Move to Remember – Exercise to help cognitive abilities
The ‘Use it or lose it’ phenomena also applies to our cognitive or thinking abilities. There is increasing evidence to suggest that physical, cognitive, and social activity can maintain or even improve cognitive functioning.
Our cognitive function can change with normal aging, as well as in neurologic conditions such as Parkinson’s disease. Fortunately, there is promising research suggesting that we may be able to prevent or at least slow the rate of this cognitive decline with physical and mental exercise.
What is the evidence for the beneficial effects of exercise?
In addition to the physical benefits from exercise, animal research has also demonstrated notable cognitive benefits from physical exercise. Studies have demonstrated that mice who exercised on a wheel running task were faster and more efficient at a spatial task requiring that they navigate their way through spatial mazes (similar to finding your way around city streets). In addition, this exercise appeared to counteract the normal age-related declines seen in memory and learning in mice and lead to performance similar to the younger mice (e.g. Albeck et al., 2006).
There are several large population-based studies that indicate a positive relation between self-reported levels of exercise and good cognitive health in people. One study found a decreased incidence of Alzheimer’s disease in individuals who exercised more than three times per week (Larson et al, 2006). Another found a reduced risk of dementia in those who engaged in physical leisure-time activities at least twice per week across their lifetime (Rovio et al., 2005). Other studies found that objective measures of cardiovascular fitness (related to aerobic exercise) were related to better cognition in older adults.
Studies evaluating the effects of planned programs are also promising. One study found improved cognitive abilities in people that engaged in an aerobic training group (and improved their aerobic fitness (Colcombe & Kramer, 2003). In addition, Kramer and his colleagues (2006) have been able to show some actual brain changes following a 6-month aerobic exercise training program. Using magnetic resonance imaging (MRI), they found evidence of restoration of some of the brain volume losses typically associated with normal aging.
One of the keys to the cognitive benefits of exercise seems to be related to the intensity of the exercise. Many studies suggest that the exercise needs to be aerobic in nature to induce the subsequent cognitive improvements. Those programs that only implemented stretching exercises typically did not show corresponding cognitive improvements.
Relaxation exercises and yoga training may also show some cognitive improvements for other reasons, such as decreased stress and increased feelings of well-being. However, there is less research available to support strong cognitive changes through these types of exercise.
The types of leisure activities one engages in may also impact cognitive functioning. One large study followed a group of older adults for more than five years and found that those who engaged in cognitively stimulating leisure activities (such as music, games and reading) had better preservation of their memory functions and decreased their risk for dementia. Better maintenance of cognition has been found in those who pursue more education and engage in more novel lifestyle experiences.
Specific cognitive exercises or stimulation have also been reported to benefit cognitive functioning. The term “neurobics” was coined by Lawrence Katz to describe these types of cognitive exercises. The idea behind these exercises is to provide some novel stimulation to the brain across multiple senses and to specifically engage the brain actively (Katz & Rubin, 1999). There are many computer games and websites that promote the benefits of their exercises and it is likely that these cognitive exercises have some benefit. However, the specific research on them is somewhat lacking. One large intervention study that is promising was conducted by Sherry Willis and colleagues (2006) and showed that a 10-week cognitive training program lead to noticeable improvements in cognitive functioning in older adults. These improvements were maintained five years after the intervention. Other studies have showed some promising results with both specific training techniques (such as mnemonic strategies) and more generalized training (see review by Valenzuela et al, 2009)
What are the mechanisms for the beneficial effects of exercise on cognition?
There are many theories regarding how exercise and stimulation may provide cognitive benefits. There are physiological explanations indicating that exercise may promote the growth of new vasculature (angiogenesis) and increase blood flow. This in turn may lead to an increase of nutrients, neurochemicals and trophic factors that contribute to cell proliferation and neuroprotection (Kramer et al., 2008). There are theories related to “cognitive reserve” which suggest that engaging in more stimulating activities across the life span will lead to a greater amount of cognitive reserve thus minimizing the impact of age-related or disease-related declines. Finally, there are psychological explanations that suggest that exercise can have a positive impact on well-being and mood, and decrease stress, which can in turn benefit cognition.
What unanswered question(s) is the focus of current research?
Although the research to-date is very suggestive and promising regarding the cognitive benefits of physical and cognitive exercise in all individuals, less is known about the specifics. Future research will continue to focus on finding the most beneficial types of exercise, as well as the amount and duration required to achieve the maximal benefits. More research examining using a combination of exercise types (cognitive and physical) to determine whether that provides additional benefits will be important. Finally, continued studies using brain imaging techniques will be important to understand the mechanisms and potential changes that occur from exercise.
Although continued research is necessary to better understand the exact nature of these benefits, at this time there is enough preliminary evidence to confirm that there are wide-spread benefits from maintaining an active and stimulating lifestyle. Learn more about Neuroplasticity, exercise and activities that improve brain health in the accompanying articles:
Neuroplasticity-practice makes perfect
Neuroplasticity- more than just movement
Author: Martha Glisky, Ph.D. Clinical Neuropsychologist, Evergreen Medical Center Department of Rehabilitation and Booth Gardner Parkinson’s Care Center, Kirkland, WA
Neuroprotection- exercise to protect dopamine nerve cells