The Compendium of Physical Activities (Compendium) was developed to standardize the assignment of physical activity (PA) intensity values in epidemiological research. Originating from studies on the protective effects of PA against coronary heart disease (CHD) in the mid-1900s, the Compendium was first published in 1993 and has been updated in 2000 and 2011. The 2024 update, re-named the Adult Compendium of Physical Activities, includes new major headings, specific activity codes, and more precise metabolic equivalent (MET) values. The Compendium has been widely used by government agencies, educational institutions, and commercial products to support national PA objectives and health-enhancing activities. The development and maintenance of the Compendium have been a collaborative effort, with contributions from multiple researchers and institutions.The Compendium of Physical Activities (Compendium) was developed to standardize the assignment of physical activity (PA) intensity values in epidemiological research. Originating from studies on the protective effects of PA against coronary heart disease (CHD) in the mid-1900s, the Compendium was first published in 1993 and has been updated in 2000 and 2011. The 2024 update, re-named the Adult Compendium of Physical Activities, includes new major headings, specific activity codes, and more precise metabolic equivalent (MET) values. The Compendium has been widely used by government agencies, educational institutions, and commercial products to support national PA objectives and health-enhancing activities. The development and maintenance of the Compendium have been a collaborative effort, with contributions from multiple researchers and institutions.