A morning bout of exercise has been found to be beneficial for older Australians' brain function throughout the day.

A morning walk could improve older Australians' brain function throughout the day with researchers unlocking the perks of moderate-intensity exercise.

Men and women, aged 55 to 80, had improved cognitive performance across an eight-hour day after morning physical activity, the study published overnight reveals.

If the same group added three-minute light-intensity walks across the day it boosted short-term memory compared with prolonged periods of sitting, the Baker Heart and Diabetes Institute and The University of Western Australia research found.

More than 65 men and women took part in the Brain Breaks study into participants' attention, decision-making, visual learning and working memory coupled with exercise.

The exercise involved them walking on a treadmill.

A protein central to the growth of information-transmitting neurons in the brain was elevated for eight hours by the exercise, in comparison to prolonged sitting, the study found.

Researcher Michael Wheeler said sitting for prolonged periods should be avoided to maintain optimal cognition across the day and a brisk walk improved brain health.

"This study highlights how relatively simple changes to your daily routine could have a significant benefit to your cognitive health," he said.

"It also reveals that one day we may be able to do specific types of exercise to enhance specific cognitive skills such as memory or learning."

The study was published in the British Journal of Sports Medicine.