Individuals with mild cognitive impairment (MCI) who took part in aerobic exercise such as brisk walking, running, jogging or swimming four times a week were found to have greater increase in brain volume as well as better cognitive functioning, researchers say.
"Any type of exercise can be beneficial. But, aerobic activity may create potential benefits for higher cognitive functioning," said Jeongchul Kim from Wake Forest University in North Carolina, US.
Individuals with MCI -- which affects memory and thinking skills -- are at risk of developing Alzheimer's disease (AD), the most common form of dementia, the study said.
"Even over a short period of time, we saw aerobic exercise lead to a remarkable change in the brain," added laura D Baker from Wake Forest University.
For the study, the team included 35 adults with MCI. The participants were divided into two groups. Sixteen adults (average age 63 years) engaged in aerobic activity, including treadmill, stationary bike or elliptical training, four times per week for six months. A control group of 19 adults (average age 67 years) participated in stretching exercises with the same frequency.
The results, based on the high-resolution MRI images taken before the intervention and after six months, revealed that for both the aerobic and stretching groups, brain volume increased in most gray matter regions, including the temporal lobe, which supports short-term memory.
"Compared to the stretching group, the aerobic activity group had greater preservation of total brain volume, increased local gray matter volume and brain tissue," Kim said.
The stretching group showed atrophy within the connecting fibres in the brain's white matter, which could be an early marker for neurological changes.
The study was presented at the annual meeting of the Radiological Society of North America (RSNA) in Chicago, US, recently.