Some fraction of what we think of as cardiovascular aging is in fact due to the lack of exercise that is so very prevalent in our society of comfort and machineries of transport, rather than due to inexorable underlying processes of aging. Those processes certainly exist, and ultimately cut down even the fittest individuals, but failing to maintain fitness in later life does tend make the outcomes of aging worse. Studies of the sort noted here are a way to assess how large the burden of a lack of fitness might be, at least when it comes to cardiovascular function. The researchers took a collection of people who are training to run a marathon for the first time, and quantified the improvements that take place in cardiovascular metrics over the course of this effort.
Aging increases aortic stiffness, contributing to cardiovascular risk even in healthy individuals. Aortic stiffness is reduced through supervised training programs, but these are not easily generalizable. The purpose of this study was to determine whether real-world exercise training for a first-time marathon can reverse age-related aortic stiffening. Untrained healthy individuals underwent 6 months of training for the London Marathon.
Assessment pre-training and 2 weeks post-marathon included central (aortic) blood pressure and aortic stiffness using cardiovascular magnetic resonance distensibility. Biological "aortic age" was calculated from the baseline chronological age-stiffness relationship. Change in stiffness was assessed at the ascending aorta (Ao-A) and descending aorta at the pulmonary artery bifurcation (Ao-P) and diaphragm (Ao-D).
A total of 138 first-time marathon completers (age 21 to 69 years, 49% male) were assessed, with an estimated training schedule of 6 to 13 miles/week. At baseline, a decade of chronological aging correlated with a decrease in Ao-A, Ao-P, and Ao-D distensibility by 2.3, 1.9, and 3.1 x 10^-3 mm/Hg, respectively. Training decreased systolic and diastolic central (aortic) blood pressure by 4 mmHg and 3 mmHg. Descending aortic distensibility increased (Ao-P: 9%; Ao-D: 16%), while remaining unchanged in the Ao-A. These translated to a reduction in "aortic age" by 3.9 years and 4.0 years (Ao-P and Ao-D, respectively). Benefit was greater in older, male participants with slower running times.