The Taça Intermunicipal 3H Resistência BTT in Amadora is a Sunday-morning mountain bike endurance event held in the Lisbon district. The primary race format is straightforward: complete as much distance as possible within three hours on a BTT course. Participants also have options for a one-hour race, a three-hour e-bike category, or a three-hour pairs category for teams of two.
The participant list emphasizes local, accessible competition over a singular elite field. Adults compete in the three-hour race, e-bike riders have their own class, and younger riders are organized into categories ranging from Juniores and Cadetes down to Juvenis, Infantis, Iniciados, Benjamins, and Pupilos. Entry fees are reasonable, with reduced rates for youth categories. Published registration figures indicate a modest field size, with the majority of participants in the main three-hour race.