Sport Books Publisher1 Body Composition

Sport Books Publisher2 Body Composition There are three interrelated aspects of the human physique: Size (volume, mass, surface area, length) Structure (skeletal, muscular, fat arrangement and distribution) Composition (amount of fat, muscle, bone)  Body composition is one of the major components of physical fitness

Sport Books Publisher3 Body Composition Most common method used in body composition analysis is the ‘Two- Component’ model of the body This model includes: Lean body mass (LBM) Fat body mass Total body fat (TBF)

Sport Books Publisher4 Lean Body Mass Refers to the ‘non-fat’ or ‘fat-free’ component of the body Includes skeletal muscle, bone, water May represent a biological lower limit beyond which health is compromised Excessive leanness may increase a female’s chances of developing amenorrhea (absence of menstruation) Amenorrhea includes a reduced production of estrogen, which may also increase a female’s chances of developing osteoporosis

Sport Books Publisher5 Lean body mass is calculated as follows: LBM = TBM -TBF Lean body mass = Total body mass - Total body fat TBF is calculated as follows: TBF = TBM x %BODY FAT 100

Sport Books Publisher6 Measuring Body Fat Direct Measurement Indirect Measurement

Sport Books Publisher7 Direct Measurement Measuring Body Fat Involves grinding tissue Measures fat via chemical analysis Impractical for living organisms Used on cadavers

Sport Books Publisher8 Indirect Measurement Measuring Body Fat Skinfold calipers Hydrostatic weighing Bod-Pod Bioelectrical impedance DEXA

Sport Books Publisher9 Skinfold Calipers

Sport Books Publisher10 Skinfold Calipers Measures skinfold thickness to predict or estimate total body fat Based on the assumption that subcutaneous fat is directly related to total body fat Accuracy is ± 3% when performed correctly

Sport Books Publisher11 YMCA Skinfold Test Equipment: Skinfold calipers Skinfold sites: Four sites: abdomen, suprailium, triceps, thigh  Calculation of % body fat: Males %fat = x (sum of 4) x (sum of 4) x (age) Females %fat = x (sum of 4) x (sum of 4) x (age)

Sport Books Publisher12 Norms for Percent Body Fat RatingMalesFemales Very Lean Lean Leaner than average Average Fatter than average Fat Overfat

Sport Books Publisher13 Circumference (Girth) Measurements Equipment: A flexible steel or cloth measuring tape  Circumference sites: Neck, chest, hips, thigh, calf, biceps, abdomen

Sport Books Publisher14 Body Mass Index (BMI) Can be used as an easy, inexpensive method for determining an individual’s healthy body weight Considers weight (kg) and height (m) BMI = Weight (kg) [Height (m)] 2 A BMI nomogram can also be used to determine BMI, it looks like this…

Sport Books Publisher15 Body Mass Index (BMI)

Sport Books Publisher16 Three general ranges: 1. Underweight 2. Healthy or Acceptable Weight 3. Overweight Severe Overweight Morbid Obesity  BMI score > 30 is classified as obese and associated with an increased risk of developing health problems  Risk of developing health problems is also associated with BMI’s classified as being within the underweight range Body Mass Index (BMI)

Sport Books Publisher17 Body Mass Index (BMI) The BMI is intended for men and women aged It is not intended for: 1. Babies 2. Children 3. Teenagers 4. Pregnant women 5. Very muscular people, such as athletes

Sport Books Publisher18 Bioelectrical Impedance (BIA) Based on differences in electrical conductivity between fat-free mass and fat mass

Sport Books Publisher19 Bioelectrical Impedance (BIA) Percent body fat is calculated from measures of body density determined by passing an electrical current through the body

Sport Books Publisher20 Bioelectrical Impedance (BIA) BIA is influenced by the subject’s hydration level The more hydrated one is, the leaner the BIA measurement will be

Sport Books Publisher21 Hydrostatic Weighing

Sport Books Publisher22 Hydrostatic Weighing Bone and muscle have a greater density than water Fat is less dense than water Thus, a person’s relative buoyancy is positively correlated with body fat That is, a person with a higher body fat percentage is less dense (weighs less in water) than a lean individual

Sport Books Publisher23 Hydrostatic Weighing To calculate body fat, the following measurements are needed: 1. Body weight on land 2. Underwater body weight 3. Water density at the performed temperature 4. Residual lung volume  More accurate measure

Sport Books Publisher24 The Bod-Pod

Sport Books Publisher25 The Bod-Pod Very expensive method Very accurate measure May facilitate measuring large or heavy individuals because it does not involve underwater submersion

Sport Books Publisher26 Dual Energy X-Ray Absorptiometry (DEXA)

Sport Books Publisher27 Dual Energy X-Ray Absorptiometry (DEXA) Can be used to determine body composition Can also measure bone density (bone mineral content)