The Taça Intermunicipal 3H Resistência BTT - Loures is a mountain bike endurance series featuring three-hour races on local circuits in the greater Lisbon area. The series takes place throughout the latter half of the year, connecting six municipalities: Alenquer, Loures, Mafra, Oeiras, Amadora, and Lisbon. Each stage employs lap counting for straightforward tracking: riders compete for three hours, with the winner determined by the distance covered before time expires.
The race locations span a wide regional BTT area, with events held at Jamor in Oeiras, Monsanto in Lisbon, Amadora, and Mafra. The participant field is diverse, not exclusively elite, offering categories for younger riders, masters, e-bikes, juniors, cadets, and a distinct youth race for benjamins through juvenis. Entry fees are set at 15 euros for the main race and e-bike category, 13 euros for juniors and cadets, and six euros for youth categories. Registration is managed via apedalar.pt. The first stage is organized by Raposas Afoitas, with backing from the local parish union in Alenquer and the Portuguese Cycling Federation.