Exercise Rewires the Heart's Nerve Network Beyond Strengthening It: Study - Video

Exercise may be doing more than strengthening your heart-it could be rewiring the nerves that control it. A new study suggests that regular aerobic exercise reshapes the heart's nerve network in a unique left-right pattern, a discovery that could eventually lead to more targeted treatments for heart disease.

Researchers from the University of Bristol published the findings in Autonomic Neuroscience, revealing for the first time that moderate aerobic exercise changes the heart's controlling nerves differently on the left and right sides of the body.

Using advanced three-dimensional imaging, the team examined nerve clusters called stellate ganglia, which regulate heart rate and rhythm by sending "go faster" signals to the heart. After 10 weeks of regular exercise, rats showed major structural changes in these nerve clusters.

Compared with untrained animals, exercising rats had about four times more nerve cells in the cardiovascular nerve cluster on the right side than on the left. At the same time, nerve cells on the left side nearly doubled in size, while those on the right became slightly smaller. These findings suggest that exercise remodels the heart's nerve network differently on each side.

Researchers believe this discovery could have important clinical implications. Overactive stellate ganglia are already targeted through nerve blocks or denervation procedures to treat arrhythmias, stress-induced "broken-heart" syndrome, and some forms of angina. Understanding the left-right differences may help doctors identify which side should be targeted for better treatment outcomes.

The research team now plans to investigate how these structural nerve changes affect heart function during exercise and at rest. They also aim to determine whether similar left-right remodeling occurs in larger animals and eventually in people using non-invasive techniques.

REFERENCE: Fernando Vagner Lobo Ladd, et al.; Asymmetric neuroplasticity in stellate ganglia: Unveiling side-specific adaptations to aerobic exercise. Autonomic Neuroscience, 2025; 262: 103338 DOI: 10.1016/j.autneu.2025.103338