A drug regularly prescribed for heart conditions could help pensioners to exercise more, according to scientists from Dundee University.
Researchers found pensioners were able to exercise for longer
Researchers discovered older people became more active when they were given an ACE inhibitor called perindopril.
The test subjects, who had an average age of 79, were able to walk further than those who were given placebos.
Academics hope the study could be used to improve the quality of life for Britain's ageing population.
Researchers said the majority of the older people did not take regular exercise, even though it increases strength and slows mental decline.
They performed a test involving 130 pensioners from the Dundee area, who had difficulties performing day-to-day activities.
Some were given a placebo and others perindopril, which is usually prescribed for heart conditions.
After 20 weeks, the research team discovered those who had been taking the active drugs were able to take more exercise and had a better quality of life than the placebo group.
The head of the university's ageing and health unit called it "a tremendously important finding".
Professor Marion McMurdo said: "We have an ageing population and so it is vital to older people and the NHS that they stay as active as possible.
"We found that the people who had been given the drug could walk on average 30m further in six minutes than those who had been given the placebo.
"This is a level of improvement in exercise capacity that is equivalent to that reported after six months of exercise training, and may make an important difference for a growing sector of the population in which people might find it difficult to sustain that level of exercise."
Prof McMurdo added that more research was needed to discover precisely why the drug worked.
She has been trying to establish if the drug has a beneficial effect on the heart, leg muscles or blood vessels.
The study follows on from previous research by her team, which found that heart failure patients were able to walk further after being prescribed ACE inhibitors.