"All parts of the body which have a function, if used in moderation and exercised in labors to which each is accustomed, become thereby welldeveloped and age slowly; but if unused and left idle, they become liable to disease, defective in growth, and age quickly. "
- Hippocrates, 3rd century B.C.
In every health-care setting, nurses are seeing more and more elderly clients. The demographic trend responsible for this change is often referred to as the "Greying of America." If this trend continues, as it is likely to do by 2020, every fourth American will be over 65 years old. Nurses can help elderly clients improve the quality of their lives and prevent some of the physical consequences of aging by teaching them to incorporate exercise into their daily routine.
The prevalence of chronic degenerative diseases as the major health problem in our country has changed the quality of our aging years. Currently, almost 85% of America's 25.5 million elders suffer from at least one chronic degenerative disease which diminishes personal independence and vitality and drains our health-care resources. Exercise very directly causes changes which can delay the onset of clinical manifestations of many chronic diseases.
Before prescribing exercises for older adults, nurses must be familiar with physiologic and psychosocial changes related to aging. These changes are listed in Table 1 . There is no doubt that there is a deterioration of all physiologic functions with aging. The work capacity of the average sedentary person declines by 30% between the ages of 30 and 70. Many researchers believe that disuse or inactivity accounts for half of this change.'
A well-known study showed development of changes roughly equal to 30 years of aging in well-conditioned young men following 3 weeks of bed rest.2 Whatever the interaction between aging and disuse, changes in all physiologic systems are well documented.
PHYSIOLOGIC AND PSYCHOSOCIAL CHANGES OF AGING
These changes, coupled with a cultural expectation that we should "slow down and take a well-deserved rest" after retirement, have created a population of older adults which is much more sedentary than necessary, or even healthy. Conrand reports common beliefs held by older people about exercise including: 1) The need for physical activity decreases with age; 2) that exercise is dangerous; 3) that light sporadic exercise is beneficial to health and; 4) that their own physical abilities were limited.3 Keeping in mind the physiologic and psychosocial context of aging, nurses are now ready to examine exercise and its potential impact on these changes.
Physiology of Exercise
The three primary types of exercise generally needed in any exercise routine are endurance, flexibility, and strengthening.
Endurance or aerobic exercise provides the most cardiovascular and general health benefits. Sustained muscular contraction requires energy. During the first minute of any exercise, this energy is supplied via the anaerobic pathway using adenosinetri phosphate (ATP) or creatine phosphate (CP) for fuel. The stores of ATP and CP are depleted very quickly. Thereafter, oxygen is used to sustain muscular contraction. "Aerobic" means "using oxygen."
PROBABLE PHYSIOLOGIC AND PSYCHOSOCIAL BENEFITS OF EXERCISE
Any sustained muscular contraction or exercise requires more oxygen. An individual's maximal oxygen uptake defines their "aerobic capacity." Aerobic capacity is greatly determined by genetics, but may be increased 10% to 20% with training. Maximal oxygen uptake or aerobic capacity peaks at 15 to 20 years of age and gradually declines with age, with the average aerobic capacity of a 60-year-old man about 2A that of a 20-year-old man. Inactivity can decrease an individual's aerobic capacity by 20% to 25%. Most of the physiologic benefits of exercise discussed in the next section result from a program of ongoing aerobic exercise.
Flexibility or stretching exercises are essentia] before and after aerobic exercise. Before exercise, static and dynamic stretching serves to gradually increase body temperature, increase circulation and oxygen delivery to muscles, decrease blood viscosity, and make muscle contraction more efficient. The risk for musculoskeletal injuries is decreased with flexibility exercises during the warm-up period. Following aerobic exercise, flexibility exercises maintain blood flow to muscles, helping to remove metabolic wastes which lessen the incidence of muscle soreness after exercise.
Low-level exercise following vigorous aerobic exercise also prevents venous pooling in lower extremities. If vigorous exercise is stopped abruptly, without cool-down exercises, the heart may need to work harder to maintain cardiac output, the brain may be deprived of blood flow, and chest pain, dizziness, hypotension, or fainting may result.
Strengthening or conditioning exercises may also be incorporated before or after aerobic exercises. Though most aerobic exercise has some strengthening effects, specific exercises such as si tups, pushups, leg lifts, or weight training will strengthen specific muscle groups. This type of exercise is helpful in treating certain orthopedic problems, reversing the weakening effects of disuse, and improving the ability to do many activities of daily living.
EFFECTIVE AEROBIC EXERCISE
Physiologic and Psychosocial Benefits of Exercise
Table 2 summarizes probable physiologic and psychosocial benefits of a regular aerobic exercise program. Perhaps the most significant benefit of regular aerobic exercise is the reduction of the risk for cardiovascular disease. Paffenbarger and colleagues have reported lower death rates from sudden death and death from coronary heart disease in groups of San Francisco longshoremen and groups of Harvard and University of Pennsylvania graduates who had high levels of physical activity during a long-term study.3 Several studies are now available to document various physiological benefits of exercise in older adults, including a report by DeVries in 1970 involving 112 men aged 52-80 who participated in a 6- week exercise program of 1 hour of calisthenics and jogging, 3 times a week.2 Significant effects included increased oxygen pulse, increased minute ventilation, increased vital capacity, decreased body fat, increased work capacity, and decreased blood pressure.
Sidney and Shephard, and Dehn and Bruce both report improved VO2 max or aerobic capacity in active older adults.3 Sidney and Shephard further report that 85% of elderly participants in an exercise program report improvement in well being and a decrease in anxiety.3 Bassett also found some psychological benefits as well as increased flexibility in shoulder, knee, and hip joints following 10 weeks of nonstrenuous exercise for older adults.3 Kay leen Sager, who has conducted exercise classes for over 2,000 seniors over the past 7 years, finds participants reporting increases in strength, flexibility, mobility, and a sense of self confidence. Older adults who initially had trouble breathing, climbing stairs, and getting in and out of chairs and bed, began to regain their ability to perform daily tasks with ease.4
These studies show that regular exercise may decrease the risk of heart and blood vessel diseases, major killers of older adults, and directly address some of the psychosocial problems associated with adjustment to retirement and old age. Additionally, older adults with diabetes will find they can more easily regulate and reduce insulin requirements by engaging in regular exercise. Lastly, of particular importance for older women, exercise can help prevent osteoporosis and resulting fractures and orthopedic problems. Smith studied a group of 30 women with an average age of 84 years. The experimental group participated in an exercise program for 30 minutes a day, three days per week for 3 years, at an intensity of only 1.5 to 3.0 METs. The exercise group showed an increase in bone mineral content of 2.29%, while the control group showed a bone mineral loss of 3.28%. 5
Clearly, older adults have much to gain by exercising regularly. Nurses can teach their clients how to begin a safe and effective exercise program, and make a major impact on the health and well being of a significant portion of our society.
Exercise Prescription and Planning for Older Adults
The first step in beginning an exercise program for most older adults is an exercise stress test to be administered by their physician, usually using a treadmill or stationary bicycle. The client exercises by walking or cycling while his heart rhythm and blood pressure are continuously monitored. This test allows the physician to observe for signs of clinical heart disease, elicit any abnormal or adverse responses to exercise, and determine the appropriate exercise intensity prescription for each individual. Nurses should advise clients to check with their physician about the advisability of this test before beginning an exercise program.
To be successful, any exercise program must be effective, safe, and have some motivational appeal for the participant. To be effective and to achieve the physiologic benefits discussed earlier, an exercise routine must be of appropriate mode, duration, frequency, and intensity, (see Table 3) Aerobic exercise consists of any mode, or type of exercise which uses large muscle groups, and is rhythmic and repetitive. Examples are cycling, walking, jogging, rowing, swimming, dancing, cross country skiing, some racquet sports and team sports. Activities which usually don't meet these criteria include gardening, weight lifting, yoga, and golf. Weight-bearing activities are the most effective for prevention of osteoporosis.
Many older adults select walking as their aerobic exercise, as it is familiar, doesn't require special equipment or location, and is usually of adequate intensity for previously sedentary persons. The duration of aerobic activity should be a minimum of 20 minutes to achieve most physiologic benefits.6 Activities such as weight lining, which aren't performed continuously for 20 minutes, don't qualify as aerobic activity. The frequency of aerobic exercise, for maximal benefit, should be 3 to 4 times per week.6 Intensity of activity is measured by the oxygen consumption required to perform the activity. This oxygen consumption can be indirectly measured by the heart rate.
HOW TO STRETCH
Thus, when a person exercises to their maximal capacity on a treadmill, they are at their maximal oxygen consumption level, and are exhibiting their maximal heart rate. To achieve the physiologic benefits of exercise, most practitioners recommend exercising at 70% to 85% of the maximal heart rate.6 This is called the target heart rate. This exercise prescription can be determined individually, based on a treadmill stress test, or can be estimated if a treadmill test is not performed. As discussed, maximal aerobic capacity (and therefore maximal heart rate) decreases with age. The following formulas have been developed to estimate maximal and target rates:
220 - age = maximal heart rate
maximal heart rate x desired % = target heart rate
Thus, an exercise intensity prescription for a 60-year-old man would be calculated as follows:
220 - 60 = 160 bpm (maximal heart rate)
160 X .70 = 112 bpm (target heart rate)
160 x .85 = 136 bpm (target heart rate)
Target heart rate range is 112-136 bpm (70%-85% of maximal)
A 60-year-old man beginning a walking program would first be assessed by the nurse for gait, station, and balance, and a medication history obtained. Nurses should keep in mind that many cardiovascular medications affect the heart rate, particularly beta blockers and calcium channel blockers. Clients taking these medications will have target heart rates based on their exercise treadmill test which may be much lower than would be estimated by the above formulas.
If no neuromuscular problems exist, and the client is not taking cardiovascular medications, the nurse would instruct the client to walk for 20 minutes, checking his pulse after 10 minutes and again after 20 minutes. He should walk fast enough to generate a heart rate of at least 112 bpm. As he becomes more fit, he may increase the intensity of his exercise to generate a higher heart rate, but should not exceed 136 bpm.
Very sedentary individuals may not even achieve 70% of their maximal heart rate during the first few sessions. These clients should be encouraged to exercise at their own capacity, increasing the intensity each session with the short-term goal of reaching a 70% target heart rate.
In addition to 20 minutes of aerobic activity, clients should be instructed to include at least 5 to 10 minutes of warmup and cool-down exercises in their routine. The easiest warm-up and cooldown routine to begin with is to simply do the chosen aerobic activity at a slower pace before and after the 20minute exercise session. As discussed earlier, flexibility and strengthening exercises can be included before and after aerobic exercise for added benefits.
Anderson's book, Stretching includes a section with specific exercises for persons over 50 years of age (see Figure 1). Strengthening exercises should be performed bilaterally and should use both the primary movers (e.g. biceps) and the antagonist muscle groups (e.g. triceps). Many flexibility and strengthening exercises can be modified to be performed while seated in a chair, reducing the risk of injury for elderly clients with limited mobility or impaired balance.
Exercise programs for seniors must be safe as well as effective. Simple instructions by nurses can help seniors avoid injury while beginning an exercise program. Proper shoes with adequate cushioning and non stick soles are essential for most aerobic activities. By avoiding hard, uneven, or slick surfaces for walking or jogging, and avoiding the most violent or ballistic calisthenics, many injuries may be prevented.
Most seniors should also avoid weight lifting initially, unless they have participated in this activity previously, as individuals with decreased lean muscle mass are most prone to weight lifting injuries. Upper arm and isometric exercises cause dramatic hemodynamic changes and may need to be avoided for persons with certain cardiac problems. Any exercise routine which includes adequate warm-up and cool-down periods, proper stretching exercises, and is designed to progress slowly in intensity is less likely to result in injuries. Older adults also should be instructed to exercise in well-lighted and uncrowded areas without noisy distractions.
Lastly, an exercise routine must have some motivational appeal if seniors are to stick with it long enough to achieve the desired results. A program with incremental, achievable goals and a mechanism to measure progress is likely to encourage participation. Successful classes often use wall charts, individual records, or even computer programs to keep track of progress. Tshirts are always popular and can be awarded for different levels of achievement, or years of participation.
Programs should be individually tailored to the needs and interests of participants and should take into consideration cost and transportation constraints common to most older adults. Classes offered through a system which is familiar and trusted (e.g. hospital, doctor's office, senior center, etc.) often have more success in recruiting participants. Instructors should keep in mind that, unlike younger participants, older adults may respond best to routines which are fairly simple, repetitive, and predictable. New exercises must be taught slowly and added one at a time to the routine.
Perhaps of even greater importance, is the ongoing assessment of the participants' response to exercises, including monitoring for changes in balance, strength, and flexibility, as well as any symptoms of adverse responses like pain, dyspnea, dizziness, or irregular heartbeats. In group exercise sessions, a strong leader who is realistic about goals, gives clear simple instructions, and develops a trust relationship with participants, is likely to succeed.
I first met Max 15 days after his coronary artery bypass surgery, in the cardiologist's office where I worked. Max was a 68-year-old retired manager from a local timber milling company. He had no significant medical problems except hypertension which had been managed with Hydrochlorthiazide for about 20 years. He was 40 pounds overweight, his serum cholesterol was 275 mg/dl, and he had quit smoking 10 years ago.
Max had always been a very robust man, often going fishing and hunting with his co-workers from the mill. In the past 5 to 10 years, Max had gradually given up doing most of the outside work at home, and had only been fishing once this year. He had turned down all invitations for overnight hunting trips over the past few years. Though he never talks about it, Jean, his wife, thinks Max has been afraid he could not keep up with his friends.
Max had never complained of chest pains until a month ago when he experienced classic angina after playing catch with his grandsons at a family picnic. He refused to go to the emergency room that day, but over the next two days he had three more episodes of pain, the last one at rest. At his wife's insistence he came to the cardiologist's office and had a thorough exam including an EKG and treadmill test which showed significant cardiac ischemia. He was then scheduled for a cardiac catheterization and subsequent bypass surgery. Since Max had not had any permanent myocardial damage prior to his surgery, he had a smooth post-op course and was discharged in seven days.
As I interviewed Max and Jean about the possibility of Max enrolling in our 8-week cardiac rehabilitation program, I saw the potential for a regular, lifelong exercise program to not only return Max to his pre-op level of health, but indeed to a higher level of wellness than he had experienced in probably 10 years. A limited exercise test on a stationary bike showed that Max was able to exercise for 5 minutes at 60% of his maximal predicted heart rate with no symptoms except fatigue. He had no neuromuscular limitations and his blood pressure medication would have no effect on his predicted heart rate response to exercise. Max signed a consent to participate in the program and received written information about exercising safely, including instructions to eat only a light meal at least an hour before exercise, and to wear loose, comfortable clothing and sturdy shoes.
Three times a week Max came to class where he bicycled for 5 minutes at a very low level of intensity to warm up, then progressed from 5 to 20 minutes at a higher level, keeping his heart rate from 60% to 85% of maximal, and finished with 5 minutes of cycling at a lower level to cool down. We monitored his heart rhythm and blood pressure frequently during exercise. After learning to take his own pulse, Max began walking at home on his days off with the same 5 min. /20 min. /5 min. routine, checking his pulse halfway through and at the end. Jean accompanied Max to class in the beginning and walked with him on the days at home. During the 8 weeks of class. Max and Jean participated in educational sessions about lowering dietary fat intake and controlling hypertension with diet and exercise. They even helped organize a potluck dinner where all the cardiac rehab patients brought low fat, low salt dishes.
Though Max and Jean had not done much together since their kids left home, now I often see them walking together downtown, holding hands like teenagers. Max loved being out of doors, and gradually lengthened his daily walks to 3, 5, and even 7 miles with Jean at his side. After the 8 weeks of rehabilitation, Max and Jean joined a local YMCA exercise class for seniors, including people with a history of cardiac problems or a high risk profile for these problems. The class was very inexpensive and scheduled to fit in with the city bus schedule for those who didn't drive.
Three times a week they got together with about 25 other folks for strengthening and flexibility exercises, followed by 20 minutes of brisk walking or even jogging around the gym. A nurse was always in attendance to check blood pressures and assess for any ill effects of exercise. The instructor was an energetic young woman who loved older adults and knew a hundred ways to modify exercises so even those with arthritis could do them. She was always available before and after class to discuss individual exercise programs or to chat with the members of the class. She helped the group organize summer picnics, breakfast outings, spring hikes, and even designed a class T-shirt. Through this class Max and Jean found new friends, support for their new lifestyle, and a whole new realm of activities they could do together.
When I last ran into Max, a year after his surgery, he was within 5 pounds of his ideal weight, his cholesterol was down to 210, he was off his blood pressure medication, and was shopping for a new sweatsuit to wear in a 10-mile walkathon he was going to with his grandson. He had returned to doing some of the yard work at home, and he and Jean were planning a week-long fishing trip with a couple from the exercise class.
Nurses can significantly impact the quality of life and disability associated with many chronic diseases of older adults by teaching their clients to begin a safe and effective exercise program. By performing some form of aerobic activity for at least 20 minutes, three to four times a week, with appropriate warm-up and cool-down periods, older adults can look forward, not to years of disease and disability, but to years of increasing health and vitality.
- 1. Smith E. Gilligan C: Physical activity prescription for the older adult. The Physician and Sports Medicine 1983; 8:91-101.
- 2. DeVries HA, Drinkwater B. Fox SM, et al: Exercise: Getting the elderly going. Client Care 1982: October 15:67-111.
- 3. Holm K, Kirchoff KT: Perspectives on exercise and aging. Heart and Lung 1984: 5:519-524.
- 4. Sager K: Exercises to activate seniors. The Phvsician and Sports Medicine 1984; 5:144-151.
- 5. Smith EL: Exercise for prevention of osteoporosis: A review. The Physician and Sports Medicine 1982; 3:72-80.
- 6 . Larson EB , Bruce RA: Health benefits of exercise in an aging society. Arch Intern Med 1987; 147:353-356.
PHYSIOLOGIC AND PSYCHOSOCIAL CHANGES OF AGING
PROBABLE PHYSIOLOGIC AND PSYCHOSOCIAL BENEFITS OF EXERCISE
EFFECTIVE AEROBIC EXERCISE