Atom Isasa Trail Xtrem

The Atom Isasa Trail Xtrem is run in Arnedo and is centred on the Sierra de Isasa, the limestone massif that closes the Cidacos valley to the south, on the border between La Rioja and Soria. Its main distance links 44.5 kilometres with 2,500 metres of elevation gain, rising from the plains of La Rioja Baja to the summits and ridges of the range via rocky paths, holm-oak scrub and old shepherds’ tracks. It is the largest concentration of mountain runners in La Rioja, with more than 2,000 participants across all its formats, and it hosts the individual Riojan championship. The start and finish are located in Plaza de España in Arnedo, right in the built-up area, and the 2027 programme includes the 44.5-kilometre marathon and the short race of 16 kilometres on 6 March, while the half marathon of 22 kilometres and the walk of 16 kilometres take place on 7 March. The long event scores for the UTMB index.