Sinharay et al. 2018, Walking a traffic-polluted road versus a traffic-free area

Randomised crossover trial (n=119, older adults). Two hours of walking in a traffic-free park improved lung function and reduced arterial stiffness for up to a day, while the same walk on a traffic-heavy street blunted those benefits, alongside higher exposure to black carbon, nitrogen dioxide and particulates. Shows traffic pollution attenuates the cardiorespiratory gains of the same exercise. Moderate (older adults, walking, acute outcomes).