Frequent exercise doesn’t just strengthen the heart – it also changes the nerves that control it, according to new research which could guide more targeted and effective care for common heart problems.

The study, led by the University of Bristol (UK), shows for the first time that moderate aerobic training reshapes nerves that drive the heart, and affects them on each side of the heart differently. The research is published in the journal Autonomic Neuroscience.

Findings highlighting this marked left-right split could ultimately be used to treat more effectively a range of conditions, including irregular heartbeats, chest pain, angina pain, and ‘broken-heart’ syndrome.

Study lead author Dr Augusto Coppi, Senior Lecturer in Veterinary Anatomy at the University of Bristol, said: “The discovery points to a previously hidden left–right pattern in the body’s ‘autopilot’ system that helps run the heart.

“These nerve clusters act like the heart’s dimmer switch and we’ve shown that regular, moderate exercise remodels that switch in a side-specific way. This could help explain why some treatments work better on one side than the other and, in future, help doctors target therapies more precisely and effectively.”

The research, in collaboration with the University College London (UCL) in the UK and the University of São Paulo (USP) and Federal University of São Paulo (UNIFESP) in Brazil, used advanced 3D quantitative imaging analysis methods called stereology. Findings showed that trained rats over a 10-week period had around four times more nerves – called neurons – in the cardiovascular cluster on the right-hand side of the body than the left compared to untrained rats. Conversely, the neurons on the left nearly doubled in size while those on the right slightly shrunk.

Dr Coppi explained: “Irregular heart rhythms, known as arrhythmias, stress-induced ‘broken‑heart’ syndrome, and certain types of chest pain are often treated by dialling down overactive stellate ganglia – the paired small nerve hubs in the lower neck/upper chest area that send ‘go faster’ signals to the heart.

“By mapping how exercise changes these ganglia on each side, the study offers clues that could one day fine‑tune procedures like nerve blocks or denervation to the side most likely to help. The findings are early-stage and in rats, so clinical studies would need to follow.”

The researchers are now planning studies to link these structural changes to how the heart actually behaves at rest and during exercise. They will then look for the same left–right pattern in other animal models and in people using non‑invasive markers. This will help ascertain whether targeting one side of the nerve cluster could make treatments such as stellate nerve blocks or denervation more effective for arrhythmias, stress‑induced ‘broken‑heart’ syndrome, and difficult‑to‑treat angina.

Dr Coppi added: “Understanding these left-right differences could help us personalise treatments for heart rhythm disorders and angina. Our next step is to test how these structural changes map onto function and whether similar patterns appear in larger animals and humans.”

Analysis of over 36,000 people with high blood pressure has shown that taking more steps, even below the recommended daily target of 10,000 steps, and walking faster, is associated with a significant reduction in the risk of major problems of the heart and blood vessels. 

The study, published in the European Journal of Preventive Cardiology, found that compared to a daily step count of 2,300 steps, every extra 1,000 steps was linked to a 17% reduction in the risk of developing a major adverse cardiovascular event (MACE), up to 10,000 steps. Additional steps above 10,000 were associated with a lower risk of stroke.  

Approximately 1.28 billion people worldwide are living with high blood pressure, and it places them at increased risk of heart disease (49% increase), stroke (62% increase) and heart failure (77-89% increase). Until now, it has been unclear how much people with high blood pressure need to increase their physical activity in order to see a reduction in their risk of MACE. 

Professor Emmanuel Stamatakis, Director of the Mackenzie Wearables Research Hub at the University of Sydney, Australia, who supervised the study, said: “This study is one of the first to demonstrate a dose-response relationship between daily step count and major problems of the heart and blood vessels. In a nutshell, we found that, if you live with high blood pressure, the more you walk with greater intensity, the lower your risk for future serious cardiovascular events.  

“These findings support the message that any amount of physical activity is beneficial, even below the widely recommended daily target of 10,000 steps.”  

The study analysed data obtained from 32,192 people who had enrolled in a sub-study of the UK Biobank study. They had been diagnosed with high blood pressure and agreed to wear an accelerometer on their wrist for seven consecutive days to measure how far and how fast they walked. Data from the accelerometers was collected between 2013 and 2015. The average age was 64 and the participants were followed up for nearly eight years, providing the researchers with data for 283,001 person-years. During this time 1,935 cases of heart problems or stroke occurred. 

In addition to a 17% reduction in overall risk for every extra 1,000 steps a day, the researchers found a 22% reduction in heart failure, 9% reduction in risk of heart attack, and 24% reduction in risk of stroke. This means that every increase of 1,000 steps a day was associated with: 

• an average reduction in the absolute risk of MACE of 31.5 events per 10,000 person-years 
• an average reduction in the absolute risk of 7.2 heart failure events per 10,000 person-years 
• an average reduction in the absolute risk of 9.9 myocardial infarctions (heart attacks) per 10,000 person-years 
• an average reduction in the absolute risk of 10.4 strokes per 10,000 person-years. 

The average (mean) intensity of the 30 minutes of fastest walking per day was 80 steps a minute and this was associated with a 30% reduced risk of MACE. There was no evidence of harm in people whose 30 minutes of fastest walking or running was over 130 steps a minute.

The researchers found similar results when they looked at 37,350 people without high blood pressure. Every 1,000-step increase in daily step count led to an average lower risk of MACE, heart failure, myocardial infarctions and stroke of 20.2%, 23.2%, 17.9%, and 24.6%, respectively. 

Prof. Stamatakis said: “Our findings offer patients accessible and measurable targets for heart health, even below 10,000 steps daily. Clinicians should promote physical activity as standard care, especially in patients with high blood pressure. Our results can inform new, tailored public health recommendations for these patients. Future recommendations on walking in people with high blood pressure could consider promoting higher stepping intensity.” 

Strengths of the study include the large number of patients, the use of accelerometers to provide detailed information on numbers of steps and speed, and the use of data from national records in England, Wales and Scotland on deaths and causes of death.  

Limitations include the fact that physical activity was measured only when people first joined the study and did not include any subsequent changes in behaviour. In addition, the researchers point out that their findings can show only that there is an association between walking further and faster and better health outcomes, not that it causes these better outcomes. However, they conducted extensive analyses to minimise the risk of what is called ‘reverse causation’ (in which, in this case, health problems could be causing both a reduction in physical activity and an increase in heart disease events). Most UK Biobank participants are White, are less likely to be obese, to smoke or drink alcohol, and to be better educated, and so they may not be representative of the general UK population. 

A major new study led by the University of Sydney suggests that walking 7000 steps a day offers similar health benefits across several outcomes as walking 10,000.

Led by Professor Melody Ding from the School of Public Health, the study was published in The Lancet Public Healthand analysed data from 57 studies from 2014 to 2025 that were conducted in more than ten countries including Australia, USA, UK and Japan.

The largest and most comprehensive review to date, the researchers examined the impact that different daily step counts have on the chance of dying from cardiovascular disease and cancer, and developing diseases such as cancer, type 2 diabetes, dementia and depression. Professor Melody Ding says the findings offer a more achievable benchmark for people who struggle to meet traditional exercise guidelines. 

“Aiming for 7000 steps is a realistic goal based on our findings, which assessed health outcomes in a range of areas that hadn’t been looked at before,” said Professor Ding. “However, for those who cannot yet achieve 7000 steps a day, even small increases in step counts, such as increasing from 2000 to 4000 steps a day, are associated with significant health gain.”

“We know daily step count is linked to living longer, but we now also have evidence that walking at least 7000 steps a day can significantly improve eight major health outcomes – including reducing risk of cardiovascular disease, dementia and depressive symptoms.”

Health benefits at different step counts

The researchers looked at studies in which participants wore step counting devices, such as pedometers, accelerometers and fitness trackers, to track their daily step counts. Starting at 2000 steps, experts compared the health outcomes of people walking more steps a day at 1000 step increments to see whether there was any difference in the risk of early death or other major diseases. 

When compared with 2000 steps a day, researchers found that: 

• Walking 7000 steps a day reduced the risk of death by 47 percent, which was almost identical to the benefit seen at walking 10,000 steps per day. 
• Dementia risk dropped by 38 percent from walking 7000 steps a day, with only a 7 percent extra reduction at 10,000 steps. 
• Risk of type 2 diabetes fell by 22 percent from walking 10,000 steps a day and reduced to 27 percent at 12,000 steps.
• Significant health improvements were seen when people increased their average daily steps from 2000 to between 5000 and 7000 steps. 

“For people who are already active, 10,000 steps a day is great,” said Dr Katherine Owen, co-author and chief analyst of the study from the School of Public Health. “But beyond 7000 steps, the extra benefits for most of the health outcomes we looked at were modest.”

“Our research helps to shift the focus from perfection to progress. Even small increases in daily movement can lead to meaningful health improvements,” said Professor Ding. 

Experts are calling for future studies to explore how step goals should vary based on age, health status and region, and to include diverse populations and longer-term data to strengthen the evidence. Professor Ding says this kind of detail is rare and will be useful for health practitioners when tailoring advice for patients.