This Technical Specification is part of a series that provides information on factors related to human anthropometry, physiology, ergonomics and performance, for the preparation of standards for performance requirements, testing and use of respiratory protective devices. This Technical Specification contains information related to respiratory and metabolic responses to rest and work at various intensities. Information is provided for: metabolic rates associated with various intensities of work; oxygen consumption as a function of metabolic rate and minute ventilation for persons representing three body sizes; peak inspiratory flow rates during conditions of speech and no speech for persons representing three body sizes as a function of metabolic rates. The information contained within this Technical Specification represents data for healthy adult men and women of approximately 30 years of age, but is applicable for the age range of the general population.