Chapter 10Aerobic 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

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

All One or more

Risk FactorsFamily history of coronary artery diseaseCigarette smokingHypertension

HypercholesterolemiaImpaired fasting glucoseObesitySedentary lifestyle

Known cardiovascular, pulmonary, or metabolic diseaseIschemiaDizziness/syncopeOrthopnea/paroxysmal nocturnal dyspneaAnkle edemaPalpitations/tachycardiaIntermittent claudicationKnown heart murmurUnusual fatigue

Risk categories for medical exams before beginning an aerobic training program (cont.)

Low Risk

Moderate Risk

High Risk

Type ProgramPrior Physical Exam

ModerateVigorous

ModerateVigorous

All

NONO

NOYES

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.

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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 very light effort)

Carrying, loading, or 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. 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 V02 reserve

• Metabolic equivalents (METs)– 20-39 yrs. 4.8-10.1 METs– 40-64 yrs. 4.0-8.4 METs– 65-79 yrs. 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 rate55-90% of maximum heart rate, depending

on the person’s fitness level220 – age in years = maximum heart rate

• Using percentage of maximum heart rate reserve40 to 85% of the maximum heart rate reserve220 – age in years = maximum heart rateMaximum 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.

• 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

Activity Average MET

Leisure activities in METs (cont.)

• Running– 5 mph– 6 mph– 7 mph

• Stair climbing• Walking

– 2 mph– 3 mph– 4 mph

• Weightlifting

8.010.011.58.0

2.54.56.53.0

Activity Average 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.

VO2 max and athletic performance

• VO2 max describes the maximum amount of oxygen that can be used in the ETS to produce ATP.

• Successful endurance athletes are characterized by high VO2 max values.

Visit Sports Coach—VO2 max at www.brianmac.demon.co.uk/vo2max.htm

Physiological factors that determine performance in endurance events

• Maximal oxygen consumption rate (VO2 max)

• The fraction of VO2 max that can be maintained

• Economy of movement

Anaerobic threshold

• The fraction of VO2 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 www.rice.edu/~jenky/sports/anaerobic.threshold.html

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 paceVisit Gatorade Sports Science Institute at www.gssiweb.com

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 VO2 max

Long (L) Tempo (T)

Comfortably hard85% of VO2 max15 seconds per mile slower than 10 K race pace

20-60 minutes 60-120 minutes 20 minutes

Not applicable

Not applicableNot applicable Not applicable

Not applicableNot 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 VO2 max

Comfortably hard85% of VO2 max15 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 minutes 11/2-5 minutes 30-90 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 slower95%-100% of VO2 max