Competing in the city of São Paulo: effects of air pollution on physiological parameters and performance during a 50 km time trial.

Abstract

Air pollution is one of thie main health risks of environmental causes and in the cities the high density of traffic is one of the main sources emitting pollutants. Exposure to these pollutants is strongly associated with deleterious effects on the cardiovascular system and lung function. Predominantly aerobic exercise counteracts these deleterious effects by triggering adaptations that positively influence inflammatory responses, the cardiovascular system, and modulation of the autonomic nervous system. However, aerobic exercise in environments with polluted air, a possible maximization of the deleterious effects caused by pollution occurs, mainly due to the increase in ventilation (VE) during exercise and the large fraction of air inhaled orally, increasing the passage of particles larger than would reach the respiratory tract without being filtered through the nasal cavity. It is also known that several environmental aspects such as the decrease in oxygen availability (O2) can / directly influence performance during predominantly aerobic exercise. Thus, our aim in this study will be to analyze the impact of air pollution on performance in a 50km time trial (CR), as well as possible changes in blood gases. Methods: 15 well-trained cyclists will make three visits to the laboratory. Visit 1: progressive test until exhaustion (TPE) to obtain the maximum oxygen consumption (VO2MAX) and peak power in the maximal incremental test (WMAX); Anthropometric measurements; Familiarization; Visits 2 and 3) CR of 40km in a clean or polluted environment conducted blindly. The collection site will be a container where is possible to filter the atmospheric air, thus simulating a clean environment with no perceptible changes. Blood will be collected for analysis of venous blood gases in ABL800 Flex (Radiometer Medical ApS, Denmark). Statistical analysis will be performed by one-way ANOVA with repeated measures will be used to compare the physiological variables along the CR tests. Tukey's post hoc test will be used to locate possible differences. We will adopt p of significance of 0.05.