If you want to protect your brain from the ravages of aging, you may need to build up your muscles.
A new study found exercises that strengthen muscles can slow down mental decline and possibly improve cognitive performance.
While research has shown that physical activity is good for the mind as well as the body, the new study, by Canadian and U.S. researchers, represents one of the first attempts to compare the mental effects of different types of exercise.
The researchers recruited 86 women who were experiencing mild cognitive impairment that often leads to dementia.
The participants, ranging in age from 70 to 80, were randomly divided into three groups. One group was assigned strength training, using free weights and gym equipment. The second group took part in a cardiovascular exercise program of outdoor walking. The rest of the women performed rudimentary balance and toning exercises and served as a control group.
After six months, women in both the strength and cardio programs did much better on a series of mental tests compared to those in the control group, according to the study published in the Archives of Internal Medicine.
But women in the strength-training group showed "significantly greater improvement" on certain mental tasks involving executive functions, said the lead research Teresa Liu-Ambrose at the Centre for Hip Health and Mobility and the UBC Brain Research Centre, both located at the Vancouver Coastal Health Research Institute. Impaired executive function is often a sign the person is headed down the road to dementia.
"Executive function involves complex thinking," explained Dr. Liu-Ambrose who is also an assistant professor at the University of British Columbia. "It's your ability to make decisions, multi-task and to plan."
So why would weight training provide a bigger brain boost than walking?
This type of exercise tends to be more mentally challenging, noted Dr. Liu-Ambrose. "You are constantly monitoring yourself to make sure you are doing the exercises properly while walking is a little automatic."
Furthermore, the creation of new muscle mass leads to higher blood-levels of Insulin Growth Factor-1, which can be beneficial for the brain. Dr. Liu-Ambrose speculates the extra IGF-1 may promote the growth and differentiation of neurons, or nerve cells, leading to a better functioning brain.
Researchers created a YouTube video that demonstrates how to do the strength-training exercises used in the study. The video, titled Exercise is Power: Resistance Training for Older Adults, can be viewed at tgam.ca/brainvideo.