Aerobic Exercise Offers Protection against Mild Cognitive Impairment

Lisa Franchi July 30, 2014

Aerobic exercises may not only help you lose weight. They can also improve your memory. Such effect may especially benefit those with mild cognitive impairment – new research revealed.

Mild cognitive impairment is a known risk factor for dementia – a neurodegenerative disease that currently affects 35.6 million people worldwide. Such figure is expected to rise to 115.4 million by the year 2050.

A group of researchers from the University of British Columbia, Canada, headed by Dr Teresa Liu-Ambrose, looked at the effect of aerobic exercise on brain function. For their study, they recruited 86 women aged 70 to 80 years with probable MCI. Participants undertook either aerobic training (brisk walking), resistance training (lunges, squats, and weights), or balance and tone training twice a week, for six months. The balance and tone training was not strenuous exercise, and was considered the “control” group.

At the start and the end, the women were given MRI scans of their hippocampal volume. The hippocampus plays important roles in short-term and long-term memory, and spatial navigation, and appears to be very sensitive to the effects of aging and neurological damage. Tests were also given to measure verbal memory and learning.

Researchers found that women who did aerobic training significantly improved left, right, and total hippocampal volumes, the team reports. “We observed a 5.6% increase in the left hippocampus, a 2.5% increase in the right hippocampus, and a 4% increase in the total hippocampus,” they write. According to them, there was evidence that hippocampal volume was linked with poorer verbal memory. However, in earlier studies, increased left hippocampal volume has been linked to better performance on verbal memory tests.

“The relationship between brain volume and cognitive performance is complex, and requires further research,” say the authors.

Aerobic exercise against dementia

“The degree of benefit in terms of brain structure might actually be greater in people with early functional complaints than in healthy older people,” the team adds. “Understanding the effect of exercise on the hippocampus will increase our appreciation of the role exercise may play in dementia prevention,” they conclude.

Aerobic exercise at 40% of resting heart rate has similar effects after three months to aerobic exercise at 60% of resting heart rate. Both led to “marginal improvements” on cognitive level as measured by the Mini Mental State Examination, and functional ability, measured by the Timed Up and Go test. “Intensity does not seem to be a determining factor when aerobic exercise is performed by people with MCI.” researchers note.

The findings were published in the British Journal of Sports Medicine.

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Aerobic Exercise May Boost Memory