Using a Standard Respiratory Air Filtering Device during Moderate Intensity Exercise does not Affect Post Exercise Pulmonary Function

Abstract

Physical exercise requiring oxidative energy transfer increases pulmonary ventilation (VE). In an air polluted environment, the exercise-induced increase in VE increases the volume of toxic gases and number of toxic particles to which the pulmonary system is exposed. Using a respiratory air-filtering device (RAFD) during exercise decreases exposure to inhaled toxic gases and particles. However, a RAFD creates external resistance to inspiration and expiration which could decrease pulmonary muscle function and pulmonary volumes, and creates an external mechanical dead-space which produces fractional rebreathing which could increase pulmonary flowrates. This experiment tested the hypotheses that using a RAFD during exercise would; decrease post-exercise peak inspiratory pressure (PPI) and peak expiratory (PPE) pressure, FVC and FEV1, and increase post-exercise flowrates. Using a repeated-measures, counter-balanced design, six healthy moderately aerobically-trained, men (mean ± SD; age 24.7 ± 1.7 years; peak oxygen utilization [VO2peak] 42.8 ± 5.3 ml kg-1 min-1) completed two 30 min exercise test sessions at a power output equal to 75% VO2peak. One session was performed not using (NORAFD), and one using a RAFD (Moldex 8000) fitted with organic vapor cartridges and combined dust and mist pre-filters (inspiratory resistance = 0.216 kPa, expiratory resistance = 0.094 kPa at 85.0 l min-1). All pulmonary function tests were performed immediately pre-(Pre) and 0 (Post-0), 5 (Post-5), and 15 (Post-15) min post-exercise. There was a significant (p1, FEV1/FVC%, PEF, and FEF50% from Pre to Post-0. There were no other within or between condition differences in any of the pulmonary muscle pressures, volumes or flowrates. It was concluded that using a RAFD during moderate intensity medium duration exercise does not affect post exercise pulmonary function.