Personalised e-coaching system needs to make deliberate efforts to design intervention experiences that fit the needs, problems, goals, and interest of their participants. In this paper, we propose architecture for Physical Activity (PA) based on the trans-theoretical model of behaviour change. The overall purpose of our personalised e-coaching system is to help constructing personalised sessions and contents that promote adherence to the PA promotion program. To achieve this, the system recognizes different patterns of activity behaviour and stage of changes of the individual, which are guided by the expert's knowledge. A key difference between our system and the other state-of-the art systems is that in our framework, the content of the personalised recommendations or advice is not only adapted based on the participant's responses, historical data, but also based on the participant's activity preferences, health conditions and different values of importance.