Wearable-Derived Cardiovascular Phenotyping of Smokers During Intense Physical Activity: A CrossSectional Precision Exercise Study

Abstract

Background: Smoking is a major modifiable risk factor for cardiovascular and pulmonary disease, yet its impact on individualized cardiovascular response patterns during intense physical activity remains insufficiently characterized. Advances in wearable technology offer opportunities for continuous physiological monitoring and precision exercise assessment. Objective: To evaluate wearable-derived cardiovascular response profiles and exercise performance among smokers and non-smokers during standardized physical activity protocols. Methods: In this analytical cross-sectional study, 43 young adults (22 smokers, 21 non-smokers) underwent the Six-Minute Walk Distance test, Balke treadmill protocol, and Ekblom-Bak cycle ergometer test. Heart rate was continuously monitored using a smartwatch, and perceived exertion was assessed using the Borg CR-10 scale. Between-group comparisons were performed using independent samples t-tests. Results: Smokers demonstrated significantly lower exercise-induced heart rate responses during the Balke treadmill and Ekblom-Bak tests (p = 0.001 and p < 0.001, respectively), while no significant difference was observed during the Six-Minute Walk test. Smokers also covered shorter walking distances and achieved lower work rates and exercise durations at higher intensities. Conclusion: Smoking is associated with blunted chronotropic adaptability and reduced exercise tolerance during intense physical activity. Wearable-derived monitoring reveals distinct cardiovascular response phenotypes, supporting its role in precision exercise assessment and personalized cardiovascular risk evaluation.