The whole day matters, but so do living conditions: reframing the 24-hour movement through an equity lens

The 24-hour movement approach has strengthened physical activity science by integrating physical activity, sedentary behavior, and sleep within the day's finite time. This Comment argues that its major contribution is also its main limitation. By treating the day as a composition of movement states, the approach extends the energy-expenditure definition of physical activity into a more complete, yet still behavior-centered, account of daily life. Physical activity should also be understood as a population condition shaped by governments, institutions, and markets through access to opportunity. This shift matters because individuals do not simply allocate movement, sitting, and sleep; labor, transport, housing, safety, gender, income, climate, commercial forces, and public infrastructure structure these activities. Moreover, in low-income settings and low- and middle-income countries, necessity often shapes activity, while choice-constrained conditions frequently limit leisure-time or volitional activity. A more equitable 24-hour framework should therefore move from movement behaviors alone to 24-hour living conditions, asking not only how time is spent but also how opportunity is distributed.