Rewires' The Heart

Scientists have long known that regular exercise can lower your heart rate and strengthen your cardiovascular system.

The study, published on September 23 in Autonomic Neuroscience: Basic & Clinical , examined the stellate ganglia, a pair of nerve clusters in the neck that help control the heart's activity.

After 10 weeks of moderate treadmill training, the rats' right-side ganglion showed a large jump in neuron numbers but a shrinkage in neuron size, while the left-side ganglion saw the opposite, with fewer changes in number but an increase in neuron size.

This side-to-side difference hints that exercise might prompt the autonomic nervous system to adapt in more complex, asymmetrical ways than previously thought, according to the authors.

This could potentially open doors to new treatments for heart rhythm problems and other conditions that involve nerve control of the heart.

To learn how exercise might alter the structure of the stellate ganglia, researchers worked with Wistar rats, a common laboratory strain known for its reliability in physiological studies.