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BACKGROUND: Air pollution and long-term aerobic exercise are diversely associated with cardiovascular disease (CVD) and mortality. However, the simultaneous effect of exercise in polluted air and vitamin C on oxidative stress markers is less clear. In this study, the effect of these variables on oxidative stress markers was investigated in rats. METHODS: The study was conducted on 50 male rats. The rats were divided into 5 groups consisting of exercise, exercise with vitamin C, exercise in polluted air, exercise in polluted air with vitamin C, and control group. Animals in the exercise groups exercised on a treadmill for 12 weeks, 5 days/week, 30 minutes/day, at 50-70% of the maximum speed. Animals in the vitamin C groups received 20 mg/kg/day vitamin C orally. After 12 weeks of intervention, 2.5 ml of blood was taken from the rats' apex. Malondialdehyde (MDA) and oxidized low-density lipoprotein (OxLDL) levels were measured using NavandSalamat's Nalondi and Eastbiopharm's OxLDL ELISA kits, respectively. Two-way analysis of variance (ANOVA) was used for data analysis in SPSS software. RESULTS: There were significant differences in MDA and OxLDL levels between all groups after 12 weeks of intervention (P < 0.050). The levels of MDA and OxLDL were significantly higher in the ExPo group compared to the Ex+VitC groups (P < 0.050). However, no significant difference was observed in MDA and OxLDL levels between the vitamin C groups (P > 0.050). CONCLUSION: These findings demonstrate the oxidative stress effects of air pollution, systemically and in the respiratory tract. Moreover, polluted air significantly increased OxLDL levels in both exercise in polluted air groups. Although, vitamin C slightly decreased MDA and OxLDL levels in the ExPo groups, the difference was not significant. Different vitamin C doses could have diverse and maybe significant results.
RESUMO
The purpose of this study was to compare the effects of two types of high-intensity interval training (HIIT) programs on aerobic and anaerobic capacity of female soccer players. Regional-level female athletes were randomly divided into heart rate-based HIIT (n = 8; age 23.4 ± 1.1 year) and speed-based HIIT groups (n = 8; age 23.4 ± 1.3 year). Athletes trained three days per week for six weeks. Before and after training, each athlete's performance was assessed directly through the Hoff test, 30-15 Intermittent Fitness Test (VIFT), and repeated-sprint ability test (RAST); maximal oxygen consumption (VO2max), power and fatigue were estimated indirectly. Both experimental groups improved power, fatigue index and VO2max after training (p < 0.05). It was noteworthy that the speed-based group had greater gains in minimal power (effect size (ES): 3.99 vs. 0.75), average power (ES: 2.23 vs. 0.33), and fatigue index (ES: 2.53 vs. 0.17) compared to heart rate-based group (p < 0.05). In conclusion, both heart rate-based and speed-based HIIT induced meaningful improvements in power, VO2max, and fatigue index in female soccer players, although the speed-based HIIT group achieved greater gains in power and fatigue index compared to the heart rate-based group.
RESUMO
PURPOSE: Exercising or doing physical activity in polluted air could expose a person to the adverse health effects of air pollution. This study aimed to compare the cardiovascular and hematologic indices following an incremental exercise test (shuttle run) under clean versus polluted air conditions. METHODS: Nineteen male athletes aged 21-27 years were assigned to either a trained athletes group (TA, n = 10) or a complete training cessation/detrained athletes group (DA, n = 9) at least 3-4 months after their competitive season. All participants performed the multi-stage shuttle run test on two separate days in either polluted air (37.4 carbon monoxide part per million) or clean air (2.5 carbon monoxide part per million) condition. RESULTS: When compared to the clean air environment, progressive incremental exercise in polluted air condition significantly (p < .05) decreased maximal oxygen uptake (VO2max), red blood cell count, and hematocrit for both TA and DA groups. Meanwhile, the participants' mean corpuscular hemoglobin, mean red blood cell volume, white blood cells, and platelets in these two groups increased significantly (p < .05) when they were exercised in the polluted air ambiance. Maximal heart rate and heart rate recovery showed significant (p = .04) increases only in the DA group. However, hemoglobin concentration remained unchanged in both groups. CONCLUSION: Acute exposure to high concentrations of pollutants during exercise resulted in decline in cardiovascular functions and hematological parameters in healthy athletes.
