provided a coping mechanism for Ukrainian runners during wartime.

Records

Phil Gore holds the world record of 119 loops, assisted by Sam Harvey at the Dead Cow Gully event in Queensland, Australia on 26 June 2025.
The female world record for a backyard ultra performance is 95 laps set by Sarah Perry at the 2025 Backyard Ultra World Individual Championship in Tennessee.

Milestone performances - Men

Milestone backyard ultra performances, including world records.
YardsNameNationalityRunner up "Assist"DateEvent/PlaceNotes
119 Phil GoreAustraliaSam Harvey 26-Jun-2025Dead Cow Gully, Qld, Australia
116 Łukasz WróbelPolandJan Vandekerckhove 1-May-2025Legends Backyard Ultra, Retie, Belgium
110 Merijn Geerts, Ivo Steyaert, and Frank GielenBelgiumn/a24-Oct-2024Retie, BelgiumBackyard Ultra World Team Championship
108 Harvey LewisUSAIhor Verys 25-Oct-2023Bigs Backyard Ultra, Tennessee, USA
102 Phil GoreAustraliaSam Harvey 21-Jun-2023Dead Cow Gully, Qld, Australia
101 Merijn Geerts, Ivo SteyaertBelgiumn/a19-Oct-2022Kasterlee, BelgiumBackyard Ultra World Team Championship
90 Merijn GeertsBelgiumKeith Russell14-May-2022Rettert, Germany

Milestone performances - Women

Milestone backyard ultra performances, including women's world records.
YardsNameNationalityRunner up "Assist"DateEvent/PlaceNotes
95 Sarah PerryGBRMeg Eckert
21-Oct-2025TennesseeBackyard Ultra World Championship 2025
87 Meg EckertUSAn/a24-Oct-2024TennesseeBackyard Ultra World Team Championship
74 Jennifer RussoUSAn/a30-May-2023Capital Backyard Ultra in Lorton, VA
68 Courtney DauwalterUSAn/a20-Oct-2020Bigs Backyard Ultra, Tennessee, USA
60Maggie GuterlUSAn/a22-Oct-2019Bigs Backyard Ultra, Tennessee, USA
Female overall winner
67 Courtney DauwalterUSAn/a23-Oct-2018Bigs Backyard Ultra, Tennessee, USA
30Katie WrightNZn/a03-May-2019Riverhead Backyard Relaps Ultramarathon, New ZealandFemale overall winner

Notable events

Significant and recurring Backyard Ultra races held around the world.
Event NameLocationFirst heldCourse recordSources
Big Dog's Backyard UltraBell Buckle, Tennessee, USA2011108
Backyard Ultra World Team ChampionshipsGlobal 2020110
Dead Cow Gully Backyard UltraNanango, Queensland, Australia2020119
Legends Backyard UltraBelgium2022116
Suffolk Backyard Ultra FestivalSuffolk, United Kingdom201888
Herdy's Frontyard UltraHerdsman Lake, Western Australia202157

Scientific research

The unique demands of the backyard ultra - specifically the combination of intermittent high-intensity exercise and chronic sleep deprivation - have made the format a subject of scientific study. Research published in PLOS One in 2024 utilized participants in the Suffolk Backyard Ultra to analyze cognitive deterioration. The study found significant impairments in reaction time and executive function as the race progressed into multi-day durations, providing data on how extreme fatigue affects decision-making.