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

Risk categories for medical exams before beginning an aerobic training program. Population Low Risk Moderate Risk High Risk men < 45 yrs. women < 55 yrs. No more than one men ≥ 45 yrs. women ≥ 55 yrs. Two or more AllOne or more Risk Factors Family history of coronary artery disease Cigarette smoking Hypertension Hypercholesterolemia Impaired fasting glucose Obesity Sedentary lifestyle Known cardiovascular, pulmonary, or metabolic disease Ischemia Dizziness/syncope Orthopnea/paroxysmal nocturnal dyspnea Ankle edema Palpitations/tachycardia Intermittent claudication Known heart murmur Unusual fatigue

Risk categories for medical exams before beginning an aerobic training program (cont.) Low Risk Moderate Risk High Risk Type Program Prior Physical Exam Moderate Vigorous Moderate Vigorous All NO 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

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 cleaningCarrying small children Swimming (moderate effort) Mowing lawn (power mower) Automobile repair General calisthenicsHome repair and paintingCleaning gutters Racket sportsStationary cycling (light to very light effort) Carrying, loading, or stacking wood Table tennisSlimnastics and jazzercise Carpentry Golf (pulling a cart or carrying clubs) Water aerobicsElectric work Fishing (standing and casting) Ballroom dancingPlumbing

The ACSM considers four components for designing aerobic exercise programs 1.Mode of activity 2.Intensity of training 3.Duration of training 4.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 V0 2 reserve Metabolic equivalents (METs) –20-39 yrs METs –40-64 yrs METs –65-79 yrs METs RPE of approx (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 VO 2 reserve and exercise intensity. It takes into account training-induced changes in the resting heart rate.

Recommended VO 2 range for improving fitness 40 to 85% of maximum VO 2 reserve VO 2 max - VO 2 resting = maximum VO 2 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 yrs. –3.2 to 6.7 METs 80 yrs. and over –2.0 to 4.25 METs

Leisure activities in METs. Basketball –Game playing –Non-game playing Bicycling ( <10 mph) Circuit weight training Football (touch) Golf –Power cart –Walking (carrying bag or pulling cart) ActivityAverage MET

Leisure activities in METs (cont.) Running –5 mph –6 mph –7 mph Stair climbing Walking –2 mph –3 mph –4 mph Weightlifting ActivityAverage MET

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 unchanged, can maintain fitness with substantial reductions in frequency and duration

Aerobic training for endurance athletes Training differs substantially from exercise prescriptions recommended for improving public health. Athletes must train at higher intensities, for longer durations, more frequently. Athletes perform much greater volume of training. Athletes must use a mode of training that mimics the sport in which they compete.

VO 2 max and athletic performance VO 2 max describes the maximum amount of oxygen that can be used in the ETS to produce ATP. Successful endurance athletes are characterized by high VO 2 max values. Visit Sports Coach—VO 2 max at

Physiological factors that determine performance in endurance events Maximal oxygen consumption rate (VO 2 max) The fraction of VO 2 max that can be maintained Economy of movement

Anaerobic threshold The fraction of VO 2 max that can be maintained during an endurance event The intensity of exercise just below that at which lactic acid buildup in the blood and the associated changes in gas exchange occur Visit Anaerobic Threshold at

Theoretical representation of the anaerobic threshold from respiratory (ventilatory threshold) and lactate (lactate threshold) responses to incremental exercise

Factors that influence economy of movement Age Muscle fiber type Altitude Gender Fatigue Temperature Wind Acceleration–deceleration versus smooth movement Pace and efficiency Velocity of running, walking, and cycling

Factors to consider when designing training programs for endurance athletes 1.Set goals and then determine the best training regimen based on those goals 2.Consider the athlete’s strengths and weaknesses when developing the program 3.Place early season emphasis on weaknesses and late season emphasis on strengths

Key elements of an effective training program 1.Efficient long-range planning 2.Wise use of rest and recovery days 3.Gradual increases in training intensity and duration

Training methods for distance events LSD training Tempo-pace training Interval training REP training Fartlek training Hypoxic training Analysis of pace Visit Gatorade Sports Science Institute at

Characteristics of training methods listed from easiest to hardest (slowest to fastest). Easy (E) Purpose Intensity Duration of each work bout Recovery time between work bouts Number of work bouts in one session Warm up, Recovery, Cool down, Early season buildup Skeletal and cardiac muscle adaptation Improve endurance by raising lactate threshold Conversational, 70% of VO 2 max Long (L)Tempo (T) Comfortably hard 85% of VO 2 max 15 seconds per mile slower than 10 K race pace minutes minutes20 minutes Not applicable

Characteristics of training methods listed from easiest to hardest (slowest to fastest) (cont.) Cruise (C) Purpose Intensity Duration of each work bout Recovery time between work bouts Number of work bouts in one session Improve endurance by raising lactate threshold Improve VO 2 max Comfortably hard 85% of VO2 max 15 seconds per mile slower than 10 K race pace Interval (I)Reps (R) 5 seconds per 400 m faster than interval pace or race pace, whichever is fastest 3-10 minutes11/2-5 minutes30-90 seconds 1 mile Repeat work bouts until quality work totals 8% of 1 weekly mileage; not over 6 miles/session 5% of weekly mileage; not over 5 miles/session 1 to 5 work: rest ratio 1 to 1 work: rest ratio Improve speed and running economy 5 K race pace or slightly slower 95%-100% of VO 2 max