Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ephe 444 > body composition > Flashcards

body composition Flashcards

1
Q

components of mass:

A

fat mass:
- essential fat
- storage fat
fat free mass:
- bone
- lean body mass
–> skeletal muscle
–> organs
–> water (~60-70%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why assess body composition?

A
  • classify disease risk (type 2 diabetes, hypertension, heart disease, stroke, cancers)
  • sport performance (biomechanical advantage?)
  • weight management: aid in nutrition& exercise prescription
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2 compartment:

A

fat mass = 15-25%
fat free mass = 75-85%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

3 compartment:

A

fat mass
fat free mass
*total body water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

4 compartment:

A

fat mass
fat free mass
*total body water
*bone mineral density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

two-compartment model: advantages/disadvantages

A

advantages:
- easier to measure?
disadvantages:
- assumes densities of tissues are constant within and between individuals, and the person measured only differs from refernce body in amount of fat
- if true FFM density > 1.10 = %BF is underestimated
- if true FFM density <1.10 = %BF is overestimated
- FFM varies with: age, PA level, ethnicity, gender, amount of body fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

multi-compartment model:
advantages/ disadvantages

A

advantages:
- doesn’t use “reference body” - takes into account age, gender, ethnicity, PA
- SEE < 1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

5+ compartment models

A

fat mass
fat free mass
total body water
bone mineral density
mineral content of soft tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

indirect methods of assessing body composition:

A
  • hydrostatic weighing
  • DXA
  • BodPod
  • BIA*
  • skinfolds*
  • BMI*
  • waist circumference*
    *doubly indirect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

hydrostatic weighing:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. r = 0.95 - gold standard
  2. r=0.99 - validated if sample is HOMOGENOUS
    assumes:
    - air trapped in body is uniform and always 110ml
    - client is motionless
    - hydration status controlled
  3. high?
  4. low
  5. high - discomfort
  6. low - specialized equipment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hydrostatic weighing:
definition/ basic protocol

A
  • find body density by estimating body volume + BW - Archimedes’ principle
  • 7-10 trials, use avg of 3 highest weight
  • need to hold breath
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

archimedes’ principle

A

upward bouyant force = weight of the water displaced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

body density =

A

body mass/ body volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

siri’s equation for hydrostatic weighing; %BF =

A

%BF = (495/body density) - 450

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

BODPOD:
definition/ basic protocol

A
  • find adjusted body volume of individual by comparing volume and pressure of front chamber w reference chamber
  • measure raw body volume w air displacement and Boyle’s law
  • must account for thoracic gas volume (total air inhaled or exhaled)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Boyle’s Law:

A

pressure-volume relationship = inverse
P1V1 = P2V2
1 = empty chamber
2 = filled chamber

17
Q

BODPOD
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. mid?
    - r=0.97 compared to hydrostatic wt
    - “fair” predictive accuracy
    - assumes control of isothermal effects of clothing, hair, body SA
  2. mid?
    - test retest reliability = 0.9-0.96
    - thoracic gas volume?
  3. high - minimal technical skill
  4. SEE is ~4%
  5. low
  6. low - size restriction, need chamber, approved clothing and skin cap, claustrophobia,
18
Q

DXA (dual energy xray absorptiometry):
definition/ basic protocol

A
  • 3 compartment model ( total body weight = BM mass + bone free lean tissue + fat mass)
  • based on calibrated x-ray beams + dual photo energy (ratios of high vs low x ray energies are? constant b/n individuals)
  • “emerging gold standard”
19
Q

DXA:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. high
    - for “healthy, normal weight in children/adults” mostly lol
    - r= 0.90 concurrent validity w hydrostatic wt
    - accounts for individual variability in BMD
  2. high - but depends
    - r= 0.90-0.99 depending on manufacturer
    - Cv = 0.8-2.7%
  3. high - as long as subject is accurately positioned (in anatomical position) on DXA
  4. good - SEE = ~3%BF
  5. low - low radiation dose BUT can’t use if pregnant
  6. mid?
    - quick, less complicated than hydrostatic wt
    - must fit bed dimensions
    - expensive
20
Q

doubly-indirect methods:

A
  • BIA (bioelectrical impedance)
  • skinfolds
  • BMI
  • waist circumference
21
Q

BIA:
definition/ basic protocol

A
  • low electrical current passed through body, resistance measured by 2+ electrodes indicates total body water = estimate % BF
  • 2 - compartment model = hydration fraction is always 73%
  • water has low resistance to current (muscle = 73% water, fat = 5-13%)
  • assumes body is perfect cylinder (unifrom length and CSA)
22
Q

BIA:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. yes…
    - in healthy, young, euvolemic adults
    - 3-8% variability…?
  2. mid?
    - r = 0.66 - 0.94 depending on manufacturer..
    - Cv from 0.3-2.8%??
  3. high, espicially w foot-to-foot devices
  4. good SSE of FFM in heterogenous pop. = 3.5-3.7kg
  5. low
  6. easy to use, but machine expensive
23
Q

BMI:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
24
Q

why measure waist circumference?

A
  • predictor of visceral fat independent of age, sex, and race (excessive body fat on trunk = higher risk factor for coronary heart disease)
  • reduce WC w/ diet+exercise to reduce cardiometabolic risk w/o change in BMI
25
Q

WC:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. low
    - doesn’t depict actual amount of body fat
    - body shape is individualized
    - most useful when combined w BMI
  2. high
  3. low = depends on administrator
  4. low?
  5. low - but may be uncomfortable
  6. high
26
Q

skinfolds:
definition

A
  • estimate total body density based of measures of subcutaneous fat
  • jackson pollock equation = validated gold standard
27
Q

Skinfolds:
1. validity
2. reliability
3. objectivity
4. sensitivity
5. participant burden
6. practicality

A
  1. meh
    - w normal weight/ lean adults
    - concurrent validity w hydrostatic wt r= 0.92
    - r = 0.76 compared to hydrostatic wt???
    - precision depends on type of callipers used
    IF administrator is consistent
    - relies on prediction equation**w
    BUT assumes
    - skin thickness is negligible
    - fat distribution is similar b/n people
  2. r= 0.99, but depends on calliper used
  3. low - dependent on administrator skill
  4. low?
    - SEE ~3.5% is trainined.. but ften greater
  5. low - but may be uncomfortable
    6.
    - equipment relatively inexpensive
    - easy to administer if trained
    - not for higher weight/ fat populations
    - a bit time consuming, less so than other methods

ephe 444 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions