HEMODYNAMIC PHYSIOLOGICAL RESPONSE TO ACUTE EXPOSURE TO AIR POLLUTION IN YOUNG ADULTS ACCORDING TO THE FITNESS LEVEL

Abstract    BACKGROUND: This study aimed to determine the impact of acute exposure to air pollution on the hemodynamic parameters and physical fitness components in two groups of healthy men differing in fitness (trained and untrained) and the correlation of parameters between the areas.    METHODS: Thirty four healthy college male students of the University of Isfahan (۱۸ low-fitness, mean age ۲۰.۴۴ ± ۲.۴۳ years and ۱۶ high-fitness, age ۲۲.۱۹ ± ۲.۰۷ years) participated in this study. First, two environments including high and moderate concentrations of ambient air pollution were determined on the basis of the environmental protection agency. Then, all participants performed a Canadian Aerobic Fitness Test (CAFT) to determine maximal oxygen uptake (VO۲max) in sport sciences laboratory. Each participant also performed ۲ sub-maximal exercise tests in two environments including polluted. The tests consisted of three phases: phase A, in non-polluted air area (laboratory); phase B, much polluted air area; and phase C, moderate polluted air area. All ۳ exercise tests were completed within a ۱-week period interval between phases. Maximal oxygen uptake (VO۲max), maximal heart rate (MHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and other anthropometric values were measured at end sub-maximal exercise test. Data were analyzed using one-way analysis of variance (ANOVA) with repeated measures and correlation.    RESULTS: At baseline, there were no significant difference between the groups in age, height, weight, diastolic blood pressure (DBP); but body mass index (BMI), body fat, resting heart rate (RHR) and systolic blood pressure (SBP) was significantly lower in subjects with high fitness (F ۱,۳۲ = ۱۰.۹۶, P < ۰.۰۰۲, F ۱,۳۲ = ۱۳.۹۱, P < ۰.۰۰۱, F ۱,۳۲ = ۲۱.۲۹, P < ۰.۰۰۱, F ۱,۳۲ = ۱۳.۷۲, P < ۰.۰۰۱, respectively). Although, baseline MHR and VO۲max were higher in subjects with high-fitness than in students with low-fitness (F ۱,۳۲ = ۱۰.۰۷, P < ۰.۰۱, F ۱,۳۲ = ۷۴.۲۳, P < ۰.۰۰۱, respectively). For both low-fitness and high-fitness subjects the mean physiological and hemodynamic measurements at baseline and after exercise were significantly associated with concentrations of ambient air pollution category (P < ۰.۰۵).     CONCLUSION: Although statistical significance was found for a number of hemodynamic parameters and physical fitness components in trained and untrained subjects, we speculate that the very small differences in the physiological responses to exercising in urban regions, which are often in contact with air pollution, are of little practical significance and would not affect the performance.      Keywords: Air pollution, VO۲max, Systolic and Diastolic blood pressure.