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BODY COMPOSITION ASSESSMENT &COMMON MYTHS
Christopher Berger, PhD, ACSM‐HFS, CSCS
University of Indianapolis
PRESENTATION OBJECTIVES
To discuss modern techniques of body composition assessment and relate those techniques to strength and conditioning professionals
To address some of the myths associated with body composition assessment and give you a chance to raise a few more
COMMON BODY COMPOSITION ACRONYMS
BIA Bioelectrical impedance analysisBMI Body mass indexDXA Dual‐energy X‐ray absorptiometrySEE Standard error of estimateUWW Underwater weighing
THE ASSESSMENT OF BODY COMPOSITION
Chapter 12 of Essentials of Strength Training and Conditioning (3rd edition)
Two‐compartment model
THE ASSESSMENT OF BODY COMPOSITION
Skinfold measurement is believed to be the most valid and reliable technique generally available to the strength and conditioning professional
THE ASSESSMENT OF BODY COMPOSITION
Classification schemes include…
… field methods, lab methods
… direct, indirect, doubly indirect
THE ASSESSMENT OF BODY COMPOSITION
Classification schemes also include…
… anthropometry(BMI, circumferences, skinfold)
… densitometry(UWW, plethysmography)
… other techniques(BIA, DXA)
SOURCE OF ASSESSMENT PROBLEMS? Do you know what you are doing?
Have you been doing ___ long enough?
Where did you get your instruction?
Is your equipment any good?
What are you telling your athlete?
5 MYTHS
1. Body composition = physical fitness2. Body mass index is worthless3. Bioelectrical impedance analysis is
unreliable but we have to use it anyway4. Dual‐energy X‐ray absorptiometry is our
“gold standard”5. When it comes to prediction equations,
any conversion will do
1.BODY COMPOSITION IS THE END‐ALL, BE‐ALL OF PHYSICAL FITNESS
What is your ability to perform physical activity?
Health‐related
Skill‐related
Physiologic
1.BODY COMPOSITION IS THE END‐ALL, BE‐ALL OF PHYSICAL FITNESS
More than half (51.1%) of health club members join “to lose weight”Source: The IHRSA Trend Report, August 2012
Active obese individuals actually have lower morbidity and mortality than normal weight individuals who are sedentarySource: Blair SN, Brodney S. Med Sci Sports Exerc. 1999 Nov;
31(11 Suppl): S646‐62.
2.BODY MASS INDEX IS WORTHLESS
BMI numbers do not take into consideration the amount of muscle mass and bone a person has.
BMI is not reliable for non‐European ethnicities.
The lower my BMI, the better!
Everybody knows that BMI is not accurate.
Probability human body What are the characteristics of
the “normal man”? Ancel Keys (1904‐2004) BMI
2.BODY MASS INDEX IS WORTHLESS
2013 NFL #1 draft pick was Eric Fisher (Central Michigan) 306 lbs, 6’7” height
BMI = 34.5
2.BODY MASS INDEX IS WORTHLESS
What should body fat % be then?
Well… … no established universal standards
… indirect methods produce errors
… no universal criterion assessment
Athletic MEN, 5‐13% (3‐5% essential)Athletic WOMEN, 12‐22% (8‐12% essential)Source: ACSM’s Resource Manual for Guidelines for Exercise Testing and Prescription
(7th ed), 2014, page 304.
Source: McArdle WD et al. Exercise physiology: Nutrition, energy, and humanperformance (7th ed). 2010, Figure 29.3, page 765.
3. BIA IS UNRELIABLE SO… LET’S USE IT!First, do not use this device…
… after drinking alcohol… after drinking a large
amount of water or aftermeals (1 to 2 hours)
… immediately after exercise… immediately after a shower,
bath or sauna
Why? BIA is sensitive to H2OSource: OMRON Fat Loss Monitor Model HBF‐306C
Instruction Manual, 2012.
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WK 1 WK 2 WK 3 WK 4 WK 5 WK 6 WK 7 WK 8
YOUBIAREALITY
Pop quiz! What’s wrong with this picture?Pop quiz! What’s wrong with this picture?
Source: McArdle WD et al. Exercise physiology: Nutrition, energy, and human performance (7th ed).Philadelphia PA: Lippincott Williams & Wilkins, 2010, Figure 28.14, page 749.
3. BIA IS UNRELIABLE SO… LET’S USE IT! Bodystat® QuadScan 4000 can estimate intra‐, extra‐cellular, total body water (hydration, edema)
“Ballpark” basal metabolic rate, body composition
4. DXA IS OUR “GOLD STANDARD” Well… sort of.
Lab reference method, provides bone mineral component of multi‐compartment models
SEE 2‐3%
4. DXA IS OUR “GOLD STANDARD” Advantages…
… fast, convenient
… minimally influenced by water fluctuation
… bone mineral densities what you do not knowSource: Ackland TR et al. Sports Med. 2012 Mar 1;42(3):227‐49.
4. DXA IS OUR “GOLD STANDARD” Disadvantages…
… very small, large, or lean subjects introduce errors higher than the reference subject
… some subjects are too tall, wide for the bed
… assumes segment tissue consistency (not true!)
… manufacturer differences
… you (may) have to be certified to use DXA
Source: Ackland TR et al. Sports Med. 2012 Mar 1;42(3):227‐49.
5. WHEN IT COMES TO PREDICTION EQUATIONS,ANY OF ‘EM WILL DO
Source: ACSM’s Guidelines for Exercise Testing and Prescription. (8th ed), 2010, page 69.
5. WHEN IT COMES TO PREDICTION EQUATIONS,ANY OF ‘EM WILL DO
Not hardly
From: Athlete (HarperCollins, 2002) and Howard Schatz and Beverly Ornstein, Schatz/Ornstein Studio
Source: ACSM’s Guidelines for Exercise Testing and Prescription. (9th ed), 2014, page 71.
SOME TAKE‐HOME POINTS
When you want body composition data, measure body composition.
If you are going to assess body composition, spend the money to do it right.
Do the numbers look screwy? If so, don’t use ‘em.
Be careful about what your athlete does with the data you share.
SUGGESTED READINGHarman E, Garhammer J. Administration, scoring, and interpretation of selected tests. In: Baechle TR, Earle RW (Eds). Essentials of Strength Training and Conditioning (3rd ed). Champaign IL: Human Kinetics, 2008, pp 252‐253, 268‐270.
Pescatello LS et al (Eds). ACSM’s Guidelines for Exercise Testing and Prescription (9th ed). Baltimore MD: Lippincott Williams & Wilkins, 2014.