New research indicates that regular physical exercise is just as effective as prescription medications in treating chronic diseases - and without all of the associated side effects of drugs.

According to a study published recently in the British Medical Journal, scientists from the London School of Economics, Harvard Medical School and Stanford University School of Medicine wanted to see if the benefits of exercise and drugs from past clinical trials were comparable, in a bid to see if they could extend a person's life.

"What we have is a body of research that looks at benefits of exercise alone and then a separate body of research that looks at benefits of drugs on their own," lead researcher Huseyin Naci, a researcher at the London School of Economics and a pharmaceutical policy research fellow at the Harvard Medical School, said.

"There's never been a study that compares these two together, so that's the rationale for this research."

Four areas of health where the evidence suggests or has shown that exercise can have some lifesaving benefits were studied by Naci's team. Those areas were secondary prevention of heart disease, prevention of diabetes, stroke rehabilitation and treatment of heart failure.

Researchers compiled a list of the different classes of drugs people commonly take to manage these conditions, and ultimately came up with 305 randomised clinical trials to analyse. The study involved 339,274 people, 15,000 of whom received physical intervention for their health conditions while the rest were included in drug trials.

Overall, the researchers saw no significant difference between exercise and drug intervention for the secondary prevention of heart disease and the prevention of diabetes. And in the case of stroke patients, exercise was found to be more effective than drug treatment at extending a person's mortality.

Given their findings, Naci argued that the study's results should not dissuade heart disease and diabetes patients from changing their current treatments.

"One thing that is very much not a takeaway is that patients should stop taking their medications without consulting with their doctors," Naci said. "However, doctors do need to have really candid conversations with patients about the lifesaving benefits of exercise."

Combination therapies utilising both diet and exercise may not be the answer either. A recent study published in the Journal of the American College of Cardiology found that statins, commonly prescribed cholesterol lowering medications, may actually block some of the health benefits seen from exercise.

Naci said that patients instead deserve a better understanding of which treatment option is best and that more clinical research is needed to address this knowledge gap.

"We need a lot more research to really tease out the lifesaving benefits from exercise," Naci said, "as well as which exercise works best for different types of individuals."