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127 Cards in this Set
- Front
- Back
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body composition
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- a field of study and a component of fitness
- related to health and performance - important in good health physiologically/psychologically |
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body comp is associated with
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- prevention of chronic disease
- optimal performance |
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body comp provides an objective way to measure
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weight loss, weight gain, growth and development, aging
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body comp is used to evaluate
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nutritional status
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overweight
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- body weight in excess of a standard
- that standard is best thought of in height, gender, and frame size |
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over fatness
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- body fat excess an average appropriate range
- obesity is best thought of as over fatness accompanied by some sort of issue (thought of as a co-morbidity) |
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co-morbidities associated w over fatness
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- glucose intolerance
- insulin resistance - type II diabetes - dyslipidemia - hypertension - increased risk for cvd and cancer |
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body comp is important in psychological health
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yup, and so
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in addition to obesity having negative physical effects, it has psychological effects. social discrimination may occur and they may be thought of as
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- lazy
- lacking will power - not capable of taking care of themselves |
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as a result, the victim may have
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- lower self esteem
- lower levels of achievement - feelings of insecurity - may be reclusive - perceive themselves as unattractive - feel discriminated against when applying for jobs - feel disrespected by healthcare workers - greater incidence of suicide - may be less active - may be embarrassed in fitness setting |
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people who are athletic have a greater chance of developing eating disorders
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yup. disordered eating can lead to eating disorders. eating disorders are very addictive and difficult to treat
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what % of elite athletes in appearance and endurance sports have an eating disorder?
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50%
its higher in females |
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up to what % of male athletes have an eating disorder
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10%
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what sport has the worst eating disorders
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jockeys; less than 10% are male
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the personality of athletes is closely matched to a profile of people with an eating disorder. these qualities are
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- competitive
- perfectionist - under 'tight control' of somebody; coach, parent |
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where eating disorders are most common
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- endurance sports (distance running, swimming)
- appearance sports (diving, figure skating, gymnastics, ballet) - weight control sports (wrestling, boxing, horse racing) |
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physiological consequences of eating disorders
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- failure of cv system
- suicide - death |
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body composition involves 3 related concepts
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- body size
- body build - body composition |
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body size is measured thru
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weight tables, relative weight, body mass index, bmi prime, body volume index
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1. weight tables
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- consider height and weight
- least specific way to assess body comp bc theres no assessment of adipose tissue |
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weight table history
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- 1959- first weight tables; metro life insurance company made the tables. they were developed for people part of the metro insurance company. The company however did not take into account the cause of death or quality of life in developing these tables (i.e. at what weight should you be to have the best quality of life)
- 1983- revisions made; when these tables were revised, they included height, weight, and frame size. they measured the width of the elbow to establish 3 different frame sizes (small, med, large); population was 50% med frame, 25% small, 25% large - 1995- more revisions; current tables |
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elbow breadth
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- measured using a sliding caliper
- Best way to measure frame size - flex right arm at elbow joint at 90 degrees, and measure width across condyles |
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alternative ways to determine frame size
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- bitrochanteric width- the width bw greater trochanters of hips. measure w calipers. its harder to measure
- wrist diameter- measure width of wrist - wrist circumference- take middle finger and thumb and wrap around wrist. overlap= small frame, meeting= med frame, don't meet= large frame |
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1983 history con't
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- these 1983 tables allowed weight to increase as you got older. however, there is no reason ur weight at age 30 should be different than ur weight at age 60. the weight u have at ur best health should be the weight u maintain all the time
- the tables did not include the entire population - uninsured people were not included. people w chronic disease were not included. it also did not include *. did not include people who smoked cigs (even tho 50% of the population smoked back then). it used predominantly white middle class ppl. also, some of these weights were self reported, rather than measured |
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1995 history con't
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- USDA came out with new tables
- no consideration for frame size - weight was done without clothes or shoes |
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height and weight tables: height
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ok
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height is measured by a
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- stadiometer (the thing that hits ur head)
- also, measured on a balance beam scale (the thing u stand on usually) |
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height is measured to
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- the nearest half or quarter inch. without shoes, heels together, looking straight ahead.
- however, if it is for exercise purposes, measure with shoes |
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height reqs
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- have the person inhale deeply so they don't slouch. then measure height while they're holding their breath.
- recommended way is to use a wall mounted stadiometer |
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diurnal variation in height
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- as much as 8mm diff bw day and night height, so record the time of day you measure it
- time of day in measuring height is very important in osteoporosis |
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age also affects height
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- bw 30-70 yrs of age, you lose as much as 7cm in height
- industrial workers may have more than 7cm in height lost - in higher socioeconomic classes, you are less likely to lose height |
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height and weight tables: weight
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ok
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weight is typically measured to the nearest
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quarter lb
- no clothing, no shoes * |
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weight con't
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- repeat measurements should be done under the same conditions, and same time of day
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day to day variation in weight
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- up to 5 lbs
- record time of day when measuring weight |
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recommendation when keeping track of weight
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- once a week, weigh yourself
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2. relative weight
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- has been used in epidemoiological studies
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relative weight recognizes body frame differences better than
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height and weight tables
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relative weight process
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- takes the midpoint of a height weight range, and compares your actual weight to the midpoint of that range
- if you're 10% greater than the midpoint- ur overweight - if you're 20% or greater than the midpoint, ur obese - if you're twice the midpoint, you're severely obese |
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relative weight faults
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- if you have a large amount of muscle, or denser bones, it'll incorrectly classify you. It Has the same limitations that bmi has, except it's a little better bc it compares you to a midpoint, an exact point, rather than a range like bmi
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3. body mass index
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- weight relative to height, weight relative to height squared, weight relative to height cubed
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most widely used bmi
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wt/ht^2
- quetelet body mass index - doesn't work in every situation - Invented by a belgian mathematician in the 1850s and Ancel Keys popularized it in the 1970s. used it to look at nutritional status |
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How does bmi relate to (hydrostatic) body fat?
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- quetelet index correlates pretty well, around R= .70
- square .70 to get the coefficient of determination (v^2=.49). therefore, hydrostatic body fat and quetelet index correlate 49% - however, don't use bmi to determine body fat bc 49% is not that great |
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4. bmi prime
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- compares your actual bmi to the upper limit bmi (25)
- indicates what % you are above or below the upper limit |
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you're overweight if you're
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25+
- optimal weight is less than 25 |
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5. body volume index
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- takes a 3d scan of your body, measures bmi, waist circumference, and waist hip ratio, and looks at the location of the body mass
- depending on where your body mass is will show if your at greater risk etc. |
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#2 of body composition: body build
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- it is the morphology and structure of the body
- largely genetically determined i.e. basketball players look the same, track runners look the same |
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Sheldon introduced the idea of
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- somatotype
- a phsyical classification, a quantitative description of body morphology |
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he developed 3 types of body build; we are a mix of all 3
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- ectomorph
- mesomorph - endomorph |
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ectomorph
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- a linear or thin appearance; ectomorphs lack shoulder muscles; small bones, thin muscles, droopy shoulders, short trunks, long limbs, flat abdomens, flat lumbar curve, fragile looking; typical cross country runner
- associated w osteoporosis, fragility, falls |
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mesomorph
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- muscular appearance, abs are prominent and thick (six pack), larger bones, legs, trunks, and arms are heavily muscle, waist is relatively slender, skin is more course than soft, typically have a deep tan; typical wrestler
- associated w cv disease, cholesterol issues - should exercise 5x a week |
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endomorph
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- roundness, softness, short neck, smoothness in contours, predominance in abdomen hanging out of thorax; typical nfl lineman
- asociated w diabetes, metabolic type disease, insulin resistance |
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each is graded on a scale
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i.e. endo-meso-ecto
3-----5------1 - low=1-2 -midrange=3-5 -high=6-7 |
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heath carter technique
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- indirectly measures morphology
-involves everything from measuring frame size to skin folds |
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#3 component of body composition: body composition
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- the "make up" of the body
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how many components in the body can be measured in body comp
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- more than 30
- the more components you can measure, the more accurate - there is no direct in-vivo (while the person is alive) method for measuring body fat. we either have to look at a relative standpoint (%), or an absolute standpoint (the quantity of fat you have) |
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with body comp u can measure things like
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- elements, chemicals, cell components, tissue components
- i.e. potassium 40- found in lean tissue; used to measure lean body mass - all of these components can be expressed in absolute or relative terms |
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typically, body fat, when referred to in terms of body composition,"",
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is referred to as relative body fat. its the same thing as saying % fat
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body composition changeability
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- unlike body size and body build, body composition is easier to change.
- by training, diet, protein supplementation, etc. you can make dramatic changes in body comp |
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relative body fat is expressed in
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- fat mass and fat free mass
- fat free mass is NOT lean body mass |
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lean body mass
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- refers to bone and muscle
- fat free mass refers to everything that isn't fat i.e. connective tissue, organs, fluids, etc |
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types of techniques to measure body composition
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lab techniques and field techniques
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hierarchy of methodology in measuring body composition
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- direct, indirect, double indirect
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direct
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- involves dissection and chemical analysis
- various tissues are isolated - this is done on cadavers- only about 13 have been done |
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indirect
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- measures a property or component of the body and converts that to relative body fat
- most common model is a 2 component model using fat mass and fat free mass - indirect is based off small sample sizes aka it could be way off - chemical analysis- protein, water content - uses a property or component; properties like the K properties of certain tissues; radioactivity of certain tissues; - components are typically fat mass and fat free mass |
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double indirect
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- BIA, skinfolds, athropometry
- rely on even more assumptions |
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Hydrostatic weighing
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- indirect
- reliable but time consuming, expensive - gotta have cooperation, and people who are not anxious by being measured - highly dependent on person doing test and motivation of person being tested - a densitometry technique - not used anymore nowadays |
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in terms of body fat estimation, there are 2 techniques that can be used
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- anthropometry- height, weight, circumferences, skin folds, measures of girth
- densitometry- density (mass/volume), limiting factor is finding accurate volume bc finding mass is easy |
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hydrostatic weighing uses
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densitometry
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hydrostatic weighing is based on
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- a comparison of components of your body vs the density of water (1.00).
- density of fat= .9 - density of ffm= 1.1 - we use archimedes principle for hydrostatic weighing; a body immersed in water is buoyed by a counterforce equal to the weight of the water displaced. aka we measure ur underwater weight and ur weight not under water. the diff= ur volume |
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what kinds of things can affect hydrostatic weighing?
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- types of scales used
- cotillion is common (the ones at the supermarket) - load cells- more accurate than cotillion; takes weight 100x a minute - water temperature- lower the temp, less dense you'll be * (should be 34-36 degrees C) - how much air in your lungs determines buoyancy |
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how much air in your lungs determines buoyancy
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- Total Lung Capacity= Vital Capacity + Residual Volume
- RV= inhale and exhale as much as you can, whatever is left (female avg 1000ml, male avg 1200ml) - as you age, RV goes up, VC goes down - VC goes up w exercise, RV goes up a little, but not much - RV affected by size, age, gender |
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LC equation SHOULD read
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TLC= VC+RV+Gastric Volume
- GV is 100ml |
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fat mass wise, air in your swimsuit, air in your hair, air on your skin make it seem like you are closer to
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.9
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hydrostatic weighing recommendations
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- wear light swimsuit
- pee and #2 beforehand - shower beforehand to get rid of air bubbles in hair and swimsuit - record highest weight at the end of exhalation while ur underwater - repeat 3-10x - scuba belt- for fat people to keep them underwater - dont do hw on ppl w flexibility issues or disabilities |
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in women for hydrostatic weighing
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- menstruation can account for as high as 3% body error
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hydrostatic weighing equations
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Density of body= wt in air/{[(wt in air-wt in h20)/density of water)]-RV+GV}
^write this down and memorize - density of water= temp - GV= 100ml - Brozek formula for body fat= 457/density of body |
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as you can see in the equation, you need RV
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- you can have up to 4% error when measuring RV
- most acceptable time to measure is when they are in the water - range for RV= 1-1.5L; depends on age, gender, body size, fitness level - in a 50-60 yr old person, 40% of TLC is RV; for a college person, its 20% - some ppl measure VC and estimate RV from there; take VC and multiply (.24 for male) (.28 for female) - 3 ways to actually measure RV - nitrogen wash out (most common and accepted) - oxygen dilution - helium dilution |
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bod pod (air displacement plethysmography)
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- indirect
- takes body volume, calculates density, and u choose a formula that calculates percent body fat - originally a helium gas displacement chamber - a dual chambered instrument; 750L, fiber glass, electronics in back, person sits in tight swimsuit (swimsuit can account for up to 5% body fat error) |
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correlation coefficient bw hydrostatic weighing and bod pod
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.93
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bod pod process
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- takes like 10 min
- density measured in duplicates, not just once - dont breathe or it can throw off value - it tends to overestimate body fat in lean individuals (validity has yet to be determined for groups like this) |
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TGV
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thoracic gas volume- the amount of air that's in ur thoracic area; it can be measured or predicted
- 3 quick puffs of air * |
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more bod pod error and recommendations
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- wear swim cap, can erase up to 2.5% error
- how much facial hair you have makes a diff, up to 1.5% - body temp should be normal - don't do bod pod on sick ppl til 48 hours after theyre better |
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Other lab methods to measure body comp
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- DEXA, BIA, Potassium 40 count, MRI, Neutron activation analysis, CT scan, Ultrasound imaging, Isotope dilution,
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DEXA
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- dual energy x-ray absorptiometry
- new, reliable, good agreement w hydrostatic weighing, safe, rapid - exposed to a certain amount of radiation (must be a licensed x-ray technician in some states) - gives you equivalent of weekly environmental background radiation in 20 min |
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DEXA No's
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- no skill involved, like in skinfolds
- no body fluids taken - no special breathing procedures |
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DEXA process
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- a series of transverse scans from head to toe are taken at 1cm intervals
- assesses body comp in 14 regions of the body - measures total bone mineral and bone minera density, fat mass, and fat free mass - easier method than bod pod for elederly, and some individuals w certain disease, but not recommended for very obese people |
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DEXA history
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- developed in 1990s
- replaced dual photon absorptiometry (DPA)- developed in 80s |
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DEXA random facts
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- 3 brands- Lunar, Norland, Hologic
- theres a diff in software, scanners, and formulas for calculating body fat aka might get a diff value per machine - DEXA measures a 3rd component- bone density |
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BIA
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- bioelectrical impedance assessment
- fast, noninvasive, cheap - don't need to be an x-ray technician or anything |
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BIA process
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- low level of current sent thru body; body offers a resistance to that current. time of flow is measured by the analyzer. how long it takes to travel thru the body is measured
- amount of current is 500-800 microamps- u dont feel it. frequency is 50khz - the greater the water content in the body, the more easy current flows. fat=20% water, lean tissue=73% water; the electricity is conducted thru the electrolytes in the water |
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BIA instruments
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- there are BIA devices that are hand to hand (measure how long it takes to get from one hand to the other)
- there are BIA devices that are total body - some instruments use more than one frequency. those are more accurate |
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Guidelines for BIA assessment
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- no eating or drinking within 4 hours of the test
- no exercise within 12 hours of the test - urinate within 30 min of the test - no alcohol within 48 hours of the test - no diuretics or meds within 7 days of the test - no testing of females who have water retention during menstural cycle - environmental temp- lower temp underestimates fat free mass - euhydration is impt - BIA is very dependent on body fluids |
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Field methods to measure body comp
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- skin folds
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skin folds
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- most widely used practical method
- quick, easy (but requires skill), cheap - can be used in lab, field, or clinical setting - first developed in 30s - measured with a micrometer or plastic skinfold caliper |
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micrometer
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- measures a double layer of subcutaneous fat, with a constant tension of 10g/mm^2
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it is estimated that 1/3 of total body fat is
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- subcutaneous; by measuring that body fat in certain places, you can measure total fat
-however, body fat depends on age, ethnicty, and gender - lean individuals tend to put more fat internally, and less viscerally |
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skinfold correlation w DEXA
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.8-.9
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skinfold equations
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- have been developed, including single site regression equations, as well as multiple site regression equations
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they key to skinfolds
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- proper identification of the site; as well as the type of folding needing to be measured (vertical, horizontal, diagonal)
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the key to correct use of the calipers
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- picking the right spots on the body to measure and picking an equation that best suits the person ur trying to measure
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skinfold process
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- done on right side of body with person standing
- grab skinfold w thumb and index finger, put calipers on for 2 sec, then take it off, or else skin gets compressed and you get a lower value - 2-3 measurements per site |
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skinfold recommendations
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- skin should be dry
- best to take measurements in morning when person is normally hydrated |
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most accurate methods overall, of the methods of measuring body comp
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- hydrostatic weighing
- air displacement plethysmography (bod pod) - DEXA 2-2.5% error |
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less accurate
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- skin folds
- BIA - anthropometry up to 4% error |
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for many of these methods, you'll get more error in a clinical population bc
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- they have more problems with hydration and stuff
- the more components being measured there are, the better off you are - all of these components are subject to differences in age, gender, ethnicity, physical activity levels, body fat levels |
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body fat
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- broken down into essential and storage body fat
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storage
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- contained in adipose tissue
- contained wither viscerally (internal) or subcutaneously (beneath skin) - nutritional reserve; protects internal organs - 1/3 of storage fat is posited subcutaneously |
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older people tend to store fat where
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viscerally; bod pod has a hard time measuring visceral fat, so it might not be accurate for old ppl
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storage fat is also contained where
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intramuscularly; red muscle fibers have more fat than white muscles
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storage fat is contained in adipose tissue, which is
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- 83% fat
- 2% protein - 15% water |
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total body fat is made of storage fat and essential fat
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yeah
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theres a difference between storage fat in males and females
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- males- 12%
- females- 15% |
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essential fat
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- males- 3%
- females- up to 12% |
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total fat in males and females
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- males- 15%
- females- 22-27%; breast tissue is like 4% |
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in females, its harder to tell whos
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obese
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essential fat facts
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- in marrow of bones, spleen, heart, lungs, breasts
- important in terms of fat soluble vitamins - includes child bearing fat - women who get below 10% essential fat have problems - for some this may even be 12% whereas some may be able to get to 8% before they start having problems (i.e. menstrual or eating problems) |
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bone density in males v females
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- about 15% of total weight in males
- 12% in female |
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muscle differences male v female
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- males- 45% of total weight
- females- 36% |
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the previous are all for college age individuals
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- body comp is very susceptible to change
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some sports encourage loss of fat
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- some olympic coaches use body fat as cutoffs for teams
- other sports encourage fat mass/weight gain |
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bmi stuff
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- about 1/2 of what makes up ur body comp cannot be explained by bmi
- if ur actual body fat is 15%, youll get a range bw 10-20% as a result of bmi. the standard error of estimate is 5% |
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bmi standards developed by national heart/lung/blood institute in 1998
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- desirable bmi: 18.5-24.9
- overweight bmi: 25-29.9 - obesity is a bmi greater than or equal to 30 (30 is in the 90th percentile) - moderate obesity: greater than 35, less than 40 - morbid obesity: greater than 40; likely to die from the problem i.e. female 5'2 240lbs |
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standards con't
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- less than 18.5= underweight, might have eating disorder; greater cv risk, malnutrition
- less than 16- starvation - less than 17.5- anorexia nervosa |
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con't
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- up to 35 bmi: bmi is a better indicator of metabolic disorders and heart disease than percent body fat
- individuals who are normal or overweight bmi, waist circumference does a better job at evaluating risk - waist circumference is a better measure of central fat and instrabdominal fat than bmi. in men, its particuarly good int erms of health risk, since men put on fat intrabdominally and viscerally |
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con't
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- a lot of health professionals use bmi. in a general way its okay, but there are better ways to assess risk
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bmi faults
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- bmi does not assess body fat
- large framed, muscular individuals are usually incorrectly classified in terms of bmi. theyll be obese - taller ppl may be misclassified. in thiscase, use body mass/height^3, rather than squared - quetella index underestimates those who have lost muscle, but not fat - bmi overestimates patients with fluid retention issues; congestive heart failure, and kidney issues - bmi does not look at fat patterning - bmi does not look at different ethnicities. i.e. 21.5 asian will have more fat than a 21.5 caucaisian - asian overweight= 23-24.9, obese= 25+ - its important to recognize other factors in bmi other than fat; muscle can cause you to be overweight; bone density, blacks have more bone than whites; plasma volume-- theres an increase of 20% as a result of exercise |
