Body fat %

  • stretch77

    Posts: 6

    May 25, 2012 3:26 PM GMT
    Yesterday at the gym I used one of these body fat meters that looks like an old video game controller and you hold it up in front of you and in like 5 seconds it reads out your body fat %.
    It came up with 22.6% for me. My profile pic is from last week.
    does that look like 22.6%? My tennis partner has a gut and he said he's 17%!
    Anybody have any idea what their percent is and what 22.6% is supposed to look like? Seems too high to me.
    thanks
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    May 25, 2012 3:40 PM GMT
    Well fat doesn't deposit only on stomach, it can be on the ass and thighs as well. Maybe the machine was malfunctioning, try again. I got 13% last time I check, and I can still feel some body fat on my stomach even though my abs showing.
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    May 25, 2012 3:43 PM GMT
    Those things aren't very accurate. The scales are getting better but they're not great either.
  • gwuinsf

    Posts: 525

    May 25, 2012 3:59 PM GMT
    I don't think the bioelectric impedance way of measuring body fat work very well. When I use calipers I get 15% BF and when I use my scale at home I get anywhere from 21-24%. It relies heavily on your hydration level so time of day can greatly impact your results.

    In the past 2 months I've lost about 10 lbs. (hopefully of BF) and my scale still pretty much says the same. Maybe it's changed 1 or 2%.

    I would suggest for your own piece of mind getting a cheap pair of calipers and measure yourself at home. They're only $5

    http://www.amazon.com/Accu-Measure-Fitness-3000-Personal-Tester/dp/B000G7YW74/ref=sr_1_1?ie=UTF8&qid=1337961541&sr=8-1
  • muscletruk

    Posts: 109

    May 25, 2012 4:03 PM GMT
    there are lots of variables, and the hand held devises are some of the leat accurate
    just off habd i would't guess you to be over 15%
  • stretch77

    Posts: 6

    May 25, 2012 4:09 PM GMT
    gwuinsf saidI don't think the bioelectric impedance way of measuring body fat work very well. When I use calipers I get 15% BF and when I use my scale at home I get anywhere from 21-24%. It relies heavily on your hydration level so time of day can greatly impact your results.

    In the past 2 months I've lost about 10 lbs. (hopefully of BF) and my scale still pretty much says the same. Maybe it's changed 1 or 2%.

    I would suggest for your own piece of mind getting a cheap pair of calipers and measure yourself at home. They're only $5

    http://www.amazon.com/Accu-Measure-Fitness-3000-Personal-Tester/dp/B000G7YW74/ref=sr_1_1?ie=UTF8&qid=1337961541&sr=8-1


    My bathroom scale also has that feature and varies from 22-26% so that's seems pretty sketchy too. I have some calipers, but didn't use them. I'll see what I find out fromthat. thanks
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    May 25, 2012 4:20 PM GMT
    i had mine done at the gym, with this machine with little electrodes... Im 14%, and i think you look slimmer than i do. I wouldn't worry about it too much thought... just a number, i suppose...like age..LOL..
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    May 25, 2012 5:46 PM GMT
    Hold on bud..... try the machine with two settings one for non-athletic and athletic. You're probably around 15%... there is usually a 7% spread in the two different settings. Your gym is scarring the athletic types or they just don't know that there is a difference...lol.
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    May 25, 2012 6:19 PM GMT
    my buddy and i did a skin-fold test using callipers. the more skin-fold sites, the better. we did skin folds on 11 points on our bodies and then calculated the average over those points. before i bulked up, i was at 11%. now i'm around 15%
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    May 25, 2012 6:38 PM GMT
    14% in the pictures i have on here from march i think. Currently 7.4% gotta update my photos
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    May 25, 2012 7:45 PM GMT
    I suspect that anything short of hydrostatic body comp testing (dunk test) is going to be a guess.
  • trakstar90

    Posts: 119

    May 25, 2012 8:13 PM GMT
    I hate the electrode machine and it hates me back lol. No real way of telling unless u get in the tub. From my measurements I'm around 7 %
  • jim_sf

    Posts: 2094

    May 25, 2012 8:15 PM GMT
    RobertF64 saidI suspect that anything short of hydrostatic body comp testing (dunk test) is going to be a guess.


    To an extent, yes. Electrostatic testing tends to be much more susceptible to things like dehydration or surgical implants than other methods.
  • PTNoge

    Posts: 58

    May 25, 2012 8:42 PM GMT
    All the feedback here is correct. To summarize:

    Bioelectric impedance depends on hydration levels and assume you to be fully hydrated.
    There are 2 settings (usually): athlete and general population. These are 2 different equations. In addition, the same reason why BMI is not a good indicator to monitor obesity. I haven't yet seen a study where they characterize the people that they use from which they create the equations. In all likelihood, they can just be people with lower muscle mass (yet still lean), thus the weight component still plays a role, along with height, in the equation, even though they are also measuring electrical impedance. All are taken into account when they develop the equations. Also, they include age because as we age, the normal person increases their internal fat (fat around organs in other tissue). So, that also throws off the reading as it's measuring more than just your subcutaneous fat, the fat between the skin and muscle hiding all those hot six packs!

    Also, the hand held ones and the scales have different equations. Both are just estimates.

    The advantage is that it will give you the same reading (under the same conditions--like full hydration): it's repeatable, but not reliable/accurate.

    Calipers are a great estimate, when done properly. Thus, these are reliable, but unless you are an expert at using them, sometimes not very repeatedable and challenging to do on yourself.

    Dunk tanks: well, these are great, but expensive and acess is limited.

    They even have MRI like scanners now that can scan the whole body, but again: expensive and acess is limited.

    Now, it's great to set goals, but really what does the number give you, except bragging rights?

    For the sake of goal setting, I suggest measuring your waist size and track that. Take the measurement at the same place each time. I even take 3 measurements along the ambodmen when I track my clients, as people store fat differently along their core. It's easy, reliable and repeatedable.

    Just food for thought.
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    May 25, 2012 9:38 PM GMT
    I also experience the same concerns with the BF% on the scales. I have lost a few kg but the BF% has not changed which alarms me as this would indicate muscle loss icon_sad.gif mine is also around 22-23%
    The issue of hydration has been discussed - what impact will dehydration have on the measurement ie higher or lower fat %?
  • PTNoge

    Posts: 58

    May 25, 2012 10:28 PM GMT
    Acute overhydration leads to increased body fat results.
    Acute physical activilty/dehydration leads to decrease body fat results.

    http://www.ajcn.org/content/47/5/789.short

    It was recommended by this study, one shoudl wait 1.25-1.5 hours to return to normal levels of hydration after these activities.

    Once again, it all depends on the equations that the device uses.

    It's also not recommend for people with extreme BMI's and to give you guys an example, because of my muscle mass and height, my BMI border over weight and obesity.

    Knowledge is power! :-)

    Cheers!
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    May 25, 2012 11:10 PM GMT
    OK guys the one I bought.... and you should own your own, measures for athletic, non athletic and hydration. You put your age, height and maleness into it.... press the button and it gives you your bf and hydration levels. It was $50.... but it's a great goal setter especially after a few good bike rides.

    Your a good guy PTnoge.... I've been doing this stuff too long i don't think about explaining it....rob
  • maxeusZA

    Posts: 5

    May 25, 2012 11:24 PM GMT
    I am actually studying this at the moment and did practicals this week

    Using Hydrostatic Weighing I have a fat content of 13%, calipers I have 14% and on BIA I have a fat level of 19%.

    So yes. The BIA method can be very inaccurate as mentioned by others here.

    If you want a true reflection - the best (gold standard) is Hydrostatic Weighing. You will need to find a biokinetist who can weight you; who has the equipment.

    On a more positive note. 20% is still considered healthy ;)
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    May 25, 2012 11:35 PM GMT
    The bioelectrics is not very accurate. I have one and it is true that your hydration level throws it off, but not more than 0.5% for mine.

    I have had mine for a few years and every year it is creeping closer and closer to 10% BF when I am in better shape than the year before.

    I researched the device and I found that AGE plays a part in how much bodyfat it claims you have. The theory is that the older you are the more fat you have around your organs. So it just adds in a bit.

    I dropped my age from 33 to 25 then to 20 and the fat just magically melted away to about 7%! icon_surprised.gif Imagine that! I plan on doing the only truly accurate bodyfat test (hydrostatic) and then setting my bioelectric to whatever age gives me a readout closest to the hydrostatic test and then just keep it on the age forever and use it to monitor. The hydrostatic will almost be like a calibration for the bioelectric I suppose.
  • Posted by a hidden member.
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    May 26, 2012 12:01 AM GMT
    Yes the basic units are inaccurate.... get one that does the hydration, ath and non-ath... age and height... they are fairly accurate....
  • Posted by a hidden member.
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    May 26, 2012 12:05 AM GMT
    At the moment, IDK... need a special weight scale or something for that right?icon_confused.gif
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    May 26, 2012 12:21 AM GMT
    Check out this featured Real Jock article. I get my body fat tested through hydrostatic twice a year since.

    http://www.realjock.com/article/1158/
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    May 26, 2012 12:24 AM GMT
    Mine tests between 14 & 17 on the machine my trainer uses and I think you are way tighter than me. So, I don't think the machine was accurate.
  • Posted by a hidden member.
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    May 26, 2012 12:37 AM GMT
    My old scale said 15%, the new one 6%. I decided the old one was a piece of crap and the new one is the cat's meow. icon_biggrin.gif
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    May 26, 2012 10:54 AM GMT
    The accuracy of hydrostatic testing is significantly impacted by how the residual volume (RV) is determined. If the RV is only estimated using tables, then the technique is not much better than skinfold methods.

    I remember trucks that did hydrostatic testing and from what I saw in one case, they only estimate RV.

    http://www-rohan.sdsu.edu/~ens304l/uww.htm