Exercise Improves Mental Health
Exercise and Its Effects on the Mental Health of Older Adults
Exercise is regularly shown to be important for our functional wellbeing. Exercise can help older adults remain autonomous, prevent falls, and improve many aspects of our overall health which improves chances of longevity and reduces morbidity. The effects of exercise on mental health are often understated. Rarely do we discuss why it may be beneficial for older adults to participate in regular structured exercise or recreational activities that can improve mood and mental wellbeing. The focus of this article will discuss exercise’s impact on the physical, emotional, and intellectual aspects of one’s mental health and the protective effects on age related declines and ailments.
With increases in longevity, we are seeing increases in age-related declines in health and wellbeing. We are also seeing an increase in sedentary lifestyles. One systematic review found through 18 studies of over 500,000 adults over the age of 65, those that were sedentary for more than 8.5 hours a day accounted for 67% of the population (Harvey & & Skelton, 2013). However, when asked about their levels of sedentary activity, many thought they were more active than they truly are. It is regularly reported that those who live less sedentary lifestyles tend to report better health, wellbeing, and longer lives than their sedentary counterparts. A consistent exercise routine incorporated into one’s life may have a variety of benefits. A active lifestyles decreases the risk of cardiovascular diseases, lower muscle mass, and risk of diabetes, but does regular exercise benefit cognitive function?
Exercise and Its Benefits on Cognitive Health
Cognitive health is the clarity of mind, decent memory retention, ability to concentrate, think, and learn. An experience of decline in these measures may be age related, or they may be symptoms of larger underlying health problems. The effects of exercise on the brain can be seen directly. Exercise changes the volume of certain areas of the brain as well as the as the vascular physiology. Exercise appears to have protective effects against cognitive decline as we age and may play a key role in protection against age related mental decline.
According to Quigley, et al. (2020), the effects of exercise on cognition can be seen through meta-analytic evidence. One of the most important forms of exercise for improving cognitive performance in older adults was aerobic exercise which could improve executive functioning. Aerobic exercise and resistance exercises combined also showed positive effects on cognition (Quigley, MacKay-Lyons, & & Eskes, 2020).
There is also evidence that mind-body exercises like tai chi, yoga, qi gong, dance or Pilates showed improvements to cognitive functioning when done 1-2 hours a week at moderate intensity. Improvements were found in global cognition, working memory, verbal memory, and cognitive flexibility in both the cognitively intact and cognitively impaired older adult groups. Moderate intensity was recommended for optimal effects (Wu, et al., 2019). Older adults who were not exhibiting cognitive impairments saw greater improvements than those with cognitive impairments, but both groups saw improvement according to Wu, et al.’s (2019) meta-analysis.
High intensity aerobic exercise is linked to reduction of proinflammatory markers in older populations. These markers are linked neuron damage and increased inflammation which has direct impacts on cognition and can be linked to multiple sclerosis and dementia (Cronin, Keohane, Molloy, & & Shanahan, 2017). Available evidence suggests that aerobic exercise has protective effects against these inflammatory markers and can protect cognitive performance in older adults.
Exercise has also been linked to changes in the function of the hypothalamic-pituitary-adrenal (HPA) axis which mediates our response to stress. Chronic acute stress activates the HPA system which has effects on our metabolism, immune response, and mood. Acute stress has effects on working memory, cognitive flexibility, and other aspects of cognition. Adults with higher rates of chronic stress are 2.7 times more likely to develop chronic conditions like Alzheimer’s (Quigley, MacKay-Lyons, & & Eskes, 2020). Exercise has downregulating effects on the sympathetic nervous system (system that responds to dangerous or stressful situations) and HPA axis and shows a potential boost in performance on executive functional tasks and improves cognition in older adults (Quigley, MacKay-Lyons, & & Eskes, 2020).
The challenge in analyzing the effects of exercise on the cognition of older adults, is many studies differ in the frequency, time, intensity, and type of exercise used within the studies making it challenging to do an overarching meta-analysis. However, despite a few conflicting reports on the extent of benefits for exercise, most studies reviewed showed modest to great effects on cognition. Exercise was shown to improve neuroplasticity, decrease cognitive inflammation, increase cerebrovascular health and reserves, improve glucose and oxygen transport in the brain, and decrease stress responses. All these factors improve attention, processing speed, executive functioning, and memory. (Quigley, MacKay-Lyons, & & Eskes, 2020).
Evidence Suggests Exercise can Reduce Dementia Risk
According to Ahlskog, et al. (2011), “A rapidly growing literature strongly suggests that exercise, specifically aerobic exercise, may attenuate cognitive impairment and reduce dementia risk.” Aerobic exercise has long-term benefits on cognition, dementia risk, and possibly dementia progression due to improvements in vascular health. This improvement can protect against atherosclerotic cerebrovascular disease and cerebrovascular small vessel disease, which reduces vascular dementia (Ahlskog, Greda, Graff-Radford, & Petersen, 2011). A study on weekly walking exercise over the course of a year showed better gray matter volumes, hippocampal volumes, and cortical volumes as compared with sedentary groups (Ahlskog, Greda, Graff-Radford, & Petersen, 2011).
Exercise was also shown to increase the expression of neuroplasticity-related transcription factors, increasing dendritic length and complexity (Eadie, Redila, & & Christie, 2005). Exercise improved brain-derived neurotrophic factors, which are a key molecule in learning and memory. This improved hippocampus volume which showed improvements in memory. Often the hippocampus size shrinks in late adulthood, increasing the risk of dementia in older adults. Adults with higher fitness levels show higher hippocampal volume. Those that start doing aerobic exercise training saw improvements to their spatial memory and saw an increased hippocampal volume by 2%. This amounts to an age reversal of volume loss by 1-2 years of age-related decline in older adults without dementia (Erickson, et al., 2011).
Physical Activity can Improve Outcomes for Those with Alzheimer’s Disease
Alzheimer’s Disease is the most common form of dementia making up 60 to 80 percent of cases, according to the CDC. While the direct relationship between physical activity and brain function is not clear, physical activity has many benefits to a variety of systems in the body that may help improve brain functionality. For instance, those with Alzheimer's Disease who take up physical activity changes cerebral blood flow to the temporal and parietal lobes. This may indicate that physically active patients have higher brain reserves, which may slow the degree of cognitive impairment. This may be able to help delay the need for institutionalization and reduce functional dependence of those with Alzheimer’s Disease (Harvey & & Skelton, 2013).
High risk factors for diabetes mellitus, hypertension, obesity, are linked to higher prevalence of Alzheimer’s Disease in several meta-analysis or systematic reviews of studies in each of these areas (Barnes, 2011). According to the narrative review of Barnes and Yaffe (2011), the combined risk factors of diabetes, hypertension, obesity, physical inactivity, depression, cognitive inactivity, and smoking may contribute up to half of Alzheimer's disease cases globally. Since these are modifiable risk factors, changing lifestyle behaviors can reduce the risk for not only Alzheimer’s but all-cause dementia as well. Physical inactivity may contribute the largest proportion of Alzheimer’s cases within the United States, and likely the third leading cause globally (Barnes, 2011). Since an exercise regimen has protective effects against diabetes, hypertension, and obesity, it may be a significant factor in reducing the risk of Alzheimer’s disease within the United States.
Exercise seems to cause changes in three areas of the brain: vascular physiology, neurogenesis, and the volume of the hippocampus (Meng, Lin, & & Tzeng, 2020). Physical exercise boosting hippocampal volume and improvements to blood flow can improve memory and cognition for older adults (Meng, Lin, & & Tzeng, 2020). One meta-analysis of 16 studies found that the risk of dementia was reduced by 28 to 45% for those who partook in regular physical activity (Hamer). Another study of 5925 women followed them over the course of 8 years. They were asked to measure how much they walked per week. Women with greater physical activity levels were less likely to develop cognitive decline, even after accounting for other adjustments like age, education levels, and comorbid conditions (Yaffe, Barnes, Nevitt, Lui, & & Covinsky, 2001).
Exercise can Boost Mood and Improve Emotional Wellbeing
Emotional health describes how we think and feel. It describes our general sense of wellbeing, ability to cope with life events, and the general regulation of our emotional state. These can include chronic conditions like depression, as well as our general sense of resilience and adaptability to life’s circumstances. It can also be related to our ability to relax and bounce back after experiencing a stressor.
Emotion and Mood
Our emotions are a strong feeling in response to a stimulus. These can roll into moods which can last for hours. For instance, if your general mood is dour, you may have more emotions like sadness, irritable, sadness. If your mood is cheerful, you may be more likely to feel emotions like happiness, excitement, interest. The emotions we experience are more often within the same family as our mood. Moods can be harder to regulate than emotions since there is a long-lasting stability to them, and it can be difficult to pinpoint triggers to moods compared to emotions.
A systematic review on dancing as a form of aerobic exercise showed an instant improvement in mood, citing increased feelings of vigor and reduced feelings of anger and depression (Hyodo, Suwabe, Yamaguchi, Soya, & & Arao, 2021). In one study on women aged 19 to 55, women who took an aerobics class showed higher mood scores both immediately following the class as well as 24 hours later when compared to the control group. This indicates that exercise can improve overall mood both immediately and long-term (Maroulakis, 1993).
Exercise when combined with proper sleep also has mood-enhancing effects. Physically active adults tend to have less sleep disruption. Cardiovascular exercise and sleep improvements are shown to improve hippocampal function, the parts of the brain responsible for memory and emotion. Acute exercise may also be linked to signaling pathways in the brain, changing upregulation of growth-factors, endocannabinoids, and stress hormones (Alfini, et al., 2020). All of which improve mood and create more positive emotional states.
Exercise produces cortisol, which we normally we associate cortisol with the stress hormone, but the effect it has depends on the binding location in the brain. After exercise it creates feedback that helps regulate and affect chronic stress showing positive results through a controllable stressor. This allows the pathway to shut down the release of cortisol and normalize the function within the body, reducing the risk of chronic stress (Alfini, et al., 2020). This has positive impacts on sleep which can reduce depressive symptoms and improve cognition.
Does Exercise Reduce Depression?
In one study of 156 adults aged 50 to 77 diagnosed with major depressive episodes took on a 16-week exercise program that consisted of 3 supervised sessions per week of walking and jogging. Participants saw a significant reduction in depression score (Blumenthal, et al., 1999). Another study compared Sertraline (antidepressant like Zoloft) therapy, exercise therapy, or a combination of both on the effects of depression. Those within the exercise groups had lower relapse rates than those that used antidepressants alone (Babyak, et al., 2000).
In a meta-analysis of 8 randomized controlled trails (paired down from 71) that were adjusted for publication bias, found with a 95% confidence interval that mixed aerobic and anaerobic exercises at moderate intensities found that there are beneficial effects of exercise. The authors of this study claim that due to publication bias, “previous meta-analyses might have inadvertently underestimated the antidepressant effect of exercise” (Schuch, et al., 2016). According to this analysis the most efficacious forms of exercise for older adults experiencing depression are moderate intensity, group training that combines aerobic exercise and resistance training (Schuch, et al., 2016).
With aging often comes an increase in chronic conditions which can be a contributing factor to the feelings of depression. These chronic conditions can put us in doubt about capabilities and give us a bleaker outlook for our future. Self-efficacy is our sense of personal mastery and control over our self and our environment. Exercise, especially when combined with social support can improve self-efficacy and improve mood (Miller, et al., 2019). Exercise has been shown to boost mood, and lack of social support is one of the strongest predictors of depressive symptoms. Exercise programs that create new experiences and build that sense of community and support may have a profoundly positive effect on depressive moods (Miller, et al., 2019). One study investigated the extent that exercise and social support independently affected psychological outcomes, and found that physical activity can have a protective effect against low social support on depression (Mochcovitch, Deslandes, Freire, Garcia, & & Nardi, 2016).
Analysis for links between depression and exercise are often faced with small sample sizes, research design, and insufficient follow up of participants making it challenging to find reliable studies. However, there does seem to be indications that there are links to exercise and improvements in mood. This may be due to the nature of improvements in health via reductions in comorbid medical illness, increases in social contact that exercise may provide, and possibly due to the nature of exercises effects on the hypothalamic-pituitary-adrenal axis (Barbour, 2005).
Anxiety Can be Lowered With Exercise
Anxiety is a common experience for the elderly with up to 40 million older adults in the United States experience this mental state. With aging comes gradual and often irreversible changes to the body that can change one’s life in a variety of ways. Anxiety can be caused by new constraints posed by chronic conditions, loss of social support, changes in physical capabilities, or triggered by situational experiences.
A meta-analysis and systematic review of 17 papers published from 2005 to 2021 found that physical exercise plays an important role in the reduction of anxiety in older adults. This review found that anxiety levels can be controlled through physical exercise intervention, showing improvement in anxiety scores as compared to the control groups (Wu, Zhang, Yang, & & Jiang, 2022). According to Wu, et al. (2022), “[a]ppropriate physical exercise can not only relieve negative mental states and induce positive mental states but also improve the loneliness, anxiety, depression, and happiness of the elderly.”
A systematic review on 8 studies indicated that physical activity may reduce high sensitivity to anxiety by training the body to recognize physical changes (elevated heart rate, muscle tension, shortness of breath) but not necessarily associate and trigger panic symptoms. This allowed the subject to recognize bodily sensations and dissociate these sensations from subjective emotions of anxiety (Mochcovitch, Deslandes, Freire, Garcia, & & Nardi, 2016).
Exercise can improve strength and other positive conditions that allow for one to better adapt to changes in the external environment. This increases feelings of competence and autonomy reducing feelings of anxiety. Exercise creates physiological changes in the cardiovascular, muscular, pulmonary, and neurological areas of the body. Regular exercise also creates an interoceptive awareness that may also reduce the risk of panic attacks by dissociating physical experiences from subjective experiences.
Bottom Line…
The links between exercise and cognition is complex, as exercise affects every system within the human body. Exercise seems to be one of the greatest factors in protection of overall health, improvements to cognitive functions, and increasing health lifespan.
It appears that the best ways to protect cognitive health and well-being well into older adulthood is to exercise 5-7 days a week at moderate intensity for 45 minutes a day or longer (Quigley, MacKay-Lyons, & & Eskes, 2020). Aerobic exercises tend to show the most effective results in boosts to cognition. Physical exercise has protective effects in non-impaired individuals more than for those who are currently experiencing cognitive impairment, but it can still be beneficial. Those who exercised regularly saw less cognitive impairment over time and had high sense of self-efficacy and improvements to overall mood.
Positive cognitive and mental health can be directly tied to exercise. Exercise improves mental well-being and improves health outcomes for a variety of mental disorders. It has protective effects against cognitive decline, depression, stress, and other aspects that directly relate to mental health. These findings should stress and highlight the importance of a regular exercise regime in maintaining mental well-being into older adulthood.
References
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