Walking for half an hour a day is equivalent to taking a "magic pill" that combats ageing and prevents premature death, an expert has said.
Dr James Brown surprised the British Science Festival by presenting the myriad benefits of a pill that could maintain healthy living and improve quality of life.
The wonder-drug was able to prevent obesity and diabetes, lower the risk of some cancers, relieve depression and anxiety, increase mobility, and reduce the chances of hip fracture by 40pc.
It also improved the ability to think and reason, slowed the progression of Alzheimer's disease, cut arthritic pain by 50pc, boosted energy levels, reduced fatigue and led to a 23pc lower risk of dying.
Then he delivered the punchline: "This isn't a pill - it's exercise." Dr Brown, from the School of Life and Health Sciences at Aston University, added: "All of these changes are not seen in people who run marathons; they're not seen in people who lift weights in the gym, or spend four hours running on the treadmill. These are seen in people who walk and who walk for half an hour a day.
"You can get all of these health benefits; you can get a reduction in all of these diseases that are associated with ageing, by just walking for half an hour a day."
During his lecture Dr Brown outlined the "use-it-or-lose-it" philosophy behind keeping active and healthy as we age.
Dr Brown described one study that compared the effect of putting a leg in plaster for two weeks in two groups of young and old participants.
The young group lost twice as much muscle mass during that time, but quickly put it back on when the plaster was removed. After four weeks of gym training, they were back to normal. In sharp contrast, the older participants' muscle mass was not restored after four weeks, or even eight.