Every move counts: but some more than others

BACKGROUND: Physical activity (PA) plays an essential role in reducing the risk of non-communicable diseases and improving health and well-being. However, current PA guidelines do not adequately reflect emerging evidence on the importance of the relationship between patterns of PA bout duration and health outcomes. MAIN TEXT: This paper explores the limitations of evidence based on self-reported, aggregated measures of PA, and advocates for greater use of time series data from accelerometers to describe daily patterns of PA bout duration. Time series data offer insights into how PA is accumulated in different bout lengths and how such patterns impact health, independent of total weekly volume of PA. Evidence from accelerometer-based studies of the association between patterns of PA bout duration and health outcomes challenges the revised World Health Organisation guideline that 'every move counts toward better health'. CONCLUSION: By highlighting the novel nature of time series data and their corresponding patterns of PA bout duration, this paper aims to challenge current public health guidelines and inform the development of future guidelines, surveillance, policies, and interventions to prevent morbidity and mortality.