Sun, 14 Mar 2027
Next race
Start time
TBC
Status
ClosedFission 20 Entry, Date & Race Guide
Hamfields, South West, UK
Closed
PB-friendly
Next race
Sunday, 14 March 2027
Location
Hamfields, South West
Distance
20 Mile
Surface
Road
Entries closed
Entries for the 2027 Fission 20 are currently closed.
Verified 6 June 2026
Upcoming dates
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Race overview
About Fission 20
The Fission 20 is a 20-mile road race in Berkeley, Gloucestershire, and is a popular option for runners preparing for a spring marathon.
The course is known for being flat and fast, making it well suited to marathon-pace practice and longer training efforts in the final build-up to race day.
It is often used as a key benchmark race, giving runners a clear indication of fitness ahead of their target marathon.
Planning to run Fission 20?
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Shop Endurance NutritionFrequently asked questions
Is Fission 20 2027 entry open?
Entries for the 2027 Fission 20 are currently closed.
When is Fission 20?
Fission 20 takes place on Sunday, 14 March 2027.
What is the Fission 20 course like?
The Fission 20 is a 20-mile road race in Berkeley, Gloucestershire, and is a popular option for runners preparing for a spring marathon. The course is known for being flat and fast, making it well suited to marathon-pace practice and longer training efforts in the final build-up to race day.
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