A marked surge of physical fitness programs began about a decade ago in the United States. Public school, university, and commercial fitness programs extolling the virtues of controlled exercise, stretching, jogging, and similar activities began to become a part of present-day American life.
This movement did not occur because of some sudden whim or fad advocated by an entrepreneur for a measure of self-gain. Many prominent physicians and researchers became intrigued with the findings of Dr Kenneth Cooper1 who, while serving in the United States Air Fbrce, discovered that many of America's young military men were quite physically unfit to perform many activities involving even moderate amounts of stress. Steps were taken to improve the physical condition of these young men by means of programs designed to improve their overall physical status with special emphasis on their cardiorespiratory status. The subjects' physiological changes resulted in improved working capacity, cardiovascular function, body composition, and muscular endurance and strength. The benefits of physical activity in the younger adult now have been clearly documented for the past 20 years.
But what about the elderly? (especially those who are temporarily or permanently limited in mobility, either because of arthritis, a stroke, fractures, general weakness due to other acute or chronic illnesses, or adverse effects of normal aging changes). What about older persons who use crutches, are in wheelchairs, or are confined to bed most of the time? Is a specific planned exercise program out of the question for these persons who need it so much?
Lack of physical mobility, especially in the elderly, contributes to the following complications: muscle atrophy; contractures; joint stiffness; decubitus ulcers; orthostatic hypotension; thrombus formation; hypostatic pneumonia; and urinary stasis, retention, and calculi. Other complications can include poor appetite, constipation, fatigue, insomnia, stress, and depression.
The primary purposes of this article are to discuss how the biological changes of aging relate to the complications of immobility and to present general guidelines and specific exercise programs for immobile elderly persons.
Biological Changes of Aging
Before discussing the many benefits of an immobile older adult participating in an exercise program, it is important to consider the biological changes that occur with age which make physical activity a necessity. Is the aging process primarily genetic or mostly the result of environmental effects? While genes determine part of the aging process, the interaction of the organism with its environment is also significantly important. To emphasize the genetic influence, Hayflick2 demonstrated that the lifespan of a lung fibroblast in cell culture is controlled by the cell's constitution; cells obtained from a human infant divided approximately 50 (± 10) times . He projected from this number of cell doublings that maximum human lifespan could be 150 years or, in other words, about 40 years longer than the current maximum life expectancy.
Why then do humans die long before the age indicated by the doubling capability of the fibroblast? The importance of the interaction of the organism with its environment must be recognized. This interaction is affected by the lifestyle of the human. At one time, infectious diseases were the primary causes of death. Modern medicine and health practices have changed the situation so that there are fewer deaths from infectious diseases and more from chronic diseases and problems related to lifestyles.
What is aging? Aging, defined both physiologically and chronologically, is the loss of ability to adapt to one's environment.3 At the approximate age of 30, peak physiological function is reached. After that age, especially in the sedentary person, physiological capabilities begin to decline. These functional declines are evident in work capacity, cardiac output, heart rate, blood pressure, respiration, basal metabolic rate (BMR), musculature, bone and joint changes, nerve conduction, flexibility, and total body water.
The ability to exercise and to perform physical work is one of the first to indicate obvious decline. Between the ages of 30 and 70, maximal physical work capacity decreases 25% to 30%. There is a cardiac output decline during this period due to declines in both maximum stroke volume and maximal heart rate. The decline of stroke volume is related to decreases in muscle mass of the heart and muscle contractility. The stroke volume appears to be adequate during mild exercise, but is unable to increase in response to more severe exercise as it does in the young. Therefore, the heart rate must accelerate to maintain adequate blood flow to the tissues. It is estimated that maximal heart rate declines by approximately six to eight beats each decade of life.3 Thus, limited heart rate and stroke volume account for a 30% decrease in maximal cardiac output and result in the lessened maximal work capacity.
Bed rest caused by immobility increases the workload of the already compromised heart action. In the patient on total bed rest, "there is a 25-30% increase in cardiac output, a 40% increase in the stroke volume . . . and a 30% increase in the total work of the heart."4
Along with the decreased cardiac output, there is an increase in resistance to blood flow. According to Shephard,5 the elderly person sustains a 20% higher systemic pressure than a younger person at half the cardiac output. The resting systolic pressure increases by 10 to 40 mmHg and the diastolic pressure by 5 to 10 mmHg. Systolic pressures may rise above 200 mmHg during exercise.
Vital capacity declines 40% to 50%6 by age 70, whereas residual volume increases 30% to 50%. 7 Maximum air movement during exercise is limited and is reached at low levels of work. Breathing rate is increased, and, therefore, resistance to air movement increases and the respiratory muscles must work harder.
There are also changes in the lungs. Total surface area declines by 25% to 30% between the ages of 30 and 70.3 Blood oxygen levels are lowered as a result of decreased lung surface area involvement as well as decreased alveoli ventilation and blood perfusion. Decreased respiratory function, together with various degrees of kyphosis and immobility, contributes to the development of hypostatic pneumonia, a major cause of death in immobile older adults.
Basal metabolic rate declines by 8% to 12% between the ages of 30 and 70. According to Tzankoff and Noms,8 the decline in basal metabolism is directly related to decline in lean body mass or totalmuscfe mass and not to changes in cell metabolism. Two major problems occur as a result of this decline:
1. Body weight and, more significantly, body fat increase if eating patterns established at a younger age are maintained; and
2. The individual will be comfortable only in a very narrow temperature range.
SPECIFIC EXERCISES FOR THE OLDER IMMOBILE PATIENT*
SPECIFIC EXERCISES FOR THE OLDER IMMOBILE PATIENT*
An immobile state also causes a decrease in BMR.
There is a 20% to 25% decline in body strength due to decreases in both the number and size of muscle fibers, which result in a 20% to 25% decline in muscle mass. Burke, et al,9 reported that grip strength and grip strength endurance peaked in a group of normal males ages 20 to 24. After age 24, grip strength endurance appeared to have declined continually, with the rate of decline of grip strength sharpened after age 60. Their findings revealed that the grip strength and grip strength endurance of 75 to 79 year olds were comparable to those of 12 to 15 year olds.
Nerve conduction velocity declines by 10% to 15% in the older adult, which results in slowed transmission of impulses from the nerve to the muscle cell membrane and, consequently, slowed muscle contraction response. Immobility further decreases muscle contraction and contractures occur rapidly.
Tissue flexibility experiences a 20% to 30% decline in the older adult. Johns and Wright10 maintain that connective tissue changes in muscles, ligaments, joint capsules, and tendons are responsible for 98% of the loss of flexibility in the elderly. It is believed that the decline in flexibility is mainly due to lack of movement. The joints and muscles not normally used in the activities of daily living are more adversely affected. Therefore, the immobile patient develops muscle atrophy, contractures, and joint stiffness.
Another significant problem for aging females and males is bone loss. According to Smith, et al,11 the problem appears to be more severe for women, with a bone loss of 1% to 1.3% each year after the age of 30 to 35 and a loss of as much as 2% to 3% per year during the climacteric period. From these estimates we can conclude that many women lose 30% of their bone by age 70. Men, on the other hand, begin to lose bone at about the age of 55 at the rate of 0.4% per year and, thus, generally do not have significant problems until the age of 80. Immobility adds to the problem of bone loss in the form of disuse osteoporosis. Unless there is stress on the bones, calcium is absorbed into the circulation rather than used by the bone, which results in a greater chance of fractures and the formation of urinary calculi.
Kidney function, which plays a vital role in clearing toxic and waste products created by the body and drugs and other chemicals taken into the system, begins to decline by approximately 30% to 50% between the ages of 30 and 70 as reported in studies by Griffiths, et al.12 As a result of this decline, the acid-base balance control, glucose tolerance, and chemical and drug clearing ability are decreased.
As stated by Rossman,13 there is a total body water decline of 10% to 15% because of the decline in total cellular water. This means that the older adult dehydrates more rapidly when confronted with a hot environment, burns, or diarrhea. When planning exercise programs for older adults, therefore, water loss from evaporation and perspiration need to be kept in mind.
Along with decreased body water, increased body fat, and decreased integrity of the cardiovascular system, there is a delayed onset of sweating in the older adult. Because older adults are 20% to 30% less able to dissipate heat due to the 15% to 20% increase in fat content, they are more susceptible to heat stroke. When engaging in exercise programs, the older adult should not be exposed to direct sunlight. Cold environments also pose a danger because cold causes vasoconstriction which, combined with higher blood pressure, may overtax the heart and result in ischemia and possibly infarction during strenuous physical activity.
Beneficial Effects of Exercising
After reviewing the major effects of aging and immobility on the body, it is important to emphasize the benefits of physical activity in slowing the rate of the aging process and preventing complications in the immobile patient. Even though modern medicine has improved physical status, thereby enhancing daily productivity and increasing longevity, there are few longitudinal studies demonstrating the benefits of physical activity in the aging adult. Among the few who have demonstrated the benefits of physical activity in the aging adult over a 10 to 15 year period are Kasch and Wallace.14 Their study indicated that the 1% per year loss of cardiovascular function could be altered or prevented through regular physical activity. Following their efforts, Sidney and Shephard15 showed that the older adult who exercised 2 to 4 times a week improved in maximal oxygen uptake (or aerobic capacity) and general cardiovascular fitness. Earlier studies by deVries16 and Sidney and Shephard15 demonstrated that both the resting systolic and diastolic blood pressure declined significantly in the actively exercising older adult.
Moritani17 conducted a test in which he observed muscular strength through physical activity in both young (18 to 26 years) and old (67 to 72 years) subjects. After participating in an eight-week regimen of isotonic strength training, there was a significant increase in strength in both groups. However, the young participants exhibited both increased neural activity and muscle hypertrophy, whereas the aged subjects increased in neural function only.
Chapman, et al18 attempted to quanlítate the decline in flexibility in the aging population. They selected 20 subjects between the ages of 63 and 88 and 20 subjects between 15 and 19. The flexibility model used to compare the two groups was the index finger. The older subjects exhibited significantly greater joint stiffness (30%) than the younger subjects. This result was determined by the criteria of torque and energy requirement in passive oscillation of the index finger. It was found that, after a six-week training program, the older and younger subjects both demonstrated improved flexibility and a significant reduction in the torque requirement in flexibility movements. The younger group made no greater gains than did the older group, thus revealing that the older subjects showed:
1 . The same ability to leam movements necessary for improvement, and
2. The ability to reverse the trend toward becoming stiff and inflexible.
Although the cause of bone loss is multifactorial, physical activity plays an important part in bone maintenance. Gravity (or weight bearing) and muscle contraction are the two primary mechanical forces acting on bone. If either of these parameters is eliminated, reduced, or increased, as in the immobile patient, bone mineral content is changed. These changes have been demonstrated by studies of limb immobilization through casting, denervation, weightlessness, or loss of muscle function.
A six-month bed rest study in which three young men lost 39% of their calcaneus was conducted by Donaldson , et al.19 It was found that bone mass returned to normal after six months of ambulation. A similar finding was reported by Mack, et al,20 who reported bone mineral loss in the Gemini IV, V, and VII flights.
Mack, et al attributed the bone mineral loss to the decreased effects of gravity and muscular pull in the weightless condition. Richards21 proposed that the decreased activity levels of the aged play a significant role in the decline of bone mineral mass. It would, therefore, be reasonable to assume that bone loss is reduced in older adults through exercise.
In 1981 the Council on Scientific Affairs of the American Medical Association developed a summarized list of the proved potential clinical benefits of a carefully prescribed and supervised exercise program in elderly coronary heart disease patients.22 The list includes:
* Improved self-image and reversal or elimination of mental depression.
* Increased maximal oxygen uptake (aerobic capacity) associated with enhanced oxygen extraction by the trained muscle groups; lowered heart rate and systolic blood pressure, both at rest and for any given submaximal work load; and faster return of postexercise hemodynamic parameters to normal.
* Lowered serum catecholamine levels.
* Reduced adipose tissue and increased percent of lean body mass.
* Favorably altered concentrations of serum insulin, glycogen, triglycérides, and, possibly, coagulation factors.
* Increased ratio of serum high-density Iipoproteins.
* Improved digestion and less constipation.
Lawrence Lamb23 maintains that physical activity helps support the strength and functioning of the muscuIoskeletal system, including the involuntary or smooth muscles found in the wall of the digestive tract, those that contract or relax the pupil of the eye, and those that control the opening and closing of numerous body valves or sphincters. He stated: "It is possible that the level of physical activity is a significant factor even in maintaining optimal functions of the endocrine glands to provide life-giving hormones for continued youth and vigor." Proper physical activity eliminates adrenalin buildup accumulated through stressful daily events. If adrenalin remains in the heart, the heart will beat faster, and the likelihood of irregularities in that organ will be enhanced.
Regular, adequate exercise helps keep up the functional capacity of the lungs by requiring them to provide more oxygen. "With regular levels of physical activity, the blood-forming organs (bone marrow, etc.) produce the same amount of red blood cells the body destroys, thus keeping the number of red blood cells in fairly constant balance."
Kenneth R. Pelletier24 added these items to the benefits of exercising properly:
* Possible increased myocardial vascularity, including capillary density, coronary collaterals, and size of the coronary artery tree.
* Reduced blood coagulability and a transient increase in fibrinolysis.
* Increased cellular sensitivity in insulin, which reduces requirements at any glucose load.
General Exercise Guidelines for the Immobile Elderly
Before beginning a systematic exercise program of any kind with the immobile elderly, the patient's physician should give approval. The program must be devised so that injury or any ill direct or side effects will be avoided. Each person should be carefully monitored during the exercise program. Warning signals such as shortness of breath, loss of normal face coloring, labored breathing, light headedness, dizziness, or pain should be noted. Safety is a must at all times.
The exercises that are included in the program must be based on the specific needs of each individual. They should be pertinent, interesting, and varied. Where feasible and possible, exercises should be aerobic and employ the large muscle groups. Rhythmic activity of large muscle masses are encouraged. Music to accompany the exercises can help make rhythmic exercises, which increase strength, coordination, stamina, and flexibility, fun and relaxing.
The program should be organized so that exercises can be performed at least three to four days each week for the ambulatory person and daily for the immobile person. Each session should last 30 to 45 minutes and must be accompanied by an appropriate warmup and cool-down period. Each individual should give his or her best effort to the exercises, but should not be pushed beyond safe limits.
The combination of normal aging changes and immobility in the elderly often results in major complications, which can result in discomfort, pain, and even death. Keeping the body active through a specific exercise program will help to prevent these complications and result in an improved quality of life for older adults.
Almost every older person, even those confined to wheelchairs and beds, can tolerate and will benefit from a modified form of movement therapy. A number of simple exercises that can be used with older people are presented in the Figure.
- 1 . Cooper KH: Aerobics. New York, M. Evans &Co, Inc. 1968.
- 2. Hay flick L: The cellular basis for biological aging, in Finch CE, Hayflick L (eds): The Biology of Aging. New York, Van Nostrand Reinhold Co, 1977.
- 3. Smith EL, Serfass RC (eds): Exercise and Aging: The Scientific Basis. Hillside, NJ, EnslowPubs, Ine, 1981.
- 4. Sorensen KC, Luckmann J: Basic Nursing. Philadelphia, W.B. Saunders Co, 1979.
- 5. Shephard RJ: Physical Activity and Aging. Chicago, Year Book Medical Pubs, Inc. 1978.
- 6. Murray JF: The Normal Lung. Philadelphia, W.B. Saunders Co, 1976.
- 7. Niinimaa V, Shephard RJ: Training and oxygen conductance in the elderly: The respiratory system. J Gerontol 1978; 33(31:354-361.
- 8. Tzankoff SP, Morris AH: Effect of muscle mass decrease on age-related BRM changes. J Appi Physio! 1977; 43(6):1001-1106.
- 9. Burke WE, Tuttle WW, Thompson CW, et al: The relation of grip strength and grip strength endurance to age. J Appi Physiol 1953; 5(10):629-630.
- 10. Johns RJ, Wright U: Relative importance of various tissues in joint stiff ness. J Appi Physio! \962; 17(5):824-828.
- 1 1 . Smith DM, Khairi MRA, Norton J, Johnston CC: Age and activity effects on rate of bone mineral loss. J Clin Invest 1976; 58(5):716-721.
- 12. Griffiths GJ, Robinson JB, Cartwright GO, McLachlan MSF: Loss of renal tissue in the elderly. Br J Radial 1976; 49(3):111-117.
- 13. Rossman I: Anatomic and body composition changes with aging, in Finch C, Hayflick L (eds): Handbook of the Biology of Aging. New York, Van Nostrand Reinhold Co, 1977.
- 14. Kasch FW, Wallace JP: Physiological variables during 10 years of endurance exercise. Med Sd Sports Exerc 1976; 8(5):5-8.
- 15. Sidney KH, Shephard RJ: Perceptions of exertion in the elderly. Effects of aging, mode of exercise and physical training. Percept Moi Skills 1977; 44(3): 999- 1010.
- 16. deVries HA: Physiological effects of an exercise training regimen upon men aged 52-88. J Gerontol 1970; 25(4):325-336.
- 17. Montani T: Training adaptations in the muscles of older men, in Smith EL, Serfass RC (eds): Exercise and Aging: The Scientific Basis. Hillside, NY, EnslowPubs, Inc. 1981.
- 18. Chapman EA, deVries HA, Swezey R: Joint stiffness: Effects of exercise on young and old men. J Gerontol 1972; 27(2):21 8-221.
- 19. Donaldson C, Halley SB, Voge JM, et al: Effect of prolonged bed rest on bone mineral . Metabolism 1970; 19(12):1071-1084.
- 20. Mack P, La Chance P, Vose G, Vogt F: Bone demineralization of foot and hand of GeminiTitan IV, V, and VII astronauts during orbital night. American Journal ofRoentologv 1967; 100:503-511.
- 21. Richards M: Osteoporosis. Geriatric Nursing 1982; 3(2):98-102.
- 22. Council on Scientific Affairs of the American Medical Association: Physician-supervised exercise programs in rehabilitation of patients with coronary heart disease. J Am Med Assoc, April 10, 1981, p 1463.
- 23. Lamb L: Stay Youthful and Fil. New York, Harper & Row, Pubs, Ine, 1974.
- 24. Pelletier KR: Longevity-Fulfilling our biological potential. New York, Delacorte Press/Seymour Lawrence, 1981.
- Suggested Readings
- Harris R, Lawrence TF: Guide to Fitness After Fifty. New York, Plenum Publishing Corp, 1977.
- Saxon SV, Etten MJ: Physical Change and Aging. New York, Tiresias Press, Ine, 1978.
- Shephard RJ: Cardiovascular limitations in the aged, in Smith EL, Serfass RC (eds): Exercise and Aging: The Scientific Basis. Hillside, NJ, Enslow Pubs, Ine, 1981.
- Shock NW: Systems integration, in Finch C, Hayflick L (eds): Handbook of the Biology of Aging. New York, Van Nostrand Reinhold Co. 1977.