Exercise and Physical Activity for Older Adults

Wojtek J. Chodzko-Zajko, Ph.D., FACSM; David N. Proctor, Ph.D., FACSM; Maria A. Fiatarone Singh, M.D.; Christopher T. Minson, Ph.D., FACSM; Claudio R. Nigg, Ph.D.; George J. Salem, Ph.D., FACSM; James S. Skinner, Ph.D., FACSM

Disclosures

March 01, 2010

In This Article

Section 2: Physical Activity and the Aging Process

Physical Activity and the Aging Process Aging. is a complex process involving many factors that interact with one another, including primary aging processes, "secondary aging" effects (resulting from chronic disease and lifestyle behaviors), and genetic factors.[152,258] The impact of physical activity on primary aging processes is difficult to study in humans because cellular aging processes and disease mechanisms are highly intertwined.[137] There are currently no lifestyle interventions, including exercise, which have been shown to reliably extend maximal lifespan in humans.[98,175] Rather, regular physical activity increases average life expectancy through its influence on chronic disease development (via reduction of secondary aging effects). Physical activity also limits the impact of secondary aging through restoration of functional capacity in previously sedentary older adults. AET and RET programs can increase aerobic capacity and muscle strength, respectively, by 20%-30% or more in older adults.[101,139]

Evidence Statement and Recommendation. Evidence Category A. Regular physical activity increases average life expectancy through its influence on chronic disease development, through the mitigation of age-related biological changes and their associated effects on health and well-being, and through the preservation of functional capacity.

Factors Influencing Functional Decline in Aging. Although the pattern of age-related change for most physiological variables is one of decline, some individuals show little or no change for a given variable, whereas others show some improvement with age.[119] There are also individuals for whom physical functioning oscillates, exhibiting variable rates of change over time,[120,187,192] possibly reflecting variable levels of physical activity and other cyclical (seasonal) or less predictable (sickness, injuries) influences. However, even after accounting for the effect of different levels of physical activity, there is still substantial between-subject variability (at a given point in time and in rates of change over time) for most physiological measures, and this variability seems to increase with age.[231] Individual variation is also apparent in the adaptive responses to a standardized exercise training program; some individuals show dramatic changes for a given variable (responders), whereas others show minimal effects (nonresponders).[24]

Determining the extent to which genetic and lifestyle factors influence age-associated functional declines and the magnitude of the adaptive responses to exercise (i.e., trainability) of both younger and older individuals is an area of active investigation. Exercise training studies involving families and twin pairs report a significant genetic influence on baseline physiological function (explaining ~30% to 70% of between-subjects variance) and trainability of aerobic fitness,[24] skeletal muscle properties,[199] and cardiovascular risk factors.[24] Although the role of genetic factors in determining changes in function over time and in response to exercise training in older humans is not well understood, it is likely that a combination of lifestyle and genetic factors contribute to the wide interindividual variability seen in older adults.

Evidence Statement and Recommendation. Evidence Category B. Individuals differ widely in how they age and in how they adapt to an exercise program. It is likely that a combination of genetic and lifestyle factors contribute to the wide interindividual variability seen in older adults.

Exercise and the Aging Process. The acute physiological adjustments of healthy sedentary older men and women to submaximal aerobic exercise are qualitatively similar to those of young adults and are adequate in meeting the major regulatory demands of exercise, which include the control of arterial blood pressure and vital organ perfusion, augmentation of oxygen and substrate delivery and utilization within active muscle, maintenance of arterial blood homeostasis, and dissipation of heat.[213] The acute cardiovascular and neuromuscular adjustments to resistance exercise (both isometric and dynamic) also seem to be well preserved in healthy older adults.[213] Accordingly, the normal age-associated reductions in functional capacity discussed in Section 1 should not limit the ability of healthy older adults to engage in aerobic or resistance exercise. In addition, long-term adaptive or training responses of middle-aged and nonfrail older adults to conventional AET or RET programs (i.e., relative intensity-based, progressive overload) are qualitatively similar to those seen in young adults. Although absolute improvements tend to be less in older versus young people, the relative increases in many variables, including V·O2max,[100] submaximal metabolic responses,[211] and exercise tolerance with AET and limb muscle strength,[139] endurance,[255] and size[203] in response to RET, are generally similar. Physiological aging alters some of the mechanisms and time course[174,253] by which older men and women adapt to a given training stimulus (i.e., older adults may take longer to reach the same level of improvement), and sex differences are emerging with respect to these mechanisms,[16] but the body's adaptive capacity is reasonably well-preserved, at least through the seventh decade.[98,217] During the combined demands of large muscle exercise and heat and/or cold stress, however, older individuals do exhibit a greater reduction in exercise tolerance and an increased risk of heat and cold illness/injury, respectively, compared with young adults.[126] Age differences in exercise tolerance at higher ambient temperatures may be at least partially due to the lower aerobic fitness levels in older adults.[126] Cessation of aerobic training by older adults leads to a rapid loss of cardiovascular[184,210] and metabolic[201] fitness, whereas strength training-induced (neural) adaptations seem more persistent,[139] similar to what has been observed in younger populations.[44,139]

Evidence Statement and Recommendation. Evidence Category A. Healthy older adults are able to engage in acute aerobic or resistance exercise and experience positive adaptations to exercise training.

Physical Activity and Successful Aging. When centenarians and other long-lived individuals are studied, their longevity is often attributed to a healthy lifestyle. Three characteristic behaviors are routinely reported; these include exercising regularly, maintaining a social network, and maintaining a positive mental attitude.[214,231] Physiological factors that are most frequently associated with longevity and successful aging include low blood pressure, low body mass index and central adiposity, preserved glucose tolerance (low plasma glucose and insulin concentrations), and an atheroprotective blood lipid profile consisting of low triglyceride and LDL-cholesterol and high HDL-cholesterol concentrations.[97,231] Regular physical activity seems to be the only lifestyle behavior identified to date, other than perhaps caloric restriction, which can favorably influence a broad range of physiological systems and chronic disease risk factors,[97,98] and may also be associated with better mental health[154] and social integration.[155] Thus, despite large differences in genetic background among those of a given age cohort, it seems that physical activity may be a lifestyle factor that discriminates between individuals who have and have not experienced successful aging.[207,214,258]

Evidence Statement and Recommendation. Evidence Category B/C. Regular physical activity can favorably influence a broad range of physiological systems and may be a lifestyle factor that discriminates between those individuals who have and have not experienced successful aging.

Physical Activity and the Prevention, Management, and Treatment of Diseases and Chronic Conditions. There is growing evidence that regular physical activity reduces risk of developing numerous chronic conditions and diseases including cardiovascular disease, stroke, hypertension, type 2 diabetes mellitus, osteoporosis, obesity, colon cancer, breast cancer, cognitive impairment, anxiety, and depression. In addition, physical activity is recommended as a therapeutic intervention for the treatment and management of many chronic diseases including coronary heart disease,[70,185,242] hypertension,[37,183,241]peripheral vascular disease,[157] type 2 diabetes,[220] obesity,[252] elevated cholesterol,[165,241] osteoporosis,[75,251]osteoarthritis,[1,3] claudication,[232] and chronic obstructive pulmonary disease.[170] Furthermore, clinical practice guidelines also identify a role for physical activity in the treatment and management of conditions such as depression and anxiety disorders,[26] dementia,[54] pain,[4]congestive heart failure,[197] syncope,[25] stroke,[79] back pain,[85] and constipation.[142] Although a detailed review of the impact of regular physical activity on the development, treatment, and management of chronic diseases is beyond the scope of this Position Stand, Table 3 summarizes a growing body of evidence that regular physical activity reduces the risk of developing a large number of chronic diseases and is valuable in the treatment of numerous diseases.

Evidence Statement and Recommendation. Evidence Category A/B. Regular physical activity reduces the risk of developing a large number of chronic diseases and conditions and is valuable in the treatment of numerous diseases.

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