First-time marathon training could rejuvenate your heart

By Dr. Liji Thomas, MDJan 8 2020

A new study published in the Journal of the American College of Cardiology reports that when first-time marathoners train, they are doing the arteries of their heart a big favor – which could improve their cardiovascular fitness.

Image Credit: Pavel1964 / Shutterstock.com

The study showed that even those who didn’t pick up enough fitness to achieve average race timings still showed a drop in their blood pressure, while age-linked stiffening of the aorta showed a reversal.

The problem with blood vessels is that they are designed for young and fit bodies. With aging and a sedentary lifestyle, they begin to stiffen. When this happens to the biggest artery in the body, the aorta, which carries blood from the left side of the heart to the entire body to supply its oxygen needs, it can result in heart, kidney and brain damage.

The study

Many people like to run for enjoyment or fitness, and the overheads are minimal, while it is almost always possible to go for a brief jog. The wide availability of this form of exercise prompted the current study, which aimed to find out the possibility of healthful effects of running on inaccessible parts of the circulatory system, such as the aorta.

Until now, aortic stiffening has been tackled successfully by carefully designed and well-supervised training programs, but this is not a measure that can be widely applied to the general population. In contrast, most healthy people can start marathon training.

The researchers looked at 138 individuals who ran the London Marathon, all between the ages of 21 and 69 years. They were almost equally male or female. Most of them had trained using the Beginner’s Training Plan recommended by the race organizers.

This plan is less rigorous compared to those used by more advanced marathoners – it requires about three runs weekly for 17 weeks. The runners had, therefore, run about 6-13 miles a week during their training. The marathon participants were free to choose this or more demanding plans.

Those who chose this plan underwent magnetic resonance imaging (MRI) of the heart, to evaluate the stiffness of the blood vessels in the heart, and also had their blood pressure (in the aorta) measured before the marathon and up to 3 weeks after it. The researchers used cardiovascular magnetic resonance distensibility to measure these parameters.

The chronological age was compared with the aortic stiffness to calculate the biological age of the aorta. The sites selected to calculate the change in stiffness were the ascending aorta, the descending aorta at the point where the pulmonary trunk just adjacent to it divides into the two large arteries to the lung (the pulmonary arteries), and the descending aorta where it pierces the diaphragm to enter the abdomen. The mean change in stiffness was calculated at each of these sites.

Three areas of the aorta were selected for the measurement of aortic stiffness. At the start of the study, the distensibility of the aorta at these sites was reduced by 2.3, 1.9 and 3.1 × 10−3 mm Hg−1, respectively, for every ten years of chronological aging.

The findings

When the people training for the marathon were assessed for aortic elasticity, the tests showed that aortic stiffness had regressed to a value more typical of people four years younger, on average. The older the runner, the greater the gain.

We were gratified to see that it’s possible to improve things in older people that you think would have established irreversible changes.”

Charlotte Manisty, UCL Institute of Cardiovascular Science

Of the three areas tested, the descending aorta at the pulmonary trunk bifurcation showed a 9% improvement in elasticity, while it improved by 16% in the aortic trunk at the diaphragm. This translates into a reduced biological aortic age by about four years. Though a small reduction, even this had not been known to happen earlier, and the finding was therefore unexpected. The benefits were more marked in the case of older male runners who took a longer time to finish the marathon.

More than the amount of elasticity regained, the fact that it occurred at all was very significant to the researchers, who explained: “Four years doesn’t seem like a significant change, but it wasn’t known you could do that before.”

Along with increased flexibility, the blood pressure also dropped by four points (systolic) and three points (diastolic).

The researchers took care to exclude people who already had high blood pressure. The beneficial effects of marathon training on this subgroup will, therefore, have to be investigated in the future. The scientists also need to see whether there must be a level of activity required to ensure that blood vessels regain their elasticity.

These benefits did not need world-class performances to be evident. Even in this novice group who ran the marathon about 30 minutes slower than the average runner, the drop in blood pressure and the improved aortic flexibility show, in the words of Manisty, that “This is running for health benefits for normal, real-world people running real-world marathons.”

Secondly, as the researchers point out, the study shows it’s never too late for a healthy person to begin to reverse the risks of aging by lifestyle modifications like low-intensity sports.

And for the incorrigible non-runners, Manisty recommends they take up other active sports, such as cycling. In fact, cycling could probably help them become more fit since it is better at aiding goal-oriented training, in the same way as training for a marathon.

Sources

Anish N.Bhuva, AndrewD’Silva, CamillaTorlasco, Siana Jones, Niromila Nadarajan, Jet Van Zalen, Nish Chaturvedi, Guy Lloyd, Sanjay Sharma, James C.Moon, Alun D.Hughes, Charlotte H.Manisty. Training for a first-time marathon reverses age-related aortic stiffening. Journal of the American College of Cardiology, Volume 75, Issue 1, 7–14 January 2020, Pages 72-75. https://doi.org/10.1016/j.jacc.2019.10.045. https://www.sciencedirect.com/science/article/pii/S073510971938369X?via%3Dihub