1. 6 Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Chapter

2. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-2 Body Composition  What Is Body Composition and Why Is It Important?  Assessing Body Mass Index, Body Composition, and Body Fat  Setting Body Composition Goals  Making Changes in Body Composition

3. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-3 What Is Body Composition and Why Is It Important?  The human body is divided into fat-free mass and body fat  Fat-free mass is body’s nonfat tissues ▪ Bone, water, muscle, connective tissue, organ tissues, and teeth

4. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-4 What Is Body Composition and Why Is It Important?  Body fat includes essential and adipose tissues  Essential fat: Fats incorporated in various tissues of the body, critical for normal body functioning  Adipose tissue: Tissue in which fat is stored  Subcutaneous fat: Fat located under the skin  Visceral fat: Fat located around major organs; also called intra-abdominal fat

5. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-5 FIGURE 6.1 Body composition of a typical man and woman, 20–24 years old SOURCE: Adapted from Brooks, G A, et al 2005 Exercise Physiology: Human Bioenergetics and Its Applications, 4th ed New York: McGraw-Hill

6. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-6 Overweight and Obesity Defined  Most important consideration: proportion of body’s total weight that is fat  Percent body fat: The percentage of total body weight that is composed of fat  Overweight: Body weight that falls above the recommended range for good health; sometimes defined as a body mass index between 25 and 299

7. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-7 Overweight and Obesity Defined  Obesity: Severely overweight, characterized by an excessive accumulation of body fat; may also be defined in terms of some measure of total body weight or a body mass index of 30 or more

8. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-8 Prevalence of Overweight and Obesity Among Americans  Prevalence of obesity increased from 13% in 1960 to 35% today  68% of adult Americans overweight  About 35.5% of men and 35.8% of women obese, according to the latest statistics  By 2015, estimates are that 75% of adults will be overweight and 41% will be obese

9. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-9 Prevalence of Overweight and Obesity Among Americans  Possible explanations:  More sedentary work and leisure activities  Fewer short trips on foot and more by automobile  Fewer daily gym classes for students  More meals eaten outside the home  Greater consumption of fast food  Increased portion sizes, and more soft drinks and convenience foods

10. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-10 FIGURE 6.2 Trends in overweight and obesity in adults age 20 and older, by sex, in the U.S., 1988–1994, 1999–2002, and 2007–2010 SOURCE: Centers for Disease Control and Prevention and the National: enter for Health Statistics 2011 2007–2010 National Health and Nutrition Examination Survey (NHANES) Hyattsville, Md: National Center for Health Statistics

11. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-11 FIGURE 6.3 Prevalence of obesity and trends in the distribution of body mass index among U.S. adults, 2010 SOURCE: Flegal, K M, et al 2012 Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999–2010 Journal of the American Medical Association 307(5): 491–497

12. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-12 Metabolic Syndrome, Diabetes, and Premature Death  Metabolic syndrome: Cluster of symptoms present in many overweight and obese people that greatly increases their risk of heart disease, diabetes, and other chronic illnesses; symptoms include insulin resistance, abnormal blood fats, abdominal fat deposition, type 2 diabetes, high blood pressure, high blood glucose, and chronic inflammation

13. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-13 Metabolic Syndrome, Diabetes, and Premature Death  Chronic inflammation: A response of blood vessels to such harmful substances as germs, damaged cells, or irritants; can lead to heart disease, cancer, allergies, and muscle degeneration

14. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-14 Body Fat Distribution and Health  Distribution of body fat is an important indicator of health  Apple shape versus pear shape  Abdominal fat is more easily mobilized and sent into bloodstream, increasing disease- related blood fat levels  Waist circumference helps assess risks of unhealthy body fat distribution

15. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-15 Performance of Physical Activities  Too much body fat makes physical activity difficult  Overfat people are less fit than others and lack muscular strength, endurance, and flexibility that make normal activity easy

16. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-16 Emotional Wellness and Self-Image  Being perceived as fat can be a source of ridicule, ostracism and can contribute to psychological problems  The popular image of the “ideal” body has changed greatly in the past 50 years

17. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-17 Problems Associated with Very Low Levels of Body Fat  Health experts generally view too little body fat as a threat to health  Too little for women: less than 8 to 12%  Too little for men: less than 3 to 5%

18. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-18 Problems Associated with Very Low Levels of Body Fat  Amenorrhea: Absent or infrequent menstruation, sometimes related to low levels of body fat and excessive quantity or intensity of exercise  Female athlete triad: A condition consisting of three interrelated disorders: abnormal eating patterns (and excessive exercising) followed by lack of menstrual periods (amenorrhea) and decreased bone density (premature osteoporosis)

19. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-19 Calculating Body Mass Index  Body mass index (BMI): Measure of relative body weight correlating highly with more direct measures of body fat, calculated by dividing total body weight (in kilograms) by the square of body height (in meters)  BMI between 18.5 and 24.9 considered healthy

20. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-20 TABLE 6.1 Classifications from the World Health Organization

21. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-21 Estimating Percent Body Fat  Underwater Weighing  Individual submerged and weighed under water  Percentage of fat and fat-free weight calculated from body density  The Bod Pod  Small chamber containing computerized sensors measures body composition by air displacement

22. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-22 Estimating Percent Body Fat  Skinfold Measurements  Typically involves measuring thickness of skinfolds at different places on the body  Caliper: A pressure-sensitive measuring instrument with two jaws that can be adjusted to determine thickness  Important to test exact sites, to measure several different times, and to take measurements at approximately the same time of day

23. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-23 Estimating Percent Body Fat  Bioelectrical Impedance Analysis (BIA)  Works by sending a small electrical current through the body and measuring the body’s resistance to it  Advanced Techniques: DEXA and TOBEC  DEXA works by measuring tissue absorption of high- and low-energy X-ray beams  TOBEC estimates lean body mass by passing a body through a magnetic field

24. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-24 TABLE 6.2 Percentage of Body Fat as the Criterion for Obesity

25. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-25 Assessing Body Fat Distribution  Waist circumference measurement and waist-to-hip ratio calculation easiest to perform  Total waist measurement more than 40 inches for men and 35 inches for women and a waist-to-hip ratio above 0.94 for young men and 0.82 for young women are associated with increased risk of heart disease and diabetes

26. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-26 Somatotype  Endomorphs are round and pear shaped, with wide hips and shoulders  Mesomorphs are lean and muscular and respond well to exercise  Ectomorphs are thin and linear, with narrow hips and shoulders

27. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-27 Setting Body Composition Goals  If assessment tests indicate that fat loss would be beneficial, first step is to establish a realistic goal  Be sure your goal is realistic and will ensure good health

28. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-28 Setting Body Composition Goals  If you are overfat or have known risk factors, consult a physician to determine a body composition goal for your individual risk profile  Decide whether the body weight the formulas suggest is realistic, meets your goals, is healthy, and is reasonable to maintain

29. Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6-29 Making Changes in Body Composition  Focus on lifestyle  Track progress  Reassess your body composition occasionally during the program