Exercise could be the best way of preventing the development of Alzheimer's disease in elderly people, according to researchers at the University of Maryland School of Public Health who have published a report in the Journal of Alzheimer's Disease.

Their findings suggest exercise stimulates parts of the brain associated with memory and helps reduce the progression of mild cognitive impairment (MCI).

The study focused on adults between the ages of 60 and 88 who were physically inactive and placed them on a 12-week exercise programme, which included treadmill walking guided by a personal trainer. The exercise wasn’t strenuous and amounted to 150 minutes a week, seeking to increase participants’ heart rates and sweat levels.

The researchers at the university then asked participants to identify famous people from their past. Using functional magnetic resonance imaging, they were then able to assess brain function.

Of the two groups studied, those with and without MCI, both showed an increased ability in memory recall and an increase of over 10 percent in cardiovascular fitness.

The findings showed exercise not only improved memory in those already diagnosed with MCI, but also increased their overall brain function. The scientists also identified that after exercise, both groups of older people used less brain power to recall the correct answers, showing an improvement in cognitive efficiency.

“After 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency – basically they were using fewer neural resources to perform the same memory task,” said lead author of the study, Dr J Carson Smith. “No study has shown that a drug can do what we showed is possible with exercise."

The group of researchers are planning a larger-scale study to include more patients and compare healthy individuals with those more prone to the development of Alzheimer's. The future study will also continue for longer to determine whether the effects of exercise are lasting.