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Dorney Triathlon (plus 5K, 10K, and Half)

Event details


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We are excited to announce the return of Dorney Triathlon in 2019. Join us at Dorney Lake; home to London 2012’s rowing and canoeing events for a sprint or standard distance triathlon. The purpose built lake is perfect for the swim and the flat grounds lend themselves to a totally flat bike and run course, ideal for chasing down a new personal best!

Review summary

6 Reviews
  • Course
  • Organisation
  • Atmosphere
"Very enjoyable run and everything was organised well. It would be nice if there..."


George B
"Great course, Dorney is a lovely lake to swim. Dead flat run and bike.<br />One..."


Chris D
"Really enjoyable, good venue, easy to get to, close transitions and very flat..."
See all reviews

How to enter the Dorney Triathlon (plus 5K, 10K, and Half)

  1. Olympic Triathlon

    Triathlon: Swim 1.5km, Bike 40km, Run 10km
    Event passed
  2. Sprint Triathlon

    Triathlon: Swim 0.75km, Bike 20km, Run 5km
    Event passed
  3. Half Marathon

    Run 21.1km
    Event passed
  4. 10K

    Run 10km
    Event passed
  5. 5K

    Run 5km
    Event passed

Dorney Triathlon (plus 5K, 10K, and Half) routes


The Swim -

The route is clockwise. The course will be well marked with swim buoys and you will complete 1 lap for the sprint distance and 2 laps for the standard distance. After completing your correct number of laps, you will head for the swim exit marked by flags.

The Bike Ride -

The 5km bike loop will be completed 4 times for sprint distance athletes and 8 times for standard distance athletes. It is your responsibility to count your own laps. We find the best way of doing this is with the aid of a bike computer or watch.

The Run -

Starting from the transition area, triathletes will run either 1 or two out and back loops, alongside the lake. The course is on pavements and is completely flat. There will be 1 drinks station on the course, manned by marshals serving water in plastic cups. This is the only drinks station and you will pass it on each lap.

Event Details

  • Chip timed results
  • Unique themed medal
  • Free official event photos
  • Fruit & Flapjacks
  • Event T-shirt included with both triathlons, available for £10 with the other races

Start Times

10:00 am - Half Marathon
10:45 am - 5K & 10K


The temperature of the lake is taken on the morning of the event and if it is over 14 C then wet-suits will be optional. If the temperature is over 22 C then wet-suits will not be allowed. Please don’t email us if wet-suits will be allowed at the race, as we can’t tell you this information until the temperature is taken on race day.

You are free to wander around the lake so you can see where the competitors will be running. It is lapped so you will see them on numerous occasions.

No volunteers needed :)

Race Rules -

Normal BTF (British Triathlon Federation) rules apply. All these rules are important but the most important of these is that all competitors must secure their cycle helmet (on their heads!) before removing their bike from the rack and must not undo or remove it before racking their bike at the end of the cycle section.

You must also fully comply with and follow all rules of the Highway Code. Our primary consideration is your safety, make it yours as well!

The Half Marathon course has a strict 3-hour time limit!

Meet the organiser

RunThrough are a running community-based in London, inspired & led by a small passionate group of running geeks. We organize events all over the UK’s capital and the North West of England.


Dorney Triathlon (plus 5K, 10K, and Half) reviews (6)

4.7 out of 5 stars

  • Course
  • Organisation
  • Atmosphere
  • Did the Sprint Triathlon in 2019

    Great course, Dorney is a lovely lake to swim. Dead flat run and bike.
    One bike turn direction was a bit unclear when entering transition from the final lap.
    Safety pins were not provided for attaching numbers to race belt.
  • Did the Sprint Triathlon in 2018

    Really enjoyable, good venue, easy to get to, close transitions and very flat so PB friendly
  • Did the event in 2013

    Very enjoyable run and everything was organised well. It would be nice if there was another water station possibly 2 more. Otherwise everything was well organised, and staff were very helpful.
  • Did the event in 2018

    The race was managed very well except there could have been another water station at the other end of the lake... it was very hot and there is no shade so an extra drink would of helped.Thanks
  • Did the event in 2018

    Excellent race, really well organised and great atmosphere. Lovely scenic setting and totally flat Course! Also great to go to a race where you then also dont have to pay more to park and there arent annoying rules about using headphones.10/10 and look forward to doing it again :)
  • Did the Olympic Triathlon in 2018

    Really excellent event. This was my first standard distance tri and as a beginner I really appreciated the simple layout. I can also appreciate the more experienced triathlete would like that it's an opportunity to push pace and times.
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