"First-time marathon runners can 'reverse ageing' on blood vessels by four years," reports the Daily Mirror.
The headline follows a UK study that recruited 138 healthy adults with no previous marathon experience. The participants then spent 6 months training for the London Marathon.
At the start of the study, researchers used a type of heart scan that measures the stiffness of the aorta – the major artery that takes blood from the heart to supply the rest of the body.
Increased artery stiffness is linked with increased risk of high blood pressure and heart disease. It's also considered to be a sign of ageing. The researchers repeated these scans after the participants completed their first marathon.
The study found that training was associated with decreased stiffness of the aorta. This was calculated to be the equivalent of up to 4 years' decrease in the "biological age" of the blood vessel. The effect seemed to be greater in:
- older participants who had stiffer arteries to start with
- those with slower marathon running times
It's worth noting that we do not know the health outcomes of the participants in the longer term, so we do not know if the decreased artery stiffness definitely translated into improved heart health and longevity. However, we do know that regular physical activity boosts health.
Running is not for everyone, and just over half of the people who signed up completed the study. Other forms of exercise such as cycling, swimming or walking may be just as beneficial. The important thing is to do regular physical activity in line with current recommendations.
If you are planning to get fit for the new year, running a marathon may be a little too ambitious as your first exercise goal. Other ways you can gradually increase your fitness levels include running shorter distances, swimming and cycling.
Where did the story come from?
The study was conducted by researchers from the University of London, University College London, Barts Health NHS Trust London, and San Luca Hospital in Italy.
The study was funded by:
- British Heart Foundation
- Cardiac Risk in the Young
- the Barts Cardiovascular Biomedical Research Centre
The study was published in the peer-reviewed Journal of the American College of Cardiology.
The UK media accurately reported that the study's main finding was that the change seemed equivalent to a 4-year reduction in biological age. However, some headlines, such as Mail Online, go a bit far suggesting "Running a marathon could add years to your life."
Although the changes seemed positive for the participants' cardiovascular health, we do not know about their health in the longer term.
The results of this study also do not mean it's necessary to run a marathon – other forms of activity may be as beneficial.
What kind of research was this?
This was a cohort study in which a group of healthy adults trained for the London Marathon and received assessments of their heart function before and after training.
The main limitation of this study is that there is no control group for comparison. For example, a group of similar adults who either did not undergo training or performed an alternative form of exercise or fitness training.
It is also a short-term study with no long-term assessments of health outcomes.
What did the research involve?
In 2016 to 2017 the study recruited healthy adults to participate in training for their first London Marathon. Participants had to:
- have no significant medical problems, such as heart disease
- have no previous marathon-running experience
- currently run for less than 2 hours a week
The researchers performed 2 physical assessments on the participants. The 1st assessment took place before training started, which was 6 months before the London Marathon. The 2nd assessment took place within 3 weeks of completing the marathon.
The assessment included measuring their blood pressure and a type of heart scan, called cardiovascular magnetic resonance, to look at stiffness of the aorta – the main artery leaving the heart.
The researchers looked at the relationship between the person's actual age and the stiffness at different levels of the aorta to assess their biological age.
All the participants were recommended to follow the "Beginner's Training Plan" for marathon running. This involved 3 runs per week, which gradually increased in difficulty in the months leading up to the marathon.
The analysis included the 138 participants who completed the marathon and returned for their final assessment. This was 58% of the 237 participants originally recruited. The participants were 37 years old on average, with an age range of 21 to 69, and 49% of them were men.
What were the basic results?
Assessments at the start of the study showed that increasing age was linked with increased aortic stiffness.
Marathon training resulted in a small decrease in blood pressure, of about 3 to 4 mmHg. Training caused decreased stiffness of the "descending" aorta, where it extends down through the chest, but made little difference to the first section of the aorta where it leaves the heart.
Training was calculated to reduce the biological age by:
- 1.5 years in the 1st section of the aorta where it leaves the heart
- 3.9 years in the upper part of the descending aorta
- 4 years in the lower part of the descending aorta, where it passes through the diaphragm, just under the lungs, into the abdomen
The effect seemed to be greater in:
- older people
- those with a slower marathon running time
How did the researchers interpret the results?
The researchers conclude: "Training for and completing a marathon, even at relatively low exercise intensity, reduces central blood pressure and aortic stiffness, equivalent to a 4-year reduction in vascular age. Greater rejuvenation was observed in older, slower individuals."
This is an interesting study that recruited untrained adults to a marathon training programme and demonstrated the effect this can have on blood pressure and arterial function.
It is well established that regular aerobic exercise within an individual's limits is beneficial to cardiovascular health and overall health and wellbeing. It is also known that increased arterial stiffness is linked with increased risk of high blood pressure and heart disease. Therefore, the finding that aerobic training reduced aortic stiffness provides evidence in support of this.
However, that does not mean marathon training is the only way to improve vascular health. This study had no comparison group of other people taking no exercise or taking up other regular exercise habits, such as cycling, swimming, walking or even gardening. Other forms of exercise may also give reductions in arterial stiffness.
Notably, this analysis only included the 58% of recruited participants who successfully completed the training and marathon, which goes to show that marathon running is not for everyone. These people had volunteered to take part in the London Marathon and felt fit enough to do so. So, they are probably not representative of most people who are at most risk of cardiovascular disease.
People who have pre-existing medical conditions should consult a health professional before taking up vigorous exercise.
Also, despite the positive signs of decreased aortic stiffness, we do not know how this would translate into cardiovascular health and risk of illness in the longer term. Training seemed to have minimal effect on the first section of the aorta as it leaves the heart, and it's not clear what this would mean for a person's health.
We also do not know what would happen if people continued with regular running in the longer term. For example, whether the aorta would continue to show increased stretch and pliability or whether the benefits would stabilise over time. This means we do not know how far you could go in reducing heart and vascular age.
Nevertheless, the study supports the general message to do regular exercise in line with government recommendations. Adults should:
- aim to be physically active every day. Any activity is better than none, and more is better still
- do strengthening activities that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms) on at least 2 days a week
- do at least 150 minutes of moderate-intensity activity each week, or 75 minutes of vigorous-intensity activity each week
- reduce time spent sitting or lying down and break up long periods of not moving with some activity.
Whatever your age or current level of fitness, it's not too late to start.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
Daily Mirror, 6 January 2020
Mail Online, 6 January 2020
The Telegraph, 6 January 2020
Links to the science
Science Direct. Published online 7 January 2020