Effects of physical activity on cardiorespiratory fitness and vascular function in adults aged 50–60 years

Objective: To examine the associations between physical activity and cardiorespiratory fitness and vascular function in adults aged 50-60 years, and to investigate the moderating role of cardiorespiratory fitness in the relationship between physical activity and vascular function. Methods: This cross-sectional study included 155 non-manual workers aged 50-60 years. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). Cardiorespiratory fitness and vascular function were evaluated using established physiological indicators. Results: Physical activity was significantly associated with both cardiorespiratory fitness and vascular function, with evident sex differences. In men, cardiorespiratory fitness increased progressively with higher physical activity levels, whereas in women, significant improvements were observed only at high physical activity levels. Vascular elasticity appeared to be more responsive to physical activity in women. Cardiorespiratory fitness significantly moderated the association between physical activity and vascular function, with a stronger moderating effect observed in men. The beneficial effect of physical activity on vascular function was most pronounced among individuals with lower levels of cardiorespiratory fitness. Conclusion: Among adults aged 50-60 years, physical activity is positively associated with cardiorespiratory fitness and vascular function and exerts beneficial effects on vascular health, with notable sex differences. Furthermore, cardiorespiratory fitness moderates the relationship between physical activity and vascular function, suggesting that the vascular benefits of physical activity vary according to sex and individual fitness levels.