The impact on pulmonary functions of exercising at different intensities during pollutant exposures was evaluated. It was apparent that there was considerable variation in exercise protocols. These variations occurred in the magnitude of the exercise load, the duration of the exercise period, and the timing of the exercise during exposure. It was also apparent that ventilation during rest and exercise was not always determined; in many instances ventilation was estimated based on other criteria, such as heart rate. The influence of ambient temperature conditions was frequently not considered. Determinations of pulmonary functions were also made at various time intervals following exercise or subsequent rest periods. All of these factors could result in some degree of misinterpretation of the consequences of pollutant exposure. (Copyright (c) American Society for Testing and Materials, 1985.)