Chapter 16: Exercise Prescriptions for

Health and Fitness

EXERCISE PHYSIOLOGY

Theory and Application to Fitness and Performance, 5th edition

Scott K. Powers & Edward T. Howley

Presentation revised and updated by

TK Koesterer, Ph.D., ATC

Humboldt State University

Introduction

• Physical activity is any form of muscular activity– Related to physical fitness

• Exercise represents a subset of physical activity that is planned, with a goal of improving or maintain fitness

• Can reduce the risk of death from all causes• Physical inactivity is a primary risk factor for

coronary heart disease

Objectives1. Characterize physical inactivity as a coronary heart

disease risk factor comparable to smoking

2. Contrast exercise with physical activity; explain how both relate to a lower risk of CHD and improvement in cardiorespiratory fitness

3. Describe the physical activity recommendation by ACSM and the CDC and Prevention to improve health status of sedentary U.S. adults

4. Explain what screening and progression mean for a person wishing to initiate an exercise program

Objectives5. Identify optimal range of frequency, intensity, & duration

of activity associated with improvements in CRF, why is more not alway better than less?

6. Calculate a target heart rate range by either the heart range reserve or percent of maximal HR

7. Explain why the appropriate sequence of physical activity for sedentary persons is walk, walk/jog, jog, followed by games

8. Explain how target heart rate (THR) helps adjust exercise intensity in times of high heat, humidity, or while at altitude

Prescription of ExerciseDose-Response Relationship

• The effect (response) of the amount of a drug (dose)– Potency– Slope– Maximal effect– Variability– Side effect

Dose-Response Relationship for Medication

Fig 16.1

Dose-Response

• Exercise dose is usually characterized by;– Intensity– Frequency– Duration– Type of activity

Physical Activity and Health

• The benefits of physical activity may be more related to total number of calories expended than exercise intensity

• The “Exercise Lite” recommendation

“Every U.S. adult should accumulate thirty minutes or more of moderate-intensity (3-6 METs) physical activity on most,

preferably all, days of the week.”

Dose Response of Exercise

• The following terms are used to describe the patterns of responses in the weeks following the initiation of a dose of exercise– Acute response – occur with one or several

exercise bouts but do not improve further– Rapid responses – benefits occur early & plateau– Linear – gains are made continuously over time– Delayed – occur only after weeks of training

Dose-Response Relationship for Exercise

Fig 16.2

Dose-Response Relationship for Physical Activity

Fig 16.3

General Guidelines for Improving Fitness

• Screening– Health status screening (PAR-Q)

• Progression– Moderate-intensity walking (3-4 mph)– Then increase duration and/or intensity

• Warm-up, cool-down, and stretching– Light exercise and stretching performed at

beginning and end of exercise session

Exercise Prescription for CRF• Frequency: two being the minimum

– Gains level off after 3 to 4 sessions/wk• Duration: must be considered with intensity

– Total work/session should 200-300 kcal

Optimal Training: Intensity, Duration, and Frequency

Fig 16.4

Exercise Prescription for CRF• Intensity: describes the overload on the CVS

needed to bring about a training effect

– 50%-85% of VO2 MAX

• Target heart rate (THR) range– Direct method form maximal GXT– Indirect method estimated by some simple

calculation

Target Heart Rate Range Determined From GXT

Fig 16.5

Sequence of Physical Activity• Walking

– Start at a comfortable speed for 15 minutes– Gradually increase duration and speed

• Jogging– Start by adding some running when walking– Gradually increase speed/duration of running

• Games and sports– Intermittent higher-intensity activities within THR

range

Strength Training

• Muscular strength is an important component of physical fitness

• Recommendations– Dynamic resistance exercises– Full range of motion– 8-10 different exercises– 8-12 repetitions per exercise

Environmental Concerns

• Environmental conditions can alter exercise heart rate

• Adjust exercise intensity in adverse environments– High temperature and humidity– Altitude– Use THR range as a guide for intensity

Physical ActivityPyramid

Fig 16.5