Current global trends in physical activity levels demonstrate that the world is not on track to achieve the 2030 target set by the Global Action Plan. The Action Plan posited that physical activity should be an integral component of "daily lives" of all individuals "across the life course".

Potential contributions to achieve global physical activity goals include the utilisation of compositional data analysis and life course epidemiology to provide a framework for the composite nature of physical activity and complex life course relationships. Combining these two traditionally disconnected fields represents a paradigm shift in physical activity research. Here, we discuss how these combined fields enable a reinterpretation of previous research findings, explore their impact on policy, and potential advantages and challenges. Careful consideration needs to be given to the implications of both fields remaining disconnected and the alternate option of consolidation to realise ambitions.