The AXtrail®series held its first edition in October 2008, connecting the Aldeias do Xisto of Casal de São Simão and Ferraria de São João, in a route that delighted trail running lovers.

Due to the acceptance of the event, Go Outdoor organised trail running circuits in 2009 and 2010 made up of double day series, made up of two events in different Aldeias do Xisto on the same weekend.

The year 2011 was marked by a very full circuit, composed of 4 series, the final of which took place in Lousã, bringing the K42 Adventure Marathon Series to Portugal.

UTAX - Ultra Trail das Aldeias do Xisto, was launched the following year as the closing race of the AXtrail®series circuit, totalling 82 km of trails in the Serra da Lousã (Lousã Mountain Range).

This success was repeated in 2013, in an event that joined 2 races: the UTAX with 77km, and also the Trail Serra da Lousã (42km).

After 6 consecutive years leading the AXtrail®series circuit, including the organisation of K42 Portugal in 2011, and UTAX in 2012 and 2013, Go Outdoor has once again decided to organise a single event in Castanheira de Pêra in 2014.

As in previous years, the third edition was produced by UTAX and TSL (Trail Serra da Lousã). The longest race totalled 109 km and covered 4 municipalities, 9 Aldeias do Xisto and some of the most emblematic places in this mountain range.

The Trail Serra da Lousã kept its 42 km course. An event that partially covered the course of the bigger race, with the possibility of the athletes from both races joining each other in the final phase and crossing the finish line side by side.

The 2014 edition, brought with it parallel races, such as the AX Inclusion Trail, the Mini Trail, and the AX Trail Kids.

The AX Inclusion Trailis a trail race, the first of its kind organised in Portugal, which marks respect for difference.

The Mini Trail was a short distance race, 24 km, where there was no lack of options for the athletes who wanted to run the trails of Serra da Lousã and enjoy a memorable day.

AX Trail Kids promoted the practice of sport and contact with nature among the younger sections of society and, at the same time, attracted new  athletes to the sport of trail running.