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Exercise is a form of medicine, which can prevent or treat many disabling or fatal diseases. Seventy percent of deaths (1.5 million) each year in the U.S. are from eight killers: heart disease, cancer, stroke, hypertension, chronic obstructive pulmonary disease (COPD), diabetes and osteoporosis. Other diseases treatable with exercise—obesity, arthritis, depression and dyslipidemia—contribute considerably to disability and premature death.
The United Nations, the World Health Organization and 37 countries, including the U.S., proclaimed 2000 to 2010 as the Bone and Joint Decade to promote the importance of a lifetime of healthy musculoskeletal structure. Slide 1
The number of people over age 50 will double between 1990 , who will want to maintain a quality of life as they age. Advances in medicine continue to make it possible for more people to live longer; however, musculoskeletal conditions and injuries account for about 102.3 million visits to physician offices, 10.2 million hospital outpatient visits, 25 million emergency department visits, 3 million hospitalizations and 7.5 million procedures—and altogether cost an estimated $300 billion. (USBJD, 2003)
Aging baby boomers, now in their 60s notice more aches and pains after performing the same activities, which were painless in their 50s . . . and hardly noticeable 20 years earlier. In 1978, Dr. Shephard of the University of Toronto pointed out, “Both aerobic power and muscle strength decline by as much as 10% for every decade of adult life, but a progressive exercise prescription can enhance function by 10 to 20%; thus, in terms of functional capacity, conditioning can reduce biological age by 10 to 20 years” (1978).
Early studies emphasized the least fit have the most to gain from exercise. In other words, the most striking reduction in mortality results when one becomes active and moves out of the poor fitness category.
The Institute for Aerobic Fitness in Dallas, TX, (1989) highlighted that people in the high-fitness group were only slightly less likely to die from chronic disease than those in the medium-fitness groups. This study shows that people benefit in proportion to their level of fitness. As in other studies, researchers found a “striking difference” in mortality rates between the least fit 25% and the next quintile of fitness. This observation concurs with the consensus that the greatest health benefits are achieved by increasing physical activity among the least fit (Mazzeo, 1998). Additionally, the study demonstrated a nearly linear reduction in risk with increasing quintiles of fitness. With each 1 MET—Metabolic Equalivant Task-hour; a MET is the caloric need per Kg per hour of activity divided by the caloric need per Kg at rest—increase in exercise capacity, there was a 12% improvement in survival. Participants whose exercise capacity was less than 5 MET were roughly twice as likely to die as those with exercise capacity of more than 8 MET.
Absolute exercise capacity measured in MET’s predicted risk of death better than percentage of age predictions. In both healthy participants and those with cardiovascular disease, peak exercise capacity was found to be a stronger predictor of death than risk factors, such as hypertension, diabetes, obesity, heart arrhythmia, high cholesterol and even smoking. Poor fitness proved to be the deadliest risk factor of all. Lead researcher Myers (2005) of Stanford University, told a national newspaper, “No matter how we twisted it, exercise came out on top.”
Exercise pays big dividends. It's even more important than smoking in its impact on life span. Greater fitness means longer life. What could be a bigger dividend than that? Doctors who don't encourage their patients to exercise are missing the boat. A summary of the message in accompanying an editorial quipped, “The data from the study compel the clinician to go beyond the identification of risk to the initiation of interventions, such as the prescription of increased physical activity and exercise in order to modify risk, particularly in patients with low levels of fitness.”(Mazzeo)
Miles Make A Difference: Research Review
A brief review of research will help emphasize the effects of exercise programs. The Honolulu Heart Program study examined 707 non-smoking retired men of Japanese ancestry, enrolled at ages 61 to 81. (Hakim, Petrovitch, Burchfield, et al, 1998) When the men enrolled between 1980 and 1982 (then at ages 45 to 68), each had a physical examination. As part of the history, men reported the average distance walked each day to be 1.8 miles (2.9 km). In the first 12 years of follow up, there were 208 deaths—33 from heart disease, 19 from stroke, 68 from cancer and 88 from other causes. The death rate was examined according to whether men walked less than 1 mile, 1 to 2 miles, or more than 2 miles a day. There were no significant differences between the three walking groups in terms of cholesterol, HDL, weight, hypertension, diabetes and diet or alcohol consumption. Slide 2
After 12 years, walking patterns were checked, confirming that men, by and large, maintained their walking patterns. The findings: The less men walked, the more likely they were to die. The reduction in mortality came not just from reduced heart disease or stroke, but also from cancer and other causes of death. The death risk in men walking less than 1 mile a day was 1.8 times that of men walking more than 2 miles a day.
Does the inverse relationship between physical activity or walking and mortality hold just for men in Hawaii? A comprehensive study of twins in Finland tells us activity has effects beyond genetics—for women, as well as men. The Finnish Twin Study examined the physical activity of 286 male and 148 female twin pairs, born before 1958. (Kujala, Kaprio, Sarna & Koskenvuo, 1998; p. 442)
Exclusions were chronic disease and deaths from injuries, suicide and homicide. After a comprehensive questionnaire, subjects were classified into three broad bands of physical leisure activity: Sedentary subjects (not participating in leisure time physical activity); occasional exercisers (participated in physical activity less than six times a month); and conditioning exercisers (exercising at least six times a month for a mean duration of 30 minutes with an intensity corresponding to vigorous walking or jogging). Slide 3
Overall the death rate between 1977 and 1994 was 12% for the sedentary, 7.4% for the occasional exercisers and 4.9% for the conditioning exercisers. Twin pairs discordant for death were examined to determine whether mortality of physically active subjects differed from that of their sex- and age-matched sedentary siblings. The result showed physical activity conferred a lower risk of death (odds ratio below 1) when compared with those who were sedentary in 1975—and adjusted for baseline smoking occupational group and alcohol use.
These
two studies demonstrate the benefit of cohort studies in
identifying risk factors. The direction and magnitude of
moderate exercise effects are similar in both studies: over 12
years walking two miles a day reduced the risk of death by half
in the Hawaiian study, while in Finland over 17 years moderate
exercise reduced the risk by 60%. Two different studies, in
different populations, using different cohorts, resulted in much
the same answer.
Myers and colleagues (2005) provide more evidence, regarding the relation between fitness and survival. The sample consisted of 6,213 consecutive male patients (mean [±SD] age, 59±11 years) referred to a clinical exercise-testing laboratory. These data differ from large cohort data drawn from population-based studies and data from subjects with a common medical condition in this way: The outcomes in subjects with cardiovascular disease are compared with the outcomes in subjects without cardiovascular disease within this large sample of men, who were tested for clinical reasons by a single group of investigators. Of this cohort, a total of 3,679 men with coronary artery disease, heart failure, peripheral vascular disease or an abnormal exercise test (angina, ST-segment depression, or both) were categorized as having cardiovascular disease; 2,534 men were found not to have cardiovascular disease. The end point of death from any cause occurred in 1,256 patients after a mean follow-up period of six years (average annual mortality, 2.6 percent).
After adjustment for age, analysis demonstrated the peak estimated exercise capacity achieved during the exercise test was the strongest predictor of death risk among patients with cardiovascular disease and those without cardiovascular disease. (Myers et al, 2005; Figures 1, 2 and 3). A nearly linear reduction in mortality was observed as fitness slides by Myers et al levels increased and each increase of 1 MET in exercise capacity conferred a 12% improvement in survival. Notably, the risk of death among those with a peak exercise capacity of less than 5 MET was nearly double the risk among those with a peak exercise capacity of more than 8 MET. The relative risk for those in the lowest quintile of fitness was four times that of those in the highest quintile of fitness, both among subjects with cardiovascular disease and among those without cardiovascular disease. Slide 4 Slide 5 Slide 6
According to subgroup analyses of patients with such cardiovascular risk factors as hypertension, diabetes, smoking, and obesity, those with an exercise capacity of less than 5 MET had a mortality rate that was about twice that among those with an exercise capacity of more than 8 MET.
Since exercise capacity declines by approximately 10 percent per decade after 30 years of age, the question became whether an evaluation of fitness relative to that expected for the patient's age was a better predictor of death than an absolute measure of fitness. (Elrick, 1992; pp.143-145. They found that the absolute peak exercise capacity outperformed the percentage of age-predicted exercise capacity for both those with cardiovascular disease and those without cardiovascular disease. One might expect to find a difference between the risk of death predicted by the absolute level of fitness and the risk predicted by the age-related level among subjects older than 65 years of age because exercise capacity is generally lower in elderly persons. No difference was found, although the number of subjects over 65 in this cohort may have been too small to allow the investigators to detect a difference.
Thus, Myers, et al can place valuable and readily applicable conclusions on the desk of the clinician. Absolute fitness levels as determined by an exercise test represent a continuum of risk (i.e., greater fitness results in longer survival). Fitness levels are important predictors of survival in persons with and without cardiovascular disease, as well as in those with specific cardiovascular risk factors, whether or not they are taking beta-blocking drugs. (pp. 796-8).
In 1998, the American College of Sports Medicine issued its first Position Statement on Aging and Exercise, which recommended strength training for frail older people. In part, the statement read , “We now know that older patients can perform to very high levels, so exercise prescription does not differ for older and younger persons, and training effects for the elderly can exceed those of younger people at the upper end of VO2 max (xxygen per cc/kg/min).”(Petrella)
The health rewards of exercise extend far beyond its benefits for specific diseases. Exercise reduces blood clotting, enhances self-image, elevates mood, reduces stress, improves appearance, increases energy and gives the feeling of well-being (probably by stimulating endorphins). Exercise reinforces other positive lifestyle changes, including healthier eating habits and smoking cessation. (Elrick, 1991) It also stimulates creative thinking. (1992, p.16) Furthermore, the ability of exercise to restore function to organs, muscles, joints and bones is not shared by drugs or surgery. Paradoxically, conventional medical practice favors physical rest and inactivity during recovery from illness.
Aerobic Exercise vs. Resistance Training
For many years, doctors have advised middle-aged and older people to get plenty of aerobic exercise—that is, exercise requiring rhythmic movement of their arms and legs. This form of exercise (including walking, jogging, swimming, bicycle riding and so on) has always been thought to be the best exercise to help prevent and/or treat heart disease. Doctors have traditionally discouraged people with heart disease or older people from engaging in strength training with weights or exercise machines because they believed that this would put dangerous stress on their hearts.
Recently, an expert panel of scientists, organized by the American Heart Association, has finally put to rest the age-old myth that weight training and other forms of resistance exercise are bad for the heart. In fact, this committee advised doctors to actually start recommending this form of exercise for their healthy older patients, as well as those with heart disease, including some people with recent heart attacks, provided they are closely monitored and supervised by experienced health professionals.
Aerobic exercise and resistance training clearly work hand-in-hand to prevent, reduce or even eliminate heart disease by preventing or controlling diabetes, high cholesterol and high blood pressure. Aerobic exercise does a great job lowering systolic blood pressure; both aerobic and resistance exercise help reduce diastolic blood pressure. This makes it much easier for the heart to do its job of pumping blood throughout the body. Both forms of exercise also strengthen the heart muscle, making it work much more efficiently.
Obviously, this is great news. Now PCPs can encourage patients with healthy hearts, no matter what the age or gender—and encourage those with unhealthy hearts (under medical supervision) to start using resistance training along with their aerobic training as an integral part of their heart-disease prevention and/or treatment program.
Dr. Kenneth Cooper coined the term aerobics in a book by the same name, Aerobics. (1968) A long-time advocate of aerobic exercise, Cooper now believes a mix of aerobic conditioning and strength training is the best exercise program for aging adults. He proposes an “aerobic-strength axis” with the balance changing, depending upon age. At age 40 and younger, he suggests 80% aerobics and 20% strength; age 41 to 50, 70/30; 51 to 60, 60/40; and at 61 and older, 55/45. Slide 7
Although Cooper still favors aerobics, the bias practically
disappears after age 60. “A good rule of thumb,” says Cooper,
“is that you should always include at least 50%
aerobic/endurance work in your personal fitness routine,
regardless of your age and sports interest.”
As individuals age they need more strength training. In Regaining the Power of Youth at Any Age (1998), Cooper writes: “Up to age 50, people lose about four percent of their strength and muscle mass per decade. After that, the loss increases to about 10 percent per decade. By age 60 the average man will have lost about one third of his muscle mass—unless he makes an effort to reverse the process through weight training.” Women have a similar decline as they age.
Cooper still leans toward aerobics because he believes the supporting evidence at this time is stronger. He cites a number of impressive studies showing endurance training slows the steady erosion of oxygen uptake capacity with age, which appears to occur for both trained and untrained individuals. He cites one study, which indicates it may even be possible to stop the decline with hard-consistent training. That study, reported in the Journal of Applied Physiology, followed a group of track athletes, age 50 to 82, who remained highly competitive for 10 years. Results? Their aerobic capacity remained unchanged during the entire time.
Chronic Diseases: Benefits From Exercise
Cardiovascular Disease
Coronary artery disease (CAD) is responsible for 2,000 deaths in the U.S. each day. About twice as many heart attacks occur every day. CAD claims many people who are at the peak of their career. Despite this discouraging mortality, exercise combined with diet therapy can reverse established heart disease. Furthermore, exercise improves heart function, reduces several coronary risk factors (hypertension, high cholesterol, low high-density lipoprotein/HDL cholesterol and obesity), enhances psychosocial well-being after a heart attack and improves survival. Exercise combined with diet therapy can reverse established heart disease. (Lavie, Milani & Littman, 1993, p. 679;Malloy, 1993, p. 478-479; Franklin, Gordon & Timmis, 1992, p. 1427; Ornish, 1991, p.164; Monsen, 1991; Blumenthal & Wei, 1993, pp.325-30) Slide 9
Numerous studies present evidence, relating exercise to improved cardiovascular disease, but few include women. Moreover, few of those have examined the effect of the most popular exercise for women: walking. A new study from the USA finds that walking, in a large number of older women, rights that wrong, and shows that walking is a good thing, especially in the presence of cardiovascular disease.
Women's Studies
A women's health observational study involved 73,700 women, ages 50 to 79 at entry enrollment, between 1994 and 1998. Of these, about 62,000 were white; 5,600 black; 2,800 Hispanic; 2,300 Asian; and 1,300 American Indian or other racial background. Observations continued to mid-2000. Women were free of cardiovascular disease and cancer at baseline. There was an average of 3.2 years of follow up, giving 233,000 person-years of observation. There were 345 newly-diagnosed cases of coronary disease, 309 strokes and 1,551 first cardiovascular events. The range of total weekly energy expenditure was from 0 to more than 33 MET-hours/weeks. Slide 10
There was a clinic visit at enrollment, during which self-administered questionnaires were completed about personal and family medical history, smoking, diet, physical activity and other lifestyle factors. Height, weight, hip-and-waist circumference and blood pressure were measured. The questionnaire on recreational physical activity was detailed and used to calculate a weekly energy expenditure score in metabolic equivalents (MET-score). A sample of 1,092 women entered a reliability study to demonstrate the reproducibility of the assessment questionnaires.
The primary endpoints were newly diagnosed coronary heart disease (nonfatal myocardial infarction and death with a coronary cause) and total cardiovascular events (myocardial infarction, death from coronary cause, coronary or carotid revascularization, angina, congestive heart failure and stroke). All endpoints were confirmed from medical records by blind observers.
The age- and multivariate-adjusted risk of both coronary heart disease and total cardiovascular disease fell as the amount of exercise rose . The mean number of MET-hours per week in each quintile was 0, 4.2, 10, 18 and 33, respectively for quintiles 1 to 5. Similar reductions were seen for walking (0->17 MET-hours per week) and for vigorous exercise (0->210 minutes strenuous exercise a week).
Nurses Health Study
One
excellent source of evidence is the U.S. nurses' health study,
started in 1976, when about 122,000 female nurses in the 30 to
55 age group were enrolled. Questionnaires were filled in and
other information was collected in 1980, 1982, 1986, 1988 and
1992. This information has shown the relationship between folate
and multivitamin use, and reduced colon cancer incidence.
Slide 11
Every two years, nurses received thorough clinical examinations, which included blood pressure, fasting plasma glucose levels and mass index. Hypertension was diagnosed using the criteria of systolic blood pressure greater or equal to 160 mmHg, diastolic blood pressure greater or equal to 95 mmHg, or both, or use of anti-hypertensive medication. Detailed questions focused on health behaviors, such as exercise, smoking, alcohol consumption, leisure time exercise (exercising long enough to sweat for 30 minutes or more), and duration of the walk to work. Exercise was classified in two ways: (1) broadly into less than once a week and at least once a week; and (2) more sensitively into less than once a week, once a week and twice or more a week.
The primary endpoint was coronary events defined as nonfatal myocardial infarction or death due to coronary disease, occurring after 1986 and before mid-1994. There were 645 coronary events. The physical activity assessed in 1986 was used as the baseline. Information was grouped into quintiles of MET hours per week, with about 14,000 to 15,000 women in each quintile. The distribution of physical activity between the quintiles is shown in Figure 1. For instance, the mean of 15 MET hours per week in quintile 4 implies that a woman would walk briskly for about four hours per week. Women in the high MET quintiles were less likely to smoke, were leaner and had lower prevalence of diabetes, hypertension and hypercholesterolemia than those in the lowest quintiles.
When adjustment was made for these factors, there remained a significant association between higher levels of total physical activity and reduced risk of a coronary event. (Figure 2) There was a 3% reduced risk for the highest total activity quintile. In women with no vigorous exercise, brisk walking had a similar effect on reducing the risk of a coronary event. (Figure 3) Using women who walked at a casual or easy pace as a baseline, women who walked briskly reduced their risk by 36%. Compared with sedentary women, women who walked briskly for one to three hours a week had risk reduced by 30% (95%, Confidence Interval 5% to 49%) after allowing for other factors.
Mild-To-Moderate Heart Failure
People with heart failure experience breathlessness and restricted activities of daily living because of their restricted heart capacity. They tend to reduce their amount of exercise, which can further reduce fitness, making their symptoms worse. A review of the literature found short-term trials of exercise training in people with mild to moderate heart failure only.
Meta-analysis of 20 random controlled trials (RCTs) by Rees & others (2005) revealed exercise training significantly increased VO2 max 2.16 ml/kg/min (95 per cent CI). This proved to be even more for programs of greater intensity and duration in that exercise duration increased by 2.38 min (95% CI), work capacity was greater by 15.1 Watts (95% CI) and distance on the six-minute walk improved by 40.9 meters (95%). Slide 14
Other studies found beneficial effects of exercise on cardiac mortality and reduced hospital readmissions over three years of follow-up. (Nugent, Schurr & Adams, 1994; Shinton & Sagar, 1993); Wagenaar, Meijer & van Wieringen, 1990) Vigorous exercise in early adulthood confers considerable protection from strokes in later life. This effect is independent of other risk factors. Furthermore, exercise is essential for restoring function following a stroke—again, a benefit not shared by drugs or surgery. Exercise, particularly aerobic exercise improved people's fitness and quality of life without causing harm.
Hypertension
Substantial evidence shows that exercise is an effective treatment for mild and moderate high blood pressure and is a useful adjunct for the treatment of severe hypertension. (Marceau et al, 1993, p.2803-11; Arroll & Beaglehole, 1993, p. 1248-9; Yeater & Ullrich, 1992, pp. 429-36; Dunbar, 1992, pp. 250-5; Martin, Dubbert & Cushman, 1990, p.1560-7)
Many patients who adhere to a regular, specifically prescribed aerobic exercise program can reduce their blood pressure without taking drugs. Thus, they avoid the potentially toxic effects and considerable expense of long-term drug therapy. Drug and exercise compliance are reported to be similar. In two weeks after exercise stops, post-exercise blood pressure reduction in both normal and hypertensive patients disappeared. Slide 15
Moderate exercise, such as walking, is a recommended part of the treatment for hypertension, but does it reduce the risk for hypertension?
The Osaka Health Survey showed regular exercise can prevent hypertension in men. (Hayashi et al, 1999; pp. 21-26)
Just as importantly, it demonstrated exercise doesn't have to be every day . Once a week is as beneficial. This is an important message since many people believe exercise has to be taken several times a week to be of any benefit—and since the commitment is too great, they do none. Once a week is less formidable, more achievable and equally beneficial.
As part of the Osaka Health Survey, a sub-set of information looked at the association of physical activity with the risk of hypertension between 1981-1997. Taking part were a group of 6,017 Japanese men, with sedentary occupations, ages 35 to 60, with systolic blood pressure less than 140 mmHg, diastolic blood pressure less than 90 mmHg, normal glucose levels and no history of hypertension or diabetes at the start of the study. The physical activity was the time/duration of the walk to work (in minutes) and the weekly frequency of that walk. Leisure time exercise was a separate variable. They were followed for 16 years. Slide 16
As the walk-to-work duration increased, the risk for hypertension decreased. Men whose walk lasted 20 minutes or more reduced their risk by 29% (relative risk 0.71, 95% [CI 0.52 to 0.97]) compared with men whose walk lasted 10 minutes or less. Increasing the walk by just 10 minutes reduced the risk for hypertension by 12% (relative risk 0.88, 95% [C I 0.79 to 0.98]). The reason why the duration of the walk reduced hypertension was not identified, but it was not the case that participants with a longer walk to work had more active lifestyles (only 33%t of men with the longest walk exercised at least once a week and adjustments were made for leisure-time exercise in the analyses).
Of 6,017 participants, 626 men developed hypertension. Adjustments were made for age, body mass index, alcohol consumption, smoking status, leisure-time exercise, blood pressure and fasting plasma glucose level.
The frequency of exercise was categorized into three groups: exercise less than once weekly, once weekly, twice or more weekly. In this case, more was not necessarily better. Men reduced their risk by 35% when they exercised once a week and by 28% when they exercised at least twice a week, compared with men exercising less than once a week (relative risk 0.65 [95% C I 0.47 to 0.90], and relative risk 0.72 [95% C I 0.59 to 0.88, respectively]).Using the results of 4,410 men over 10 years (with 375 cases of hypertension), it was calculated that for every 26 men who walk 20 minutes or more compared with those walking 10 minutes or less, one case of hypertension will be prevented. For men who walked 11 to 20 minutes, the number needed to walk increased to 111 (compared with men walking 10 minutes or less).
Men who exercised at least once a week reduced their risk by 30%, compared with men who exercised less than once a week (relative risk 0.70 [95% C I 0.59 to 0.84]). The comparison was also made after four years since the men's leisure time exercise could change over the 16-year study. After four years, men who exercised at least once a week reduced their risk by 39%, compared with those who exercised less than once a week (relative risk 0.61 [95% C I 0.47 to 0.80]).
Recap: This large, long-term study gives us another good reason to walk or take moderate amounts of regular exercise. A daily walk lasting 20 minutes or more significantly reduces the risk of hypertension in men. For every 26 men who walk 20 minutes or more, one case of hypertension will be prevented. Alternatively, as little as 30 minutes vigorous exercise just once a week will also significantly reduce the risk. Furthermore, a key message from this study is that exercising more than once a week will not necessarily reduce the risk any further.
Diabetes
Exercise can prevent or delay the serious complications of diabetes—the vascular disease of the brain, heart, kidney, eyes and legs—which commonly occurs in diabetics who are under age 40. (Bell, 1992, p. 183-4; McCargar, Taunton & Pare, 1991, pp. 179-81; Armstrong, 1991, p.176)
The same benefits of exercise are seen in those who develop the disease in later life. Exercise improves the abnormal blood lipid pattern and reduces the high blood pressure common in people who have diabetes. In addition, exercise increases insulin effectiveness and sugar metabolism, thereby reducing insulin requirement. In turn, this reduces the risk of vascular disease. Elevated blood insulin has been implicated in the pathogenesis of arteriosclerosis.
The complexity of diabetes treatment requires a combination of methods to achieve healthy blood sugar levels and to prevent or reduce the serious complications of the disease. An exercise regimen, properly taught and followed, helps accomplish this goal and allows diabetic patients to lead healthy, active lives. Both vigorous exercise (e.g., running) and moderate exercise (i.e., walking) reduce the risk of Type 2 diabetes in women. The more exercise taken, the greater the risk reduction. Just over three hours a week of vigorous exercise reduces the risk by 46%. Just three hours a week brisk walking reduces the risk by 42%. In other words, a daily brisk walk of 30 minutes almost halves the risk of Type 2 diabetes in women. Slide 17
Seventy thousand (70,102) women, ages 40 to 65, from the U.S. Nurses' Health Study participated in an activity and Type 2 diabetes study. All women were free from diagnosed diabetes, cardiovascular disease and cancer at the start of the study in 1986. Information on physical activity was subsequently obtained by questionnaire in 1986 and updated in 1988 and 1992.
Physical activity was assessed by asking the average amount of time spent a week on several physical activities such as walking, running, or aerobics, ascertaining usual walking pace (easy/casual = less than 3.2 km/h; normal/average = 3.2 to 4.8 km/h; brisk = 4.8 to 6.2 km/h), and then calculating weekly energy expenditure in METs. Walking was defined as a moderate form of exercise, requiring an energy expenditure of 2 to 4.5 METs, depending on pace. Vigorous exercise, such as running or bicycling, was defined as an activity requiring 6 METs or more (a 6-fold or greater increase above resting metabolic rate). Results were categorized into quintiles of MET score, represented on a Likert Scale by 1 for the lowest activity to 5 for the greatest activity. An example of the MET for duration and type of exercise is 5 MET hours per week vigorous exercise scored the equivalent of 45 minutes per week; 5 MET hours per week walking was the equivalent of 1.5 hours brisk walking per week.
Every two years, each participant was asked if she had been diagnosed with diabetes. If so, she was sent an additional questionnaire on symptoms, diagnostic tests and hypoglycemic therapy to confirm the diagnosis, according to criteria set forth in the study. Cases were confirmed by an endocrinologist using medical records, unaware of the information in the supplementary questionnaires. During eight years of follow-up, 1,419 cases of Type 2 diabetes were confirmed.
As physical activity increased, risk of diabetes decreased. (Hu et al, 1999; pp. 1433-9)
Using the first quintile as a comparison at the lowest activity of lest than 20 MET, the reduced risk of diabetes across the other quintiles of MET hours per week from least to most activity was 23%, 25%t, 38% and 46%. Results were adjusted for age, smoking status, alcohol consumption, menopausal status, parental history of diabetes, history of hypertension and high cholesterol level. After further adjustment for body mass index, the reduced risk across the quintiles was 16%, 13%, 23% and 26%.
Hu and others also compared sedentary women (less than 2 MET hours/less than 20 minutes per week) with active women (more than 10.4 MET hours/more than 1.5 hours per week) and found the active women had a reduced risk of 41%. In women whose only exercise was walking (using the first quintile as a comparison), the reduced risk of diabetes across the other quintiles of MET walking scores was 9%, 27%, 31% and 42%. Further adjustment for body mass index attenuated these risk reductions. Slide 18 Slide 19 Slide 20
Walking pace was also associated with risk for diabetes. After adjusting for time spent walking per week, compared with an easy walking pace, risk reductions were 28% for a normal pace and 9% for a brisk pace. After further adjustment for body mass index, the risk reduction was 41% for a brisk pace.
This large study gave impressive results. It provides yet another example of the tremendous benefits gained from just a little exercise, demonstrating that walking is just as beneficial as vigorous activities. Additionally, exercise improves the abnormal blood lipid pattern and reduces high blood pressure associated with diabetes. (Bell, 1992; pp.187-190)
Diabetes Education cites increased benefits of exercise training by increasing insulin effectiveness and the metabolism of sugar, which thereby reduces the insulin requirement and reduces the risk of vascular disease and subsequent pathology associated with arteriosclerosis. ( McCargar, Taunton & Pare, 1991, p.182; Armstrong, 1991, pp. 175-7)
Osteoporosis
Osteoporosis affects 20 to 24 million postmenopausal American women and an unknown number of men over the age of 80. It results in musculoskeletal weakness, loss of height, bone fractures primarily spine and hip and painful disability. In the U.S., 250,000 hip fractures occur annually, resulting in 12,000 deaths and $11 billion in medical expenditures.
A meta-analysis of 18 randomized controlled trails (RCTs) on different types of exercise programs showed a significant improvement in bone mineral density (BMD). Aerobics, weight-bearing and resistance training were all effective on BMD of the spine. (Hatori et al, 1993; pp. 412)
The WMD for the combined aerobics and weight bearing program on the spine was 1.79 [95% CI 0.58, 3.01]). The analyzed results showed walking was effective on both BMD of the spine 1.31 [95% CI 0.03, 2.65)] and the hip 0.92 [95% CI 0.21, 1.64]). Aerobic exercise was effective in increasing BMD of the wrist 1.22 [95% CI 0.71, 1.74)]. However, only one study reported exercise did not appear to prevent fractures during the first two years of exercise. (Chesnut, 1993, supplement; Inoue, Kushida, Kobayashi et al, 1993 S 166-8)
A meta-analysis of bone mass in women following exercise training was reported in Bandolier. The study treatment effect was calculated, which was the difference between the percentage changes in bone mass in one year in the training group minus the percentage change in bone mass in one year in the control group. A positive figure indicates a protective effect of exercise. There were 34 randomized comparisons and 19 non-randomized in training programs ranging from 6 to 24 months. The effects of training on bone mass at the lumbar spine in 552 postmenopausal women showed significant increase in the percentage of bone mass. (Hatori, Hasegawa, Adache et al, 1993;p. 411-13)
The overall treatment effect was a one-year percentage difference due to training of 0.79% for endurance and strength training programs. For 204 pre-menopausal women, there was only a 0.91% benefit. Slide 21 Slide 22
The bottom line from this review is that exercise training programs prevented or reversed bone loss of almost 1% per year, compared with the controls. The effects were consistent for the lumbar spine and the femoral neck. The variability in the results was seen mostly in the smaller trials; larger trials showed results consistent with the overall effect.
The result is important—yet, another benefit of exercise for women's health. Most of the exercises were somewhat more vigorous than a brisk walk, including treadmill walking and running, as well as some resistance and back strengthening exercise or aerobics. Taken together, these are also a useful teaching aid for critical appraisal dyslipidemia.
Abnormalities of blood fats (high total cholesterol and triglycerides and low HDL cholesterol) are major risk factors for vascular disease of the heart, brain, kidney, eyes and legs. Controlled research, however, shows regular exercise reduces total cholesterol and triglyceride levels and raises HDL cholesterol. (Hughes, Fiatarone & Ferrara et al, 1994; p. 820 -824; Nieman, Warren & O'Donnel et al, 1993, p.1340; Angelopoulos, Robertson & Goss et al, 1993, p.197-199).
Exercise training studies usually observe lower plasma TG concentrations. Large plasma TG reductions after exercise training are reported for previously inactive people with higher baseline concentrations, although subjects with low initial TG concentrations have smaller TG reductions after exercise training. (Franklin, Gordon& Timmis, 1992, p. 1428-9)
Exercise training studies do not support an exercise-induced change in total cholesterol. Rather, total cholesterol reductions are associated with body weight, body fat percentage and dietary fat reductions.
After eight months of regular exercise participation, and after three weeks of diet and brisk walking, subjects exhibited greater LDL particle sizes with lower LDL-C. Cholesterol was decreased in the more-dense LDL subfractions and increased in the less-dense LDL fractions; these changes correlated with TG reductions. Plasma lipoprotein(a) [Lp(a)], an LDL subfraction containing apo(a), is highly homologous with plasminogen and competes with plasminogen for fibrin-binding sites, inhibiting fibrinolysis. Lp(a) does not change after regular physical activity participation.
Exercise training longer than 12 weeks with good adherence is more likely to increase plasma HDL-C in a dose-dependent manner. Exercise-induced increases in HDL-C range from 4% to 22%, whereas absolute HDL-C increases are more uniform and range from 2 to 8 mg/dL. Findings show that exercise training without altered body weight and/or composition can increase HDL-C, augmented by body fat loss. HDLs can be divided into various particle sizes with the HDL3b particle directly related to CHD risk and the HDL2a, HDL2b particles associated with reduced CHD risk. Exercise training is usually associated with increased HDL2b and decreased HDL.
The impact of exercise training on apolipoproteins has been reviewed previously. Increased apolipoprotein (apo) A-I levels are observed, whereas apoB changes after exercise training usually parallel LDL-C changes.ApoE levels in response to exercise appear to be mediated by many factors,such as age and phenotype, with phenotype playing a strong role. Exercise training studies provide direct evidence of a possible interactive effect between apoE polymorphism and exercise training lipoprotein/lipid change. Greater TG decreases are found in apoE2 and apoE3 phenotype subjects, whereas greater HDL-C increases occurred only in apoE2 subjects after exercise training. Although not statistically significant, increased post heparin lipoprotein lipase (LPL) activity in apoE2 phenotype subjects supports exercise reductions of common CHD risk markers and the function of apoE in facilitating TG clearance.
In comparison with endurance training, less information exists to support resistance training as a modifier of plasma lipids. Studies are often contradictory, with some showing positive benefits of resistance exercise on the lipid profile and others finding no benefits. A decrease in body fat percentage and an increase in lean body mass after resistance training are associated with decreased total cholesterol and LDL-C. Both total cholesterol and LDL-C may be reduced after circuit resistance training. In most studies, HDL-C concentrations are unresponsive to resistance training, yet increases have been reported.
The magnitude of change found for lipid and lipoprotein/lipid concentrations after a single exercise session is similar to that seen after the completion of a longitudinal exercise training program. A measurable, beneficial effect on circulating lipids and lipoproteins/lipids may be expected after a single exercise session during which 350 kcal is expended, whereas trained kcal to elicit comparable changes. Lp(a) concentrations were not changed after short-duration exercise or longer-duration exercise sessions that required 1500 kcal of energy expenditure. To maintain beneficial lipid and lipoprotein/lipid changes, exercise must be performed regularly.
High-intensity exercise and high-energy expenditure that cause depletion of intramuscular TG stores are needed to increase muscle LPL synthesis and release. Increased plasma post heparin LPL activity usually is not found until 4 to 18 hours after exercise,but is reported for endurance athletes; LPL activity usually is increased after exercise training. Ethnic differences exist, with higher LPL values in white, but not in black men after 20 weeks of endurance training.
An inverse association exists between resting hepatic lipase activity and HDL2 cholesterol, but hepatic lipase is directly related to HDL3 cholesterol. In general, no changes in resting hepatic lipase activity are reported between inactive and active individuals. A single exercise session results in no significant hepatic lipase activity changes. Low cholesterol ester transfer protein (CETP) activity may provide an antiatherogenic effect by slowing hepatic HDL2 catabolism and decreasing the amount of plasma cholesterol-rich particles. Cross-sectional studies report elevated plasma CETP activity in physically active people, whereas longitudinal exercise training studies report decreased CETP activity. In addition, lecithin cholesterol acyltransferase activity is increased in physically active men but not after exercise training.
Current data support a favorable impact for exercise training on lipid and lipoprotein profiles. Because much is known about the mechanisms responsible for changes in plasma lipid and lipoprotein modifications as a result of exercise training, a comprehensive medical management plan can be developed that optimizes pharmacological and lifestyle modifications. Scientific investigations are focusing on the molecular basis for lipid and lipoprotein change as a result of various interventions (e.g., knowing a person's apoE genotype). Findings from these studies can provide a better understanding of why some people respond to exercise, whereas others do not. Information about the interactive effects between regular exercise participation and pharmacological therapy is lacking.
Obesity
The amount of body fat is a useful indicator of health and fitness, as well as an early warning signal of many serious diseases. Excess body fat is a risk factor for heart disease, hypertension, diabetes, many cancers (breast, prostate, colon, uterus, and gall bladder) and premature death from other causes. It appears that being overweight aggravates a wide spectrum of diseases and is also a handicap to getting a job, obtaining admission to a university and forming social relationships. (Stefanick, 1993, pp.364-90; Walberg-Rankin, 1992, pp.31-3; Miles, 1991,pp. 157-67)
The magnitude of the problem in the U.S. is greater than in any other country. Estimates of the number of overweight Americans range from 50 million to 200 million. The average American is said to have 20 to 30 pounds of excess body fat. (Lohman, Houtkooper & Going, 1997, pp.32-34; Lohman, Foche & Martorell, 1988, pp.56-80,161-6)
Daily, lifelong exercise is an essential strategy for achieving and maintaining optimal weight. Diet, though essential, cannot be relied on exclusively for successful weight loss and maintenance. (Tanaka, Nakadomo & Kitao et al, 1991, pp.119-23)
Villareal et al, 2006, in a small study (17)
looked at
the
effect of weight loss and exercise on frailty in obese older
adults.
The treatment group lost an average of 8.4% of body weight, compared with no weight loss in the control group, which was instructed to maintain usual diet and exercise habits (P=.001).
Fat mass decreased by a mean of 6.6 kg in the intervention group compared with a mean of 1.7 kg in the control group (P=.001).
The intervention group increased an average of 2.6 points on the Physical Performance Test _ a standardized measure of physical function _ versus a 0.1 increase in the control group (P=.001). Slide 25
Volunteers in the intervention group also significantly improved in strength, walking speed, obstacle course performance, and one-leg limb stance time (P<.05 for all).
Sleep Disorders
Three studies deal specifically with the benefits of exercise among older adults, depressed adults and post-menopausal women. Older adults: 48 people (average 62 years) were randomized into two groups, with 20 completing the exercise program and 23 completing the no-intervention control period. Adherence to exercise was high. Results showed initial sleep onset was about 27 minutes in exercise and control groups at baseline, falling to 15 minutes after 16 weeks of exercise. (Singh et al, 1997; p. 95)
Initial sleep duration was about six hours in exercise and control groups, rising to 6.8 hours after 16 weeks of exercise. Better exercise duration was associated with better night-time sleep and less daytime sleep. Slide 26
Depressed Adults
Eligibility for this study was based on a proper diagnosis of unipolar major or minor depression of dysthymia and over 60 years old, as well as aerobic exercise more than twice a week. The intervention was high-intensity progressive resistance training three days a week for ten weeks. The control was enrollment in a health education program without exercise training. Outcomes were standard sleep scales, measured before and after the intervention period, using sleep diaries and sleep quality indices.
Twenty-eight participants had an average age of 71 years, and adherence to the exercise program was high. (Martinsen, 1990; pp.380-8)
Exercise reduced the proportion of poor sleepers and more exercise participants reported improved sleep, compared with controls (Table 1). Six of 15 (40%) depressed adults in the exercise group reported improved sleep, compared with none in the control group. (King, 1997, p.35)
Though numbers were small, this implies a number needed to treat about 2.5 for one depressed adult to have improved sleep. (Stewart, McMullen & Rubin, 1994, p. 27; Smith, 1991, pp.271-8)
Actually, it may be better than that because two patients in the control group actually reported worse sleep.
Change in sleep quality at the end of the intervention for exercise and control groups
Improved Same Worse
Exercise (n=15) 6 9 0
Control (n=13) 0 11 2
Postmenopausal Women
Eligible women were post-menopausal, taking no hormone replacement therapy. Smokers and those with medical conditions where exercise was contraindicated were excluded. They were randomized to an exercise program or a stretching program. Exercise involved moderate aerobic exercise five days a week for a year, some at a center and some at home. Stretching involved a 60-minute low intensity stretching and relaxation session each week for a year.
Over a year of exercise or stretching made little difference to sleep-quality indicators, though stretchers used less sleep medication. (Two, 2003, pp.830-35)
Because the study was designed to assess morning versus evening exercise, an analysis showed that morning exercisers who exercised for more than 225 minutes a week had significantly less trouble falling asleep, while evening exercisers who exercised more than 180 minutes a week had more trouble falling asleep.
This is not been the whole literature on exercise and sleep. There are other studies, which may have included some exercise or other interventions; and there are certainly observational studies. Some of these also associate improved sleep with more exercise. (Kelley, 1998; pp.798-804)
The down side is there are not many trials of exercise for sleep. They are in people with different sources of problem, such as depression or postmenopausal. While they may be randomized, none could be blind. Just over 200 participants took part in these small studies, yet all show a consistent pattern of improved sleep measures with exercise.
It may be that some threshold of exercise is needed to obtain better sleep, or perhaps morning exercise is better than evening exercise, but some measures of improved sleep were consistently found. Exercise is good for the heart, weight, lungs and bones. Whatever the effect on sleep, it is going to do some good. So for those who have poor sleep and want to do something about it, a useful New Year's resolution might be to get in at least four to six hours of moderate exercise a week.
Cerebrovascular Disease
Vigorous exercise in early adulthood confers considerable protection from strokes in later life. (Nugent, Schurr & Adams, 1994, p.400; Shinton & Sagar, 1993, p. 6896; Wagenaar, Meijere, van Wieringen et al, 1990, p. 2-4)
This effect is independent of other risk factors. Furthermore, exercise is essential for restoring function following a stroke-again, a benefit not shared by drugs or surgery.
Alzheimers
Hendrie et al reviewed nearly 100 studies on factors, which may affect brain health. Iinvestigators at six centers and three institutes of the National Institutes of Health concluded the same lifestyle and demographic factors affecting cardiovascular health seem to have significant influence on the cognitive and emotional health of those older than 65.
“Based on our review of cardiovascular risk factors, the link between hypertension and cognitive decline was the most robust across studies,” said Hugh Hendrie, M.B., Ch.B., D.Sc., a professor of psychiatry at Indiana University School of Medicine here, who chaired the study committee.
Depression
Depression, the most common mental disorder in America, affects approximately 5% (about 12 million) at any given time. Psychologists have observed that walking or running has both physiologic and psychological benefits for people who are depressed. These forms of exercise reduce depression and anxiety, increase feelings of well-being, improve tolerance to everyday stress and improve the self-image of depressed patients. (Stewart, McMullen & Rubin, 1998, pp. 22-9; Smith, 1991, pp.271-79; Martinsen, 1990, pp. 384-8)
It is difficult to sustain depressed feelings while one is physically exercising. Furthermore, exercise stimulates the release of the “feel-good” hormones (endorphins).
One report (Smith) concluded that walking or running while talking with depressed patients was more effective than talking and listening to them in an office because (1) the walking approach is non-confrontational—the patient and therapist are side by side, looking ahead rather than looking directly at one another; (2) the talking is being done in a less threatening setting; and (3) the patient is actively experiencing life, rather than passively observing it in a chair. Slide 28
Fibromyalgia
Supervised aerobic exercise training has beneficial effects on physical capacity and fibromyalgia (FMS) symptoms. Slide 27 Strength training may also benefit some FMS symptoms. A mega-analysis reported in Cochran Review found tha16 trials involving a total of 724 participants were assigned at random to exercise intervention groups, control groups or groups receiving alternative treatment. Seven studies were high-quality training studies. (Busch, Schachter, Pelosa & Bombadier, 2005)
The four high-quality aerobic training studies reported significantly greater improvements in the exercise groups versus control groups in aerobic performance (17.1% increase in aerobic performance with exercise versus 0.5 increase in the control groups), tender point pain pressure threshold (28.1% increase versus 7.0% decrease) and improvements in pain of 11.4% decrease in pain versus 1.6% increase. Slide 29
Arthritis
In patients who have rheumatoid or degenerative arthritis, exercise improves endurance, strengthens muscles and increases joint flexibility and range of motion. These, of course, are benefits drugs or surgery cannot achieve. Slide 30
Exercise appeared to be as beneficial as treatment provided on a one-to-one basis. These are the conclusions from a meta-analysis of studies on the benefits of exercise on OA that was reported in the Cochran Review. (Busch, Schachter Pelosa & Bombadier, 2005, Issue 2; Fransen, McConnell & Bell, 2001. Slide 29
Seventeen studies provided data on 2,562 participants with OA of the knee. For pain, combining the results revealed a beneficial treatment effect of 0.39, while for self-reported physical functional beneficial treatment effect of 0.31. Group format programs appeared to be as effective as treatments provided on a one-to-one basis. Physical exercise can prevent disability in activities of daily living in older persons with OA..
Fitness Arthritis & Seniors Trial
There were 250 participants free of disability of daily living activities at baseline, with a mean age of 69 years and 6%t of whom were women. Compliance with exercise declined over time, with 85% compliant during the first three months, dropping to 54% at 12 to 18 months. Over the 18 months, 105 of 250 persons (42%) developed disability of activities of daily living. This was significantly higher in the participants in the attention control group. (53)
A Plan For Therapy
Each person should have an individualized lifelong exercise program designed to fit his or her lifelong situation and preferences The daily goal is to exercise for at least 30 to 60 minutes, making a conscious effort to do body movement throughout 16 hours of the day (i.e., doing household chores, working, shopping, gardening, running errands, visiting or socializing in an active manner). (Elrick, 1991; and Elrick, 1992, p.140)
The major form of aerobic exercise should be walking, running, cycling, swimming or cross-country skiing. Variety is an important part of the prescription: At least two, or preferably, three different activities are recommended; for example walking-running-tennis or walking-cycling-swimming. The choice of exercise should be guided by individual preference and previous experience. Walking and running are most often recommended because they do not require special training or skills. They are inexpensive, readily available, safe and suitable for doing alone or with others. The acronym DF ALIVE is helpful to guide a patient's exercise prescription: Daily, Fun, Available, Lifelong, Independent, Variety and Endurance.
Patient Evaluation
In recent decades, research has validated the effectiveness of regular exercise as a way to reduce and/or prevent age-related functional decline and reduce the risks of a sedentary lifestyle. (USDHHS, 1996)Most medical groups recommend regular physical activity. (USPSTF, 2nd ed)People over age 65 carry the highest load of chronic disease, disability and healthcare utilization. (King, Rejeski & Buchner, 1998; pp. 317-29)Though many of these problems are preventable, PCPs rarely provide their older patients with an appropriate exercise recommendation, which includes an individualized motivational message, a pre-participation evaluation to ensure a safe exercise program and a tailored exercise prescription. (Will, Demko & George, 1996; pp. 580-81)Office-based practitioners can complete a pre-participation evaluation during routine visits to identify healthy older patients, who are good candidates for exercise training. Healthy is defined as the absence of conditions, which would preclude participation in regular physical activity that can reduce the risk for certain chronic degenerative diseases and improve metabolic fitness, VO2 max and daily functioning. A follow up visit can be scheduled to complete laboratory and physical testing.
History
The first step in the pre-participation evaluation is to assess for contraindications to exercise testing and training and identify any risks or limitations relevant to the exercise prescription. An efficient screening questionnaire addresses previous exercise programs: present activity (frequency, duration and intensity); existing chronic or acute disease(s), especially chronic obstructive pulmonary disease, cardiovascular disease and extreme motor limitations because of severe arthritis; family history of cardio respiratory disease; and coronary artery disease risk factors. The history should also include a current systems review, risk factors that are possibly modifiable through exercise and a medication review to determine any potential interaction with exercise testing or training.
Though most of the risk of exercise-related morbidity and mortality is associated with preexisting cardiac conditions, contraindications to exercise testing and training are the same for older and younger adults. Absolute contraindications to formal exercise testing include recent electrocardiography changes or acute myocardial infarction, unstable angina, third-degree heart block and acute congestive heart failure. (Mahler, 1995; pp. 1-37)
Relative contraindications to exercise testing include elevated blood pressure, cardiomyopathies, valvular heart disease, complex ventricular ectopy and uncontrolled metabolic diseases.
Physical Examination & Lab Tests
The physical exam and laboratory tests focus on the patients' functional abilities and/or limitations. The average office-based evaluation takes about 20 minutes, although additional time is required if treadmill testing, bone mineral density scans or respiratory function tests are needed. The physical examination should include vital signs and cardio-respiratory and thorough musculoskeletal evaluation.
The American College of Sports Medicine (ACSM) recommends cardiac treadmill stress testing before commencing vigorous exercise; that is, exercise intensity greater than 60% of maximal oxygen uptake for men over age 40, women over age 50, and all older patients who have cardiac risk factors with or without symptoms (Mahler). A stress test is needed if the patient is older than 65 and sedentary.
Treadmill test, which can be used to estimate the patient's aerobic capacity, is useful for prescribing exercise intensity. If a treadmill test is unavailable, the Kasch pulse-recovery test can be performed in the office to give PCPs a general idea of a patient's functional and aerobic capacities. (Kasch, 985; p.1387)
The test is based on the principle that the better one's level of fitness, the sooner the heart rate returns to baseline after exercise. The patient's pulse and blood pressure are measured at rest and 1 minute after s/he has stepped up and down (with both feet and a 12-inch step), 24 times per minute for 3 minutes. (Kasch, Phillips & Ross et al, 1966; pp.558-60)
To help patients adhere to this pace, a metronome set to 96 bpm may be helpful. Respiratory function can be determined simply by measuring the patient's forced vital capacity and forced expiratory volume in 1 second.
The Exercise RX
Medical students spend a year learning pharmacology and receive instruction on drug prescribing throughout their education and clinical training. Often, the drugs they study will no longer be recommended by the time these student become licensed practitioners. On the other hand, medical students are not instructed on how to prescribe exercise, the best and most economical medicine of all.
Physicians need more training in how to make best use of this powerful therapy: exercise. Physicians and other PCPs can successfully encourage increased activity by handing the patient a written exercise prescription, along with printed advice on how to design a safe, enjoyable routine.
Prescribing exercise is like prescribing medications, surgery or other therapy. It is a thoughtful compromise between potential benefits and side effects. After careful consideration of these factors, the physician and patient reach an agreement on the most effective plan. Important considerations include the goal of exercise (e.g., osteoporosis prevention, weight loss, strength improvement, marathon training) and patient preferences. Expanding on current exercise habits is a good starting point because choosing activities the patient already enjoys improves adherence.
For maximum effectiveness in therapy or health enhancement, an exercise prescription must fulfill certain basic requirements: It must be a daily activity (7 days a week), it must be fun, pain free and not excessively fatiguing. And it must fit an individual's preferences. (Elrick, 1991 & 1992 p. 150).
The selected activities must be readily available, not distant or difficult to reach, and preferably be close to the home or workplace. The clothes, equipment and/or club membership associated with the activity must be inexpensive. Ideally, the activity should not depend on other people (team, class or partners), but should permit group participation if desired. And finally, the activity must be suitable for lifelong participation. Use the time-honored and recognized way to recommend exercise as therapy: your prescription pad. A local physical therapist (PT) can evaluate the current physical status as a bench-mark. The PT can supervise initial exercise and set up a daily program with the patient. Working with PT , together the physician can develop handouts to serve as guides for patients. At some point, the physician might even want to try out a program that the PT has developed. This will give the physician first-hand experience in working exercise into a busy schedule and increase credibility, recounging changes in the physician’s own fitness.
As physicians becomes more attuned to using exercise as treatment, they might find they are writing fewer referrals to PT and begin the exercise prescription with educational material or in-office referral to a health educator. Exercise guides can be attached to a prescription with a notation: Complete attached exercise program as recommended, follow-up visit in 4 weeks.
Often, insurance will cover evaluation visits to PT or health education as part of a treatment plan. Patients can choose individual or group exercise sessions once the initial evaluation is made. One-on-one sessions can supplement group programs or serve as motivational events.
Setting Goals With Patients
The ACSM recently published separate position statements on exercise for healthy adults. (Pollock et al, 1998; p. 975-7) and older adults (Mazzeo et al, 1998, p.991-1006). Kligman et al (1999, #11) have adapted these recommendations, combined with those from the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) into a helpful chart, outlining basic exercise prescriptions for a range of health and fitness goals. (Pate, Pratt & Blair, 1995, p. 402-7) Slide 31
Selecting Activities
The exercise prescription addresses the type, frequency, duration and intensity of physical activity for each fitness component. Though the type of exercise is often determined by available facilities and equipment, the patient's preference should carry considerable weight. For example, a patient who enjoys golf should be encouraged to occasionally substitute that activity for a treadmill and resistance training session.
Physicians should balance the benefits of each exercise mode with the patient's health goals and physical limitations, such as walking, bicycling and swimming provide excellent cardiovascular benefits, but the weight-bearing nature of walking provides a greater stimulus for bone mineral deposition than cycling or swimming does. On the other hand, swimming is better tolerated by patients who have joint limitations.
Cross-training is an effective compromise among several appropriate options. Patients can mix exercise modes within any given week or within a single session. Cross-training programs help prevent boredom, condition more muscle groups and reduce the risk of overuse injury.
As shared previously . . .
The major form of aerobic exercise should be walking, running, cycling, swimming or cross-country skiing. Variety is an important part of the prescription: At least two or preferably three different activities are recommended, for example walking-running-tennis or walking-cycling-swimming. The choice of exercise should be guided by individual preference and previous experience. Walking and running are most often recommended because they do not require special training or skills. They are inexpensive, readily available, safe and suitable for doing alone or with others. The acronym DF ALIVE is helpful to guide a patient's exercise prescription: Daily, Fun, Available, Lifelong, Independent, Variety and Endurance.
Medical practices that include adults, children and pregnant can use an Exercise RX. Working with each patient to identify goals is essential for compliance. Writing the prescription means the phyisician believes the patient needs exercise as therapy and provides documentation, recognizing that need. A physician’s office can develop a form to record progress and note goal achievement. As the physician becomes more attuned to exercise, patients will come to expect new and renewed prescriptions.
Determining Frequency, Duration & Intensity
Exercise variables can be manipulated to enhance compliance, but the dose-response relationship must be considered. Though exercising more often, longer or harder affords greater conditioning, the relationship between effort and outcome is rarely linear. The point of diminishing return is often reached even before patients approach levels that pose a risk of excessive fatigue or injury.
Surprisingly little exercise is required to meet the recommendations for disease prevention (CDC-NIH recommendations)59. Physicians and exercise physiologists often make frequency and duration recommendations at minimal and optimal levels, with instructions to perform the minimal exercise during the busiest weeks and meet the optimal criteria on all others.
Exercise intensity is always prescribed as a range (e.g., a target-heart-rate range of 120 to 145 beats per minute or muscle fatigue in 8 to 12 repetitions). Using an age-predicted target heart rate has limited value and is often misleading, especially as patients age because 70% to 85% of age-predicted maximal heart rate is often off by 15 to 20 beats per minute. Physiologic change occurs when the body is exposed to stimuli greater than it can currently handle, a concept called “teasing the physiologic threshold.” The concept is useful even in balance and agility training. Slide 32
Many patients underestimate their exercise capacity, considering physical activity to be uncomfortable, hazardous or medically unwise. However, Fiatarone et al demonstrated the safety and effectiveness of a strength-training program, even for nonagenarians. The quantity and load of the exercise were adjusted as function improved. Thus, the exercise prescription should involve monitoring or teaching patients to assess their own progress.
MET levels are useful for setting exercise goals. A list of common physical activities classified by intensity in METs is available. Practitioners can obtain a copy of this original comprehensive list to share with patients and customize exercise recommendations, according to the patient’s skill level and geographic location. Slide 33 Slide 34
The
Borg perceived exertion scale,
As function improves, increasing the intensity or duration of exercise should raise the challenge. In strength training, a common recommendation is to lift to muscle fatigue (inability to complete another lift while maintaining good form) in 8 to 12 repetitions. For older adults, 12 to 15 repetitions using slightly lighter weights may be more appropriate. Weight is increased when the patient can consistently complete 13 repetitions; then he or she repeats the process. The rate of improvement varies among individuals and may be slower in older adults. See Slide 35 Slide 36 Slide 37 Slide 38 for some suggestions of equipment you might consider using. The local YMCA usually has all of this equipment as well as trainers to help use them.
Medical Conditions
Older patients come to the pre-participation examination with an array of physical abilities and body compositions. Systematic evaluation, as in the reports below, help physicians quickly assess patients’ functional status and note what areas of the body need special emphasis and what medical conditions need to be considered in the exercise prescription. The keys to successfully motivating patients are professional support, regular assessments, new goals, self-control and social support.
Do Patients Need A Personal Trainer?
A trainer can be a valuable asset to patient exercise programs. They can teach proper form and technique, provide motivation, vary the exercise to avoid boredom, monitor the progress and provide constructive criticism.
Picking a trainer: The Big Three in certifications.
· NSCA—The National Strength & Conditioning Association (requires a college degree)
· ACE—The American Council on Exercise
· ACSM—The American College of Sports Medicine
The key questions to ask before hiring a trainer: How much time and effort is a patient willing to devote to getting back in shape? Once decided, there are two distinct types of training needed: weight training, which builds and strengthens muscles, and cardiovascular training, which burns off body fat and improves endurance and boosts metabolism.
As a beginner, great results come from weight training, two or three times a week and by performing two to four 30-minute cardio sessions a week. If equipping a personal gym, these pictures suggest some potential equipment.
Before hiring a trainer, there are several questions to ask. See Slide 39 for specific questions.
Exercise Prescription Case Studies: Medical Conditions
Older patients come to the pre-participation examination with an array of physical abilities and body compositions. Systematic evaluation, as in the reports below describing patients who visited a health resort, helps physicians quickly assess patients' functional status and note what areas of the body need special emphasis and what medical conditions need to be considered in the exercise prescription. The keys to successfully motivating patients are professional support, regular assessments, new goals, self-control and social support.
Patient 1 : 62-Year-Old Female
History. A Black 62-year-old woman has a medical history for osteoporosis without fractures. Her activity history includes walking.
Physical examination: Sub maximal exercise testing predicted the patient has a maximal aerobic capacity of 9.8 METs, which corresponds to a VO2 max of 34 mL/kg/min. The patient's body fat is 34%, which represents 40 pounds of fat weight and 78 pounds of lean body mass for her weight (118 pounds). Balance testing was not done.
Assessment.: This is a classic case of normal weight but “under lean” body mass. The low lean mass and bone mineral density suggest a need for aggressive resistance training. Her cardiovascular fitness level is excellent for her age and gender.
Exercise prescription: The patient's exercise prescription is modified to include interval training to further enhance cardio respiratory fitness and decrease her percent body fat. It is also recommended she work with a personal trainer 2 to 3 days per week to improve her overall strength, lean body mass and bone mineral density. She should do a series of 8 to 10 exercises of varying volume and intensity, along with site-specific exercises for osteoporosis. Balance and agility exercises are recommended to decrease her risk of falls and recreational activities of 4 to 5 METs with an agility component (such as tai chi and social dance) are recommended. Because of her osteoporosis, she is advised to avoid abdominal crunches and modify other abdominal exercises.
Identify a patient who might fit this profile, then consider how to write an exercise RX for that patient. What facilities might the patient use? List the goal developed.
Patient 2: 72-Year-Old Male
History: A 72-year-old man in for a skin lesion talks about his exercise program. He says that he exercised on his treadmill 6 to 7 days per week for 45 minutes at 4 mph, using a 4% grade some of the time. He had not included any strength training or flexibility training.
Physical examination: His upper- and lower-body strength had decreased from previous years; he had a decreased score in his flexibility rating, based on previous annual sit-and-reach tests. His body fat was 29%, which represented 51 pounds of fat weight and 125 pounds of lean body mass for his weight (176 pounds).
Assessment: His body fat was above the “basic health” classification and his lean body mass were on the lowest edge of ideal. This patient fit the profile reported by Pollock et al (1) of older athletes who do not include strength training in their fitness program.
Exercise prescription: The patient’s training was enhanced by adding a basic weight training program to improve strength and body composition. He was advised to start a home-based program of six to seven exercises, two to three days a week.
Identify a patient who might fit this profile, then consider how to write an exercise RX for that patient. What facilities might the patient use? List the goal developed.
Patient 3: Sedentary 65-Year-Old Female
History: A 65-year-old woman has medical history of | |