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Old 10-27-2010, 08:59 AM   #1
Andrew Perlot
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Body Composition Results Don't Make Sense

Hi. I'm using a bioelectrical impedance scale to measure my bodyfat, muscle, water, and bone.

The results don't seem to add up, though, and the instructions are of no help.

My scale tells me I am 172.8 pounds.

Of that it gives me a reading of

Fat: 20.6 percent
Bone: 7.0 pounds
Water: 60.5 percent
Muscle: 46.8 percent

Adding the percents up I arrive at 127.9 percent.

What am I missing here? Shouldn't thy add up to 100 percent?

Any ideas?

Thanks.
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Old 10-27-2010, 09:07 AM   #2
Katherine Derbyshire
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Re: Body Composition Results Don't Make Sense

All tissues, even bone, contain substantial amounts of water. Calling it out separately is almost guaranteed to give weird results.

This is one reason why most people will tell you to ignore bf% calculations from those scales.

Katherine
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Old 10-27-2010, 09:28 AM   #3
Thom Knapp
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Re: Body Composition Results Don't Make Sense

The mirror is much more effective at measuring body comp...
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Old 10-27-2010, 12:04 PM   #4
Jason Peacock
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Re: Body Composition Results Don't Make Sense

Seriously, all the "bioelectrical impedance" BF devices are useless. They're good for entertainment, but that's it.

If you read the fine print, you need to buy different models depending on whether you're "normal" or an "athlete" b/c they use different formulas for the calculation..and they're still wrong. Mine has said that I'm at 31% BF for the last 2 years, yet I've gone from 32% to 20%. I get more variance depending on how hydrated I am than from what I eat.

The skin-fold test is better, but do some searching and find a dunk tank for testing your BF % if you really want to know.

Otherwise as mentioned before the mirror is the best - just be honest with yourself, and take pics so you can compare changes month-to-month.
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Old 10-27-2010, 12:11 PM   #5
Jay Rhodes
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Re: Body Composition Results Don't Make Sense

Those scales are worthless for the most part... What you can use them for is to track change. It wont be valid, but it will be reliable if you stay on the same scale.
I get readings anywhere from 6-19% BF on different scales and I've done the calipers and am 5-6%
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Old 10-27-2010, 02:22 PM   #6
Jesse Gray
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Re: Body Composition Results Don't Make Sense

I have a pretty good use for those things, they let me know how much I had to drink the night before. The drunker I get, the more dehydrated I become and the lower my "body fat" is in the morning. If I'm between 10-8% I probably had a really good time, if I'm 8-6% I probably had a good time but I can't remember it and if I'm below 6% I was probably arrested.
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Old 10-27-2010, 03:45 PM   #7
Jay Rhodes
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Re: Body Composition Results Don't Make Sense

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Originally Posted by Jesse Gray View Post
I have a pretty good use for those things, they let me know how much I had to drink the night before. The drunker I get, the more dehydrated I become and the lower my "body fat" is in the morning. If I'm between 10-8% I probably had a really good time, if I'm 8-6% I probably had a good time but I can't remember it and if I'm below 6% I was probably arrested.
lol amen brother!
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Old 10-27-2010, 08:56 PM   #8
Júlíus Magnússon
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Re: Body Composition Results Don't Make Sense

Quote:
Originally Posted by Andrew Perlot View Post
Hi. I'm using a bioelectrical impedance scale to measure my bodyfat, muscle, water, and bone.

The results don't seem to add up, though, and the instructions are of no help.

My scale tells me I am 172.8 pounds.

Of that it gives me a reading of

Fat: 20.6 percent
Bone: 7.0 pounds
Water: 60.5 percent
Muscle: 46.8 percent

Adding the percents up I arrive at 127.9 percent.

What am I missing here? Shouldn't thy add up to 100 percent?

Any ideas?

Thanks.
Don't worry about that crap. Most body fat measurement methods are extremely unreliable.

If you're interested in measuring fat loss, measure your waist, horizontally over your belly button. When this number goes down, you're getting leaner.
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Old 10-27-2010, 09:04 PM   #9
William F. Burgess
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Re: Body Composition Results Don't Make Sense

When I was at the university they let me use the hydrostatic weighing tank. That was neat.
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Old 10-28-2010, 01:01 PM   #10
Steven Low
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Re: Body Composition Results Don't Make Sense

Impedence is terrible.

If you get an experienced caliper person it would be more accurate.

Also, hydrostatic weighing is better.

Dexa scan the best obviously
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