Bioelectrical Impedance Accuracy

Discussion in 'Fitness & Nutrition' started by LancerV, Dec 20, 2005.

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  1. LancerV

    LancerV Something Happened OT Supporter

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    How accurate is this thing? Compared to skinfolds, skin folds or BIA. Im think this thing is way the fuck off :hsugh:
     
  2. gtpjim

    gtpjim New Member

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    Way the fuck off.

    The PT guy was convinced I was 7.8% bodyfat. I was like I can't even see my abs. "All your fat must be there!" "Ok buddy"
     
  3. LancerV

    LancerV Something Happened OT Supporter

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    Mine said I was at 42% I was like :hsugh: That means I would need to weigh 130 to get to 10% BF :eek4: Skin Fold said between 24-26%
     
  4. LancerV

    LancerV Something Happened OT Supporter

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    Bioelectrical Impedance

    What is it: This method is based on the fact that the lean (muscle) tissue of the body is much more conductive due to its higher water content than fat tissue. The more lean tissue present in the body, the greater the conductive potential, measured in ohms.

    How it works: While you’re on your back, the bioimpedence meter is attached to your body at the extremities (one electrode attached to the foot and one on the hand). A small 500-800 micro-amp (50 kilohertz) signal measures the body's ability to conduct the current. The current flows through the body, finding varying resistance depending on the density of the muscle, the amount of body fat encountered, and the hydration of the tissue. The slower the signal, the more fat is present, because fat interferes with the signal.

    This technique is commonly used with a hand held device (found at many local gyms) or a digital scale (found at most retail stores). The limitation with these instruments is that the hand held device only measures upper body fat, and the scale only measures lower body fat.

    Accuracy: Bioelectrical impedance can have a large margin of error, especially if the subject is extremely obese or extremely lean. In one study, female distance runners averaged 20 percent body fat using this method, but more reliable methods showed that they were actually closer to 10 percent. Dehydration can also skew the results; the signal slows down, and the subject appears to have more fat than they actually do. Compared to other testing methods (girth, skin-caliper) this is the less accurate.

    Limitations: f protocol is not followed (no eating or drinking 4 hours prior to the test, no exercising 12 hours before the test, etc.), the test will be inaccurate. Inconsistency in hydration, body fluids and intestinal content can result in high degree of variation from day to day. This makes this method less suitable for repeated testing when measuring small changes in body fat level. The test also tends to overestimate percent body fat in very lean individuals and underestimate body fat in obese people.

    Where you can get it: Bioelectrical impedance testing can be found at local gyms, YMCAs, community centers and universities. Prices range from free to $30 per test. Home machines can be purchased for anywhere from $100-$400.

    Fuck Dat
     
  5. gtpjim

    gtpjim New Member

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    a lot even*
     
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