Aerobic exercise improves artery function, an estimated 24% cut in heart disease risk

Aerobic exercise has long been recognised as one of the most potent stimuli for improving markers of cardiovascular disease risk, from blood pressure to fitness and blood lipids. One of the most telling of those markers is endothelial function, the ability of a blood vessel's inner lining to make the artery widen when blood flow demands it, commonly assessed by flow-mediated dilation of the brachial artery in the arm. Previous meta-analyses had examined some of these markers individually, but none had comprehensively evaluated how changes in the wider set of cardiovascular markers relate to changes in endothelial function. This study set out to close that gap and to ask which exercise-driven adaptations actually travel together with healthier arteries.

The researchers conducted a systematic review and meta-analysis of randomised controlled trials investigating the effect of aerobic exercise on brachial-artery flow-mediated dilation, with the protocol prospectively registered in the Open Science Framework. The primary outcome was the change in flow-mediated dilation from before to after each intervention. Secondary outcomes spanned endothelial blood biomarkers, haemodynamic measurements, cardiorespiratory fitness, body composition, glucose metabolism and lipid profile. Changes were summarised using a random-effects model, and meta-regression analyses then tested whether changes in those secondary outcomes moderated the changes in flow-mediated dilation. In total, 72 studies comprising 3357 participants met the inclusion criteria.

Aerobic exercise significantly improved flow-mediated dilation, with a mean difference of 2.35%, which the authors say corresponds to an estimated 24% reduction in cardiovascular disease risk. Significant improvements were also observed across multiple other cardiovascular disease markers rather than in the artery measurement alone. The meta-regression added the most interesting layer: improvements in flow-mediated dilation were significantly moderated by changes in body weight and body fat, systolic and diastolic blood pressure, maximal oxygen uptake, and insulin levels. In plain terms, the people and trials in which these markers moved most favourably tended to show the largest artery improvements.

The direction of this finding is not new; aerobic exercise improving vascular health is a well-established idea, and earlier meta-analyses had covered individual markers. What is new is the integration: the authors describe this as the first meta-analysis to connect endothelial changes with the full range of cardiovascular markers through meta-regression, showing that body composition, cardiorespiratory fitness, blood pressure and insulin regulation collectively contribute to the vascular adaptation. That strengthens the mechanistic case for exercise as a nonpharmacological strategy for cardiovascular prevention. Open questions remain about which types, intensities and durations of aerobic exercise deliver the most, and how the effect differs between healthy people and those with existing disease, since the included trials spanned both.

If you already do regular aerobic exercise, this is strong pooled evidence that it is doing quiet, measurable work on your blood vessels, not just your stamina. The estimated 24% reduction in cardiovascular risk is a translation from an artery measurement rather than a count of prevented events, so it should be read as a signal of direction and plausibility rather than a guarantee. The moderation findings are worth knowing too: the artery benefit was largest where weight, body fat, blood pressure and insulin improved and fitness rose, which suggests these gains arrive as a package. This is a reason to view cardio as vascular maintenance with benefits that compound across the body.