Earlier research showed that aerobic exercise boosted brain function in older adults, but there had been much less research on how this affected young adults, the researchers said.
Otago psychology department senior lecturer Dr Liana Machado said the ''surprising'' findings of Otago researchers provided compelling evidence that regular exercise, at least five days a week, sharpened the ''cognitive ability'' of young adults.
The researchers, led by Dr Machado, had set out to test the often-held belief that the brains of young adults in their prime might not benefit as much as older people from regular sustained exercise.
The research focused on a study undertaken by Otago psychology doctoral student Tracy Cameron for her science degree dissertation.
This study involved taking 52 female tertiary students, aged 18 to 30, and putting them through a series of cognitive tests while measuring oxygen availability in the frontal lobe of their brains, as well as their self-reported exercise frequency.
The findings, just published online in the journal Psychophysiology, showed that both blood supply to the brain and cognitive functioning appeared to benefit from regular exercise, Dr Machado said.
The findings challenged the ''assumption that living a sedentary lifestyle leads to problems only later in life''.
The idea that young people did not have to worry about exercising because they were in their prime developmentally was ''rapidly being overturned'' by mounting evidence that young adults also benefited from regular exercise.
Dr Machado had noticed over the years that university students appeared progressively less fit.
More research was needed but she was ''glad'' the recent study clearly highlighted the value of regular physical exercise for young people.
Such exercise could involve brisk walking or more vigorous activity, and could be made up of a few 10-minute bouts of exercise, rather than a continuous ''block''.
Dr Machado is also serious about maintaining regular physical activity herself, cycling to and from her Port Chalmers home to work and playing golf three times a week.
The researchers also found body mass index was not a key factor in how well the brain functioned, indicating that regular engagement in physical activity may be more important than body weight.
