Does traffic-related air pollution exposure alter blood gas parameters in recreationally trained male cyclists during prolonged endurance exercise?

Exposure to air pollution has been a significant challenge in large cities as São Paulo, Brazil, particularly for individuals exercising outdoors. The increasing on ventilation (VE) during physical effort can lead to greater pollutant inhalation. Our goal in the present study evaluated whether air pollution exposure affects venous blood gases and if it has an impact on performance during a 50-km cycling time trial (TT). Ten male cyclists performed the TT in an environmental chamber under TRAP and filtered air conditions. Venous blood samples collected pre- and post-TT were analyzed for pH, PvCO₂ (partial pressure of carbon dioxide in venous blood), PvO₂ (partial pressure of oxygen in venous blood) hematocrit (Htc), hemoglobin (Hb), and oxygen saturation (SvO₂). PM_2.5 levels were significantly lower in filtered air (11.2 ± 4.7 μm/m³) than in TRAP (34.6 ± 10.8 μm/m³). There was no significant difference in mean power output between conditions (p = 0.907, d = 0.038). Blood gas parameters showed no condition effect or interaction, but time significantly affected PvO₂ (p = 0.04), Hb (p < 0.01), Htc (p < 0.01), and PvCO₂ (p = 0.02). These findings suggest recreationally trained cyclists experience no performance impairment under TRAP, with minimal changes in venous blood gas parameters.