Final Exam Slideshow 12.1 Flashcards
Relative body fat (%BF)
Classifies level of body fatness
%BF spectrum for 20- to 29-year-olds
Average for:
Men
Women
Men: 15.0%
Women: 20.0%
BC Methods
Reference Methods: 3 of them
1) hydrostatic weighing
2) air displacement plethysmography
3) dual-energy X-ray absorptiometry
BC Methods
Field Methods
Field Methods
1) skinfold
2) ultrasound
3) bioimpedance
4) anthropometry
Body Composition: Two-Component Model
Assumptions
- Density of fat = 0.901 g∙cc –3
- Density of FFB = 1.10 g∙cc –3
- Densities of fat and FFB components are same for EVERYONE
FFB Water (73.8%); Protein (19.4%); Mineral (6.8%) - Densities of the various tissues composing the FFB are constant within
an individual - Individual being measured differs from the reference body only in the
amount of body fat
Whole body =
fat + fat-free body (FFB)
Body Composition: Two-Component Model
Factors:
FFB density known to vary
Age
Sex
Ethnicity
Physical Activity
%BF
Variance due to % water and % mineral within FFB
Body Composition: Multi-Component Model
Eliminate much of guesswork in 2C model assumptions
Measure %water and %mineral
Useful for developing population-specific formulas
Hydrostatic Weighing (HW)
Valid and reliable densitometric method
Estimates body volume (BV)
Requires total body submersion
Computation of Db
Db = total body mass / BV
Residual lung volume (RV) measurement
increases accuracy
Pretest guideline adherence a must