Significant updates and additions have been made in the 12th edition of ACSM’s Guidelines for Exercise Testing and Prescription (GETP) to reflect evidence-based contemporary practice. Special emphasis was placed on presenting information in a manner that can be used in testing labs, fitness facilities, and clinics to optimize care for individuals working with exercise professionals. Noteworthy, but not all, changes and additions include, broadening the section on resistance training principles, providing guidance on identifying cardiac and/or pulmonary limitations during a cardiopulmonary exercise test, and adding new sections on transgender people, POTS, SCAD, or ME/CFS.