C H A P T E R 19

1. C H A P T E R 19 PRESCRIPTION OF EXERCISE FOR HEALTH AND FITNESS

2. Learning Objectives w Find out how physically active American adults are in relation to the medical community’s recommendations for fitness. w Review the importance of receiving medical clearance before undertaking an exercise program. w Learn methods of testing fitness levels via exercise tests. w Review the components of a sound exercise program. w Discover how to become more active and gain the benefits of regular exercise.

3. National Problem More than 60% of American adults are not regularly physically active; 25% of all adults are not active at all. Nearly 50% of American youths 12 to 21 years of age are not regularly vigorously active and physical activity declines during adolescence.

4. Kenneth Cooper, M.D. Founder of the Cooper Institute and author of the book, Aerobics, in 1968, which is credited with starting the “fitness revolution” in the U.S.

5. Surgeon General: Physical Activity and Health Published in 1996, recommendations included the following: w People of all ages, male and female, benefit from regular physical activity. w Thirty minutes of moderately intense exercise (e.g., 30 minutes of brisk walking) on most, if not all, days of the week can improve health. w Additional health benefits are gained with maintaining a regimen that is greater in volume and intensity.

6. Importance of Medical Clearance w Provides opportunity to check for early stages of disease w Helps identify those with risk factors w Helps develop an appropriate exercise prescription w Helps motivate to know your current blood pressure, body fat, and blood lipid values w Provides a baseline for changes in health

7. Who Must Receive Medical Clearance? w Men over 40 w Women over 50 w Anyone, any age, who has two or more risk factors for CAD or symptoms or signs of cardiopulmonary disease

8. Components of a Medical Clearance w Coronary artery disease (CAD) screening w Physical examination w Exercise ECG

9. • Pain or discomfort in the chest, neck, jaw, or arms • Shortness of breath at rest or with mild exertion • Dizziness or syncope (fainting from reduced blood flow to the brain • Orthopnea (inability to breathe except in upright position) or paroxysmal (sudden reoccurance) nocturnal dyspnea • Ankle edema • Palpitations or tachycardia • Intermittent claudication (limb pain during exercise) • Known heart murmur • Unusual fatigue or shortness of breath with usual activities Major Symptoms or Signs Suggestive of Cardiopulmonary Disease

10. Exercise ECGs w Obtained while exercising on a treadmill or cycle ergometer w Graded test by progressing rate of work from low up to maximal intensity w Monitored for arrhythmias and CAD indicators that occur during exercise but not rest w Consideration of sensitivity, specificity, and predictive value for specific subject

11. ECG Screening in the Young? The value of using an exercise ECG to screen for CAD in young, healthy individuals is questionable. The sensitivity and predictive value of an abnormal test are generally low in this population where there is a low prevalence of CAD. A medical examination might not be necessary if moderate exercise is started gradually in people without symptoms of cardiopulmonary disease.

12. Exercise ECG Test Sensitivity (SN), Specificity (SP), and the Predictive Value (PV) of an Abnormal Test With Respect to Coronary Artery Disease (CAD) as Verified with an Arteriogram Exercise test result Those with CAD Those without CAD Positive (abnormal) True positive (TP) False positive (FP) Negative False negative (FN) True negative (TN) SN = [TP/(TP + FN)] SP = [TN/(FP + TN)] PV = [TP/(TP + FP)] Note. CAD = coronary artery disease. An abnormal exercise test is defined as one in which the ST segment of the electrocardiogram is depressed, suggestive of a myocardial ischemia. Example: 100 subjects tested; 6 true positive; 10 false positive; 4 false negative; 80 true negative – SN = 6/(6 + 4) = 60%; SP = 80/(10 + 80) = 89%; PV = 6/(6 + 10) = 38%

13. Intensity—generally 55% or 60% to 90% of HR max or 40% or 50% to 85% of VO2max, although this varies individually and health benefits can occur at lower intensities . Components of Exercise Prescription Type—usually one or more cardiovascular endurance activities plus resistance training Frequency—3 to 5 days per week (or more) Duration—20 to 30 minutes at the appropriate intensity is optimal (optimal is defined as the greatest benefit for time invested)

14. Minimum Threshold for Benefits A minimal threshold for frequency, duration, and intensity must be reached to gain aerobic benefits from an exercise. This threshold varies individually. For this reason, relatively unfit individuals should use preconditioning activities such as walking, jogging, aerobics, or cycling to gain fitness before switching to a sport or recreational activity.

15. DISEASE RISK MODEL (e.g., CAD, hypertension, type II diabetes)

16. Training heart rate (THR) . w Can use linear relationship with VO2max w Can use the Karvonen method of maximal heart rate reserve w Can set a THR range Monitoring Exercise Intensity Metabolic equivalents (MET)—Oxygen requirements of an activity and its intensity Ratings of perceived exertion (RPE)—Subjective rating of the difficulty of work

17. THR at 75% of VO2max

18. Karvonen Method Instead of using VO2, THR is determined as a percentage of the maximal heart rate reserve. Maximal heart rate reserve = HRmax − HRrest Thus, to train at 60% of maximal heart rate reserve: THR60% = HRrest + 0.60(HRmax − HRrest)

19. Heart Rate Range Establishing a training heart rate range (THR) is a sensible way to monitor exercise intensity. Start exercise with your heart rate in the low end of the range and progress to the upper end of the range over time.

20. Metabolic Equivalents (METS) 1.0 MET = resting metabolic rate (~3.5 ml O2/kg/min)

21. Borg RPE Scale Individual subjectively rates how hard she is working – when used correctly, it can be reasonably accurate

22. Relative intensity (%) . Rating of %VO2max or perceived Classification HRmax %HRmax reserve exertion of intensity < 35% < 30% < 9 Very light 35-59% 30-49% 10-11 Light 60-79% 50-74% 12-13 Moderate 80-89% 75-84% 14-16 Heavy ³ 90% ³ 85% > 16 Very heavy Adapted from Pollock and Wilmore (1990). Classification of Exercise Intensity Based on 20 to 60 min of Endurance Activity Comparing Three Methods

23. Use It or Lose It One of the best ways to ensure health benefits from exercise is to continue a consistent exercise program throughout life. Health benefits are rapidly lost once an exercise program is discontinued.

24. Exercise Program 3-4 days per week w Warm-up and stretching w Endurance exercise w Cool-down and stretching Alternate days w Flexibility training w Resistance training w Recreational activities

25. Warming Up and Cooling Down w Low intensity calisthenic-type exercises and stretching w Can decrease risk of injury and muscle soreness - No! w Warm-up prepares the cardiorespiratory and muscle systems for more intense exercise. w Cool-down prevents blood from pooling in the extremities.

26. Rehabilitation Through Exercise w Cardiopulmonary disease w Cancer w Obesity w Diabetes w Renal disease w Arthritis w Cystic fibrosis w Transplants

27. Physical Inactivity increases the incidence of these 26 unhealthy conditions: Menopausal symptomsObesity (weight control)OsteoporosisPancreatic CancerPeripheral vascular diseasePhysical frailtyPremature mortalityProstate cancerRespiratory problemsSleep apneaStrokeType-2 diabetes Arthritis painArrhythmiasBreast cancerColon cancerCongestive heart failureDepressionDigestive problemsGallstone diseaseGastroesophageal diseaseHigh blood triglycerideHigh blood cholesterolHypertensionLess cognitive functionLow blood HDLLower quality of life

28. Physical inactivity increases the progression of 9 disabilities resulting from conditions such as: w ChemotherapyChronic back painDebilitating illnessesDisease cachexiaFalls resulting in broken hipsPhysical frailtySpinal cord injuryStrokeVertabal/femoral fractures

29. SEDS • 26 unhealthy conditions form the syndrome. One in 10 deaths is premature due to SeDS. • The cost of sedentary-related conditions is $1.5 trillion over the next 10 years. • Children are now getting adult-onset (type 2) diabetes • 60% of overweight children have at least one cardiovascular risk factor. • Many adolescents who are in the top 30% projected in body weight are already pre-diabetic. • Children watching 1 hour of TV a day have less obesity than those watching 4 hr a day. • Three out of four adults are sedentary and candidates for SeDS. • Adult-onset diabetes increased 5-fold from 1958 to 1996. • Three days of complete bed rest produces a prediabetic blood sugar. • Secretary of Health, Human Services, and Labor Tommy Thompson estimates that moderate exercise could prevent 5.8 million new cases of type 2 diabetes. • The first observable defect in type 2 diabetes usually often occurs in inactive skeletal muscle. • Adult obesity increased 57% from 1991 to 1999. • The CDC has written in JAMA: "Clearly, genes related to obesity are not responsible for the epidemic of obesity because the US gene pool did not change significantly between 1991 and 1999." Lack of exercise is an important factor.

30. SEDS • We are performing less physical activity than our ancestors, but our genes require us to be active in order to produce proteins that keep us healthy. • It only takes 600 additional feet of walking each day by adults for the next 10 years to prevent adding 10 pounds of fat. The distance to prevent adding 10 pounds of fat in the next 10 years for 7- and 15-yr olds is 1200 and 730 feet, respectively, as kids have less weight to carry. • Physical activity reduces colon cancer by 50%. • "Bad" blood lipids are removed from the blood after moderate physical activity. • The increase in type 2 diabetes at age 65 yrs is largely due the decrease in physical activity with aging. • The 43 million without health insurance will not have access to expensive gene therapies, tissue replacements, stem cell therapies, etc. The highest frequency of chronic diseases occurs in the lower income group. An appropriate approach would be to practice primary preventive medicine including 30 minutes of moderate physical activity each day. • Moderate physical activity lessens the incidence of the decline in female cognitive function with aging. • The average American was expected to spend 2.28 yrs during their lifespan in a nursing home in 1985. A program of physical activity that would delay their entry to nursing home by 1 year would save $50 billion.