Evaluation of Physiologic Responses to Woodsmoke Inhalation During Exercise in Blood Pressure-Sensitive/Chronotype-Stratified Individuals

Introduction: We examined the physiologic alterations in respiratory and cardiovascular parameters during and after acute exercise under controlled woodsmoke inhalation conditions. Methods: This study involved 20 recreationally active participants (10 males and 10 females) divided into groups based on their sensitivity to the cold pressor test (CPT⁺vs CPT⁻) and their chronotype, as assessed by the Morningness-Eveningness Questionnaire. Participants completed a 120-min stationary cycling session at 50% VO₂max while exposed to woodsmoke at a concentration of 250 μg·m^–3. Assessments of heart rate variability, pulse wave velocity, blood pressure, pulmonary function testing, and oxidative stress were performed before, immediately after, and 24 h after exercise. Results: In the CPT⁺group, significant alterations were noted in the pulse wave velocity variable, augmentation index, and heart rate variability metrics of logarithmic transformation of high- and low-frequency powers of heart rate variability immediately following exercise, whereas no such changes were observed in the CPT⁻group. Conclusion: Classification of participants indicated a potentially susceptible subpopulation when exposed to a single acute exercise session in the presence of woodsmoke.