67: Determining the Appropriate Use of Exercise for Older Adults

Physical activity has a profound positive impact on health, chronic disease prevention, function, and fall prevention, especially for older adults; higher levels of physical activity have been linked to reduced morbidity and mortality. New evidence has emerged indicating the positive impact of physical activity on cognition and psychological health. Although physical activity has clear benefits to health and function, most older adults are not physically active or do not engage in activity at high enough intensities to obtain the noted health benefits. In fact, less than 10% of older adults meet the recommended guidelines for physical activity (ie, 30–60 minutes of moderate-to-vigorous physical activity per day, 5 or more days a week), accumulating only 5–10 minutes of moderate-to-vigorous physical activity per day.

Physical activity is not synonymous with exercise. Physical activity is “any bodily movement produced by skeletal muscles that results in energy expenditure,” whereas exercise, a subset of physical activity, is “planned, structured, and repetitive bodily movement done to improve or maintain one or more components of physical fitness.” Physical activity may not achieve the increased fitness levels that are often expected with exercise; however, physical activity can reduce the risks and complications of many chronic conditions and increase well-being if it is of sufficient intensity.

Multiple methods exist to identify the level of intensity of an activity. One method compares the energy cost of the activity to the energy cost at rest, assigning metabolic equivalents, or MET values to different activities. Estimates of the MET values are summarized in the Compendium of Physical Activities, and the level of intensity of an activity is based on its MET value. However, the Compendium was developed based on data from healthy adults. Because energy use may be more inefficient in older adults, the intensity based on the MET value may underestimate the intensity at which the older adult is working. For this reason, the best use of the Compendium in the older adult population is to create a hierarchy of activities that can be used to select gradually increasing energy-demanding activities, rather than using it to define the exact intensity of an activity.

Because MET levels may not be the best method to determine the intensity of an activity, other methods should be used to estimate how hard the older adult is working, such as heart rate, rating of perceived exertion (RPE), or the talk test. Using a percentage of the estimated maximum heart rate, traditionally calculated by subtracting the person’s age from 220, is a simple way to determine intensity. Moderate intensity is defined as 64% to 76% of estimated maximum, and 77% to 93% of estimated maximum is considered vigorous intensity. Using heart rate methods is not appropriate in the presence of conditions that alter the heart rate response to exercise, such as the use of β blockers, some pacemakers, and many atrial arrhythmias.

Another option is the Borg RPE scale. While participating in an activity, a person rates how hard he is working on a scale from 6–20. Moderate intensity activity would be rated in the 12–13 range.

Another simple, although informal, method for determining intensity level is the talk test. While exercising at moderate intensity, a person should be able to talk, but not sing. If the person can sing, the activity is light intensity; if the person can only respond with a couple of words before needing to take a breath, the activity is vigorous intensity.

The healthcare provider should assess medical safety for exercise and recommend modifications for different conditions. The provider should also give the older adult key recommendations for safe, unsupervised exercise and be involved in improving patient adherence to exercise programs. Many websites exist for both the patient and the clinician to use as resources (Table 67–1). The challenge for the clinician is to prescribe activity that is appropriate and feasible based on the individual needs of the patient.

The need to screen an older adult prior to becoming physically active is controversial. Most exercise screening guidelines focus on recognizing conditions that require modifications to activities (Table 67–2) and determining safety during exercise (specifically cardiac screening and contraindications to exercise); however, cardiac screening (ie, exercise stress testing) is difficult to perform for many older adults and uncovers a huge reservoir of silent cardiac disease of unclear clinical significance. Many older adults do not plan to undertake a vigorous activity program, and moderate activity may be associated with negligible accumulated cardiac risk because of the associated cardiac risk reductions. For healthy and asymptomatic older adults, standard recommendations and precautions are appropriate with no need for cardiac screening. Cardiac screening is also not necessary for sedentary older adults beginning a low- to moderate-intensity activity program, especially considering the risks associated with being sedentary are worse than the risks of being physically active. Discussion of the symptoms during exercise that may indicate an inappropriate response to activity (eg, chest/jaw/arm pain, excessive dyspnea, palpitations, etc) is sufficient for these groups. Individuals with known cardiovascular disease are at risk for symptoms during activity and would benefit from cardiac screening prior to beginning an activity program.

The very few contraindications to physical activity include recent myocardial infarction, unstable angina, uncompensated congestive heart failure, severe valvular heart disease, resting systolic blood pressure above 200 mm Hg, resting diastolic blood pressure above 100 mm Hg, and significant abdominal aortic aneurysm. Some acute conditions, such as major bone fracture, nonhealing lesion on a weight-bearing extremity, or febrile illness may transiently limit activity.

The exercise prescription is based on the individual’s current health and physical activity level. The prescription includes frequency, intensity, duration, and progression, as well as inclusion of warm-up, cool-down, different types of exercise (eg, aerobic, strength, etc), stretching, and safety precautions. Exercise frequency, intensity, and duration will vary depending on the type of exercise. Moderate intensity is often recommended; however, not all older adults will be able to perform moderate levels of intensity. An activity that is light intensity for one older adult may be vigorous activity for another older adult. The recommended duration of 30 minutes or more for aerobic exercise may be intolerable for more deconditioned older adults. Brief episodes of activity (ie, stopping before fatigued) several times per day can help build toward more sustained activity.

All programs should progress over time so as to induce a level of stress on the body that results in change to the tissues. Duration should be progressed toward bouts of activity that lasts 20–30 minutes before intensity is progressed. It can take weeks or even months to reach this goal in the older adult population. All activity should begin with a warm-up of somewhat easy activities that slightly increase energy demands to prepare the body for exercise. The cool-down after exercise is also important as it is the transition phase for heart rate and oxygen consumption to return to resting levels. Slower walking or biking are examples of appropriate activities for warm-up and cool-down. Stretching should be performed after the warm-up and/or during the cool-down. General safety guidelines (Table 67–3) should also be included in the exercise prescription.

Exercise can be performed in the community, within the healthcare system, or at home, and can be supervised or unsupervised. Advantages and disadvantages exist for each situation, and the best fit for each patient depends on the needs of that patient.

Most older adults have at least 1 medical condition that requires consideration when prescribing a physical activity program. Activities can be adapted to benefit specific needs or to avoid problems based on the condition (see Table 67–2). Many resources are available that provide specific guidelines and tips on how exercise prescription will differ for various diagnoses. Some older adults may appear independent in activities of daily living but have subclinical disability, demonstrated by reduced physical performance, requiring modifications to the exercise prescription.

The current public health recommendation for older adults is to accumulate 30 minutes of moderate-intensity physical activity on most days of the week; recommendations for the other types of exercise (strength, flexibility, and balance) are in addition to this recommendation. Physical activity can be easily incorporated into daily life—simple ideas, such as taking the stairs instead of the elevator or parking further from the entrance to a building, can increase physical activity. Cross-training promotes variability in an activity program, reduces boredom, and decreases risk for injury. Activities such as swimming and use of exercise equipment that requires upper extremity effort can complement lower-extremity activities such as walking or bicycling.

Exercise is a subset of physical activity. Multiple types of exercise exist, including, but not limited to, aerobic, strength, flexibility, and balance. The recommendations for aerobic exercise are typically considered to be the physical activity recommendations (ie, 30–60 minutes 5 or more days a week). Strength training to all major muscle groups is recommended 2 or more days per week, but not on consecutive days to allow for muscle recovery. Flexibility exercises should also be performed at least 2 days per week, and can be incorporated into an aerobic or strength program. For those older adults at risk for falls, balance exercises should be performed 3 times per week. Examples of the different types of activities or exercises for each of the categories are provided later in this chapter.

Older adults benefit from a prescription that includes all types of exercise, as all types are important for mobility and function. Major constraints on combined programs are time and fatigue; it is unrealistic for most older adults to undertake a program that demands hours of exercise each day. Some programs combine a mix of aerobic, strength, and balance activities into an hour-long session 3 days a week. The individual’s preferences and current level of health should dictate the details of the prescription (Table 67–4).

Aerobic

Aging limits peak performance of aerobic exercise, but not the ability to benefit from training. Unsupervised aerobic exercise is appropriate for healthy older adults who are able to walk steadily at a brisk pace. Supervised aerobic exercise is appropriate for persons who have clinical or subclinical disability and cannot exercise continuously at moderate intensity.

Some examples of aerobic activity include walking, jogging/running, biking, and swimming. Other activities can be considered aerobic exercise if done at a high enough intensity; activities such as dancing, golfing, gardening, vacuuming, cleaning windows, and mowing the lawn are just a few examples.

The major risk associated with aerobic exercise is a cardiac event, such as myocardial infarction or death; however, this risk has been described after participation in vigorous exercise. Participating in regular aerobic exercise improves many cardiac risk factors and subsequently reduces the risk of cardiac events during activity.

Strength

Aging is associated with loss of muscle mass and power but both are responsive to strength training in older adults. Strength training can be performed with weight machines, free weights, or using body weight for resistance. Weight machines offer safe ways to lift heavier weights and provide complex systems to control the rate of muscle contraction. Using free weights such as wrist or ankle weights, low-tech items such as elastic bands, or household items like milk jugs or tin cans will work for strength training. Bearing the weight of the whole body in standing, transfers, and walking or performing active range of motion exercises can be a strength training activity for many frail older adults. Examples of body weight exercises include repeated chair stands, wall squats, and step ups.

Strength training should be performed for all major muscle groups, including, but not limited to, the shoulders, arms, hips, legs, ankles, back, and trunk. The lower-extremity muscle groups are larger and more important for functional mobility and independence; however, upper-extremity exercises will induce a higher heart rate response. Initial durations may be much briefer than with lower extremity exercise, as many people tend to have more deconditioned arms than legs.

The major risks with strength training include muscle soreness and musculoskeletal injury. Completing the exercise in good form by moving in a smooth, controlled manner rather than shaking or jerking through the movement will reduce the risk of injury. Starting with a low number of repetitions and a low amount of resistance will also reduce the risk of injury. It is also very important to avoid holding one’s breath during strength training as it induces increased blood pressure. Key breathing guidelines are to start by taking a breath before lifting, exhale during lifting, and inhale during controlled release.

Flexibility

Flexibility decreases with age and can become significantly restricted with disease or disuse. Loss of range of motion affects mobility and function, and, in the worst case, can result in contractures that limit standing, walking, and reaching. Stretches should last 30–60 seconds and involve all major joints of the upper and lower extremity and trunk. The stretch should cause a sensation of pulling but not acute pain. To prevent injury, light to moderate activity to warm up the muscle before stretching for flexibility is advised. Contraindications to flexibility exercises include acutely inflamed joints, fused joints, and recent fracture.

Balance

Balance training is recommended for those older adults at risk for falls. The types of exercises and activities included in “balance training” are rarely defined in the literature, and there is little to no consensus on the frequency, intensity, and duration needed to induce benefits. Healthy older adults can improve balance through recreational activities that require displacement and recovery, such as dancing or tennis. Balance training for the very frail person involves movement practice in a seated position that requires displacement of the trunk and arms. Balance training in water allows patients to explore the margins of their ability to displace and recover without fear of injury, as falls are cushioned by the water.

Balance training requires progression of difficulty, making it inherently more dangerous than other types of exercise due of the increased risk of falling. Therefore, to reduce this risk, an older adult should only begin a balance training program after proper instruction by a health professional.

Recommendations exist for physical activity/aerobic exercise, strength, flexibility, and balance; however, these recommendations leave out an important aspect of physical activity in older adults—the timing and coordination of movement. Aging and disease can alter the timing and coordination of walking and subsequently reduce gait efficiency, resulting in older adults working harder to walk than they should be. Performing exercises to improve the timing and coordination of walking (ie, stepping and walking patterns with progression of difficulty) result in improved gait efficiency and subsequently improved walking ability. While the evidence for the benefits of this type of exercise is just emerging, it might be considered as part of an exercise prescription.

Another aspect of physical activity prescription that is often forgotten is that activity should be fun. Common barriers to exercise include the lack of motivation to participate in regular activity and the often boring and repetitive nature of many types of activity (ie, walking, jogging, bicycling, etc). Providing the older adult with examples of ways to make exercise fun, such as listening to music while performing the exercise or doing interactive video-based fitness activities, may be one way to increase participation and adherence.

Convincing an older person to exercise can be a formidable challenge. Modern civilization has created a living environment that, although immeasurably beneficial, reduces the need for physical activity in daily life. How to begin and adhere to an exercise program is an important aspect of prescribing an activity plan that should be discussed with all patients.

Prior experience, knowledge, and beliefs about exercise will influence attitudes and expectations toward exercise. An older adult is more likely to participate in physical activity if he feels confident in his ability to succeed and that the activity is safe and enjoyable. For many older adults, the opportunity to socialize during exercise is a key motivating factor. Identifying these important contributors to participation and adherence for each older adult will encourage the initiation and maintenance of an exercise program.

Progression

All exercise requires a minimum frequency, intensity, and duration to achieve gain by inducing moderate physiological stress; thus, exercise must include a plan for progression over time. Many sedentary older adults are unable to sustain a moderate intensity activity for more than a few minutes. For this reason, the exercise program often must begin with a gradual increase in duration before any effort to increase intensity is considered. A necessary and important part of the exercise prescription includes checking with the older adult as to how the program is going and if the frequency, intensity, or duration of the activities needs to be adjusted.

Adherence

Adherence to an activity program improves when an individual commits to personally meaningful and measurable goals, uses a self-monitoring plan such as a calendar to record exercise, receives specific feedback, and has access to support as desired from others. A physician’s formal recommendation to exercise, delivered as a prescription based on individualized risks and needs, increases motivation and adherence.

Physical activity positively impacts multiple aspects of life, and is beneficial to almost all older adults. Very few instances exist in which physical activity is contraindicated. Depending on the needs and preferences of the individual, physical activity programs can be performed in a supervised setting or unsupervised, incorporating all types of exercise. Providing an exercise prescription that is tailored to the individual, sets reasonable and attainable goals, and monitors the individual’s maintenance and progression of the activity program are key for initiation and adherence.