Intensity matters: vigorous activity is associated with lower pressure-independent arterial stiffness in the UK...

Arterial stiffness, a predictor of cardiovascular disease, reflects both structural properties of the arterial wall and load-dependent effects of intra-arterial pressure. Although exercise improves vascular health, its optimal intensity and effects on these stiffness components remain unclear in older adults.

We analyzed 34 105 UK Biobank participants (mean age 64; 49% female) with finger-derived arterial stiffness index (ASI) and International Physical Activity Questionnaire-assessed activity. ASI was regressed on mean arterial pressure and decomposed into pressure-independent (ASI-PI; residuals) and pressure-dependent (ASI-PD; total minus ASI-PI) components. Multivariable models tested associations with total and intensity-specific MET-minutes, adjusting for demographic, socioeconomic, cardiometabolic, and medication factors.

Higher overall physical activity was associated with lower total ASI (9.45 ± 2.93 for high activity vs 9.72 ± 2.89 for low; p < .001), and lower ASI-PI (-0.01 ± 2.91 for high vs 0.26 ± 2.88 for low vs; p < .001). The association between physical activity and ASI-PD was minimal. Each 1 SD higher total MET was associated with lower ASI-PI (β = -0.094, 95% CI -0.119 to -0.068; p < .001) but not ASI-PD. In intensity-specific models, vigorous activity was consistently associated with lower ASI-PI (β ≈-0.12; p < .001), whereas moderate activity showed modest positive associations, and walking activity was not significantly related. When total activity volume was held constant, vigorous METs were associated with lower ASI-PI, while associations with ASI-PD remained negligible.

Vigorous activity was consistently associated with lower ASI-PI, suggesting beneficial vascular adaptations to exercise beyond its effects on hemodynamic load.