New York, July 16 (IANS): Older adults can improve their brain function by raising their fitness level, a study shows.

"Basically, the more exercise you did, the more benefit to the brain you saw," said Jeffrey Burns, professor of neurology at the University of Kansas Medical Center.

The team led a six-month trial conducted with healthy adults ages 65 and older who showed no signs of cognitive decline.

The results of the study were published in the journal PLOS ONE.

The team focused on the relationship between exercise and brain metabolism for years.

"For improved brain function, the results suggest that it is not enough just to exercise more," said lead author Eric Vidoni, associate professor of neurology at University of Kansas Medical Center.

The randomised controlled trial attempted to determine the ideal amount of exercise necessary to achieve benefits to the brain.

Trial participants were placed in a control group that did not have monitored exercise, or they were put into one of three other groups.

One group moderately exercised for the recommended amount of 150 minutes per week, a second exercised for 75 minutes per week, and a third group exercised for 225 minutes per week.

All groups who exercised saw some benefit, and those who exercised more saw more benefits, particularly in improved visual-spatial processing.

Participants who exercised also showed an increase in their overall attention levels and ability to focus.

The study said that the intensity of the exercise appeared to matter more than the duration.

A number of research studies is also being conducted on how exercise may help prevent or delay the onset of Alzheimer's.