Presentation Package for Concepts of Physical Fitness 14e

1. Presentation Package for Concepts of Physical Fitness 14e Section V: Concept 13 Body Composition Possessing an optimal amount of body fat contributes to health and wellness. All rights reserved

2. Understanding & Interpreting Body Composition Measures • Component of health-related fitness & a component of metabolic fitness. • Standards have been established for healthy levels of body fatness (see next slide) • Health standards have been established for the Body Mass Index. • Assessing body weight too frequently can result in making false assumptions about body composition changes. Concepts of Physical Fitness 14e

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4. Methods Used to Assess Body Composition • DXA • Underwater Weighing • Bod Pod • Skinfold technique • Other Concepts of Physical Fitness 14e

5. Dual-energy Absorptiometry(DXA) • “Gold Standard” measure of body composition. • Provides whole body measurements of body fatness as well as amounts stored in different parts of the body. • Highly accurate measure of body composition for research and a criterion measure that has been used to validate other, more practical measures of body composition. Concepts of Physical Fitness 14e

6. Click for more info Underwater Weighing • A person is weighed in air and under water, and the difference in weight is used to assess the levels of body fatness. • Body fat provides more buoyancy, so a fatter person weighs less (on a relative basis) than a lean person. Web13-3 for info on underwater weighing Concepts of Physical Fitness 14e

7. Bod Pod • Uses the same principles as underwater weighing, but relies on air displacement to assess body composition. • Evidence suggests that it provides an acceptable alternative to underwater weighing and is particularly useful for special populations (obese older people and the physically challenged). Concepts of Physical Fitness 14e

8. Skinfold Technique Layers of subcutaneous fat are measured at different sites of body to estimate total body fat levels Cross sectional view Concepts of Physical Fitness 14e

9. Benefits of Skinfold Technique • Skinfold measurements are the preferred, practical method of assessing body fatness. • Fairly accurate • Easy to perform • Inexpensive Lab 13a info Concepts of Physical Fitness 14e

10. Common Skinfold Sites 7 site procedure Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Jackson and Pollack Males Female Chest Triceps Abdomen Supraillium Thigh Thigh Alternative Sites (Males & Females) Tricep Abdomen Calf Validation statistics on 3 site test: - r = .97 with 7 site procedure - R2 = .80 with underwater weighing Concepts of Physical Fitness 14e Web13-04

11. Research Quality Skinfold Calipers Harpenden Calipers Lange Calipers Concepts of Physical Fitness 14e

12. Other Body Composition Assessments • Bioelectrical Impedance • Infra-Red Spectroscopy • Ultrasound • Imaging Techniques Click to seemore info on all techniques Concepts of Physical Fitness 14e

13. Anthropometric Measurements Lab 13binfo • Body Mass Index (BMI) • Waist to Hip Ratio (WHR) • Circumference measures More info More info More info Concepts of Physical Fitness 14e

14. Body Composition AssessmentImplications of Results • Values are estimates (+/- 2-3% at best) • Values are personal and confidential Proper uses of results: - Serve as baseline data for repeated testing - Provide motivation for goal setting - Provide awareness about health risks Concepts of Physical Fitness 14e

15. Health Risks Associated with Being Overweight • Coronary heart disease • Hypertension • Hypercholesterolemia • Diabetes • Premature death • Physical fitness provides protection from the health risks of obesity. There are also health risks associated with being too thin! Concepts of Physical Fitness 14e

16. Click for more info on fatdeposition Male (apple) Female (pear) Higher health risk Lower health risk Regional Fat Deposition • Abdominal body fat poses greater health risks than fat stored in other areas • Males store more fat centrally and have increased health risks associated with body fatness Concepts of Physical Fitness 14e

17. Health Risks Associated withExcessively Low Body Fatness • Anorexia Nervosa • Bulimia • Anorexia Athletica • Female Athlete Triad • Muscle Dysmorphia (males) • Fear of Obesity Concepts of Physical Fitness 14e

18. The Origin of Fatness Lab 13c info • Obesity is a multifactorial disease that is influenced by both genetics and the environment. • Body weight is regulated and maintained through complex regulatory processes. • Set-point • Fatness early in life leads to adult fatness. • Changes in basal metabolic rate can be the cause of obesity. • “Creeping Obesity” (see next slide) Concepts of Physical Fitness 14e

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20. Relationship Between PA & Body Composition • Combination of regularPAanddietaryrestriction is the mosteffectivemeans of losingbodyfat. • PA that can be sustained for relatively long periods is considered the most effective for losing body fat. • Strength training can be effective in maintaining a desirable body composition. • Regular PA is critical for building and maintaining bone health. Concepts of Physical Fitness 14e

21. PhysicalActivity Daily moderate PA; 3-6 days/wk vigorous PA Slow, low-intensity that results in ≤1-2 lbs/week of fat loss 30-60 minutes Diet Consistently and daily Modest caloric restriction Moderate meals Target Zone - Body Fat ReductionTable 3, p. 285 F I T Concepts of Physical Fitness 14e

22. Obesity Trends* Among U.S. AdultsBRFSS,1990, 1995, 2005 (*BMI 30, or about 30 lbs overweight for 5’4” person) 1995 1990 2005 No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30% Concepts of Physical Fitness 14e

23. Web Links • Behavioral Risk Factor Surveillance System (BRFSS) Interactive Web Page http://www.cdc.gov/brfss/ Concepts of Physical Fitness 14e

24. Summary • Obesity is prevalent in society. • Need to find ways to maintain optimal body composition. • Use assessments to determine body composition and make the necessary healthy changes to physical activity and diet. Concepts of Physical Fitness 14e

25. Web Resources Online Learning Center “On the Web” pages for Concept Concepts of Physical Fitness 14e

26. Supplemental Graphics Lab Information Detail on BMI calculations Graphics on Obesity Trends

27. Lab 13a InformationEvaluating Body Composition - Skinfolds • The purpose of this lab is to evaluate body composition with the skinfold assessment. • Comparisons will be made between different procedures and testers to learn about the accuracy of the tests. Concepts of Physical Fitness 14e

28. Lab 13a InformationSkinfold Technique Return to presentation • Measurement Technique: • Mark site with marker • Pinch fold above and below mark with left and right hand • Measure fold with caliper using the right hand • Scoring Procedure: • Sum skinfolds from the 3 sites • Look up percent body fat valuefrom chart in the book Concepts of Physical Fitness 14e

29. Lab 13b InformationEvaluating Body Composition – Height, Weight, and Circumference Measures • The purpose of this lab is to evaluate body composition with some anthropometric assessments • Height/Weight • Body Mass Index • Waist to Hip Ratio Concepts of Physical Fitness 14e

30. Lab 13b InformationBMI Measurement Technique Return to presentation • Convert weight to kilograms (2.2 kg/lb.) • Convert height to meters (.0254 m/in) • Square the height in meters • Divide the squared height value into the weight value BMI = Wt (kg) / Ht2 (m) See Web13-06 for BMI calculators Concepts of Physical Fitness 14e

31. Lab 13b InformationWHR Measurement Technique Return to presentation • Waist:Measure at the "natural waist" (smallest circumference) or at the level of the umbilicus • Hip:Measure at the maximum circumference of the buttocks Divide the hip measurement into the waist measurement to obtain the WHR Concepts of Physical Fitness 14e

32. HT (in.) WT (lb.) BMI 72 150 21 72 180 25 72 190 26 72 200 28 Sample BMI Values Return to presentation This chart reveals how BMI values change for a hypothetical 6 foot tall person of different body weights See Web13-06 for BMI calculators Concepts of Physical Fitness 14e

33. Definitions of Overweight(Based on BMI values) Return to presentation • BMI accounts for differences in frame size better than height weight tables. BMI = Wt (kg) / Ht2 (m) Standards: • Overweight: > 25 • Obesity: > 30 • Severe obesity > 40 Problem: BMI does not take muscles mass into account Web13-1 for moreinformation on standards Concepts of Physical Fitness 14e

34. Lab 13c InformationDetermining Your Daily Energy Expenditure Return to presentation • Estimate your basal metabolism. • First determine the number of minutes you sleep. • Monitor your activity expenditure for 1 day. Record the number of 5-, 15-, and 30-minute blocks of time you perform each of the different types of physical activities (e.g., if an activity lasted 20 minutes, you would use one 15-minute block and one 5-minute block). Be sure to distinguish between moderate (Mod) and vigorous (Vig) intensity in your logging. • Discuss your daily caloric expenditure. In addition, comment on whether you think you should modify your daily caloric expenditure for any reason. Concepts of Physical Fitness 14e

35. Regional Fat DepositionVisceral Fat • Visceral body fat poses greater health risks because this fat is more labile and has greater access to the circulation. • The accumulation of visceral body fat is typical of the android (male) fat pattern • males: visceral accounts for 10-35% of total fat • females: visceral accounts for 8-13%of total fat Concepts of Physical Fitness 14e

36. Abdominal Body FatRelationships with CHD Risks • Abdominal obesity predicts CHD risk independent of BMI, smoking, cholesterol and hypertension.(Kannel et al., J. Clin Epid., 44, 183-190, 1991). • Abdominal obesity predicts CHD risk independent of total body fatness.(Larsson et al. ,Appetite, 13, 37-44, 1989). • Abdominal obesity statisticallly accounts for difference in CHD rates between men and women.(Larsson et al., Am. J. Epi., 135: 266-273, 1992). Concepts of Physical Fitness 14e

37. Abdominal Body FatRelationships with other risk factors • Abdominal obesity is strongly influenced by genetics - similar gain among twins (r=.72). (Bouchard, NEJM, 322, 1477-1482, 1990). • Abdominal obesity is greater in smokers than non-smokers due to the presence of androgens (Barrett-Conner, Ann. Int. Med. 111, 783-787, 1989). • Abdominal body fat is preferentially lost during a physical activity program(Kohrt, J. Gerontology, 47: M99-M105, 1992) Concepts of Physical Fitness 14e

38. Waist to Hip Ratio (WHR) Return to presentation • Waist to Hip Ratio is an effective way to examine regional fat distribution. HEALTH RISK MEN WOMEN High Risk > 1.0 > .85 Moderate Risk .90 -1.0 .80-.85 Low Risk < .90 < .80 Concepts of Physical Fitness 14e

39. Underwater WeighingMeasurement issues Return to presentation • Based on body density calculations • Density of lean tissue = 1.1 g/cc • Density of fat tissue = .9 g/cc • Sources of error • Residual lung volume • Bone density varies by age, ethnicity and activity level • General conclusions • Gold standard measure (1-2% error) • Impractical for most applications Concepts of Physical Fitness 14e

40. Bioelectric Impedance(Measurement Issues) Return to presentation • Based on resistance to current flow • Lean tissue has more water - less resistance • Fat tissue has less water - more resistance • Sources of error • Temperature • Hydration status • General conclusions • Overestimates lean / underestimates obese • Practical, but expensive, measure for general population Concepts of Physical Fitness 14e

41. Infrared Spectroscopy(Measurement Issues) Return to presentation • Based on differential absorbance rates • Lean tissue has a different energy absorption and reflectance pattern than fat tissue • Sources of error • Validity of absorbance readings is questionable! • General findings • NOT a valid measure! Concepts of Physical Fitness 14e

42. Ultrasound(Measurement Issues) Return to presentation • Based on reflection of sound • Fat content increases the time is required for sound to reflect off of bone and muscle. • Sources of error • Representative sites for measurement • Measurement error • General conclusions • Highly accurate measure of body fat - especially for obese • Expensive and not practical for most applications Concepts of Physical Fitness 14e

43. Imaging Techniques(Measurement Issues) Return to presentation • Based on imaging of body tissues • Based on cross sectional area measures calculated at different levels of the body • Sources of error • Representative sites for measurement • Measurement error • General conclusions • Very precise measure of body composition • Expensive and not practical measure for most uses Concepts of Physical Fitness 14e

44. Circumferences(Measurement Technique) Return to presentation • Based on circumference measures • sample prediction equation:% fat = - 47.372 + (.579 x abdomen) + (.252 x hip) + (.214 x iliac) + (.356 x BW) • Sources of error • Location of sites • Inability to distinguish fat and muscle • General conclusions • Provides reasonable estimate of body fat • Not as accurate as skinfold and takes same time Concepts of Physical Fitness 14e