For performance or pleasure, for the view or atmosphere, to be in your own bubble or connected to the world. There’s as much motivation as those taking part in Marseille-Cassis, but this year some runners may be exhilarated by the idea of trying the next Olympic marathon. We call this the breaking phenomenon. Twice a year, if conditions permit, it is possible to view Mount Canigou from above Marseille. Likewise, further east, Corsica is sometimes visible from the Côte d’Azur. But if some participants on Sunday were to guess from afar from the top of Gineste, the top floor of the Eiffel Tower, it would not be due to a fracture, but to what we might call another phenomenon.