Saturday, July 23, 6 a.m. The rays of the sun gradually reveal the ridge line of the Belledonne massif, a long mountain range in the Northern Alps. In the center of Uriage-les-Bains, in the Isère valley, reigns an unusual agitation. Behind an inflatable arch planted in the park of the Grand Hotel in this spa town 15 km from Grenoble, a young dark-haired woman in sportswear takes off her rings, readjusts her earrings and puts it in her hair. With a slightly tense face, Christine Selman, 32, joins the starting point of the Ultra Tour des 4 massifs (UT4M), her first ultra-trail, a long-distance version of trails, these foot races in natural and rugged environments. .