Chalfont Park
Choose your distance on the day — anything from 10K to 41 Mile Ultra.
One entry. Every distance.
The course is a 10.97 km loop. You run as many laps as you want, and you decide on the day — not at the point of entry. Stop after one lap or keep going until 6pm.
| Distance | Laps | Actual |
|---|---|---|
| 10K | 1lap | 11.0 km |
| Half Marathon | 2laps | 21.9 km |
| 32K | 3laps | 32.9 km |
| Marathon | 4laps | 43.9 km |
| 34 Mile Ultra | 5laps | 54.9 km |
| 41 Mile Ultra | 6laps | 65.8 km |
Distance guaranteed. Because you run whole laps, every distance comes in slightly over the standard figure — never under. Your marathon counts.
Exact distances are shown above. Every lap passes the aid station and your drop bag, so you can reassess each time round.
£20 for up to 15K. New to this, or just want a shorter day out? Enter the short distance for £20. If you feel good and want to keep going, let us know before your next lap and pay the difference on the day.
Start and finish marked. Drag to pan, and use the buttons or ctrl-scroll to zoom.
What's included
- Manual timing with Webscorer, and a finisher's medal whatever distance you run
- Aid station every lap — water, soft drinks, and vegan and vegetarian food
- Indoor bag drop and proper toilets
- Qualified medics on site all day
- Free parking
Common questions
Do I have to decide my distance in advance?
No. You enter the race, not a distance. Run as far as you like on the day and we'll record whatever you complete.
What if I want to stop early?
Then you stop. Finish a lap, and that's your distance — you keep your number, you get your medal, and nobody records it as a DNF. There's nothing to drop out of.
Is there a cut-off?
The course closes at 6pm, giving you 9 hours from the 9am start. Walkers are welcome within that.
Is this suitable if I've never raced before?
Yes. A single 11.0 km lap is a perfectly good day out, and you'll be lapped by people running four times as far who will cheer you on as they go past.