The lack of effective preventive and treatment strategies against Alzheimer’s disease is an alarming problem. There is a need to find effective preventive and treatment strategies that will offer hope to an aging population, to Alzheimer’s disease patients, and their caregivers.
An urgent need to identify these strategies has risen among older adults at increased risk for memory loss. Among people at the greatest risk for Alzheimer’s disease are older adults diagnosed with Mild Cognitive Impairment (MCI). Some of the earliest signs of memory loss and possible Alzheimer’s disease involve damage to a part of the brain called the hippocampus. Scientists have been searching for drugs to stop the rate of memory loss by trying to preserve the neurons in the hippocampus, thereby improving its memory function. These attempts have failed.
However, recent research has shown that exercise and physical activity benefit cognitive function and may offer neuronal protection. Amazingly, the protective effects of exercise on brain function have been shown to be extremely robust in the hippocampus, the very brain structure targeted early on in Alzheimer’s disease. But these effects have never been demonstrated in older adults at greater risk for Alzheimer’s disease, such as in those diagnosed with MCI. As you can imagine, there has been excitement and great interest among scientists, but until now only speculation, regarding whether or not the protective effects of exercise on the hippocampus and memory function also occur in people who show signs of accelerated memory loss.
Our studies test the effects of exercise in those most at risk for Alzheimer’s disease–people diagnosed with MCI, people with a genetic risk, and those who have metabolic risk factors such as a past stroke or TIA. Exercise appears to offer cognitive benefits with a low risk of side effects. However, it is unknown if exercise training will improve brain function and brain blood flow in people with MCI. To measure the effects of exercise on brain function we will use magnetic resonance imaging (MRI) to measure brain activation during simple memory test consisting of famous and non-famous names. We will also use MRI to measure the amount of blood flow in the brain after the exercise program, particularly in the hippocampus. Our central hypothesis is that exercise promotes a neural reserve that can be drawn upon to promote enhanced brain function and cognitive performance in the face of early neurodegenerative processes related to Alzheimer’s disease. This work will advance our understanding the effects of exercise on brain function in those at increased risk for AD, with the long term-goal of determining if exercise may help prevent or delay conversion to Alzheimer’s disease.
Over the past decades, an emerging body of evidence suggests that exercise is an effective strategy to enhance cognitive function across population of all ages. Exercise is associated with structural changes in the brain; greater and robust structural alteration for younger adults and prevention of age-related atrophy in older adults and functional changes; shifted exercise-induced activation during cognitive task and increased connectivity between brain regions. Exercise also promotes producing biochemical biomarkers related to enhanced cognition (e.g. brain-derived neurotrophic factor). Many forms and (aerobic, resistance, yoga, and Tai-chi) as well as varied intensities (e.g. light, moderate, and high) exercise enhanced cognition. Active lifestyle, therefore, keeps not only body, but also the brain fit.
Mild cognitive impairment (MCI) is a stage between the expected decline of normal aging and the more serious decline of dementia. MCI can lead to issues in memory, language, thinking, and judgment. A recent systematic review and meta-analysis looked at the experimental effects of exercise on memory function in older adults with MCI. They found that overall exercise has a small to moderate positive effect on long-term and short-term memory function. Meanwhile, dementia is a term that describes a group of symptoms associated with memory loss that is severe enough to reduce a person’s ability to perform everyday activities. Unfortunately, most randomized controlled trials looking at the effects of exercise on dementia have failed to show any effects. Studies conducted so far suggest that exercise may be more fruitful for preventing dementia than reversing it.
Loprinzi, P. D., Blough, J., Ryu, S., & Kang, M. (2019). Experimental effects of exercise on memory function among mild cognitive impairment: systematic review and meta-analysis. The Physician and sportsmedicine, 47(1), 21-26.
Öhman, H., Savikko, N., Strandberg, T. E., & Pitkälä, K. H. (2014). Effect of physical exercise on cognitive performance in older adults with mild cognitive impairment or dementia: a systematic review. Dementia and geriatric cognitive disorders, 38(5-6), 347-365.
The American Psychological Association (APA) defines anxiety as “an emotion characterized by feelings of tension, worried thoughts and physical changes like increased blood pressure“. Anxiety may become a medical disorder if one frequently experiences disproportionately high levels of anxiety. Despite estimates of anxiety disorders affecting almost 40 million people in the United States, it is projected that only 37% receive treatment. A systematic review of randomized clinical trials recently concluded that exercise seems to be effective as an adjunctive treatment for anxiety disorders. Studies have provided mixed results as to whether exercise provides more or less benefit that antidepressant treatment, however, studies have consistently found additive effects when patients undergo exercise and antidepressant interventions than solely exercise or antidepressant interventions alone.
Bystritsky, A., Khalsa, S. S., Cameron, M. E., & Schiffman, J. (2013). Current diagnosis and treatment of anxiety disorders. Pharmacy and Therapeutics, 38(1), 30.
Jayakody, K., Gunadasa, S., & Hosker, C. (2014). Exercise for anxiety disorders: systematic review. Br J Sports Med, 48(3), 187-196.
Depression is a significant health problem and 7% of adults in the US suffer from depression. Major depressive disorder brings about significant morbidity, mortality, disability, and suffering for patients and their families. Although the most frequent treatment for depression is medication, physical activity shows comparable therapeutic effects. Performing an acute bout of exercise immediately brings about improvement in depressed mood. Regular participation in exercise training is associated with significant reductions in depressive symptoms which was as effective as antidepressant medication. An important caveat for the beneficial effects of long-term exercise on reducing depression is exercise should be continued over time.
Babyak, M., Blumenthal, J. A., Herman, S., Khatri, P., Doraiswamy, M., Moore, K., & Krishnan, K. R. (2000). Exercise treatment for major depression: maintenance of therapeutic benefit at 10 months. Psychosomatic medicine, 62(5), 633-638.
Weinstein, A. A., Deuster, P. A., Francis, J. L., Beadling, C., & Kop, W. J. (2010). The role of depression in short-term mood and fatigue responses to acute exercise. International journal of behavioral medicine, 17(1), 51-57.
Sleep is an essential component of health and well-being. On average, healthy adults take 20 minutes when attempting to initiate sleep and sleeps for 7-8 hours. Sleep is positively or negatively influenced by many environmental factors and one of them is exercise. Population-based studies show that physical inactivity is associated with sleep problems. Chronic exercise elicits beneficial effects on people who report sleep problems. Also, a single session of exercise has its largest effect on total sleep time as well as deep-stage sleep such as rapid eye movement (REM) sleep latency and total REM in good sleepers. There is a myth that exercising before bedtime results in insomnia; however, studies suggest that exercise performed shortly before going to bed does not usually produce insomnia. It is still largely how exercise impacts sleep, not alone the mechanism of how exercise benefits sleep, which should be discovered in the future.
Kim, K., Uchiyama, M., Liu, X., Shibui, K., Ohida, T., Ogihara, R., & Okawa, M. (2001). Somatic and psychological complaints and their correlates with insomnia in the Japanese general population. Psychosomatic medicine, 63(3), 441-446.
O’Connor, P. J., Breus, M. J., & Youngstedt, S. D. (1998). Exercise-induced increase in core temperature does not disrupt a behavioral measure of sleep. Physiology & behavior, 64(3), 213-217.
Youngstedt, S. D. (2005). Effects of exercise on sleep. Clinics in sports medicine, 24(2), 355-365.
A concussion is a traumatic physiological brain injury that results in widespread cognitive, emotional, and physiological effects. Most children and adults recover from a concussion within 2 to 4 weeks, however approximately 30% experience persistent postconcussive symptoms which can have a negative impact on physical, psychological, social and environmental metrics of quality of life. Animal and human work suggests that rest may be most beneficial immediately following a concussion and that excessive exercise too soon after a concussion may prolong recovery. Yet, evidence from a recent randomized controlled trial suggests strict rest beyond 2 days for athletes may be detrimental for mental health and observational studies indicate that moderate levels of aerobic exercise within the first week after injury may reduce the incidence of persistent postconcussive symptoms. The most recent concussion in sports group international consensus statement is that there is still insufficient evidence that prescribing complete rest promotes recovery from concussions.
McCrory P, Meeuwisse W, Dvorak J, et al. Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. Br. J. Sports Med. 2017; 51:838–47. doi: 10.1136/bjsports-2017-097699. PubMed PMID: 28446457.
Reddy, R. P., Rajeswaran, J., Devi, B. I., & Kandavel, T. (2017). Cascade of traumatic brain injury: A correlational study of cognition, postconcussion symptoms, and quality of life. Indian journal of psychological medicine, 39(1), 32.
Leddy, J. J., Haider, M. N., Ellis, M., & Willer, B. S. (2018). Exercise is medicine for concussion. Current sports medicine reports, 17(8), 262-270.
