Cardio plus weights may be the best mix for blood-vessel health

The endothelium — the inner lining of your blood vessels — is where cardiovascular trouble often shows itself first, and endothelial dysfunction is an early vascular abnormality in adults carrying excess weight. Exercise is known to improve vascular function, but two practical questions have remained unclear: which type of exercise works best, and how much per week delivers the biggest return. This study set out to answer both at once, comparing exercise modalities and mapping the dose-response curve for brachial artery flow-mediated dilation, a standard measure of how well arteries widen on demand.

The researchers ran a systematic review and Bayesian dose-response network meta-analysis of parallel-group randomised controlled trials. Eligible trials enrolled adults with overweight or obesity, compared at least 4 weeks of exercise against a non-exercise control or another modality, and reported brachial FMD before and after the intervention. Weekly exercise dose was standardised as MET-minutes per week, and eight different dose-response functions were tested to find the best fit. Forty-seven trials with 2,211 participants made the cut, and certainty of evidence was graded with CINeMA.

Exercise improved brachial FMD in a dose-dependent fashion, with the largest overall model-estimated improvement at 1,500 MET-min/week — a mean difference of 4.72 percentage points. Among modalities, combined aerobic and resistance training showed the largest estimated improvement at that dose (5.77 percentage points), and doses of 1,200-1,600 MET-min/week were most consistently ranked among the highest predicted responses, with 1,400 MET-min/week ranked first. Results held in sensitivity analysis excluding high-risk-of-bias trials, and subgroup patterns were broadly consistent. Crucially, though, certainty of evidence was low or very low across all 13 network comparisons.

The finding that mixing aerobic and resistance work beats either alone echoes a broader pattern in exercise science, and the dose-response shape — a quadratic curve rather than a straight line — suggests diminishing or plateauing returns rather than 'more is always better'. But the authors are unusually explicit about the limits: these are model-based estimates, the mind-body exercise optimum fell outside the observed data range and is an unreliable extrapolation, and every comparison rests on low or very-low certainty evidence. Confirmation in higher-quality head-to-head trials with standardised FMD protocols is the stated next step.

For anyone carrying extra weight, this adds to the case that exercise measurably improves how blood vessels function, and that combining cardio with resistance training may pay off more than picking one. The specific weekly figures are best read as rough anchors from a statistical model rather than targets to chase — the researchers themselves caution against treating them as ready-to-apply thresholds. The direction of the finding is more trustworthy than its precision.