Ch 5 Body composisiton Flashcards
Classification purposes related to health, fitness and wellness
Relative body fat (%BF)
%BF spectrum for 20-29 year olds
Men
Minimal - 3.0%
Average - 13.5%
Excessive - >22.0%
Women
Minimal - 10.0%
Average - 20.0%
Excessive - >32.0%
Ideal %BF for men
Essential Fat
Athletes
Fitness
Average
Obese
Essential Fat - 2-5%
Athletes - 6-13%
Fitness - 14-17%
Average - 18-24%
Obese - 25% +
Ideal %BF for Women
Essential Fat
Athletes
Fitness
Average
Obese
Essential Fat - 10-13%
Athletes - 14-20%
Fitness - 21-24%
Average - 25-31%
Obese - 32% +
Assumptions for two component model
Fat + FFM
Density of fat = 0.901 gcc-1
Density of FFM = 1.10 gcc-1
Densities are same for everyone
Densities of various tissues are constant
Indirect measurement of subcutaneous body fat
Invasive method
Skinfold Method (3-4% ME)
3 Skinfold sites for male and female
Male - chest abdomen and thigh
Female - Triceps suprailiac and thigh
Major sources of error for skinfolds
Technician Skill
Type of SKF caliper
Client factors
Noninvasive
Uses many of same sites as SKF
Hand-held want sends and receives sound signals
Ultrasound
Conversion of sum of wanted site subcutaneous fat similar to sum SKF to %BF
Proprietary derivations to sum SKF equations
A-mode ultrasound
Bands depict tissue depth and interfaces
Standard SKF sites %body position inappropriate for estimating %BF
Interpretation of results is main challenge
B-mode ultrasound
Sources of error in ultrasound
Technician
Mode of Ultrasound
Signal frequency
Sound speed
Combination of pairs of sending and receiving electrodes
Tissues either interfere or conduct electrical currents
Bioelectrical impedance analysis
Assumptions for BIA
body is perfect cylinder
Tissues are current conductors or insulators; current seeks path of least resistance
Is skinfold or Bioelectrical impedance analysis better for someone who is obese
bioelectrical impedance analysis (due to excessive adipose tissue)
bioelectrical impedance analysis sources of measurement error
Analyzer being used
Client Factors
Technician skill
Environmental factors
FFM prediction equation
Anthropometric methods
Based on body size and proportions
Assists in classifying disease risk
Methods: Body mass index, circumferences, skeletal size
BMI classifications
Underweight
Normal Weight
Overweight
Obeisty
Class 1
2
3
Underweight - <18.5
Normal Weight - 18.5-24.9
Overweight - 25.0-29.9
Obeisty
Class 1 - 30.0-34.9
2 - 35.0-39.9
3 - >40
Is body comp taken into account with body mass index
No
Measures of girth
Affected by everything beneath the tape measure
Use anthropometric tape measure to increase accuracy
Circumfrences
Measure of abdominal adiposity
No standard waist location
Waist circumference
Navy tape measure method
Mens body fat calculation
Abdominal-neck=circumference value
Navy tape measure method
Womens body fat calculation
Waist+hips-neck=circumference value
Sources of measurement error for anthropometric methods
Equipment
Technician skill
Client factors
How to calculate Waist to hip Ratio
Divide waist circumference by your hip circumference
Estimates body volume
Requires total body submersion
body density= total mass/body volume
Residual lung volume measurement increases acuracy
Hydrostatic weighing
gold standard
Proportions of FFM constituents that are assumed constant for everyone in hydrostatic weighing
Water - 73.8%
Protein - 19.4%
Mineral - 6.8%
based on byles law of pressure volume relationships
Air Displacement Plethysmography
Bod Pod
Best method to estimate mineral contribution to FFB
Dual-Energy X-ray Absorptiometry (DXA)
