The grueling Ultra-Trail du Mont-Blanc: Filmmakers capture one of the hardest ultramarathons

Every summer, Tour de France viewers marvel at its acrobatic cameramen, balanced on the backs of motorcycles hurtling up mountain passes. They would be just as impressed if they saw the camera operators at work during the Ultra-Trail du Mont-Blanc. France2 Denis Sébastien and Nicolas Baker, with France24 Peter O’Brien report.