Exercise Changes the Heart in a Way Researchers Never Expected

For many years, exercise has been recognized as one of the most effective ways to maintain a healthy heart. Doctors encourage people to engage in it to help lower blood pressure, improve circulation, alleviate stress, and even prevent heart disease. Most people think that all that exercise does is make the muscles of the heart stronger and more enduring.

What recent studies show is even more interesting than that. It turns out that regular exercise may actually alter the nervous system that controls the heart. Instead of just getting your heart muscles to be healthier, exercise makes changes to your body’s regulatory system that controls heart rate, blood pressure, and stress reactions.

The Secretive Structure That Manages Your Heart Function

Although most individuals consider the heart a durable organ working all the time efficiently, it is not completely true. In reality, it operates under the control of the nervous system which gives it particular instructions every second. Among structures controlling the heart, there are the ones called stellate ganglia. It refers to small clusters of neurons located in the base of the neck and upper thorax which have a responsibility to stimulate heart rate and blood pressure changes in stressful periods or physical activities.

When a person exercises, experiences excitement, or gets scared, it makes nerve clusters start sending commands to make the heart work faster and provide the body with additional oxygen. Scientists have been paying too much attention to the beneficial effects of exercise on muscles but have paid no considerable attention to their impact on such delicate nerve centers of the body. However, the situation is changing.

The Research Project that Shocked Scientists

Scientists from the University of Bristol decided to conduct experiments and find out if aerobic exercise would have any effect on cardiac nervous system physiology. The outcome was surprising. Utilizing cutting-edge 3D imaging methods, the scientists investigated the stellate ganglia of rats who underwent 10-weeks of treadmill exercise at moderate intensity and compared their data with sedentary rats.

It turned out the assumptions about aerobic exercise had to be reconsidered. Instead of having an equal effect on the two parts of the nervous system, aerobic exercise created an imbalance in terms of structural changes between the right and left sides. In particular, the researchers found that there were four times as many neurons in the right stellate ganglia in comparison with the left part. While the size of neurons on the left increased significantly, those on the right side became smaller.

The volume of neurons in total decreased following the training period. This means that exercise can produce selective effects on nervous structure.

Importance of These Discoveries

On the surface, these findings appear to be insignificant technical matters. However, they may hold great importance for studying the state of cardiac health. Nervous system regulation is essential for maintaining heart rhythm. Any disruption in the nerve-heart connection is associated with potentially dangerous disorders including:

• Heart rhythm disorders (arrhythmia)
• Recurrent chest pains
• High blood pressure
• Stress-induced heart diseases
• A particular type of heart failure

Medicine specialists currently use the stellate ganglia in their attempts to treat patients suffering from certain serious heart conditions. Nerve blockage or denervation techniques are applied to inhibit overactivity of the nerves stimulating life-threatening rhythms of the heart.

These results indicate that there may exist certain disparities between the functions of these two parts of the nervous structure. If further research proves the discovered difference in human patients, physicians will probably be able to create more targeted therapies based on which side of the nervous system causes the problem.

Exercise Does More Than Strengthen Muscles

What is most fascinating about this study is how it has broadened our perspectives regarding the effects of exercise. Historically, there has always been an association between exercise and noticeable changes such as:

• Strength building
• Cardiovascular fitness
• Managing weight
• Flexibility gains
• Increased metabolic activity

However, researchers have recently found that exercise triggers many changes on a deeper level within the body. It seems that exercise affects inflammation levels, immunity, hormonal release, brain function, and cellular repair activity. It is observed that exercise acts as a physiological signal for the organs to adapt themselves and become better.

Based on current studies, it is also clear that the nervous system governing heart function has high plasticity. Therefore, it looks like your workout not only helps you lose some pounds and make you stronger, but also makes your body learn to regulate its functions neurologically.

What Makes Aerobic Exercise Special?

The researchers concentrated specifically on aerobic exercises, which require increased heart rate over time. These include:

• Walking briskly
• Running
• Riding a bicycle 
• Swimming
• Dancing
• Hiking
• Rowing

During aerobic training, the cardiovascular system is constantly subjected to certain pressures. With time, the body learns how to cope with such challenges better, improving its oxygen delivery mechanisms. Scientists suggest that the repetitive demands put by aerobic training could explain why the nervous system starts to change its structure.

The nerve pathways responsible for heart activity may not be as stable as previously thought, and may actually be able to adapt to the physiological changes of the body. Such phenomena as neuroplasticity are often described only for the brain, but this study shows that other parts of the nervous system might possess it as well.

How Can Exercise Actually Aid In the Regeneration of the Heart?

This notion is even more intriguing in light of earlier studies on the topic.

Exercise has been shown to induce the growth of new heart muscle cells in a number of different studies. Scientists noted an increase in the rate of regeneration occurring in the hearts of exercising animals and even those who had suffered heart damage. Specifically, in one experiment, the number of new heart muscle cells that grew in active mice was significantly greater than that of sedentary mice.

Although much more research will be necessary before we can fully understand this effect, there is no doubt that scientists are discovering something very important about the effects of exercise on our cardiovascular systems. The heart is doing more than just becoming strong; it is also becoming rejuvenated.

Limitations That Should Not Be Overlooked

While the results are certainly intriguing, one must remember to maintain some perspective when considering them. For example, the most recent study was conducted on rats rather than humans. While studies using animals can offer many useful conclusions, the same does not always hold true for humans. Many issues remain unresolved at the moment:

• Can humans expect similar changes in their nerve activity?
• What effect do such changes have on heart function?
• Are these changes positive under all circumstances?
• How much exercise is needed to make these changes occur?
• Is there any difference between exercises and their effect on the body?

Only future studies that involve larger animals and humans can help answer these questions.

The Larger Context: A Novel Perspective on Exercise

For decades, exercise has been understood mainly as a mechanism of enhancing health and disease prevention. Current scientific knowledge is providing a completely different perspective. Current studies show that exercise affects virtually all body systems. It impacts muscle performance, blood flow, hormone production, immune responses, metabolic processes, brain activities, and potentially even the heart’s nervous system.

It further strengthens the growing view that exercise is not just an activity but rather an important biological stimulus to make the body adjust, recover, and improve. The finding that exercise alters the heart’s nerve network brings yet another dimension into this perspective.

Conclusion

Current studies on exercise and cardiovascular health offer a truly surprising perspective on physical activity. It seems that aerobic exercises can alter the structure of nerve networks responsible for regulating heart rate, resulting in different modifications in the left and right sides of the body.

While this area of research requires additional investigation, potential applications might lead to better medical treatment of various arrhythmias, constant chest pain, and other diseases. Moreover, current results once again draw our attention to the impact of exercise on the human body.

It appears that each time you do physical activities, you not only strengthen your muscles, but also affect the nervous system involved in heart functioning. Therefore, exercise turns out to be an even more important component of good health than it was thought before.