Movement and Aging

Abstract

Movement is a fundamental function of life. Human beings move through the act of breathing before they learn language and speak. Movement is central to all of life’s processes: growth and development, energy production and utilization, and environmental adaptation. This chapter will explore the power of human movement and how it can be harnessed to address the challenges of aging. Movement in this chapter refers to physical activity and exercise. The challenge of aging for the future is not simply prolonging human life at any cost or by any means but rather extending self-sufficiency and quality of life. Aging adults need to keep on moving to keep their independence, self-care and improve their quality of life. The chapter will present current knowledge and new insights from contemporary research as we explore how physical activity and exercise can help address challenges of aging in these areas: musculoskeletal health, pain, immune system and brain health.

1. Introduction

Movement comes from the word “movere” which means to move. It is the act or process of moving. In a broader perspective, it is change or development. This chapter will focus on physical activity and exercise as movement. The World Health Organization (WHO) defines physical activity as any bodily movement that is produced by the contraction of skeletal muscle and that increases energy expenditure above a basal level. It refers to all movements including during leisure time, for transport to get to and from places or as part of a person’s work. The US Centers for Disease Control and Prevention (CDC) also defines exercise as a form of physical activity that involves planned, structured and repetitive bodily movement with the goal of improving or maintaining health or fitness. Although all exercise is physical activity, not all physical activity is exercise.

The challenge of aging for the future is not simply prolonging human life at any cost or by any means but rather extending self-sufficiency and quality of life [1]. Movement is critical to address the changes of aging that prevent self-sufficiency and affect quality of life. Physical activity is required for self-care and determines an individual’s level of independence or self-sufficiency. This challenge is compounded by the fact that 1.4 billion adults (27.5% of the world’s adult population) or more than 1 in 4 adults do not meet the recommended level of physical activity to improve and protect their health [2]. Furthermore, both men and women become less active as they get older despite clear evidence that being active benefits older adults in relation to preventing falls, remaining independent, reducing isolation and maintaining social links to improve psychosocial health [2].

The cost of physical inactivity is not only chronic diseases and premature deaths but a large economic burden. The WHO global status report on physical activity in 2022 states that physical inactivity costs health care systems US$ 27 billion a year due to preventable non-communicable diseases (NCDs). In the US, half of all American adults have one or more preventable chronic diseases like obesity, type 2 diabetes, heart disease, many types of cancer, depression, anxiety and dementia resulting in approximately $117 billion in annual health care costs and about 10 percent of premature mortality [3]. Furthermore, WHO projects almost 500 million (499,208 million) new cases of preventable NCDs between the years 2020–2030 if there is no change in the current prevalence of physical inactivity. The burden of new cases is highest among lower income countries (41 percent), with the Western Pacific Region predicted to be hardest hit. Globally, hypertension (47% prevalence accounting 22% health care cost), depression (43% accounting 28% health care cost) leads new cases of preventable NCDs. Dementia will account for 21% of health care costs due to the nature of its management and duration for which it is needed.

To explore how movement through increasing physical activity levels and engaging in regular exercise will help address aging challenges, a narrative review of relating movement with the four areas of health were chosen as the focus of the literature search: musculoskeletal health, pain, immune system and brain health. From the authors’ discussion, these are the health areas that movement will impact directly or indirectly and will influence the aging populations’ independence, self-sufficiency and quality of life. A preliminary search to validate the idea of relating aging with the four areas was conducted in the ONEsearch database. The key words “aging” paired with each of the areas of focus: musculoskeletal health, pain, immune system and brain health was used, and only peer-reviewed articles were included. The inclusion and exclusion criteria were formulated and refined after the preliminary search. The inclusion criteria included the following: worldwide peer-reviewed articles from 2020 and onward, English publications only, all types of research (quantitative and qualitative primary and secondary studies and tertiary research) were considered, and no dissertation work was included.

The evidence about the health benefits of regular physical activity is well established supported by studies that examined the role of physical activity in health and disease. There is evidence that even lower intensity activities demonstrate cardiometabolic and health benefits in an aging population [4]. A systematic review [13] found that 2.5 hour/week (equivalent to 30 min daily of moderate intensity activity on 5 days a week) compared with no activity was associated with a reduction in mortality risk of 19%, while 7 hour/week of moderate activity compared with no activity reduced the mortality risk by 24%. [5]. These studies clearly emphasize the importance of avoiding inactivity to delay death from all causes.

As one ages, being self-sufficient and pain free are among the utmost desires in sustaining a high quality of life [6]. Knowledge and practices that have been proven to regulate those goals have and continue to lead directly to movement [1]. Movement is dynamic and changes throughout the lifespan due to changes in musculoskeletal or nervous systems, fatigue, posture, injury, disease, or the environment. Changes related to age, include but are not limited to, changes in muscle fiber type, reduced vision, balance, range of motion, base of support, strength, reaction time and vestibular function in addition to increased postural sway, flexed posture, and pain. These changes influence functional mobility, balance and posture in older adulthood. However, it is important to emphasize that these changes are controllable through movement training and exercise.

2. Movement and musculoskeletal health

Musculoskeletal deficits are among the most detrimental effects of aging due to loss of muscular strength, flexibility, balance and functional ability [7]. Loss of muscle strength accelerates with age. By the age of 75–85 years, a typical person has lost about 45–50% of their muscle strength and by the age of 85, more than 55% [1]. Muscle strength plays a role in walking speed as weak muscles provide less power to support walking speed. Regular strength and neuromuscular training assists in reversing or slowing down a decline in walking speed due to the aging process. Joints are subject to the state of muscles, connective tissue and cartilage and concentrating on stretching and ROM exercises will aid in improving flexibility in older adults.

Sarcopenia, the loss of muscle mass, strength and function affects 10–50% of people over 60 years of age [8]. It is considered a precursor syndrome for the physical manifestation of frailty leading to impaired mobility and reduced independence. It has been shown that older adults with sarcopenia have poorer bone health [9]. Over time osteoblast activity is reduced affecting bone loss and skeletal strength. Older adults engaging in high physical activity/low sedentary behaviors have greater skeletal muscle strength and muscle power [10]. Resistance training exercise helps to maintain muscle strength and size in older years. Inactive adults after the age of 60 have less strength due to sarcopenia or loss of muscle mass and exercise clearly helps to maintain muscle mass needed for daily living activities and injury prevention [11]. Exercise, proper diet and endocrinological balance are recommended as interventions that are interconnected to improve musculoskeletal health and quality of life.

Obesity, which is involved in the development of many chronic diseases, also affects musculoskeletal health. Older adults with a BMI of 30 kg/m2 or greater significantly demonstrate functional limitations [12]. Being overweight and/or obese has been suggested to lead to alterations in the musculoskeletal system that place overweight individuals at higher risk of musculoskeletal pain and restricted range of movement [13]. There is a dose-response relationship between obesity and knee osteoarthritis (OA), meaning the greater an individual’s BMI, the greater the likelihood of developing OA [14]. Furthermore, obese adults with BMI over 35 perform poorly on tasks of executive function involving planning and mental flexibility when compared to normal individuals [15]. Older obese adult males showed deficits in cognitive functioning when completing cognitive tasks evaluating learning and visual memory [16]. The multidimensional nature of mobility issues among older adults with obesity requires a multidisciplinary approach to assessment and intervention with movement training (e.g., postural control and motor planning) as requirements.

Activities of daily living (ADL’s) are used as a gauge of functional independence. Physical activity improves physical function among individuals of all ages, enabling them to conduct their daily lives with energy and without undue fatigue. This is true for older adults, for whom improved physical function reduces risk of falls and fall-related injuries and contributes to their ability to maintain independence. Among the elderly, fall-related injuries are a primary public health challenge [2]. Furthermore, projections of fall-related injuries continue to increase [17, 18]. Aging consequently worsens the efficacy of musculoskeletal systems and functional abilities [7]. Due to the increasing frequency of falls among the vastly growing population of older adults, targeted interventions to minimize fall risks are of utmost priority. Physical activity in general for the elderly has proven reductions in the rate of fall related injuries [19, 20]. However, correlating specific activity programs is challenging given the vast array of types of exercises, individual differences and limitations of high-quality clinical trials. Programs that focus on balance [21] and have high doses of physical activity have been proven successful in fall reduction [20]. Increased reaction time as one ages is a proven risk factor in falls [22]. Similarly changes in gait and mobility from aging are associated with functional decline [23] and gait kinematics have been linked to predicting fall risk [24, 25, 26]. Older adults exhibit several changes in gait and paired with increased reaction time and decreased strength, endurance and visual acuity, falls are a major public health issue. Identifying training programs that focus on decreasing the risk of falls are of tremendous value. Although neurophysiological changes as one ages will occur, reaction and response time reduction is curtailed by regular physical activity.

Functional mobility, which requires both strength and flexibility, is another musculoskeletal challenge among older adults. Regular physical activity, specifically stretching, has been shown to create instantaneous and long-lasting changes to maximal joint range of motion and improves flexibility and functional mobility. Several studies reported that stretching efficacy was not limited to the targeted joint being moved [27, 28, 29]. For example, unilateral stretching performed on one lower limb also increased the range of motion of the contralateral limb; stretching of the lower limb increased the maximal range of motion of the distant upper limbs and vice versa. The role of fascia and connective tissues provides an explanation of the efficacy of stretching beyond the targeted joint. Recent histologic findings showed that fascia contains contractile cells, free nerve endings, and mechanoreceptors and therefore plays a proprioceptive and mechanically active role that functions as a body-wide mechanosensitive signaling network [30]. Full body exercises that include full body stretching therefore offer more benefits for musculoskeletal health.

3. Movement and pain

As we age, pain is viewed as an inevitable part of life. Low back pain, for example, is one of the most common and complex musculoskeletal ailments. Reducing low back pain in many cases may be accomplished through improving strength, balance and flexibility. We begin with little aches and pains due to sports injuries, to more extreme injuries due to falls. In order to address pain, we begin by taking over the counter medication to numb the pain, but persistent pain sometimes occurs. In most cases, over-the-counter medication helps, and we continue with our daily living activities. According to the Consumer Healthcare Product Association (2023) approximately 23% of U.S. adults use Acetaminophen weekly. The Mayo Clinic (2023) states that Acetaminophen is “usually recommended as the first line treatment for mild to moderate pain.” The struggle to manage pain is rather complex and has been discussed with much detail in the last decade, but pain management has been an integral part of medicine throughout history, where medication was almost always the preferred choice. In the 17th Century European doctors gave opium to their patients to relieve pain and by the 20th Century morphine and heroin were used to control pain [31]. While opioid use can be very effective in pain management relief, The American Society of Anesthesiologists states that it is also highly addictive. In fact, they report that “The risk of addiction is especially high when opioids are used to manage chronic pain over a long period of time” [32]. Older adults should be given the lowest analgesic dose for the shortest possible time to adequately manage their pain.

But what is pain? Pain, as described by the International Association for the Study of Pain (IASP) is, “an unpleasant sensory and emotional experience associated with, actual or potential tissue damage, or described in terms of such damage” [33]. There are two major types of pain: acute pain and chronic pain. Acute pain comes on quickly, can be severe, but in most cases a temporary condition that does not last for a long period of time. Chronic pain lasts beyond normal tissue healing time, generally taken to be 12 weeks/3 months and limits quality of life because it contributes to disability, anxiety, depression, sleep disturbances, poor quality of life and healthcare costs [34].

Pain among older adults leads to functional impairment, sleep disturbance, reduced socialization, depression, reduced mobility and impaired or slowed rehabilitation. There is an estimated 70–80% reduction in the ability to perform activities of daily living among older adults with pain. They also exhibit decreased gait speed, weaker grip strength and decreased self-reported physical activity [35]. Frailty, a common clinical syndrome among older adults often display reduced functional reserve and pain related impairments profoundly impact cognition and independence [36]. Pain is the most common reason people seek health care and the leading cause of disability in the world. In 2011, one in every five adults worldwide suffers from pain and one in every 10 adults is diagnosed with chronic pain each year [37]. The 2020 Global Pain Index reports that one third of the world’s population is in pain everyday [38]. Acute pain is experienced regularly by up to 49–83%of elderly individuals above the age of 60 living in care homes and 40% of elderly individuals living in the community [38]. The prevalence of chronic pain among US adults ranged at 20.5–21.8% [39]. According to the Center for Practical Bioethics (2021) more than 116 million Americans are impacted by chronic pain, resulting in high healthcare costs. A report published by John Elflein [40] who conducted a survey in 2021 with 29,482 participants over the age of 18, showed that 26.8% of adults between the ages of 45 and 64; 30% of adults between the ages of 65 and 84; and 34.3% of adults 85 and over live with chronic pain in the United States. Chronic pain, especially in the elderly population, is more prevalent as pain is a frequent side effect of chronic illness. Although the aforementioned study did not discuss the causes of pain, it did demonstrate that chronic pain increases with age. While each individual’s level and frequency of pain differs, as one ages, the duration of pain increases [41]. Stressful situations, depression and anxiety can exacerbate chronic pain because pain and these mental health states share overlapping nerve biological pain pathways in the brain. Prevalence of pain is common among the older age group highlighting the need for pain management that goes beyond analgesics and considering alternative options [42].

For many years, the non-pharmacological treatment choice for pain included recommendations for rest and inactivity [34]. However, movement or physical activity programs and exercise regimens are increasingly promoted to reduce chronic pain and improve mental health and physical functioning. Although pain is a normal protective response to injury and potentially harmful stimuli, prolonged or dysfunctional neuromuscular adaptations in response to pain may contribute to disability and chronicity in a variety of pain conditions [43]. Clinically, pain produces a large range of motor adaptations. This ranges from subtle motor compensations during task completion to complete avoidance of painful movements and/or activities [44]. Movement, individualized exercise programs and specific motor learning/functional tasks are often prescribed to help decrease pain and restore/improve function. Studies provide evidence of the effectiveness of exercise for the treatment of pain. For example, exercise is effective for the management of chronic low back pain and for fibromyalgia strength, endurance training and stretching of the neck and upper extremities improve neck pain [45].

Physical therapy or physiotherapy is another non-pharmacological treatment for pain. Physical therapists or physiotherapists are considered movement experts who treat pain and improve quality of life through hands-on approaches: stretching, soft tissue release, joint mobilizations, fascial release, etc. Treatment also includes exercise-based approaches to strengthen muscles, improve balance and sharpen coordination. Physical therapy takes on a more holistic approach to pain relief because the interventions are based in the knowledge that all forces in the body affect each other. It works to restore the balance of coordination, flexibility and strength so that movement, blood flow and nerve functioning are facilitated. For example, pain due to a nerve pinch may happen because of compression from a muscle or fascia. Reducing the strain and restoring fluid movement through physiotherapy helps alleviate the pain. Many of the exercises used in a physical therapy session are encouraged to continue at home. Physical therapy works to restore movement and improve functional mobility, eliminate pain and reduce the need for surgery and pain medicines like opioids.

Studies also support that those engaging in regular physical activity are associated with less frequent back pain and reduced incidence of musculoskeletal pain [46, 47]. Some studies show that regular physical activity may reduce pain sensitivity, and some demonstrate no change, but greater pain sensitivity has never been observed. It should be noted that some acute exacerbation of chronic pain when beginning an exercise program may happen and therefore the need to gradually increase physical activity is critical with the goal of eventually reaching recommended guidelines. Regular exercise leads to chronic adaptations that provide the greatest benefit to addressing pain. It is recommended that engaging in physical activity at a young age builds muscle, helps with range of motion, and improves overall movement.

4. Movement and the immune system

As we grow older, our immune system slows down, weakens, and loses the ability to fight against illness, such as infections, cancer, and appropriate wound healing [48]. Our immune system plays an important role in protecting us from harmful substances, germs, and cell changes. It is made up of two parts: the innate immune system and the adaptive immune system. Innate immunity responds immediately to an invading pathogen, is antigen-independent, and has no immunologic memory [49]. Innate immunity is known as the first line of defense against germs or foreign substances. Adaptive immunity is antigen-dependent and antigen-specific and has immunologic memory which enables for an immune response when it recognizes the same antigen [49]. Inflammation is the body’s immune response to any form of irritant.

A review conducted by Ghauri [50] showed that chronic pain negatively impacted the immune system. An immune response to chronic pain is the release of inflammatory substances such as antibodies, cytokines, and chemokines. When the immune system attacks the body, it results in inflammation of joints, which may cause pain, stiffness, and difficulties with mobility [51]. Inflammation contributes too many age-related degenerative joint diseases such as frailty, osteoporosis, atherosclerosis, type 2 diabetes, sarcopenia, and Alzheimer’s disease [52]. Inflammation can be acute or chronic: acute inflammation will respond immediately to trauma due to injury, whereas chronic inflammation is slow, and long-term lasting [53].

With age, the risk of inflammation increases due to an unhealthy lifestyle, such as an unhealthy diet or physical inactivity. A review of studies conducted shows that, “…lifestyle interventions such as exercise training and dietary modifications may provide a low cost and long-term alternative to limit inflammation and slow declines in the elderly.” [54].

According to Pahwa, et al., [53] 350 million people worldwide and almost 42 million Americans, suffer from arthritis and joint diseases of which osteoarthritis and osteoporosis occur more in menopausal women than older men [55]. As osteoarthritis is the most common age-related disorder in the world [56], the deterioration of the connective tissues that holds the joints together is found to be a major contributor to the development of osteoarthritis, which results in the increase of stiffness of ligaments and tendons [57]. To slow down the progression of osteoarthritis or osteoporosis, an exercise program that consists of spinal extensor strengthening with progressive measured resistance is recommended to prevent falls and fractures [58]. In addition to resistance training, movement to improve range of motion and overall functional performance should become a part of every aging adult. The Arthritis Foundation states the “movement is the best medicine for osteoarthritis.”

Oxidative stress or reactive oxygen species (ROS) can cause chronic inflammation and affect a variety of physiological and pathological processes playing a role in age-related diseases like sarcopenia, cancer, cerebrovascular and neurodegenerative diseases. ROS induces cellular senescence eventually leading to cell death. Studies show that low to moderate levels of exercise-induced ROS production plays an essential role in exercise-induced adaptation of skeletal muscle [59]. Lack of exercise, suboptimal amount and quality of sleep, and poor diet all contribute to the accumulation of ROS. Homocysteine, an amino acid, influences ROS accumulation. There is evidence that elevated levels of homocysteine is associated with lower muscle strength in women and considered a risk factor for vascular and coronary heart disease. Recent studies report on the positive effects of Nordic walking (walking with poles mimicking the motion of cross- country skiing), reducing homocysteine levels and ensuring adequate supply of vitamin D. Vitamin D is essential for bone health and skeletal muscle function and continuously decreases over a lifetime. Vitamin D supplementation combined with outdoor activity in fresh air lowers homocysteine levels compared to supplementation alone.

There is growing evidence that depression is accompanied by increased levels of proinflammatory cytokines. This is based on a theory of a link between innate immunity and the central nervous system leading to decreased synthesis of serotonin and increased cortisol levels, characteristics of depressive conditions. Several studies have shown the benefits of movement and showed that regular physical activity improves immunity and may limit the effects or delay immunological aging. Regular aerobic exercise increases immune system function to prevent and defend against infection through reducing age-related increase in proinflammatory cytokines.

Recent genomic and functional studies suggest that immune and inflammation pathways are involved in the pathogenesis of Alzheimer’s disease (AD) and Parkinson’s disease (PD), the most common age-related neurodegenerative disorders. Both of these diseases are characterized by chronic inflammation in the brain. The chronic neuroinflammation compromises the blood–brain barrier (BBB) integrity, increasing its permeability and leading to loss of immunological protection of the central nervous system. There is body evidence that regular physical exercise has anti-inflammatory effects and reduces blood-brain barrier permeability reinforcing antioxidative capacity and reducing oxidative stress [60]. Furthermore, regular physical activity improves endothelial function and increases the density of brain capillaries. Therefore, physical training should be a component of prevention programs to reduce the risk of neuroinflammatory diseases.

Gentle stretching helps resolve inflammation and reduce pain. Stretching exercises and guided exercise programs with a prominent stretching component like Yoga, Tai-Chi and Essentrics have been found to decrease levels of circulating pro-inflammatory cytokines. Researchers from Harvard found that rats who were comfortably stretched for 10 minutes twice per day had better mobility (longer gait), less pain and reduced inflammatory infiltration in the connective tissues 2 weeks after pain injection. Furthermore, stretching also increased the rate of healing [30].

5. Movement and brain health

As we age, it is inevitable that not only our physical ability declines, but our cognitive ability declines, as well. As with physical impairment, cognitive impairment can be prevented and delayed. But what is cognition? Cognition is defined as “the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.” [61]. Cognitive impairment in older adults can have many causes, including, but not limited to, the side effects of medication, infections, depression, dementia, and stress to name a few. A cohort study conducted by Kulsheshtha et al. [62] with 24,448 participants over the age of 45 found that there is an association between stress and cognitive impairment. Another study conducted in Sweden showed a significantly higher level of perceived stress in adults of advanced age [63]. Acute and chronic stress can result in oxidative stress, neuroinflammation and dysfunction of the blood–brain barrier leading to poor health outcomes. Anxiety and depression often accompany aging, increasing by up to 6% among those over the age of 65. Significant changes due to aging can cause feelings of insecurity, loss of self-esteem, anxiety and depression. Regular exercise therapy reduces stress and depression. In fact, studies show that running therapy was shown to have more beneficial effects on biological aging than antidepressant medications. Many studies have also shown the benefits of exercise in cognition. A literature review conducted by van Uffelen et al. [64] showed that exercising programs that included strength, flexibility, and balance training, improved cognition in both healthy older adults as well as older adults with cognitive decline. A study by Lautenschlager [65] reported that physical activity reduces the risk of cognitive decline later in life. Aspects of cognitive function that may be improved include memory, attention, executive function (the ability to plan and organize; monitor, inhibit, or facilitate behaviors; initiate tasks; and control emotions).

The protection of the aging brain and the central nervous system from neurodegeneration poses significant challenges. In addition to apparent physical changes due to aging, there are often equally significant changes in the brain and in mental health. The brain shrinks in volume, particularly in the frontal cortex and its weight declines with age at a rate of around 5% per decade after age 40. The white matter found in the deeper tissues of the brain that contain nerve fibers wrapped by a fatty sheath called myelin deteriorates after around the age of 40. Memory loss is the most widely seen cognitive change associated with aging. There are four sections that comprise memory functioning: episodic, semantic, procedural and working memory. Loss of episodic memory characterizes memory loss in Alzheimer’s disease. Several studies demonstrated that physical activity, especially aerobic exercise performed by elderly people is protective against Alzheimer’s disease, slowing the decline in cognition and slows disease progression through reducing amyloid-B level deposition. On the other hand, sedentary life patterns and lack of physical activity increase the risk of dementia and Alzheimer’s disease [66].

There is a growing interest in the gut-brain axis and there is accumulating evidence that the gut microbiota is critical to health and disease. Dysbiosis, a term for poor gut health, is characterized by microbiota dysregulation and results in an unbalanced microbiome in the gut. A healthy microbiome (symbiosis) promotes overall health. The gut-brain axis is the bidirectional link between the central nervous system (CNS) and the enteric nervous system (ENS). It seems like an “unhealthy gut” can lead to an “unhealthy brain”. Dysbiosis is associated with neurodegenerative diseases including Alzheimer’s, Parkinson’s, Huntington’s, and multiple sclerosis. For example, a review conducted by Ref. [67, 68] highlighted the role of Vitamin D deficiency or hypovitaminosis D among patients with Parkinson’s disease due to a deterioration in the gastrointestinal function. Furthermore, the paper also states that neurodegenerative diseases and hypovitaminosis D led to frailty, a concept that has grown in importance in understanding the functional status of older adults’ health. Frailty is a condition of risk and vulnerability diminished resistance to stressors and is associated with poor gut health [68]. Meanwhile, there is compelling evidence that shows many different types of exercise not only enhance cognitive functioning but provide a promising role for neurodegenerative diseases [1]. Exercise has been shown to increase the diversity of the microbiota, balancing beneficial and pathogenic bacterial communities and enhance colon health. Regular physical activity also increases butyrate-producing bacteria critical for maintaining the mucosal barrier, modulating immune response, preventing infections and regulating energy expenditure. Furthermore, exercise increases both endogenous and exogenous production of vitamin D which further increases the capacity to exercise.

Brain-derived neurotrophic factor (BDNF), a key protein molecule involved in learning and memory, decreases with aging. BDNF is also considered as the main player in brain plasticity. Movement, particularly aerobic and resistance exercise and endurance activity plays a neuroprotective role by increasing BDNF production [68]. Some studies indicate that exercise improves neuropsychiatric and cognitive symptoms in people with mental disorders. Interestingly, these studies show that the delivery of exogenous BDNF into the patient’s brain had no therapeutic effect on the disease but releasing BDNF through physical activity was neuroprotective. Irisin, commonly referred to as the “sport hormone” is released from muscle cells after physical activity that induces oxygen consumption and heat production. Irisin protects against neuroinflammation by acting directly on glial cells in the brain, reducing oxidative and physiological stress, and protects against cerebral ischemia [1].

Regular physical activity provides a variety of other benefits, including helping people sleep better, feel better, and perform daily tasks more easily. There is a bidirectional relationship between sleep and exercise. Studies demonstrate that moderate to vigorous physical activity improves quality of sleep among adults. On the other hand, insufficient or poor quality of sleep leads to lower levels of physical activity. Regular physical activity reduces the length of time it takes to go to sleep, reduces the time one is awake after going to sleep and before rising in the morning and lengthens deep sleep. Exercise is also used to treat sleeping disorders. For example, 4 months of aerobic exercise training in a sample of older adults with insomnia significantly improved sleep quality while also reducing daytime sleepiness and depressive symptoms. Another research study found that 12 weeks of moderate-intensity aerobic and resistance exercise resulted in a 25% reduction in obstructive sleep apnea (OSA) severity despite less than 1 kg of weight loss [69]. Indeed, regular exercise leads to better subjective and objective sleep and improvements in daytime functioning.

6. Recommendations

Past studies have aimed to determine an ideal movement program for older adults to combat changes in aging. Combining scientific support and motivational attributes, educating adults about the type and dose of movement in quality of life both before and at the onset of such reductions is critical [6]. Various forms of movement have all shown to be beneficial in some way in countering various weaknesses from aging, whether it be resistance training [70], endurance training and concurrent strength [71], Tai Chi [72, 73], multidimensional exercise training [7], functional training [74], dance [75], vibration therapy [76, 77], dynamic stretching [78, 79, 80] and static stretching [78, 81].

Both medical professionals and community/public health programs are essential in promoting movement as prevention and treatment. This ideology is the foundation for the American College of Sport Medicine (ACSM) Exercise is Medicine global initiative. ACSM and Health Level Seven International (HL7), a global health care database network approved a Physical Activity Implementation Guide that includes physical activity as a vital sign to facilitate health care professionals providing referrals to exercise professionals [82]. The Physical Activity Guidelines for Americans (2018) recommends that adults should move more and sit less throughout the day acknowledging that some physical activity is better than none. Furthermore, it recommends that at least 150 minutes (2.5 hours) to 300 minutes (5 hours) a week of moderate intensity or 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity will lead to substantial benefits and even more additional health benefits beyond 300 minutes (5 hours). Recommendations for older adults (aged 65 and older) are the same but with additional elements of including multicomponent physical activity that emphasizes balance training, aerobics, and muscle-strengthening activities at moderate or greater intensity on 3 or more days a week to enhance functional capacity and to prevent falls. These recommendations align with the WHO recommendations (Table 1, Figures 1–3).

Older adults should do at least 150–300 minutes of moderate-intensity aerobic physical activity; or at least 75–150 minutes of vigorous-intensity aerobic physical activity; or an equivalent combination of moderate- and vigorous-intensity activity throughout the week, for substantial health benefits. Older adults should also do muscle-strengthening activities at moderate or greater intensity that involve all major muscle groups on 2 or more days a week, as these provide additional health benefits. As part of their weekly physical activity, older adults should do varied multicomponent physical activity that emphasizes functional balance and strength training at moderate or greater intensity, on 3 or more days a week, to enhance functional capacity and to prevent falls.

Table 1.

WHO guidelines for physical activity and sedentary behavior for older adults.

Figure 1.

WHO guidelines on physical activity and sedentary behavior for adults.

Figure 2.

WHO guidelines on physical activity and sedentary behavior for older adults.

Figure 3.

WHO guidelines on physical activity and sedentary behavior for adults with chronic conditions.

The intensity of exercise is based on absolute rates of energy expenditure commonly described as light, moderate, or vigorous intensity. Light intensity activity is non-sedentary waking behavior including walking at a slow or leisurely pace (2 mph or less), cooking activities, or light household chores. Moderate intensity activity includes activities like walking briskly (2.5 to 4 mph), playing doubles tennis, or raking the yard. Vigorous intensity activity samples include jogging, running, carrying heavy groceries or other loads upstairs, shoveling snow, or participating in a strenuous fitness class.

Aerobic physical activity is also classified into levels: inactive, insufficiently active, active, and highly active. The classifications are useful to help one determine his/her level and how to work on becoming more active. Inactive is basic movement derived from daily life activities. Insufficiently active is doing some moderate- or vigorous-intensity physical activity but less than 150 minutes of moderate-intensity physical activity a week or 75 minutes of vigorous-intensity physical activity or the equivalent combination. This level is less than the target range for meeting the key guidelines for adults. Active is doing the equivalent of 150 minutes to 300 minutes of moderate-intensity physical activity a week. This level meets the key guideline target range for adults. Highly active is doing the equivalent of more than 300 minutes of moderate-intensity physical activity a week. This level exceeds the key guideline target range for adults.

Guided exercise programs provide opportunities for older adults to meet the additional elements of including multicomponent physical activity that emphasizes balance training, aerobics, and muscle-strengthening activities to enhance functional capacity and to prevent falls. The most popular are Yoga, Tai-Chi and Pilates. A 10-year comparison study conducted in Australia showed that participation in Yoga, Pilates, and Tai Chi exercises increased over the course of time, with Yoga and Pilates being the preferred method of movement in adults age 55 and over [83]. Recently, Essentrics, a full body guided exercise program that seeks to rebalance the body was introduced in Canada as a “reverse aging” program and is becoming popular. Essentrics may have the most potential benefits and the least number of side effects because of its gentle approach and focus on aging. Although there are differences between these guided exercise programs all forms of movement are designed to improve physical and mental health using a full body approach.

6.1 Essentrics

A holistic approach was introduced as a full body work-out that uses a dynamic combination of strengthening and stretching aimed to rebalance the body. Essentrics was created by Miranda Esmonde-White a former ballerina with the National Ballet of Canada and draws on the slow and flowing movements of Tai-Chi, the strengthening techniques of ballet and the healing principles of physiotherapy. Essentrics relies on bodyweight as the source of resistance, which contrasts with traditional strength training or resistance training programs that use external weights. The movement sequences of Essentrics consist of low impact full body stretches emphasizing alignment to loosen and decompress the joints and relax the muscles. A study conducted by Zarco et al. [79] included older adults who participated in a guided exercise program, which showed an improved flexibility, balance, and strength (Figures 4 and 5).

Figure 4.

Essentrics sample exercise - windmill sequence.

Figure 5.

Sample Essentrics exercise - washes and lullabies sequence.

6.2 Yoga

The practice of yoga was developed in Northern India around 2700 BC and offers physical benefits as well as mental wellness [84]. It is a type of exercise in which the body moves into various positions to become more fit or flexible, to improve breathing, and relax the mind. There are many different types of yoga in the world, but “Hatha Yoga” is the most popular in the West [85]. Blending western gymnastic styles with classic yoga became very popular. Since, the United Nations Assembly announced an “International Day of Yoga,” in 2015, and UNESCO claimed yoga as an “intangible cultural heritage” [84]. The benefits of yoga include increased joint flexibility and joint function, and with regular practice it can reduce joint pain [86]. In a randomized control study conducted by [87] yoga improved flexibility, strength, and balance in older adults. Yoga is especially recommended for aging-related chronic ailments [88].

6.3 Tai Chi

Another form of complementary therapy is Tai Chi. Tai Chi is a form of Chinese martial arts. It was developed around 1670 by Chen Wangting as a method for self-defense but has shown to have great health benefits [89]. Tai Chi is a type of exercise where different postures and flowing movements result in attaining optimal physiological and psychological benefits [90]. Tai Chi is used to manage chronic pain conditions since slow motion and weight shifting may improve musculoskeletal strength and joint stability. A review of studies showed that a 24-week Tai Chi exercise program for patients diagnosed with osteoporosis resulted in reduced pain, particularly in reduced lower back pain [91].

6.4 Pilates

Joseph H. Pilates developed these exercises in the 1920s as a method of conditioning ballet and modern dancers. Pilates is defined as an exercise regimen that is typically performed on a floor mat or with the use of a specialized apparatus and aims to improve flexibility and stability by strengthening the muscles, especially torso-stabilizing muscles of the abdomen and lower back. It focuses on controlled movement, posture, and breathing [92] A review conducted by [93] showed that the Pilates method reduces the risk of falls in older adults and improves balance and mobility.

These guided exercise programs share the same fundamental goal of mastering control over lifting and moving the body in space, are low impact and use the body weight as the resistance force for strengthening. Furthermore, they all utilize synchronized breathing with movements and varying degrees of body and mindful awareness. Studies on Pilates, Yoga, and Tai Chi have all had significant effects on the improvement of strength, body composition and flexibility. Furthermore, studies on Yoga and Pilates show it’s beneficial in reducing inflammation. Pilates strengthens the bones and joints while yoga helps to build and increase the flexibility of the muscles around the joints [94]. Studies on Tai Chi show that it improves balance because of increased joint stability and postural control. There are few studies on Essentrics but initial studies show improvements in balance, strength, flexibility and address pain (Table 2).

Be active		Sit less	Build strength	Improve balance
Vigorous	Moderate		Improve functional mobility
Run; Play Sports; Climb Stairs	Walk; Cycle; Swim	Limit Sitting; Time, Sofa; Time and; Computer; Time	Weight Training; Essentrics; Yoga; Pilates	Dance; Tai Chi; Essentrics; Bowls
A total of 75 minutes of; vigorous intensity or 150; minutes of moderate intensity; or a combination of both PER; WEEK		Break up; sitting time; per day	2 days or more PER WEEK
10-30 or more minutes per; session per day			10-30 minutes or more per session per day
		Something is better than nothing.
		Start small and build up gradually.

Table 2.

Suggested physical activities or guided exercise programs for aging adults.

It has been generally accepted that a reduction in functional capabilities is just a natural part of aging. However, more recent ideologies suggest that changes in functionality are not simply due to mere aging but increasing sedentariness or an inactive lifestyle. Distinguishing inevitable age-related changes versus those resulting from inactivity are critical for preserving quality of life. It is inevitable that aging and slowing down go hand and hand. However, this linkage is largely a result of a sedentary lifestyle. There is overwhelming evidence that the body is capable of responding to exercise throughout one’s life and gives hope to all that effective movement may be sustained as we age. Although it’s never too late, learning movement skills early in life will assist in maintenance with greater ease over the life span. Undeniably, movement, physical activity and exercise benefit aging and streamlining technology-based analyses, conducting research at the cellular and molecular levels and pinpointing interventions is the wave of future directions.