by Susan G. Mason
Physical Activity and Brain Structure
Exercise was measured by the number of city blocks walked per week. For cognitively impaired individuals, walking 58 blocks, for a total of about 5 miles per week, was sufficient, according to Raji, “to maintain brain volume and slow cognitive decline.” For active participants, memory loss was reduced by 50% over 10 years.
The speed of walking did not make any difference, and there were no incremental improvements in brain volume when the amount of exercise was doubled to 10 miles per week.
Raji hypothesized that any amount of aerobic activity equivalent to walking a little less than a mile a day would show similar results but explained that he focused on walking since it an accessible form of exercise, open to people regardless of age or location.
Meta-analysis Lends Support
They concluded that “physical exercise, aerobic exercise in particular, benefits global cognition in MCI patients.” Global refers to overall cognition, and includes an array of functions such as memory, attention, decision making, language facility, and mental flexibility.
A Randomized Control Trial
Interestingly, but not surprisingly, Song and Yu’s community study showed that the exercise group also had improved sleep quality and fewer symptoms of depression.
Exercise Improves Brain Bloodflow
The initial differences in the movement of blood through certain areas of the brain between the cognitively normal and the cognitively impaired groups had improved by the end of the 12-week exercise period. The exercise program helped both the working memory and the verbal fluency of the MCI group.
Effects of Exercise on Specific Cognitive Functions
- Spartano NL, et al. Association of accelerometer-measured light-intensity physical activity with brain volume: The Framingham Heart Study. JAMA Netw Open. 2019;2(4):e192745. doi:10.1001/jamanetworkopen.2019.2745.
- Raji C. Radiological Society of North America (RSNA) 96th Scientific Assembly and Annual Meeting: Abstract SSA17-01. Presented November 29, 2010.
- Song D, et al. The effectiveness of physical exercise on cognitive and psychological outcomes in individuals with mild cognitive impairment: A systematic review and meta-analysis. Int J Nurs Stud. 2018;79:155-164. doi:10.1016/j.ijnurstu.2018.01.002.
- Song D, Yu DSF. Effects of a moderate-intensity aerobic exercise programme on the cognitive function and quality of life of community-dwelling elderly people with mild cognitive impairment: A randomised controlled trial. Int J Nurs Stud. 2019;93:97-105. doi: 10.1016/j.ijnurstu.2019.02.019.
- Alfini AJ, et al. Resting cerebral blood flow after exercise training in mild cognitive impairment. J Alzheimers Dis. 2019;67(2):671-684. doi: 10.3233/JAD-180728
- Chun-Kit L, et al. Physical exercise attenuates cognitive decline and reduces behavioural problems in people with mild cognitive impairment and dementia: a systematic review. J Physiother. 2020;66(1):9-18. doi: 10.1016/j.jphys.2019.11.014.