The evolution of physical activity promotion. Are we entering a liquid age?

In order to counteract risk factors for non-communicable diseases, promotion of physical activity has become increasingly relevant. This article outlines recent developments in this field, adopting a perspective based on Zygmunt Bauman's concepts of liquid modernity and liquid life. Five trends in physical activity promotion are identified: (Trend 1) The expansion of physical activity recommendations from a narrow focus on exercise to a broad concept of 24-h movement guidelines, (Trend 2) the increasing number of population groups targeted by these recommendations, (Trend 3) the ascent of efforts for physical activity promotion to the global level, (Trend 4) the emancipation of physical activity promotion from an add-on to a stand-alone public health topic, and (Trend 5) the ongoing conflict between sport, health and other sectors about the leading role in physical activity promotion. Based on these developments, physical activity might be classified as 'liquid' in Bauman's sense, that is, as being elusive and in a constant state of flux.