Regular exercise may do more than strengthen the heart. It could also reprogram the nerves that control how the heart beats, new research has found.

The discovery could eventually help doctors better treat common conditions such as irregular heart rhythms, chest pain, angina and stress-related “broken-heart” syndrome, according to scientists at the University of Bristol in the U.K.

The study, which looked at lab rats trained over 10 weeks, found that moderate exercise does not affect the heart’s nerve control system evenly. Instead, it produces distinct and opposing changes on the left and right sides of the body. a split researchers say has gone largely unnoticed until now.

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“The discovery points to a previously hidden left–right pattern in the body’s ‘autopilot’ system that helps run the heart,” Dr. Augusto Coppi, the study’s lead author and a senior lecturer in veterinary anatomy at the University of Bristol, said in a statement.

“This could help explain why some treatments work better on one side than the other and, in the future, help doctors target therapies more precisely and effectively,” Coppi added.

After 10 weeks of aerobic exercise, the researchers examined the animals’ heart control nerves and found left–right differences that did not appear in inactive rats, according to the research published in the journal Autonomic Neuroscience in September.

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On the right side, the nerve hub that sends “go faster” signals to the heart developed many more nerve cells, suggesting increased wiring. On the left side, however, the number of nerve cells did not rise as much. Instead, the existing cells grew significantly larger, indicating a different kind of adaptation.

The findings show that exercise reshapes the heart’s nerve control system in a side-specific way rather than affecting both sides equally, the researchers said. Understanding that process could help doctors better target treatments, especially for patients who cannot exercise or whose symptoms persist despite lifestyle changes.

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Researchers compared the nerve clusters, known as the stellate ganglia, to a “dimmer switch” that fine-tunes how strongly the heart is stimulated. That fine-tuning is important because overstimulation of these nerves is linked to chest pain and dangerous heart rhythm problems.

The findings are early stage and based on animal research, however. So, they do not prove the same effects in people. More studies are needed before they could affect patient care.

Researchers say future studies will explore whether similar left–right nerve changes occur in people and whether they could help explain why some heart treatments work better on one side than the other, potentially paving the way for more precise, personalized care for angina and heart rhythm disorders.

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The study was conducted in collaboration with researchers from University College London, the University of São Paulo and the Federal University of São Paulo in Brazil.

The findings add to growing evidence that regular, moderate exercise benefits the heart in ways scientists are beginning to understand better.

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Fox News Digital has reached out to the study authors for comment.

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Older adults discharged from hospitals on multiple medications are less likely to regain independence during rehabilitation, a new study suggests.

The Japanese study, published in the journal BMC Geriatrics Dec. 17, explored the effects of polypharmacy — defined as taking six or more regular medications on a regular basis — at a convalescent rehabilitation hospital in Japan.

The retrospective observational study looked at 1,903 patients 65 and older who underwent rehabilitation at the hospital from April 2017 to March 2024, according to a press release.

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The patients had one of three conditions: cerebrovascular disease (a disorder of the brain’s blood vessels that reduce or block blood flow), motor disorder (a condition that affects movement and muscle control) or disuse syndrome (inactivity leading to muscle weakness and physical decline).

Of the total group, 62.1% of the patients were taking six or more medications when they were discharged from the hospital, and more than 76% of them were 80 or older. 

Those taking multiple medications were also more likely to be taking benzodiazepine receptor agonists (taken for anxiety or insomnia), laxatives and psychotropic medications (mainly used for depression, anxiety, psychosis and other mood disorders). 

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The researchers determined that those with polypharmacy who had cerebrovascular disease and disuse syndrome scored significantly lower in the functional independence measure (FIM), which assesses how independently a person can perform everyday activities, especially after illness, injury or hospitalization. Those in the motor disorder group didn’t show any link between polypharmacy and FIM.

The negative effects were stronger among adults over 80 and those recovering from stroke-related conditions or general weakness due to inactivity.

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Based on these findings, the researchers suggest that reviewing and reducing unnecessary medications could help improve recovery for those undergoing rehabilitation.

Dr. Marc Siegel, Fox News senior medical analyst, refers to polypharmacy with seniors as a “risky proposition.”

“Even though each medication may have a purpose, often important, we must keep in mind that the ability to tolerate various medications and metabolize them efficiently diminishes as you get older,” he told Fox News Digital.

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“For example, a med that sedates you or even has the potential to disorient you may be more likely to do so as you become elderly.”

Drug interactions also tend to increase as patients grow older, Siegel added. 

“This must all be monitored carefully by your physician, and, sometimes, less is more,” he said.

The study did have some limitations, the researchers acknowledged. Due to its retrospective and observational design, it does not prove that the medications caused the outcome.

The researchers also lacked data on specific doses of the medications and the intensity of the rehabilitation, they noted. Also, the study was conducted at just a single hospital, so the results may not apply to more general populations.

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Future research is needed to determine which specific medications most affect recovery and to explore the best approaches for reducing prescriptions.