The best thing you can do to counter the cognitive decline that usually accompanies aging is to exercise regularly. Aerobic exercise helps. The same goes for strength training. And according to a new study, there may be a third option (and it's not "none of the above").
In Frontiers in Physiology, researchers at the University of Montreal and several other institutions report that eight weeks of motor skills training – a broad category that includes obstacle courses and learning to balance – boosted cognitive function in older adults and raised levels of a brain growth chemical called brain-derived neurotrophic factor, or BDNF, rather than a combination of aerobic and strength training. The results add to a growing body of evidence suggesting that a healthy brain needs more than routine physical exertion.
Most research on physical fitness and brain health has focused on aerobic exercise, which raises blood flow to the brain and stimulates the formation of new blood vessels to deliver blood into the brain. The impact is significant: one study estimated that convincing 25% more people to exercise would prevent one million new cases of Alzheimer's disease worldwide.
Strength training also has possible benefits. There is evidence that it triggers a different set of brain chemicals associated with neuron growth and survival, in addition to those triggered by aerobic exercise.
With this in mind, the original aim of the University of Montreal study was to test a combination of high-intensity aerobic interval training and lower-body strength training three times a week in adults between 60 and 85 years of age. And to evaluate the results, they needed a control group that entered the lab, had the same interactions with the researchers, but did not get fit or stronger.
"We created this idea of thick motor activities mainly for [control] participants interested in the program, "admits Nicolas Berryman, one of the authors of the study and now professor at Bishop's University in Lennoxville, Qué. Asking them to go to the gym and do stretching exercises for eight weeks would have been very annoying, according to the researchers.
Instead, the control group followed a program that included yoga-style flexibility exercises, breathing exercises, obstacle walking, juggling classes, and ball-throwing against targets. And to everyone's surprise, "control" participants saw both cognitive function improvement and exercise participants.
When Berryman and his colleagues delved into the scientific literature, they found that other researchers were finding the same effect. Training programs involving coordination and balance training, hula hoops, obstacle courses, and other unconventional elements seemed to have as much effect on the brain as a more conventional exercise.
Exactly how this works is still unclear. Heavy motor activities (a term that refers to the coordination and movement of large arm, leg and trunk muscles) clearly require more cognitive engagement, and there is some evidence that this stimulates the growth of more connections between neurons. New findings from the University of Montreal also suggest that brain chemicals such as BDNF may play a role.
The most general is that exercise should involve your brain and your body. This was the implication of another recent study that produced a surprising result. British researchers gave conventional or electric bicycles to 74 older adults and asked them to pedal three times a week for eight weeks.
Both groups improved their cognitive functions – but, contrary to expectations, the e-bike group did as well as the regular group of bikes, although presumably not having to pedal as much. Staying out and exploring, as well as learning to ride a non-family bike, had benefits beyond the simple aerobic challenge, the researchers concluded.
Berryman and his colleagues, led by neuropsychologist Louis Bherer, are seeking further studies, trying to isolate the distinct contributions of physical and mental exercise to cognitive health. Meanwhile, descriptions of their motor tasks – navigating obstacles, throwing balls at targets, and so on – do not seem so difficult to replicate outside the laboratory. In fact, they look a lot like my Friday night basketball game.
Alex Hutchinson is the author of Support: Mind, Body, and Curiously Elastic Limits of Human Performance. Follow him on Twitter @sweatscience.
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