PurposeThis study proposes a new model, called the Integrated Human Health Model (IHHM), to improve the design and effectiveness of Workplace Health Promotion (WHP) interventions.Design/methodology/approachEighteen participants were purposefully selected from 44 participants in a 2.5-day WHP intervention targeting multiple health behaviours (MHB). The intervention has shown to improve quality of life and health-related behaviours in rigorous studies. Qualitative data collection methods were observations, repeat semi-structured interviews and weekly e-journals collected over three months. Template analysis was used to develop the IHHM describing participants' experiences.FindingsThe IHHM describes the health behaviour change process using eight themes: facilitation, assessment, desired life, barriers, knowledge and skills, insights, action planning, and monitor and support.Practical implicationsWith the paucity of evidence informing WHP intervention effectiveness, this study provides a preliminary model serving practitioners to design more effective interventions and scholars to improve evidence.Originality/valueThis study proposes a practical comprehensive model for practitioners and leaders to more effectively design and evaluate successful MHB WHP interventions compared to existing models.