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There's tough, and then there's Trionium....the hardest stuff known to man!

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The Knacker Cracker 10k

1 January 2023

The Leith Hill Half Marathon

5 March 2023

The UK Wife Carrying Race

5 March 2023

The Midsummer Munro half marathon

25 June 2023

ARG's Ashtead 10k + 2k Fun Run

17 September 2023

The Trionium Leith Hill Half was voted the Best Race in Britain in 2015 (Runner's Word, February 2016) and the Trionium Midsummer Munro was voted the Best Race in Britain in 2008 (Runner's World, February 2009).

The Trionium races seen above (not including ARG's Ashtead 10k) have donated £68,171.00 to charity since the first Knacker Cracker race on 1 January 2004 (to 31 January 2021).

Trionium events will not last forever - enter them while you still can!

Trionium races are permitted by the Association of Running Clubs (ARC)

Former Trionium events - alas no longer organised...

Man v Bike


An experiment!

The Greensand Marathon & Half

Greensand Logo

Legendary trail race

The Picnic Marathon

Picnic Marathon logo

Hardest Marathon

Thank You NHS and keyworkers Run

October 2020 - A one-off!

The Yellowhammer Challenge

Perpetual + Free


Irish Sailing and Mountaineering Adventure Challenge


Bath Hilly Half & Ultra-10k

19 November 2023

A Trionium-based team completed the Three Peaks Yacht Race 2016 - see the write-up

The Surrey Hills Society aims to promote the protection and enjoyment of the Surrey Hills. We enjoy the hills, and we think that they should be protected too!

Find other races with Fetch Everyone!

Other worthy races...

'Top 100 toughest races in the world....'

The Challenge Hub - including 24-hour and 50-mile challenges

This is definitely worth a look (YouTube video)

Saab Solomon Hellrunner - various dates

The G3 race series (etc) January
Hestercombe Humdinger (February, UK)
Grizzly (mid-March)
Orion 15 (March, Chingford)
Steyning Stinger (March - a classic!)
Three Forts Marathon (end of April)
Green Belt Relay (early May)
Fellsman (2nd w/e in May)
The Hurt (July)
UK Ironman (August)
Sierre-Zinal (31k, August, Alps)
Race the Train (August, Wales)
Berlin Marathon (September)
Shere 40k (September)
Folkestone Half (end September)
Surrey Badger (September)
Beachy Head Marathon (end of October)
Snowdonia Marathon (end of October)
Loch Ness Marathon (start of October)
Brocken Marathon (October, Germany)
Talybont Trial (October)
Hankley Hustle (October, Surrey)
Everest Marathon (November)
Marlow Half Marathon (first week of November)
Sodbury Slog (mid-November)
New York Marathon (November)
Bath Hilly Half (end of November)
Round Rotherham (80k, December)
Naked Runs (including Naked Ambition, UK, May)

Let us know if you think that any other races/events should be included!

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Trionium issue 4 is a work in progress...

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