Kenney8E_PP_chap13 PDF

Prescription of Exercise for Health and Fitness CHAPTER 13 Overview (1 of 2) • Health benefits of regular physical activity and exercise • Exercise and cognitive function • Physical activity recommendations • Health screening (continued) CHAPTER 13 Overview (2 of 2) • • • • Exercise prescripti...

Prescription of Exercise for Health and Fitness CHAPTER 13 Overview (1 of 2) • Health benefits of regular physical activity and exercise • Exercise and cognitive function • Physical activity recommendations • Health screening (continued) CHAPTER 13 Overview (2 of 2) • • • • Exercise prescription Monitoring exercise intensity Exercise programming Exercise and rehabilitation for people with diseases Health Benefits of Exercise • Exercise provides health benefits. – 1992: inactivity major risk for CAD (AHA) – 1994: exercise public health initiative (CDC/ACSM) – 1995-1996: statement on exercise and cardiovascular health (NIH) – 1996: report on health benefits of exercise (Surgeon General) – 2000: identification of sedentary death syndrome Exercise and Cognitive Function • Habitual exercise reduces age-related cognitive decline. – Mechanisms not clear – Cardiovascular benefits likely help maintain brain health • Benefits – – – – Improved memory and executive function Reduce deteriorations in gray and white matter Preserve brain volume Maintained cerebral vascular function Physical Activity Recommendations • Exercise is not a priority in U.S. population. – Awareness of health benefits high – Application of knowledge low – Health benefits undeniable • Exercise should not intimidate. – 30 min brisk walking, 15 min running – Every day or almost every day – Health benefits as duration and intensity ACSM Guidelines for Exercise Prescription • Adults (18-65 yr): moderate aerobic PA ≥30 min on 5 d/wk or vigorous aerobic ≥20 min on 3 d/wk or a combination – ≥10 min per session • Muscular strength and endurance training ≥2 d/wk • Dose–response: improved results when exceeding recommendations Physical Activity Guidelines for Americans • U.S. Dept. of Health and Human Services (HHS) – Original guidelines published in 2008 – Updated guidelines published in 2018 • Reaffirm the goal of 150 min moderateintensity PA per week • State that any amount of daily PA (big or small) is beneficial to health Video 13.1 Health Screening (1 of 2) • Medical evaluation is useful before starting an exercise program but not mandatory for all. – Medical information can be used to develop an exercise prescription. – Provides a baseline for measuring progress. • High-risk individuals should exercise only under medical supervision. (continued) Health Screening (2 of 2) • Medical evaluation provides motivation. – Blood pressure – Percent body fat – Blood lipid values • Periodic medical evaluations can identify dangerous conditions earlier. Health Screening: Assessing Risk • Low-risk and healthy individuals – Medical evaluation is not required. – Medical system could not handle patient load. • Moderate-risk individuals – Have 2+ risk factors for cardiovascular, pulmonary, or metabolic disease but no signs or symptoms. – Medical evaluation is recommended. • High-risk individuals – Have at least one sign or symptom of disease. – Medical evaluation is recommended. Table 13.1a ACSM Preparticipation Algorithm for Subjects Who Do Not Exercise Regularly Medical clearance Health status No CV, metabolic, or renal disease and no signs or symptoms of these Known CV, metabolic, or renal disease and asymptomatic Any sign or symptom of CV, metabolic, or renal disease Recommended Follow exercise prescription guidelines on progression Not Light-intensity necessary exercise (30%<40% HRR) Moderateintensity exercise (40%<60% HRR) Recommended Vigorousintensity exercise (≥60% HRR) May progress to this intensity x Recommended, Recommended, after medical after medical clearance clearance May progress to this intensity x Recommended, Recommended, after medical after medical clearance clearance May progress to this intensity x Recommended Table 13.1b ACSM Preparticipation Algorithm for Subjects Who Exercise Regularly Medical clearance Health status No CV, metabolic, or renal disease and no signs or symptoms of these Known CV, metabolic, or renal disease and asymptomatic Any sign or symptom of CV, metabolic, or renal disease Recommended Follow exercise prescription guidelines on progression Not Light-intensity necessary exercise (30%<40% HRR) x May continue at this intensity x May continue at this intensity May continue at this intensity x x Stop exercising Moderateintensity exercise (40%<60% HRR) May resume after medical clearance May resume after medical clearance Vigorousintensity exercise (≥60% HRR) May continue or progress to this intensity* May continue this intensity after medical clearance May resume after medical clearance Health Screening: Health-Related Fitness Testing • Body composition – Central or abdominal adiposity – Fat versus fat-free mass • Muscular strength and endurance – 1RM, 5RM, or 10RM – Push-up test • Flexibility – Sit-and-reach – Trunk flexion • Cardiorespiratory fitness – VO2max Health Screening: Risk Stratification • Used by health and fitness professionals during screening process • Helps identify – individuals with medical contraindications, – individuals with clinical conditions who need a medically supervised exercise program, – individuals at risk for disease who need medical evaluation and exercise testing prior to exercise, and – special needs that affect testing and prescription. Health Screening: Graded Exercise Testing (1 of 4) • Graded exercise test (GXT) – Treadmill most common – Intensity gradually increased to maximal – Subject monitored for discomfort, warning signs • Exercising ECG necessary – Resting ECG may not reveal all abnormalities. – Exercising ECG can unmask coronary artery disease (CAD). (continued) Health Screening: Graded Exercise Testing (2 of 4) • Can detect arrhythmias and ST segment changes (myocardial ischemia). • Results are positive or negative (possibility of false negative or false positive). • Positive ECG requires follow-up tests. – Coronary arteriogram – CT, MRI scans of heart (continued) Figure 13.2 Figure 13.3 Health Screening: Graded Exercise Testing (3 of 4) • Sensitivity of exercise ECG – Can GXT correctly identify clinical populations? – Low (66% identified) for asymptomatic CAD • Specificity of exercise ECG – Can test correctly identify healthy individuals? – Higher (84%) specificity • Predictive value of abnormal exercise ECG – Do abnormal results indicate disease? – Low (~24%) for asymptomatic CAD (continued) Health Screening: Graded Exercise Testing (4 of 4) • Holds limited value for young and healthy persons – Accuracy of ECG questionable – Actual risk of cardiac arrest low – Expensive, less accessible test • Is recommended for moderate- and highrisk cohorts Video 13.2 Exercise Prescription (1 of 2) • Exercise programs: designed to improve aerobic capacity in untrained individuals • Six basic factors of exercise prescription – – – – – – Mode or type of exercise Frequency of participation Intensity of the exercise bout Duration (time) of each exercise bout Weekly volume Progression (continued) Exercise Prescription (2 of 2) • Minimum threshold – Point below which no improvement occurs – For frequency, duration, intensity – Variable across individuals • If minimum threshold exceeded, aerobic capacity increased Exercise Prescription: Mode (1 of 2) • Modes most frequently prescribed – Walking, hiking, jogging, running – Cycling, rowing – Swimming • Less common modes – Spinning – Aerobic dance – Racket sports (continued) Exercise Prescription: Mode (2 of 2) • Mode should be enjoyable and motivating. • Should be challenging. • Should produce needed benefits. • Using multiple modes can be helpful. – Inclement weather – Boredom Exercise Prescription: Frequency and Duration • Frequency – Optimal: 3 to 5 days per week – Gradual start, avoidance of fatigue and burnout – Frequency less important than intensity or duration • Duration – Optimal: 20 to 30 min per day – One long bout or multiple shorter bouts – Inverse relation between duration and intensity Exercise Prescription: Intensity • Intensity most important factor – – – – • Minimum recommended: 50% to 60% VO2max Upper limit dependent on training purpose • Upper limit seldom >80% VO2max For most, 40%-90% HRR • High-intensity, low-volume interval training – Marked increase in aerobic capacity – Results in 2 weeks Exercise Prescription: Volume and Progression • Volume – MET = metabolic equivalent (quantifies intensity) – MET-minutes per week = single measure that combines intensity, frequency, volume – ACSM recommends 500-1,000 MET-minutes per week • Progression – Highly variable – Individualized Exercise Prescription: Breaks in Prolonged Sitting • Continuous sitting (≥30 min) – – – – Insulin resistance increased Metabolism negatively affected Storage of fat promoted Effects not offset by regular exercise • Nonexercise physical activity thermogenesis (NEAT) – Planned interruption of sitting time – May prevent chronic disease Monitoring Exercise Intensity (1 of 5) • Training heart rate (THR) • – Based on linear relation between HR, VO2 • – Use of target HR corresponding to target % VO2max • – 75% VO2max = 87% HRmax (not 75% HRmax) • Karvonen method for THR – Maximal HR reserve = HRmax – HRrest – THR calculated as percentage of maximal HR reserve – THR75% = HRrest + 0.75(HRmax – HRrest) (continued) Figure 13.4 Monitoring Exercise Intensity (2 of 5) • Training HR range – One example is 50% to 75% maximal HR reserve. – Ensures training response. – Start at low end and move up. • HR correlated with cardiac work – THR ensures constant rate of work done by heart regardless of environmental conditions. – Is safe for high-risk patients. – Allows for improved aerobic fitness. (continued) Monitoring Exercise Intensity (3 of 5) • • • VO2 reserve (VO2R) method – – – – – ACSM position stand • • • VO2R = VO2max – VO2rest • Exercise prescribed as % VO2R • Assumption: 1 MET = universal resting VO2 • Assumption: resting VO2 = 3.5 ml/kg/min • • % maximal HR reserve versus % VO2R (continued) Monitoring Exercise Intensity (4 of 5) • Metabolic equivalent (MET) – Intensity gauged on basis of O2 consumption – 1 MET = 3.5 ml O2 · kg−1 · min −1 – 1 MET = resting metabolic rate • Published MET values for activities – But MET can vary considerably among individuals. – Also, values fail to account for environmental conditions and physical conditioning. (continued) Exercise Intensity (5 of 5) • Ratings of perceived exertion (RPEs) – Individual ratings of how hard exercise feels – Numerical rating scale • Borg RPE scale – 6 to 20 – Corresponding with HR – Very accurate when used correctly Table 13.3 Classification of Exercise Intensity Based on 20 to 60 Min of Endurance Activity: Comparing Three Methods Relative intensity Classification of intensity Very light HRmax HRR, V\od\O2R <57% <30% Rating of perceived exertion <9 Light 57%-64% 30%-40% 9-11 Moderate 64%-76% 40%-60% 12-13 Vigorous 76%-96% 60%-90% 14-17 Near maximal to maximal ≥96% ≥90% ≥18 Exercise Program (1 of 8) • Elements 1. Warm-up, stretching activities 2. Endurance training 3. Cool-down, stretching activities 4. Flexibility training 5. Resistance training 6. Recreational activities • First three activities: three or four times per week (continued) Exercise Program (2 of 8) • Warm-up and stretching activities – Start with low-intensity calisthenics, stretching. – Gradually increase HR, breathing. – Prepare exerciser for more vigorous exercise. • Sample warm-up – 5 to 10 min of stretching – 5 to 10 min low-intensity activity (continued) Exercise Program (3 of 8) • Endurance training – Develops cardiorespiratory endurance – Improves capacity and efficiency of cardiovascular, respiratory, and metabolic systems – Controls body weight • Best modes: walking, jogging, running, cycling, swimming, rowing • Poor modes: golf, bowling, softball (continued) Exercise Program (4 of 8) • Cool-down and stretching – Should conclude every endurance workout. – Reduces intensity. – Do not stop abruptly. • Stretching after exercise  flexibility (continued) Video 13.3 Exercise Program (5 of 8) • Flexibility training – Supplements warm-up and cool-down periods. – Is useful for those with poor flexibility, joint pain. – Should be performed slowly. • Timing of flexibility training – Perform after workout. – Tissues may be more adaptable and responsive after exercise. (continued) Exercise Program (6 of 8) • Resistance training – Starting point: 10 repetitions at 1/2 1RM – Proper starting weight: fatigue at repetition 8 to 10 – Weight increased if 15 repetitions reached • 2 or 3 sets per day, 2 or 3 times per week • Reduction to 1 or 2 sets if needed (results still produced in untrained people) (continued) Exercise Program (7 of 8) • Neuromotor exercise (functional training) – Is aimed at improving ability to perform everyday activities. – May prevent falls in older adults. – May reduce injury in athletes. (continued) Exercise Program (8 of 8) • Recreational activities form important aspect of comprehensive exercise program. • Guidelines for selecting recreation – Activity can be learned and performed with moderate success. – Provides opportunities for social development. – Keeps costs within budget. – Maintains long-term interest. – Is safe given health and age. Exercise and Rehabilitation for People with Diseases • Exercise is a major component of rehabilitation. • Is used in rehabilitation programs. – – – – – – – Cardiopulmonary disease Cancer Obesity, diabetes Renal disease Osteoporosis Arthritis, chronic fatigue, fibromyalgia Cystic fibrosis