How do teacher trainers cope with reforms? To answer this question, we designed an intervention-research (IR) with an ergonomic approach to the activity in support of a demand from trainers who, faced with a third reform in less than ten years, are questioning the implementation of a new training scheme designed to operationalise work-linked training. This IR is designed with a threefold aim: exploratory, then transformative and epistemic. We first carried out an exploratory diagnosis and then helped to initiate and support a process of development of professional activity with trainers involved in IR. Our main results show that, in order to work with these forced changes, without institutional support or the creation of spaces for collective exchange, trainers recycle old ways of doing and thinking about training. Subsequently, the environment generated by the IR will allow the development of a working collective capable of mobilising psychosocial resources to develop new goals that will enable each individual to regain the power to act and to re-develop the rules of the trade. At the end of this research, we maintain that another mode of reform should be suggested by mobilising the expertise and experience of trainers. We believe that by using the methods and tools of analysis of real work, within collective work spaces, a collective reworking of the prescriptions of the reform can be undertaken, the intention of which is no longer the rupture but the efficient transformation of what already exists through its improvement.