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

BACKGROUND: The purpose of this study was 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 student males (18 low-fitness, mean age 20.44±2.43 years and 16 high-fitness, age 22.19 ± 2.07 years) who were students of the Isfahan University participated in this study. First, two environments including with 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 (VO2max) in sport sciences laboratory. Each participant also performed 2 sub-maximal exercise tests in two environments including polluted. The tests consisted of three phases: phase A, in non-polluted air area (laboratory), and phase B, very polluted air area, C, moderate polluted air area. All 3 exercise tests were completed within a 1-week period interval between phases. Maximal oxygen uptake (VO2max), 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 differences between the groups in age, height, weight, DBP, but body mass index(BMI), body fat, resting heart rate(RHR) and SBP was significantly lower in subjects with high fitness (F 1,32 = 10.96, P < 0.002, F 1,32 = 13.91, P < 0.001, F 1,32 = 21.29, P < 0.001, F 1,32 = 13.72, P < 0.001, respectively). Although, baseline MHR and VO2max were higher in subjects with high-fitness than in students with low-fitness (F 1,32 = 10.07, P < 0.01, F 1,32 = 74.23, P<0.001, 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<0.05). 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.