Purpose: To assess the impact of first-time marathon training on age-related increases in aortic stiffness.
Methods: Untrained healthy volunteers were recruited prior to starting training for the London Marathon. Assessment pre-training and two weeks post-marathon included central (aortic) BP (cBP), and phase contrast 1.5T CMR in the ascending (Ao-A) and descending thoracic aorta at two levels (pulmonary artery bifurcation and diaphragm – Ao-P and Ao-D). Aortic distensibility and beta-stiffness (ß, a pressure-independent measure) were measured and correlated with chronological age at baseline to derive biological aortic age before and after training. Data are mean changes (95% confidence intervals).
Results: The cohort comprised 139 first-time marathon completers (age range 21-69 years, 50% male). As expected, increasing age decade was associated with decreasing distensibility by 2.3, 1.9 and 3.1 x10-3mmHg-1 for the Ao-A, Ao-P, and Ao-D respectively (partial r=0.4-0.5), Figure.
Training decreased cSBP and cDBP by 4(2.5-5.3) and 3mmHg(1.6-3.6), Table. With training, descending aortic distensibility increased at both Ao-P and Ao-D levels (by 9%,p=0.009 and 17%,p=0.001), whilst unchanged in the ascending aorta. This translated to a reduction in biological aortic age at Ao-P by 3.9(1.1-7.5) and Ao-D 4.5years(1.8-8.2). ß decreased by 7% at the Ao-D level,p=0.02. Participants with slower marathon running times (Ao-P partial r:-0.20,p<0.05), and older age (Figure) showed a greater increase in descending aortic distensibility with training.
Conclusions: Training for and completing a marathon improves central blood pressure and aortic stiffness even in novice athletes. These changes are the equivalent to a ~4-year reduction in vascular age. These benefits were greatest in older, less fit individuals.