Studies suggest that e-Health coaching applications should be tailored to each user in order to elicit motivation and long-term adherence. E-Health coaching and current models for adaptive human-computer interactions could thus benefit from Psychology theories related to motivation and inter-individual differences. This article introduces the PAD-MEH model (Personality-based Adaptive moDel for Mobile E-Health) which inspires from the Self-Determination motivational Theory and the Regulatory Focus personality Theory. We describe the two dimensions of this model ("Triggering Elements" and "Adapted Elements") and we explain how they enable to adapt the interaction with different users to better motivate them for physical activity. We conclude by future directions regarding PADMEH's validation.