
Sumarpo
Nene Valley Swimrun Festival
Sibson Lake,
31 Great North Rd, Stibbington
PE8 6LS
Saturday 7th June and Sunday 8th June 2025
The Nene Valley Swimrun Festival
We’re excited to launch our 2025 season this weekend with the Fenland Runner Intro 5K Swimrun taking place on Saturday — a perfect way to dip your toe into swimrun and soak up the atmosphere.
Then on Sunday, it’s time a full day of epic adventure across multiple distances:
- 🏃♂️ Sprint 10K Solo
- 🏃♀️ Half 21K Solo & Team
- 🏃♂️ Full 31K Solo & Team
No matter your level, there’s a challenge waiting for you!
Join Us for the Pre-Race Supper – Saturday at 7PM
Come and share a relaxed evening with fellow racers, volunteers, and organisers before the big day. All are welcome — it's the perfect chance to meet your swimrun community and fuel up for race day.
A Big Thank You to Our Local Supporters
We are incredibly grateful for the generous support of the local parishes and landowners, including:
Castor, Alwalton, Stibbington, Yarwell, Sutton, Elton, Fotheringhay, Nassington, and Wansford Parish Councils,
Yarwell United Charities, and Elton Hall.
Their cooperation and kindness are what make it possible for us to deliver such a stunning course through some of the most beautiful countryside and villages in the region.
The Course:
All swim sections take place in the gorgeous, clean waters of the River Nene, with both upstream and downstream sections adding variety and adventure.
The races feature flat, off-road runs along compact trails, field paths, and quiet tracks
We can't wait to welcome you to the start line for a weekend full of challenge, community, and outdoor adventure.
See you in the valley!

Our Intro 5k Swimrun race consists of approx.
1125m of open water swimming and 3910m of mixed terrain running. 4 swim sections 5 run sections. Longest run 1800m Longest swim 500m
Our Sprint 10k Swimrun race consists of approx.
2155m of open water swimming and 7850m of mixed terrain running 5 swim sections 6 run sections. .Longest Run 3250m. Longest swim 700m
Our Half 21k Swimrun race consists of 2 laps of the 10k course
Our Full 31k Swimrun race consists of 3 laps of the 10k course
SCHEDULE
(subject to change)
Saturday 7th June
- 1515hrs to 1830hrs Registration Opens.
- 1615hrs Mandatory Race Safety Brief 5k Intro
- 1630hrs Race Start 5k Intro
- 1835hrs Mandatory Race Safety Brief for 10k, 21k and 31k**
**Race Safety Brief for the 10k, 21k and 31k is in your Racebook for those unable to attend this brief.
It is a Mandatory Requirement to read the Racebook or attend this safety briefing.
- 1900hrs PRE RACE SUPPER
Sunday 8th June
- 0745hrs to 10.45hrs Registration Opens.
- 0900hrs Race Start 3k
- 0900hrs Race Start 21k
- 1100hrs Race Start 10k
PRICING
- Intro 5k solo £35
- Sprint 10k solo £55
- Half 21k solo £105
- Half 21K team £205
- Full 31k solo £175
- Full 31k team £350
No extra fees at checkout
THE COURSES
5k Solo Swimrun Course
Saturday 7th June 2025
Start time 1630hrs
Splits
Run 1 400m
Swim 1 500m downstream
Run 2 800m
Swim 2 275m downstream
Run 3 860m
Swim 3 150m
Run 4 1800m
Swim 4 200m
Run 5 50m
Course Details
Distance 5.116 km
Ascent/Descent 5 m / 6 m
Uphill 1.08 km (21.1%
Downhill 0.81 km (15.8%)
Flat 2.97 km (58.1%)
Height Gain 4 m
Steepest Uphill +0.7% (at 0.00 km)
Steepest Downhill -1.1% (at 0.27 km)
Longest Uphill 0.81 km (at 3.24 km)
Longest Downhill 2.97 km (at 0.27 km)
10k Solo Swimrun Course = 1 lap
21k Solo & Team = 2 laps
31k Solo & Team = 3 laps
Sunday 8th June 2025
Start time
0900 hrs 21k and 21k
1100hrs 10k
Splits
Run 1 400m
Swim 1 750m upstream
Run 2 3250m
Swim 2 150m downstream
Run 3 3000m
Swim 3 740m upstream
Run 4 1000m
Swim 4 375m upstream
Run 5 1100m
Swim 5 280m upstream
Run 6 50m
Course Details
Distance 10.066 km
Ascent/Descent 26 m / 26 m
Lowest Point 6 m (at 6.39 km)
Highest Point 13 m (at 6.12 km)
Uphill 1.71 km (17.0%)
Downhill 1.71 km (17.0%)
Flat 6.57 km (65.3%)
Height Gain 7 m
Steepest Uphill +4.4% (at 5.94 km)
Steepest Downhill -4.4% (at 0.36 km)
Longest Uphill 2.52 km (at 6.39 km)
Longest Downhill 0.99 km (at 2.88 km

Camping
Camping is available at this venue please book below
