Disclosed is a method for adjusting the travel of a stretching sliding rod that belongs to a device for forming hollow bodies made of thermoplastic material by stretch blow molding, with the stretching rod being controlled cyclically in terms of sliding from a rest position to an adjustable stretching end position by stretching the malleable wall of a hollow body, before returning to its rest position to begin a subsequent stretching cycle of another hollow body, with the method including a control step that consists in detecting whether an axial force that opposes the sliding of the stretching rod at the end of travel is above a determined upper boundary. The stretching end position is adjusted automatically by being subjected to the axial force that is detected during the control step.