© 2007 McGraw-Hill Higher Education. All rights reserved. Chapter 16 Exercise Prescriptions for Health and Fitness EXERCISE PHYSIOLOGY Theory and Application to Fitness and Performance, 6 th edition Scott K. Powers & Edward T. Howley

© 2007 McGraw-Hill Higher Education. All rights reserved. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. Objectives 1. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. Objectives 5. Identify optimal range of frequency, intensity, and 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

© 2007 McGraw-Hill Higher Education. All rights reserved. Prescription of Exercise Dose-Response Relationship The effect (response) of the amount of a drug (dose) –Potency –Slope –Maximal effect –Variability –Side effect

© 2007 McGraw-Hill Higher Education. All rights reserved. Dose-Response Relationship for Medication Fig 16.1

© 2007 McGraw-Hill Higher Education. All rights reserved. Dose-Response Exercise dose is usually characterized by: –Intensity –Frequency –Duration –Type of activity

© 2007 McGraw-Hill Higher Education. All rights reserved. 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.”

© 2007 McGraw-Hill Higher Education. All rights reserved. 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 responses – occur with one or several exercise bouts, but do not improve further –Rapid responses – benefits occur early and plateau –Linear – gains are made continuously over time –Delayed – occur only after weeks of training

© 2007 McGraw-Hill Higher Education. All rights reserved. Dose-Response Relationship for Exercise Fig 16.2

© 2007 McGraw-Hill Higher Education. All rights reserved. Dose-Response Relationship for Physical Activity Fig 16.3

© 2007 McGraw-Hill Higher Education. All rights reserved. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. 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 kcal

© 2007 McGraw-Hill Higher Education. All rights reserved. Optimal Training: Intensity, Duration, and Frequency Fig 16.4

© 2007 McGraw-Hill Higher Education. All rights reserved. Exercise Prescription for CRF Intensity: describes the overload on the CVS needed to bring about a training effect –50%-85% of VO 2 MAX Target heart rate (THR) range –Direct method form maximal GXT –Indirect method estimated by some simple calculation

© 2007 McGraw-Hill Higher Education. All rights reserved. Target Heart Rate Range Determined From GXT Fig 16.5

© 2007 McGraw-Hill Higher Education. All rights reserved. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. 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

© 2007 McGraw-Hill Higher Education. All rights reserved. Physical Activity Pyramid Fig 16.5

© 2007 McGraw-Hill Higher Education. All rights reserved. Chapter 16 Exercise Prescriptions for Health and Fitness