Welcome to UMUK, UK’s only ultraman distance triathlon, established in 2011.

Our events are widely considered the toughest ultra-distance staged triathlons in the world due to the unpredictable weather and tough elevation profiles, with both long gradual and short but brutally steep climbs.

UMUK offers three exciting events (UMUK 515, UMUK 355 and UMUK Team Relay) in the heart of the beautiful Snowdonia National Park in North Wales.

Competing in a UMUK event is an enormous undertaking which requires a huge amount of dedication and determination.

Organisers will select and invite a limited number athletes on a first come, first served basis as the applications are received and following review of your entry form.

BIG NEWS for 2027 !!

There will be no entry fees for the 2027 edition rather we will require that each athlete commit to raising funds through our crowdfunding page (www.gofundme.com/f/UMUK-Triathlon-2027).