Physiological Cost and Air Flow Resistance of Respiratory Protective Devices

Abstract

Using one of three respiratory protective devices or a ‘no mask’ control, five male subjects were tested at grades of 0, 5 and 10 per cent and a constant speed of 3·5 miles per hour for a total of twelve tests per man. Exercise heart rates and recovery oxygen consumption values were recorded. Air flow resistance values were determined in laboratory bench tests. The resistance of the devices did not significantly alter the exercise pulse rates but did significantly increase the recovery oxygen consumption, particularly at the higher work levels. Recovery oxygen consumption values and the air flow resistance figures were positively related at the higher levels of work. It is suggested that the relationship offers further support for the use of laboratory bench tests as an estimator of the added physiological burden imposed on the wearer.