Want to go long(er) – 255 Triathlon launches

If an iron-distance race isn't quite enough for one day, perhaps the new 255 Triathlon from TriBourne Multisport Events could be calling you?
225 Triathlon
Get the ultimate guide to destination racing

The World’s Longest Single-Day Triathlon Launches – 255 Triathlon 

  • 5km swim, 200km bike, 50km run
  • A unique experience for both competitors and spectators
  •  The event will take place at the historic Goodwood Motor Racing Circuit on Sunday 8th August 2021

TriBourne Multisport Events, organisers of the award-winning Eastbourne Triathlon, are excited to launch a brand-new format to the triathlon world – 255 Triathlon. Consisting of a 5km swim, 200km bike and 50km run, the 255 Triathlon is the longest single-day triathlon in the world. This gruelling physical and mental challenge will be the first of its kind anywhere in the world.

225 Triathlon

The inaugural 255 Triathlon will take place in the UK next summer at Goodwood Motor Racing Circuit, West Sussex. The first edition of the race will be limited to 300 competitors, swimming in the nearby Westhampnett Lake before making their way onto the historic motor racing circuit. After completing 52 traffic-free laps on the bike, athletes will head out onto the run for ten laps on the circuit’s perimeter path. Competitors tackling this ultra-endurance event will have up to 18 hours to complete the distance.

This traffic-free, multi-lap format will offer a unique race experience for both participants and spectators. The pit lane will provide the focal point of the event with spectators able to support athletes continuously throughout the day. With music, commentary, live lap timing and leaderboards, this will provide a race experience like no other. 

Race Director, Matthew Dowle, said “Ironman has always been widely regarded as the ultimate single-day endurance event. We feel the time is right to introduce the next step for endurance triathletes. 255 Triathlon will not only push competitors to a new level of physical and mental endurance but will also provide an unparalleled level of engagement for spectators throughout the whole event. We’re very excited to share our vision with the triathlon world.”

Registration is now open, but places are filling up fast.

To guarantee your place in this historic event head over to 255triathlon.com and secure your spot.

225 Triathlon
Written by
Press Release

Ten of the best – Unforgettable triathlon moments that have defined 2026 so far

IRONMAN 70.3 Lapu Lapu 2026 results: Wire-to-wire wins for Schoeman and Van Coevorden

70.3 Northern California next for Sam Long after one of his ‘best ever’ performances

Mika Noodt opens up on ‘trauma’ after horror Swansea ambulance crash

Beaugrand world title bid is ON as WTCS Weihai start lists are revealed

‘The most crazy thing’ – Harry Palmer devastated as injury halts impressive season

Alpe d’Huez 2026: Results and report as Alanis Siffert and Thomas Steger claim victories

World Triathlon confirms formal bid for Commonwealth Games return at Amdavad 2030

Ten of the best – Unforgettable triathlon moments that have defined 2026 so far

IRONMAN 70.3 Lapu Lapu 2026 results: Wire-to-wire wins for Schoeman and Van Coevorden

70.3 Northern California next for Sam Long after one of his ‘best ever’ performances

Mika Noodt opens up on ‘trauma’ after horror Swansea ambulance crash

Beaugrand world title bid is ON as WTCS Weihai start lists are revealed

‘The most crazy thing’ – Harry Palmer devastated as injury halts impressive season

Alpe d’Huez 2026: Results and report as Alanis Siffert and Thomas Steger claim victories

World Triathlon confirms formal bid for Commonwealth Games return at Amdavad 2030

Share to...