There is known, from document US 2002/0116147, a method for detecting and analyzing a jump by means of a measuring unit mounted on travel means used by an athlete for taking a run-up before the jump and being situated in contact with the ground before and after the jump. The travel means are for example skis or a snowboard. A calculation unit, for example a watch worn by the athlete, makes it possible to determine and to display parameters of the jump, in particular the duration of the jump, from measurements produced by the measuring unit. More precisely, the measuring unit picks up vibrations of the travel means in order to detect when the travel means leave the ground and return to the ground, which makes it possible to detect a jump and to calculate the duration thereof.
This method has the disadvantage of requiring the use of a measuring unit to be fixed to the travel means in order to measure the vibrations to which they are subjected. Furthermore, the method does not make it possible to calculate the duration of a jump effected without travel means in contact with the ground before or after the jump, for example a jump into water from a cliff.