MDS ULTRA 2026 - Is it possible to change the distance chosen during registration? If so, until when?

Yes, you can change the distance on your MDS account.
Additionally, it will be possible to change the distance until the start of the race, but also during the race until the split located around the 60th km. The course is therefore common for the first 60 km and the end of the course, with a single start and a common finish line.