Honza Rejmanek competed in the Red Bull X-Alps 5 times. His last was in 2015 but apparently nutty runs in the family and he and his son Martin have been doing incredible 8 day tandem vol-biv adventures for the past three years in the Alps. Their style is pure- no mechanical support is allowed (ie they fly or they walk), food is collected or carried, where they start and end is fixed so if they don't make it one year they just come back the next! Honza says compared to the X-Alps they move at about one quarter of the speed but with four times the weight and no support crew!