Gravel Duathlon
Sat 5 Oct 2024 Hexham, Northumberland, UK

Active Northumberland Gravel Duathlon

This course circumnavigates Kielder Water, the largest man-made lake in northern Europe! Take on hard-packed trails through pine forests on this almost entirely off-road route.

Enter now
  • Sat 5 Oct 2024
Kielder Waterside Caravan Park, Hexham

Gravel Duathlon



Age 17 & over on 31 Dec 2024

  • 10 km trail running
  • 34 km mountain biking
  • 6.4 km trail running


A full weekend of running and cycling celebrating everything that's amazing about Kielder Water, northern Europe's largest man-made lake. 

Surrounded by lush pine forest and with hard-packed trails weaving around its perimeter, the water is the perfect location for these popular races.

forest trails

2,500 runners and duathletes will descend on Northumberland to test themselves over off-road courses, including the headline marathon, half marathon, 10K, standard-distance duathlon and two junior races.

With breathtaking views and professionally organised events, the Kielder Marathon Weekend is definitely one for your calendar!


  • wild location

    Kielder Water is a spectacular backdrop for these races, set amidst verdant pine forests.

  • stunning course

    Mostly off-road, the routes cover hard-packed trails with some undulating terrain.

  • sell-out event

    The weekend is growing in popularity and regularly attracts thousands of athletes and spectators.

  • family-friendly weekend

    With two separate junior races, there's something for everyone at Kielder!

This event is part of Kielder Marathon Weekend.

Event video

  • All fitness levels
  • Event village
  • Free venue entry
  • Spectators
  • Traders at event


  • 10:30 | Car park shuttles start
  • 11:30 | Athletes are asked to turn up at least 90 minutes before race start
  • 13:00 | Gravel Duathlon
  • 13:00 | 10K


  • 08:45 | Athletes are asked to turn up at least 90 minutes before race start 
  • 10:15 | Marathon
  • 10:15 | Half marathon
  • 10:45 | Ospreys run
  • 10:45 | Falcons run

  • Bag storage
  • Bar
  • Cafe
  • Camping
  • Free parking
  • Music
  • Restaurant
  • Rural
  • Toilets

Event HQ

Kielder Waterside Caravan Park
NE48 1BT

Why not make a short break of it and bring your friends and family along? There is plenty to do in and around Kielder Water and the wider Northumberland countryside!

event hub

  • 1 lap
  • Distance markers
  • First aid
  • Marshals
  • Mass start
  • Toilets
  • Traffic free
  • Undulating
  • Water stations
  • Way markers

Route description

Transition 1 is located at Kielder Waterside to allow for easier sign-on before the event, and easier access to the course for spectators.

The first run stage takes you on the Kielder 10K course around Bull Crag peninsula, arriving back to the start/finish area at Kielder Waterside for your first Transition.

The next stage sees you leave Kielder Waterside on your bike following the Lakeside Way up to Kielder Village, then taking in the North Shore on two wheels, covering 34km you will return over the impressive Kielder Dam to the South Shore and Transition 2 on the approach to Bull Crag Peninsula.

The final stage is a 6.4km run taking in the final stages of the 10k route and the stunning Bull Crag Peninsula and back along the Lakeside Way to the finish at Kielder Waterside.

Distances are approximate.

route map
The course circumnavigates the largest man-made lake in northern Europe, Kielder.

Bike type

Mountain bikes, hybrid bikes, gravel bikes or cyclocross bikes. Not road bikes.


Your running kit will be transported between transition areas and your bike will be returned to Transition 1 for collection.

Cut off time

4.5 hours.

Athletes must be confident they can complete the course in under 4.5 hours.

  • Goody bag
  • Medal
  • Technical t-shirt


  • Medal
  • Tech t-shirt
  • Goody bag
  • Free Park and Ride system for all runners
  • Secure baggage drop
  • Prizes for top 3 male and female

Optional extra

  • Spectator pass - Β£3 per day
  • Local produce and refreshments

  • Age 17 & over on 31 Dec 2024
  • Entries open
  • Enter online
  • Race pack by post
Enter now

Teams of 3

Relay team members age 16+

Enter as a team of 3 and take on the event in a relay. Give yourselves an inventive team name. All competitors will receive free transport to and from transition areas.


Entry fees

Entry fee (Unaffiliated)


Valid to 31/12/2023

Entry fee (Affiliated)


Valid to 31/12/2023

Team entry fee


Valid to 31/12/2023

Entry fee (Unaffiliated)


Valid from 01/01/2024

Entry fee (Affiliated)


Valid from 01/01/2024

Team entry fee


Valid from 01/01/2024

Kielder is marketed as Britain’s most beautiful and now I can truly understand why it is a beautiful place, with a very tough course. How many hills? Absolutely loads, so many I totally lost count. It was a new experience for me as I am not used to trail routes and it was a tough task... The sense of achievement when reaching the finish line really was a special one as this is no easy half marathon to take on! Caroline A

It is certainly Britain's most beautiful half marathon. I urge anyone to do it. You won't get a more scenic half and it's by water and so peaceful, what more could you want? Claire W

This is quite a special event to do in a stunning location and will certainly cater for those who want a different challenge over a marathon distance rather than a flat or tarmac surface to run on. The course undulations add to this challenge as well as running off road on very well maintained trails. The scenery is beautiful, the event is friendly and laid back and there is a lot of things to do for families as well. Great end of season event, would definitely recommend it. Stephan B

Really enjoyed the course and support at various points on the course. Well organised, plenty of information given. Lots of toilets and area to keep warm and dry at start. The ‘village’ at the end was perfect, warm dry, clean and welcoming. Kandis W

All round amazing event. I have completed the half marathon and the full marathon a few times. Will be back again, love the atmosphere, the volunteers, everyone involved. Clare M

Excellent marshalls Easy navigation Beautiful scenery Annoyingly undulating (in a good challenging way!) Comment of the day “ignore the hill and enjoy the zig zags” I don’t think anything can be improved except my fitness for next year. Michele S

Did Kielder Half. Loved it. Kenneth J

An absolutely fantastic race, very challenging but amazing, I will definitely be joining you next year. Coolio P

Oh, let me tell you about the Active Northumberland Kielder 10K – it's like a burst of sunshine in the running world! This event is an absolute hoot and a half.. the scenery is like running through a fairytale forest.. The atmosphere is as cheerful as a group of giggling unicorns, with fellow runners high-fiving and cheering each other on. It's impossible not to catch the infectious enthusiasm in the air! Andrew G

Reviews thanks to RaceCheck

Other races at event

  • Sat 5 Oct
  • #2 of 6
Kielder Waterside Caravan Park, Hexham




Age 15 & over

  • 10 km trail running
  • Sun 6 Oct
  • #3 of 6
Kielder Waterside Caravan Park, Hexham




Age 18 & over

  • 26.2 miles trail running
  • Sun 6 Oct
  • #4 of 6
Kielder Waterside Caravan Park, Hexham

Half Marathon



Age 17 & over

  • 13.1 miles trail running
  • Sun 6 Oct
  • #5 of 6
Kielder Waterside Caravan Park, Hexham

Junior | The Ospreys



Age 6-10

  • 1.5 km trail running
  • Sun 6 Oct
  • #6 of 6
Kielder Waterside Caravan Park, Hexham

Junior | The Falcons



Age 11-15

  • 2.5 km trail running