Ricky wrote:
Quote:
The body fat measurement was done using bio-impedance analysis. I know it's not perfect but I would expect it be somewhere around where I'm actually at. I'm naturally lean.
Unless they are using a dunk tank
Ricky,
Hydrostatic weighing in a dunk take is not the "Gold Standard" is been touted to be.
Hydrostatic weighing is based on some small analysis numbers, statistics. The smaller number in a statistical survey, the less dependable the accuracy. Hydrastatic weighing is based on the dissection of five cadavers.
There are other problems with hydrostatic weighing.
Fat FloatsThe theory about hydrostic weighing is that fat floats. Thus, the more you float, the greater your precentage of body fat.
A problem with many labs is that they don't measure residual lung volume. The retension of air in your lungs makes you float.
Residual lung volume is measured prior to hydrastatic weighing so a much more accurate measurement of body fat percentage can be obtained.
Bad IdeaMany labs don't measure residual lung volume. The use a "one size" fits all formula. That a Bad Idea.
If residual lung volume is NOT measured prior to hydrastic weighing, the test is worthless.
Protocol NOT FollowedAnother problem is the testing protocol is at times is hard to follow. A friend's son was hydrostaticly weighed a while back. They also calipered him, as well.
The calipers determined he had about 7% LESS body fat than the hydrostatic weighing did.
What Was The Problem?In discussing the his son's hydrostic weighing, he stated that his son was unable to sit on the scale under water and completely expel all of the air in his lungs.
That meant the his son retained more air in his lungs, making him float higher in the water. That indicated he has a higher body fat percentage that he really had.
Thus, the major reason for the 7% higher body fat percentage reading with hydrostatic weighing had to do with his son not being able to follow the protocol.
The lab did NOT measure his son's residual lung volume, either.
Blowing all of the air out of your lungs. Then sitting there for a while under water is hard to do.
I've been hyrostaicly weighed. It took me about four tries to finally be able to sit motionless with no air in my lungs.
Quote:
...the way they are measuring your bodyfat will have a greater margin of error than what you are seeing. Testing impedance will definitely have a margin of error of at least 5%
I am not sure what the "martin of error" is but it is obserd.
Also as I noted in my previous post, the percentage will be lower or higher dependent of if you use the scale you step on or the hand held BIA devices.
If you have more body fat in lower body than your upper body, standing on the scale BIA's will indicate you are "fatter" than you really are.
It is the same for the hand held BIA device.
The opposite is true, too. If you store less fat in you lower body than your upper body, standing on the scale BIA will indicate you are "leaner" than you really are.
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