The Intermunicipal Cup 3H Resistance MTB is a mountain bike endurance race series held in 2026 across six events in various municipalities including Alenquer, Loures, Mafra, Oeiras, Amadora, and Lisbon. The final event takes place in Monsanto, Lisbon on October 25, 2026.

The race features a 3-hour resistance format with courses approximately 4 to 7 km long, alongside juvenile MTB races with shorter circuits from 500 meters to 3 km depending on age categories. The competition is open to licensed and non-licensed amateur athletes aged 5 and above, with multiple age and gender categories, including e-Bikes.

This series offers a competitive amateur atmosphere with point-based classifications and prizes for top finishers, supported by local cycling clubs and municipalities. Juvenile races run concurrently with the main events, providing a family-friendly environment.