Health Articles

Exercise programs should always be individualized. A written exercise prescription should delail Ihe recommended aclivity. including initial intensity, duration, frequency, and ways to increase activity as fitness improves. The prescription should include instructions lo slop exercising promplly and see a physician if ischemia-related symptoms develop (eg, chest pain, marked dyspnea, dizziness, claudication, or extreme fatigue). Patients should also be told to drink ample amounts of fluid and to refrain from vigorous aclivity in extreme heat and cold, Physicians should consult exercise physiologists or physicians or nurses in cardiac rehabilitation units il’they are uncertain about Ihe details of an exercise prescription.
Generally, jogging is inappropriate for older persons not already accustomed lo it. Walking, cycling, dancing, and swimming all provide excellent conditioning (aerobic or otherwise), with less stress on Ihe lower back. hips, knees, and ankles. Swimming is particularly heneficial in persons with painful joints. Physical activity should also be incorporated into a person’s daily routine. For example, using a shopping cart may enable a person to walk to stores rather than drive or ride, and taking stairs may be preferred to using an elevator.
Men and high-risk women should begin exercising in a supervised setting; low- or average-risk women may not require supervision. Medically supervised exercise programs can he found through hospital or cardiac rehabilitation programs, the American Heart Association, or senior citizen groups. Persons with a history of heart disease and those with abnormal stress test results who arc allowed to exercise should begin programs more vigorous than walking only under supervision. If no adverse effects occur after 3 to 6 mo, such persons may continue independently at the same intensity level.
Very frail elderly persons, those who cannol walk several blocks without difficulty, and those with cognitive impairment precluding reliable self-monitoring also should increase activity only under supervision. If musculoskeletal symptoms of overuse occur, the activity should be stopped or changed (eg, swimming instead of jogging) until the person is pain free. If injury or illness causes exercise to cease for > I wk, activity should be resumed at a lower intensity.
Exercise may be performed alone or with a group. Except for those who require supervision (generally provided in a group setting), either is appropriate. The social interaction of a group may provide psychologic support and facilitate adherence to the program. Selecting an activity the person likes, setting attainable goals, and providing encouragement and reinforcement during training and at follow-up visits also foster adherence.
With appropriate screening and individualized exercise prescriptions, regular physical activity can and should be incorporated into the lifestyles of older persons. Increased activity can bring major benefits in functional capacity, sense of well-being, and other improvements in health.

For aerobic conditioning, a program that produces a training benefit in sedentary elderly persons is based on heart rate reserve, which is calculated as maximal heart rate (MHR: 220 minus age in years) minus resting heart rate (RHR). A training benefit occurs when 30% to 45% of the heart rate reserve is added to the RHR. This is the target heart rate range, about 65% to 80% of predicted MHR, somewhat lower than Ihe 70% to 85%i of MHR recommended by Ihe American Hearl Associalion for aerobic conditioning in younger persons.
The target heart rate range fora70-yr-old with an RHR of 84 is calculated as follows:
220 - age = MHR
220 - 70 - 150
MHR - RHR = heart rale reserve 150 - 84 = 66
Figure 30% and 45% of heart rale reserve 30%. x 66 - 20         45% X 66 - 30
Add to RHR
K4
+ 20 = 104         84 + 30 = 114
Target heart rate range =  104 to 114
This method allows for variability in RHR. Persons who are not physically lit. who generally have a higher RHR and thus smaller heart rate reserve, require a smaller increment to achieve training benefit. This calculation may underestimate the true range, but taking a conservative approach and reassessing (he increase in range after a period of sustained training is belter lhan overestimating the range.
To calculate an exercise heart rate, the radial pulse is palpated in the first 10 sec after ceasing activity (exercise heart rates fall off very rapidly). The result is multiplied by 6, which should yield a rate within the calculated target range. Kach person should be laught to adjust, or titrate, the intensity of exercise. If the heart rate is below the target range, intensily should be increased; eg, a person who is walking should adopt a brisker pace. Conversely, if the heart rate is above the targel range, intensity should be reduced.
Initially, participants’ calculations of heart rate should be checked by a monitor or by a person skilled in performing such measurements. Because the pulse is measured for only a fraction of a minute, an error of a single beat is mulliplied sixfold.
Most studies show that an optimal Iraining benefit results from a 30-min period of increased heart rale three to four times a week. Lower-intensity exercise (50% lo 60% of MHR> may produce a training benefit if duration is extended. However, less frequent exercise is unlikely to improve fitness. Exercising more than five times a week increases Ihe risk of musculoskeletal injury; high-intensity exercise increases both musculoskeletal and cardiovascular risk, especially if the target range is exceeded. Participants should not exercise beyond the stress test intensity.
Initially, most sedentary persons arc unable to sustain a target heart rate for 30 min. A program should begin gradually, eg, by alternating 2 lo 3 min of exercise with 2 lo 3 min of rest over 15 min. Activity should be increased by 2 to 3 min/wk until a total of 30 min is reached. Then the exercise interval should be increased by 1 to 2 min/wk until Ihe target heart rate can be sustained for 30 min. For previously inactive persons > 75 yr. lower-intensity and more frequent but shorter periods of activity are advised. An appropriate goal would be 15 lo 20 min of walking
six limes a week.
The previously inactive or frail patient > 75 yr should use shorter intervals to build endurance (eg, alternate 30 sec of activity with 30 sec of rest) and increase Ihe aclivity intervals by 30 to 60 sec/wk as endurance improves. In those who are physically unfit, work capacity may be so low that aerobic conditioning occurs as the by-product of a program thai otherwise would produce no Iraining benefit. Clinical signs of improved aerobic capacity include a lower RHR and decreased perceived exertion. The distance walked in (> min can also be used to assess fii-ness: The patient is asked to walk a measured course (eg, up and down a 100-ft hall) for 6 min. As filness improves, the patient is able to walk farther during the (S-min period. Fitness also means strength. The frail elderly may benefit from very low-level, repetitive weight training, especially when it involves the lower extremities. Falls may be reduced or even prevented by incorporaiing strengthening exercises (ie, resistance or static exercise) into the routine tsee TABI.U 31-CI). Examples ol strengthening exercise include the use office weights (eg, 5 lo 10 Ib) and frequent repelition on Medex, Nautilus, or Universal types ol equipment.
Activity intensity is often expressed in metabolic equivalents, or METs {one MET is the oxyficn expenditure at rest, about 3.5 tnlJkg ojbody weight per minute). Maximal oxygen uptake (MET capacity) can be derived from stress test data. When the heart rate response is normal, 80% of MHR corresponds lo 70% of MET capacity. TABLE 31-7 shows the MET level of some common activilies.

Exercise sessions should begin with 5 to 10 min of gentle stretching and flexibility exercises for the neck, trunk, and limbs (eg. sitting stretches to reach the iocs; neck rotation; and hamstring, quadriceps.and lateral trunk slretches). The person should hold the stretch for 10 sec (just beyond what is comfortable) and refrain from bouncing (ballistic maneuvers); bouncing increases muscle tension by stimulating antagonist muscles. Light limb exercises should follow. Such warm-up periods decrease musculoskeletal complications and reduce myocardial ischemia during exercise.
Cool-down and flexibility exercises should be repeated at the end of the session; muscles tend to shorten during more vigorous exertion, and stretching lifter the workout decreases the risk of muscle cramps. When aerobic conditioning is contraindicated. stretching and range-of-motion activities can be prescribed either alone or before and after walking.

Symptoms and ECG changes occurring near maximal exertion are relative conlraindications to an exercise program. Unless the medical and family history suggests a high risk of coronary artery disease, activity may still be prescribed a! a lower heart rale, generally 75% of that at which abnormalities occurred, although initially the activity should be medically supervised.
ST segment abnormalities are most indicative of coronary disease when they occur with angina, arrhythmias, or an abnormal blood pressure response or at very low exertion. A pretest high likelihood of disease (history of symptoms or risk factors) also increases Ihe test’s positive predictive value. Patients who develop hypotension or significant ST segment depression during the first 3 min of exercise have a substantial risk of high-level (triple-vessel or left main artery) coronary disease and require prompt diagnostic follow-up. Exercise is contra-indicated until a definitive diagnosis is made and symptoms are appropriately treated.
TABLE 31-4 compares the cardiovascular responses to aerobic exercise in the elderly with responses in patients who have ischemic heart disease. Notably, neither group experiences a change or fall in oxygen uptake with submaximal exercise. However, training can bring about a rise in oxygen uptake during maximal stress. Submaximal stress testing is insufficient for assessing cardiovascular capacity.
Elderly persons who develop significant ST segment depression without chest pain or other symptoms, particularly at higher levels of exertion, are difficult to assess. For instance, 25% to 50% of abnormal exercise stress tests occur in asymptomatic older persons, particularly women; however, 25% to 45% of these abnormal lesl results arc normal when the test is repeated, or the ST segment depression resolves with conditioning. TABL.K 31-5 lists causes of false-positive tesl results.

True maximal stress testing is defined as reaching a plateau of oxygen consumption. Predictions from submaximal treadmill tests systematically underestimate (by 15% to 25%) maximal capacity in elderly patients, partly because of reduced mechanical efficiency in sedentary persons. Patients must adapt to the treadmill or bicycle ergometer before testing, and their ability to understand and perform ihc test should be assessed. Maximal heart rates in North American elderly populations may exceed those assumed in common VOjmax prediction nomograms, possibly because these populations arc in poorer condition than the European populations for whom the nomograms were developed.
Precise assessmenl of maximal capacity increases the accuracy of an exercise prescription. However, -r xh of elderly patients do not meel the criteria for maximal stress testing. Furthermore, maximal tests increase the risks of testing, particularly in those with impaired cardiovascular or musculoskeletal [’unction. Testing to 85% of age-predicted maximal heart rale equals or exceeds the level of exertion recommended in exercise programs for the elderly. ECG abnormalities occurring at less ihan 85% of age-predicted maximal heart rate identify those who should not exercise or who require medically supervised exercise. Indications for terminating an exercise stress test are listed in TABLE 31-3.

Graded exercise testing identifies a safe range for heart rale and blood pressure during exercise, whether or not the person has coronary artery disease. Patients without evidence of coronary artery or other cardiovascular disease do not require stress (esting if the planned exercise program consists of only walking. Stress testing is recommended for those who plan to do more intense exercise or those with a history of significant cardiovascular disease.
Maximal stress testing is not required, although patients should reach at least 85% of age-predicted maximal heart rate (see THE EXERCISE PRESCRIPTION, below, for calculation of maximal hear! rate). Either a treadmill or a bicycle ergometer provides a satisfactorily graded stress under continuous F.CG monitoring. Although treadmills use walking, which is a familiar activity, many older persons have problems with balance, particularly as speed and grade increase. The modified Balke or Naughton protocols are tolerated better than the Bruce protocol. Because bicycle ergometers allow the patient to sit and hold on to handlebars, they are appropriate for persons with gait or visual disorders. However, since cycling is less common than walking, local muscle fatigue may impede performance before an adequate heart rale is reached.
Patients should continue taking their usual medications, including digitalis or ^-adrenergic blockers, when testing. If heart rate and blood pressure are suppressed by medication, (he rating of perceived exertion (RPE) is used to gauge the patient’s graded exercise testing responses. The Borg RPE is one such scale (see TABLE 31-2). The patient rates his perception of overall effort according to the scale. Perceived exertion and heart rate together predict maximal capacity more accurately than heart rate alone, aiding fitness evaluation and the subsequent exercise prescription.
Submaximal values (eg. heart rate, blood pressure) achieved at a given work load can also be used to assess fitness and monitor Ihe effect of exercise. As fitness improves, the heart rate required to reach a given level of exertion falls. Some researchers have used RPEs to regulate exercise intensity; however, these ratings have not proved accurate in guiding hearl rale range at the lower work levels appropriate for older persons. One practical guideline: If a person is unable to talk comfort ably while exercising, he is probably exceeding Ihc anaerobic threshold (about 50% of Vozmax), ie, bui|ding an oxygen debt. The pulse should be checked promptly lo ascertain thai it is wilhin the training range (sec THE EXERCISE PRESCRIPTION, below).

Preexercise screening facilitates choosing an appropriate activity program for all except those for whom any physical exertion is an unwarranted risk. Some 10% to 43% of community-dwelling persons who volunteer to participate in unsupervised moderate exercise programs (ie, achieving 70% to 85% of maximal heart rale) are medically excluded and thus require a lower level of exercise. Reasons for exclusion include active coronary artery disease or clear risk factors, severe arthritis or other musculoskeletal disability, and uncontrolled hypertension or diabetes. Of these exclusions, 70% to 80% occur before stress testing.
Aerobic conditioning should not be an automatic exercise goal but is appropriate for many young-old and for those > 75 yr who have always been physically active.
Assessment should include previous and current activity; cardiovascular, mental, and metabolic status; balance; and gait stability. Subtle cognitive decline might limit a person’s ability to follow an exercise prescription, and sensory impairment or balance problems could predispose to falls.
The pertinent history should include the above areas, as well as respiratory symptoms, musculoskeletal complaints, and drug history (all medications as well as alcohol and tobacco use). Physical examination should focus on visual and mental status and on the cardiovascular, respiratory, and musculoskeletal systems, including range of motion. The patient’s walk should he observed, and functional capacity should be assessed by observing how far the patient can walk and whether the patient can climb stairs. If the history suggests a high-risk patient or if abnormalities occur with moderate exertion, then noninvasive tests such as exercise thallium scintigraphy, rest adenosine-thallium scintigraphy, or exercise echocardiography may help determine an appropriate exercise program. Nutritional status and weight should also be evaluated. Although individual health status and the availability of recent test results determine which tests are needed, in general laboratory tests should include a resting ECG, hematocrit and blood glucose studies, urinalysis, and any tests indicated by the history and physical examination. For many, an exercise stress test is not required.
TABLE 31-1 lists common drugs that may affect ability to exercise. Patients taking drugs that can cause volume depletion or orthostatic hypotension should have blood pressure and pulse checked while both reclining and standing. Patients taking diuretics should have potassium levels measured. p-Adrcncrgic blockers do not preclude regular exercise, but the blunting of exercise-induced tachycardia must be considered. Patients (aking these drugs must rely on their own sense of perceived exertion—see under EXERCISE STRESS TESTING, below.
Persons with diabetes need to be evaluated for metabolic control, particularly risk of hypoglycemia; as exercise increases, those taking insulin or oral hypoglycemics should be monitored for need to reduce dosage. Insulin must not be injected directly into muscle groups used in exercise; the increased blood flow may speed insulin uptake and precipitate hypoglycemia. For example, a walker or tennis player should inject the insulin subculaneously into the abdominal (issue.

The most serious adverse effects of exercise are cardiovascular, including sudden death. Although such sequelae arc rare, they usually occur in persons with decreased left ventricular function and myocardial ischemia. A survey of cardiac arrests occurring in cardiac rehabilitation centers showed a nonfatal arrest rate of 1/34,673 patient-exercise hours and a fatal arrest rate of 1/116,402 patient-exercise hours. No comparable data exist for cardiac arrests among community-dwelling elderly exercising in unsupervised settings. The risk of sudden death increases severalfold during vigorous exercise: however, at comparable exertion levels, those who exercise regularly are at lower risk than those who are sedentary. Since inactivity is an independent risk factor for ischemic heart disease, the relative risks and benefits of exercise in addition to loss of bone mass and muscle strength must be assessed
individually.
Possible injury from falls and other musculoskeletal complications should be considered. All active older persons should wear shock-absorbing shoes with traction soles (eg, running or walking shoes).
Proper warm-up, gentle slretching, and gradual onset of activity help prevent injuries. Most community-dwelling elderly are able to walk; walking, coupled with stretching exercises, is an excellent way to maintain function and reduce the risks of extreme inactivity.

Aging, especially in sedentary persons, is associated with an increase in body fat and a decrease in lean body mass. (The loss of muscle mass is sometimes called sarcopenia.) Exercise enhances weight control by expending more calories and suppressing appetite, but it is not a substitute for decreasing caloric intake in ihosc who are overweight. When exercise accompanies negative caloric balance, fat is lost and lean body mass is preserved as long as daily protein intake exceeds 1.2 gm/kg. Blood pressure declines independently of weight reduction. HDL cholesterol rises and LDL cholesterol falls. Persons with diabetes, particularly type II (non-insul in-dependent), may benefit from increased insulin sensitivity associated with exercise-facilitated uptake of glucose by
muscle.
Physical activity retards osteoporosis by slowing the rate of bone loss, but adequate dietary calcium (1 to 1.5 gm/day) is needed for healthy bone remodeling. Other treatments for osteoporosis may also be required (see Ch. 73). Increased muscle strength m;iy protect vulnerable joints (eg, quadriceps exercises improve knee function) and the lower back, thus enhancing overall physical ability. A strength-train ing program for the biceps, triceps, and quadriceps muscles in nonagenarians has resulted in increased muscle size and strength. Thus, age is not a contraindication to strength training.
Although the appropriate use of growth hormones and anabolic steroids has not yet been defined, they have been shown to increase muscle mass.. These drugs are most beneficial to persons whose plasma growth hormone or testosterone levels are low. However, studies that show a possible improvement in function (ic. slreng(h) are inadequate, and no conclusions have been reached about their effectiveness beyond increasing plasma growth hormone or testosterone levels.
Studies suggest thai perceived well-being and self-image improve with regular exercise, probably as a result of both social interaction and physical conditioning. Symplomatic improvement of depression and certain aspects of cognitive function, including reaction time, has also been reported. Anxiety (particularly its somatic manifestations) decreases, and sleep patlerns and bowel function may improve. Ultimately, drug therapy may be reduced in dosage or need.

Only 29% of (hose > 65 yr report doing any regular exercise, including walking. Aerobic capacity (usually limited more by cardiovascular than respiratory decline) is so low that even in healthy seniors (— 65 yr), carrying out activities such as making beds, doing light shopping, or dressing and undressing may use > 50% of the average person’s maximal capacity. Raising the maximal capacity by even !()% to 15% greatly improves functional ability and quality of life and prolongs independence. The very sedentary (ie, those who do not walk outside the house or exercise) achieve even greater benefit from a small increment in physical activity.
Hxereise goals differ among subgroups of the older population and from those of younger persons. In those > 75 yr, Ihe emphasis is on maintaining flexibility, strength, coordination, and balance, as well as aerobic conditioning. Aerobic or cardiovascular conditioning improves the ability of the heart and lungs Io supply muscles with oxygen and is best accomplished by walking, jogging, cycling, or swimming. To be effective, aerobic conditioning exercise must be sustained for at least 15 to 20 min at a time. Walking and range-of-motion exercises are appropriate for previously sedentary persons. In those 65 through 74 yr and those i: 75 who have remained physically active, exercise may also include moderate aerobic conditioning. Physicians should prescribe activity based on a patient’s previous exercise experience, current activity, general physical condition, and medical history.