The GRP Tour des Lacs covers 80.9 kilometres from Vielle-Aure in a loop through the Hautes-Pyrénées, accumulating 5,100 metres of elevation gain across the Néouvielle natural reserve and up to the Pic du Midi de Bigorre at 2,877 metres. At 68.4 metres of elevation gain per kilometre, it ranks 47th out of 390 races in the DiscoverTrailRaces database — placing it in the top 12 percent for vertical density. The single largest descent covers 1,410 metres of drop and ranks 33rd globally — top 9 percent — reflecting the extreme ridge-to-valley topography of the high Pyrenees.
The start is from the Vielle-Aure square at 5 a.m., with the best runners completing the course in around 10 hours and a 25-hour cutoff. The 2026 edition is sold out. Organised since 2012 by the Association Majuschule, the race draws over 1,200 finishers on the 80km distance alone, part of a five-day festival bringing 8,000 runners to the Hautes-Pyrénées each August.