Do you want a stronger brain? Then start lifting weights.
Researchers from the University of New South Wales and the University of Adelaide conducted the study. They looked at 100 men and women with mild cognitive impairment. All of them were 55-68 years old. Mild cognitive impairment means that brain function impairment can be detected on testing, but is not significant enough to interfere with daily activities. But don't feel too relaxed about it; mild cognitive impairment is not as mild as it may sound. Eighty percent of patients diagnosed with it go on to develop Alzheimer's disease in the next six to eight years. So it's a warning sign of worse things to come.
For the study, the researchers assigned some of the men and women progressive resistance exercise – including weightlifting. Progressive resistance exercise means that as they became stronger they were able to increase the intensity of the exercise. The researchers had others simply sit and stretch. And the researchers had still others use a computer-based cognitive training program. All of the men and women performed their activities two to three times a week for six months. Before and after the study, the researchers used the Alzheimer's Disease Assessment Scale to measure cognitive function. They also measured peak upper body, lower body, and whole body strength. And they also used VO2 testing to determine aerobic fitness. Here's what happened.
Not surprisingly, the progressive resistance training increased all the strength scores and the aerobic fitness scores more than the stretching and computer training. But what was surprising was that while the stretchers and the computer people had absolutely no improvement in their cognitive testing, the resistance exercisers did. And that's not all.
The greater the gains were in strength, the greater the improvement in cognitive scores. In other words, the stronger their muscles were, the stronger their brains were! According to the authors, “What we found in this follow-up study is that the improvement in cognition function was related to their muscle strength gains. The stronger people became, the greater the benefit for their brain.” So, what was the resistance training like?
In the trial, the participants worked to at least 80% of their peak strength. What does that mean? Let's say that you go to lift a weight and the maximum number of times you can lift it is 30 times. Then, since 80% of 30 is 24, exercising at 80% of your peak strength would be lifting the weight 24 times every time you did the exercise. As the men and women got stronger and their peak strength increased, they gradually increased the weights. So how does this help your brain?
Your brain works only to the degree that the brain cells can make energy. But brain cells are unique. Unlike the other cells of the body, they cannot make energy effectively from fat. They rely completely on sugar for energy production. This process is called glucoregulation. And it's absolutely critical for brain function. And here's the connection. Glucoregulation is impaired in Alzheimer's disease and in many dementia cases. However, previous studies have shown that resistance training improves glucoregulation. So, that's one way it works.
Another problem with Alzheimer's and dementia is a decrease in the way blood circulates to the brain. Resistance training improves this as well. In addition, resistance exercise has also been shown to improve specific cognitive processes such as selective attention, planning, organizing, and multitasking. Some studies have also shown a connection between an increase in the size of certain brain areas and exercise training.
For example, a part of the brain called the hippocampus is known to reduce in size with aging. This leads to cognitive impairment. However, progressive resistance exercise can increase the size of the hippocampus by 2%. But there's more.
The men and women in this study not only saw an improvement in their strength. They also improved in aerobic fitness. But the aerobic fitness gains were not what improved their brain function. According to the authors, "Strength gains, but not aerobic capacity changes, mediate the cognitive benefits of progressive resistance training." In other words, it's not exercise per se that caused the cognitive improvements. It was specifically gains in overall strength, particularly lower body strength. So, while aerobic exercise is critical for preventing so many other problems, it needs to be combined with strength training for maximum cognitive effects.
Mavros Y, et al. Mediation of Cognitive Function Improvements by Strength Gains After Resistance Training in Older Adults with Mild Cognitive Impairment: Outcomes of the Study of Mental and Resistance Training Journal of the American Geriatrics Society. 24 OCT 2016
Stronger muscles lead to stronger brain by Ana Sandoiu Published: Tuesday 25 October 2016