Arc of Attrition by UTMB® is one of the UK's most iconic coastal ultra marathons, taking runners along the spectacular South West Coast Path through some of Cornwall's most dramatic landscapes.

Taking place each January, the Arc 100M, Arc 100K, Arc 50K and Arc 20K challenge competitors with rugged cliff paths, relentless climbs and unpredictable winter conditions.

Since its launch in 2015, the Arc of Attrition has grown from a single 100-mile race with just 50 runners into one of the UK's largest and most sought-after trail running events. Whether you're taking on your first coastal trail race or tackling the full 100-mile ultra marathon, there's an Arc challenge for every level of trail runner.