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Body Composition
Measurement Methods
Overview
• Body composition in general
• Body composition applications
• Body composition models
• Body composition assessment (reference) methods
• Field methods
Skinfold method
Bioelectrical Impedance Analysis Method
Petra Polster, MSc
[email protected]
BODY
COMPONENT
MODEL
• Additional Anthropometric Methods
Body Compartment models
Body Weight (BW)
Body Fat (BF)
Lean
Lean Body Mass
(LBM)
Body Fat (BF)
Body Fat (BF)
Extracellular Mass (ECM)
Mass (ECM)
ECW
ECM
Body Cell Mass (BCM)
BCM
ICW
Scale
Body Composition
Skinfolds
BIA
Reference man
• different types of tissue:
1. fat free mass: muscle, bone and organs
water,
t mineral
i
l and
d protein
t i
2. fat (adipose) tissue
Body mass componen
nt (kg)
= different compartments that make a person’s weight
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Reference women
Body Composition
Body mass componen
nt (kg)
Essential and storage fat
Essential fat
• heart, lungs, liver, spleen, kidneys, intestines, muscles
and lipid-rich tissues of the central nervous system and
bone marrow
• ~ 10 % of total body lipid
→ normal physiological function
Storage fat
• primarily in adipose tissue
• visceral fat tissue (organ protection)
• subcutaneous fat
Body Composition
Body Composition Applications
Fat Free Mass (FFM) and Lean Body Mass (LBM)
• Identification of the health risk associated with excessively low or
high levels of total body fat
Fat Free Mass (FFM)
• FFM = body mass – fat mass
• non-fat
f t components
t off the
th human
h
body
b d
• skeletal muscle, bone and water
Lean Body Mass (LBM)
• FFM + essential lipids
• Promoting the client’s understanding of health risks risk associated
with excessively low or high levels of total body fat
• Monitoring of changes in body composition that are associated with
certain diseases
• Assessment of the effectiveness of nutrition and exercise
interventions in altering body composition
• Estimation of a healthy body weight for clients and athletes
• Formulation of dietary recommendations and exercise prescriptions
• Monitoring of growth, development, maturation, and age-related
changes in body composition
Body composition and health
Body composition and performance
Fat Free Mass (FFM)
• association between body composition and physical
performance
• FFM and its component – relationship to health and
athletic performance
• low levels or loss of FFM:  impaired functional capacity
 ↓ energy expenditure
 ↑ risk gaining FM
• low bone mineral mass:  ↑ risk osteoporosis
• body composition data of an athlete for
 tracking changes – effectiveness of training
 estimating an optimal body weight for weight class sports
 screening and monitoring the athlete’s health status
Body composition and sport performance
1. Fat Mass (FM) and performance
2. Fat Free Mass (FFM) and performance
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Body composition and performance
Body composition and performance
Percentage body fat in athletes grouped by sport category
Fat Mass and Performance
Inverse relationship between FM and performance of PA:
• body movements either vertically (jumping) or horizontally
(running)
• excess fat: ↑ metabolic cost of PA
• in contact sports and swimming for example – advantages of
relatively high FM compared to other athletic groups
Body composition and performance
Body composition and performance
Body composition of top American male athletes
Fat Free Mass and Performance
+ activities that require force application (e.g., throwing, pushing)
 large absolute amount of FFM – negative effect on
performance that requires body translocation (e.g., running,
jumping) or body rotation (e.g. gymnasts)
+ positive correlation between physical
performance and FFM in
military-related tasks
+ high FFM:FM ratios –
generally better performance
Body composition and performance
Body composition and performance
Problems of extreme leanness
Problems of extreme leanness
• risk groups for e.g. gymnasts, dancers, distance runners etc
• severe weight loss, starvation and dehydration →
↓ isometric and dynamic strength
• long-term-effect: abnormal kidney function
• ↑ risk for developing eating disorders → triad:
• male athletes with the lowest body fat levels in weight-class
sports (e.g. boxing, lightweight rowing etc.)
• low %BF – performance benefits, but also negative effect
(men < 5 % and women < 12 %)
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Body composition assessment methods
Hydrodensitometry / Underwater Weighing
• Laboratory vs. field methods
• measures body density (Db)
• “gold standard”
• estimation of total body volume – water displacement • combination with measurement of residual lung volume
• 4 reference methods:
1. Hydrodensitometry / Underwater Weighing (UWW)
Principle and Assumptions
• Archimedes’ Principle
2. Air Displacement plethysmographie (ADP)
3. Hydrometry
4. Dual‐Energy X‐Ray Absorptiometry (DEXA)
Hydrodensitometry / Underwater Weighing
Hydrodensitometry / Underwater Weighing
Archimedes' Principle of displacement
Testing procedure
• The density of fat mass and fat-free mass are constant.
• Lean tissue is more dense than water.
• Fat tissue is less dense than water.
 person with more body fat will weigh less underwater
and be more buoyant.
1. Weigh the subject to the nearest 0.1 kg.
2. Measure or estimate the subject's RV.
3. Tare (zero) the scale in the underwater weighing tank.
Air Displacement Plethysmography (ADP)
Air Displacement Plethysmography (ADP)
• Bod Pod measures body density (Db)
• estimation of total body volume – air displacement • advantages compared to UWW
Principle and Assumptions
• relationship between pressure and volume
Testing Procedure
• client sits in a chamber
• changes in pressure within a closed chamber between the front testing chamber and a reference chamber
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Hydrometry
Hydrometry
• measures the body water content
• human body: 60 % of the body weight = water (variable)
• association between TBW and FFB
3. Tracer equilibrium is achieved relatively rapidly.
4. Neither the tracer nor body water is metabolized during the equilibration time.
5 The relative hydration of the FFB is 73 2 %
5.The relative hydration of the FFB is 73.2 %
Principle and Assumptions
• measurement of TBW, ECW and ICW via dilution of isotopic tracers – estimation of TBW and %BF
• Assumptions:
1. The tracer is distributed only in body water.
2. The tracer is distributed evenly throughout all water compartments.
Testing Procedure
• collecting of saliva before and after drinking the solution
• drinking of an isotope solution
• analysis of the collected saliva
Dual-Energy X-Ray Absorptiometry
Dual-Energy X-Ray Absorptiometry
• measures bone mineral density, bone‐free LTM, FM soft‐tissue mass (LTM + FM), FFM, and %BF
• 2 X‐ray beams with differing energy levels are aimed at the patient'ss bones
the patient
bones
Testing Procedure
• calibrating of the DEXA‐Scanner
• height and weight measurement of the client
Principle and Assumptions
• the measurement is dependent on the thickness, density, and chemical composition of the underlying tissue – X‐ray energies through fat, lean tissue, and bone varies
• these attenuation ratios = constant for all individuals (= assumption)
Field methods of body composition assessment
Skinfold Method
Body Mass Index (BMI)
= kg/m2
• body weight classification • but: no distinction between fat and lean body mass
Practical use of • SKF is a good measure of subcutaneous fat
• distribution of fat subcutaneously and internally is similar for all individuals within each gender
similar for all individuals within each gender
• relationship between skinfold thickness and Db
• relationship between skinfold thickness and %BF
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Skinfold Method
Equipment
• Caliper Skinfold Method
measurement tape
Testing Procedure
• measurements: right site of the body
measurements right site of the body
• identification of the measurement sites
• marking the measurement sites
• grasping the skinfold
• placing the caliper jaws
directly on the mark
• keep the fold elevated while the measurement is taken
• releasing the jaw pressure slowly
• result reading after 4 seconds
• opening of the jaws and removing it from the site
• the measurement should be repeated 3 times
• calculating %BF – SKF prediction equations (Siri‐Equation)
SKF Equations for Athletes - Examples
SKF Equations for Athletes - Examples
Jackson and Pollock (1978)
• sum of 7 skinfolds (physical active men > 18 years)
• Db = 1.112 – 0.00043499 * (Σ 7SKF) + 0.00000055 * ((Σ 7 SKF))2 – 0.00028826 * (age)
( g )
Jackson and Pollock (1978)
• sum of 7 skinfolds (physical active men > 18 years)
• 7 skinfolds: chest + midaxillary + triceps + subscapular + abdomen + anterior suprailiac
p
+ thigh
g
Jackson et al. (1980)
• sum of 4 skinfolds (female athletes)
• Db = 1.096095 – 0.0006952 * (Σ4 SKF) + 0.0000011 * (Σ4 SKF)2 – 0.0000714 * (age)
• Db = 1.096095 – 0.0006952 * (Σ4 SKF) + 0.0000011 * (Σ4 SKF)2 – 0.0000714 * (age)
SKF Equations for Athletes - Examples
SKF Equations for Athletes - Examples
Jackson and Pollock (1978)
Db = 1.112 – 0.00043499 * (Σ 7SKF) + 0.00000055 * (Σ 7 SKF)2 – 0.00028826 * (age)
Jackson et al. (1980)
• sum of 4 skinfolds (female athletes)
• 4 skinfolds: triceps + anterior suprailiac + abdomen + thigh
g
%BF (percent body fat)
• resistance trained: (5.21/Db) – 4.41
• endurance trained: (5.03/Db) – 4.59
• all sports: (5.12/Db) – 4.68
• Db = 1.112 – 0.00043499 * (Σ 4SKF) + 0.00000055 * (Σ 4 SKF)2 – 0.00028826 * (age)
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SKF Equations for Athletes - Examples
Skinfold Method
Jackson et al. (1980)
Db = 1.112 – 0.00043499 * (Σ 4SKF) + 0.00000055 * (Σ 4 SKF)2 – 0.00028826 * (age)
Advantages:
• simple method
• not expensive
%BF (percent body fat)
• resistance trained: (4.97/Db) – 4.52
• endurance trained: (4.95/Db) – 4.50
• all sports: (4.97/Db) – 4.52
Measurement errors
• technician measurement skills
• type of caliper
• SKF prediction equations
(age, gender, physical activity level)
Bioelectrical Impedance Analysis (BIA)
Bioelectrical Impedance Analysis (BIA)
Method
• rapid, noninvasive, and relatively inexpensive method Equipment: BIA Models Segmental BIA
• impedance measurement of each arm, leg and torso
• using 8 electrodes
• low‐level electrical current – passed through the body
• measures the resistance of body tissues to the flow of the electrical signal
Principle
Multifrequency BIA
• single‐frequency BIA devices: 50 kHz
• 4 electrodes
Upper‐Body and Lower‐Body BIA Analyzers
Bioelectrical Impedance Analysis (BIA)
Bioelectrical Impedance Analysis (BIA)
Testing Procedure
• Pre‐Testing Guidelines
• client: lying flat on a non‐conducting surface
• measurement on the right side of the body
• cleaning the skin at the electrodes site (with an alcohol pad)
• placing the sensor electrodes
Pre‐Testing Guidelines
• No eating or drinking within 4 hours of the test!
• No exercise within 12 hours of the test!
• Client should urinate within 30 minutes to the test!
• No alcohol consumption within 48 hours of the test!
• No diuretic medications within seven days of the test!
• No testing of female clients who perceive they are retaining water during that stage of their menstrual cycle.
• attaching the lead wires to the appropriate electrodes (red – wrist and ankle; black: hand and foot)
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Bioelectrical Impedance Analysis (BIA)
Advantages
• very simple method
• testing takes less than a minute
• comfortable ‐ transportable
• not expensive
Waist and Hip Circumference
Additional Anthropometric Methods
The circumference technique
• measures body shape, using a tape measure
• same investigator - repeated measurements
• subjects are required to wear underwear during the
measurement, so that the thickness of clothing
does not influence the result.
• morning measurement
• subjects are measured in the standing position
• normal breathing at the time of the measurements
• measurements are made in duplicate
Body Composition
Measurement Methods
Thank you for listening!
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