The middle of the common ultra distances at just over 60 miles, 100K ultra marathons are a big step up from the marathon. Despite this, distance is not always the key challenge with ultra runs - the total ascent gives a much better indication of how hard it will be. Select your location to find 100K ultra runs in your area or scroll down to browse events coming up.
Featured events are listed below - select your region to see all events.
Featured events are listed below - select your region to see all events.
Walk, jog or run along the capital to coast route for charity, with a range of distance options available and superb support all the way, for all abilities and experience levels.
Take on 50 historic miles across the beautiful Southern Upland Way - one of the greatest trails in the UK. Ultrarunners will tackle several ascents, pass through forests, valleys and by lochs.
Take on England’s finest countryside for charity, at your own pace, with stunning views en-route. With distances from 10km right up to 100km there’s a Lake District Challenge for everyone!
Take on the full 100K Race to the King ultra marathon challenge in one go. Fully supported through day and night on a route combining castles and coastal scenery.
Test yourself for charity in the rolling hills of the Cotswolds featuring the Cotswold Way, trails and fabulous views, with routes from 10km right up to 100km there’s something for everyone!
From the idyllic basecamp hub in Bakewell, charity challengers will head into the fabulous Peak District National Park on a route from 10 miles right up to the full 100km with full support!
Take on the full 100K Race to the Stones ultramarathon in one go. Fully supported through day and night on an incredibly scenic and historic route.
Take on the full 100K Race to the Stones ultramarathon with an overnight stop at the all-inclusive Basecamp, meaning a good nights' sleep in between the 50K stints.
Take on the full Race to the Stones 100K ultramarathon over two days, making your own arrangements for overnight accommodation at the halfway point.
Visiting the heartland of the Scottish Borders, runners and walkers will take to the Borders Abbey Way to complete the full waymarked loop as individuals, teams or a relay of four.
The South Downs National Park is a superb backdrop for a real charity challenge featuring Beachy Head, the Seven Sisters and the South Downs Way with a choice of distances from 25km right up to 100km!
England’s greatest river provides a fantastic backdrop for an unforgettable 'festival' charity challenge weekend, with distances from 10km right up to 100km there’s a Thames Challenge for everyone!
An exciting and spectacular event exploring the beautiful Brecon Beacons and finishing deep in the heart of the Black Mountains with incredible support guaranteed.
Select your location for 100K ultra marathons in your area.