Chapter 10 Aerobic Exercise Prescriptions for Public Health Cardiorespiratory Fitness and Athletics Exercise and medical evaluations Individuals are categorized as Low risk Moderate risk High risk Visit Physical Activity and Health Executive Summary at www cdc gov nccdphp sgr sgr htm Risk categories for medical exams before beginning an aerobic training program Population Risk Factors Low Risk men 45 yrs Family history of coronary artery disease Cigarette smoking Hypertension Moderate men 45 yrs Two or more women 55 yrs Risk Hypercholesterolemia Impaired fasting glucose Obesity Sedentary lifestyle High Risk All Known cardiovascular pulmonary or metabolic disease Ischemia Dizziness syncope Orthopnea paroxysmal nocturnal dyspnea Ankle edema Palpitations tachycardia Intermittent claudication Known heart murmur Unusual fatigue No more women 55 yrs than one One or more Risk categories for medical exams before beginning an aerobic training program cont Type Program Prior Physical Exam Low Risk Moderate Vigorous NO NO Moderate Risk Moderate Vigorous NO YES High Risk All YES Physiological changes during a warm up Muscles relax and contract faster Increased temperature decreases viscous resistance in muscles and improves efficiency Hemoglobin and myoglobin give up more oxygen and dissociate more rapidly The rates of metabolic processes increase with temperature Physiological changes during a warm up cont Warm up provides more time for aerobic metabolism to supply the energy needs of the activity and so may reduce lactate accumulation during actual exercise Vascular resistance decreases with increasing temperature Total pulmonary resistance to blood flow decreases with increasing temperature Warming up before exercise is important Provides more time for aerobic metabolism to supply the energy needs of the activity Reduces the risk of musculoskeletal injuries and improves heart function Increases blood flow to muscles and the temperature of tendons and ligaments Gradually increases blood flow to the heart An effective warm up Involves low to moderate intensity exercise Mimics the physical activity to follow Stretching not a substitute Benefits of cooling down Helps to clear lactate from the blood more rapidly than an inactive cool down Prevents blood pooling in the lower extremities which can cause dizziness Helps maintain increased muscle and connective tissue temperature increasing flexibility Exercise for public health Adults should accumulate 30 minutes or more of moderate intensity activity on most preferably all days of the week The 30 minutes can be in one continuous bout or several smaller bouts of at least 10 minutes each Exercise can consist of a variety of activities Rigid highly structured aerobic exercise programs are not necessary Visit Physical Activity and Fitness Healthy People 2010 at www health gov healthypeople default htm Examples of moderate intensity physical activities Brisk walking 3 4 mph Canoeing 2 3 9 mph Sweeping garage or sidewalk Cycling 10 mph Home care and cleaning Carrying small children Swimming moderate effort Mowing lawn power mower Automobile repair General calisthenics Home repair and painting Cleaning gutters Racket sports Stationary cycling light to Carrying loading or very light effort stacking wood Table tennis Slimnastics and jazzercise Carpentry Golf pulling a cart or carrying clubs Water aerobics Electric work Fishing standing and casting Ballroom dancing Plumbing The ACSM considers four components for designing aerobic exercise programs 1 2 3 4 Mode of activity Intensity of training Duration of training Frequency of training ACSM s recommendations regarding mode of activity for developing and maintaining fitness Uses large muscle groups Can be maintained continuously Is rhythmical Is aerobic ACSM s recommendations regarding intensity of activity Approx 55 to 90 maximum heart rate Approx 40 to 85 maximum heart rate reserve Approx 40 to 85 maximum V02 reserve Metabolic equivalents METs 20 39 yrs 40 64 yrs 65 79 yrs 4 8 10 1 METs 4 0 8 4 METs 3 2 6 7 METs RPE of approx 12 16 somewhat hard to hard Methods of determining exercise intensity include monitoring Heart rate Oxygen consumption rate Metabolic equivalents Perceived exertion Recommended target heart rate range Using percentage of maximum heart rate 55 90 of maximum heart rate depending on the person s fitness level 220 age in years maximum heart rate Using percentage of maximum heart rate reserve 40 to 85 of the maximum heart rate reserve 220 age in years maximum heart rate Maximum heart rate resting heart rate maximum heart rate reserve Advantages of the percentage of heart rate reserve method over the percentage of maximum heart rate method The percentage of heart rate reserve method more closely tracks the relationship between VO2 reserve and exercise intensity It takes into account training induced changes in the resting heart rate Recommended VO2 range for improving fitness 40 to 85 of maximum VO2 reserve VO2max VO2resting maximum VO2 reserve Recommended METs range for improving fitness 20 to 30 yrs 4 8 to 10 1 METs 40 to 64 yrs 4 0 to 8 4 METs 65 79 yrs 3 2 to 6 7 METs 80 yrs and over 2 0 to 4 25 METs Leisure activities in METs Activity Average MET Basketball Game playing Non game playing Bicycling 10 mph Circuit weight training Football touch Golf Power cart Walking carrying bag or pulling cart 8 0 6 0 4 0 8 0 8 0 3 5 4 5 Leisure activities in METs cont Activity Average MET Running 5 mph 6 mph 7 mph Stair climbing Walking 2 mph 3 mph 4 mph Weightlifting 8 0 10 0 11 5 8 0 2 5 4 5 6 5 3 0 Rating of Perceived Exertion RPE RPE is used to quantify an individual s subjective experience of exercise intensity Advantage is simplicity Disadvantage is its subjective nature 12 to 16 somewhat hard to hard is recommended intensity range for improving cardiorespiratory fitness Rating for perceived exertion RPE scale Duration of training Should range from 20 to 60 minutes Can be accomplished in single continuous bout or multiple bouts of at least 10 minutes each Intermittent bouts may result in better adherence to program Frequency of training ACSM recommends three to five days per week Payoff for six or seven vigorous exercise sessions per week may not outweigh potential for injuries decrease in adherence and risk of overtraining Detraining Decreases in fitness may occur in as little as two weeks after stopping exercise Can result in loss of almost all improvement in 10 weeks If intensity is