This is an excerpt from Physiology of Exercise and Healthy Aging-2nd Edition by Albert W. Taylor & Michel J. Johnson.
By Andrea Lazosky PhD, C Psych, ABCN/ABPP
The Role of Physical Activity on ÂMental Health With Aging
Once encouraged for prevention of chronic disease alone, it is now recognized that participation in physical activity such as leisure pursuits, hobbies, and Âhouse and yard work, positively influences Âmental health in older adults. Maintaining an active lifestyle improves Âmental health and may prevent Âmental health probÂlems like depression among elÂderly Âpeople. It may also delay functional decline and help manage both depression and dementia. Deslandes et al. (2009) suggest that exercise has a positive relationship with outcome in depression and neurodegenerative diseases, as well as quality of life. Conversely, a sedentary lifestyle, among other Âfactors, is significantly correlated with depression morbidity in Âlater life (Blay et al. 2007).
Bauman et al. (2016) preÂsent a conceptual framework (see figure 9.1) for the effects of physical activity on the physiology of aging that encompasses chronic disease prevention and risk reduction, functional status outcomes, psychological well-Âbeing, and social outcomes. The biological mechanisms by which physical activity affects brain health and, in turn, Âmental health remains poorly understood, but Âthere have been some intriguing findings:
- Control of cardiovascular risk Âfactors: Chronic disease prevention predominantly targets cardiovascular risk Âfactors that have been shown to impact both LLD and cognitive decline. Exercise, including moderate intensity aerobic activity and muscle strength training, has been established as a benefit in the prevention and control of diabetes (see chapter 5), hypertension, and other forms of cardiovascular disease (see chapter 1).
- Impact on incidence of dementia: Physically active older adults have a reduced risk of cognitive decline and dementia (Blondell et al. 2014; see also chapter 3). Both aerobic exercise and reÂsisÂtance training have shown positive effects on cognition, including executive function, attention, and proÂcessing speed (Scherder et al. 2014). Risk of developing Parkinson’s disease is lower in physically active older adults, and exercise has benefits to strength, walking, motor control, and balance in individuals with a Parkinson’s diagnosis (Bauman et al. 2016).
- Stimulation of brain-Âderived neurotrophic Âfactor: The production of brain-Âderived neurotrophic Âfactor (BDNF) is stimulated by aerobic physical activity. BDNF is a protein involved in preventing neuronal loss and increasing the growth, differentiation, and survival of neurons (Dinoff et al. 2016).
- Increased brain volume: Magnetic resonance imaging (MRI) of the brain has been used to show that aerobic fitness training, but not nonaerobic stretching and toning exercises, significantly increases brain volume in older adults. Colcombe et al. (2006) showed increased brain volume over a 6-Âmonth trial in an aerobic exercise group in both gray and white Âmatter (predominantly) in the prefrontal cortex and temporal lobe cortex, brain regions previously shown to have substantial age-Ârelated deterioration. In another study, greater physical activity predicted greater volumes of frontal, occipital, and medial temporal regions of the brain nine years Âlater (Erickson et al. 2010). More specifically, Erickson et al. (2011) found that aerobic exercise selectively increases anterior hippocampal volume and improves spatial memory in older adults, effectively reversing age-Ârelated volume loss by 1 to 2 years. They also found a relationship between hippocampal volume and BDNF, with increased hippocampal volume associated with higher serum levels of BDNF.