Simple as the subject which is better and why ?
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Simple as the subject which is better and why ?
I have done both, and I think that the hydrostatic is widely accepted as the more accurate indicator. The bodpod can have alot more risk of error depending on body hair, temperature, hydration levels etc..getting dunked has way less chance of being inaccurate (though nothing is 100% perfect). Hydrostatic weighing is the gold standard for a reason.
Welcome to Body Fat Test Home
check that out...had it done last weekend myself
I always thought bod pod was more acurate, it takes into account for bone density organ tissue etc.... Hydro static is more a guess do to age, sex and height... But I'm deff no expert...
nope, bodpod is not as accurate as hydrostatic. If I recall correctly, hydrostatic is 98% accurate and bodpod is 96% ish...which means that it can be off 3-4 percent (say 17-23 if it says 20%)...that is what I recall..could be slightly off
Ive read the opposite that the bodpod is more accurate then the hydorstatic
Hydro static goes by a chart of height sex weight etc then a math is done after weighting yourself in the tank.... It may be more accurate I honestly don't know, I just assumed bod bod was the better... Now I'm interested to hear more..
Also hydrostatic you have to expell the air from ur lungs while sitting perfectly still, not as easy as it sounds and usually 3 test are taken and u use the best result so the accuracy may depend alot on the person being tested.
I've never had a bod pod test done on myself but have been in a tank a few times..
Sorry to take this a little off of what your asking but I'm pretty obssesive with bodyfat testing and can share my personal experiences with bodpod at least. I have never done the dunk tank but very familar with the bodpod along with military tape testng standards. Two weeks ago the wife and I had both Dexa and BodPod tests done.
Our last testing was via bodpod 8 weeks prior.
BodPod Testing in Jan
Me: 10.5%
Wife: 33%
The recent test was 8 weeks later and in that time I have been bulking and gaining and the wife dieting, wife was doing great with losing inches but not much weight throughout this time period. The dexa results were very confusing since it put me leaner then expected and the wife much heavier then expected.
3-16 testing
Me (gained 17 lbs albeit mostly water retention)
Dexa: 9.9%
BodPod: 13.0%
Wife
Dexa: 33.9%
BodPod: 20.9%
Dexa put me 3% leaner then the bodpod and put the wife 13% heavier. Another oddity with the dexa testing was the staff kept fusing over the wife telling her how fit and athletic she looked, meanwhile she's ready to cry looking at the 33% (obesse) number wondering what the hell they were talking about. Also I know Im retaining a lot of water at the moment but im not anywhere near seing my abs, I just cant belive Im at 10%. So again a bit confused with both our results and claims at this testing method being the most accurate.
I can say it was pretty neat in the info it gives though including weighing and giving you the bodyfat of each of your limbs seperatly to compare complete symetry.
The bodpod and dunk tank are both formula based meaning there are several different forumlas the tester gets to pick from and use for your testing, each of which could provide different results. This is just my opinion but to me this shows the test is not equal to all and will have a range of inaccuracy.
Both have about the same margin for error (1.5% for hydro and about 3% for air displacement as per recent studies so we are talking 98.5 vs 97% accurate but the margin doesn't directly correlate to being off 1.5% or 3% it is a margin). Hydration plays a roll as do a few other things. The idea with hydro is fat is lighter than muscle and relies on the spirometer data before hand to be equal to the same expelled air once in the tank. Air displacement is the same idea but with air instead of water. DEXA tends to be even more accurate than both but you don't have access to that normally. For ease of use and due to how common they are becoming bodpod is my goto.
The interesting thing becomes how that is calculated as how do you define an absolute to figure out how much they are off without killing people and taking direct measure of composition. A 3% margin for error isn't bad, margins on foods nutritional compositions are bigger, heck margin for error on almost anything is bigger. I'd say either is a fine choice.
Well said NutNut
Both tests are highly regarded and I wouldnt worry so much about the accuracy as the consistency for future comparisons. For example the resulting percentage isnt as importing as accurately seeing what progress you made. If you lost or gained 2% then you want to see that progress to determine if your diet or workout program needs adjustments.
Last edited by SugarFree; 03-29-2012 at 05:57 PM.
If I could find a testing location, I'd like to give the dunk test a try too. I cant imagine though its as convient as the bodpod or dexa. With the bodpod you just step into an egg shaped looking phone both and sit still for about 30 seconds. The test is then repeated a second time to make sure it matches (at least the way my tester does it) and done. The Dexa scan was slightly longer but just as simple. You laid on a table and an x-ray type machine hovers from head to toe for a couple minutes and thats it. Both tests were $50 where I went but have seen many different prices cheaper and more expensive while surfing the web at different places.
How does hydration change a bodpod reading? Lamens terms here science nerds! as in if you are dehydrated will it read higher or lower bf?
I found a research study designed to see how hydration affected different methods of body composition analysis, it compared hydrostatic weighing (HW in the results), air displacement via bodpod (ADP) and skinfold (SK)
here is a portion of the results, I will include a link to the paper at the bottom.
hydration status (N 66).
Hydrated Dehydrated
Weight (kg) 76.7 13.1 74.7 12.9*
%BF HW 11.3 4.8 11.1 4.7
%BFADP 11.0 5.3 10.1 5.1*
%BFSK 12.4 4.8† 12.2 4.5‡
FFMHW (kg) 67.7 10.1 66.1 10.0*
FFMADP (kg) 67.9 9.7 66.8 9.7*
FFMSK (kg) 66.9 10.5 65.4 10.3*
Values are expressed as mean SD.
* Significantly different from the hydrated state (P 0.001) (multiple pairedsample
t-tests with Bonferroni’s adjustment).
† Significantly different from the corresponding body composition variables by
HW within the hydrated state and dehydrated state (‡) (P 0.05) (repeatedmeasures
one-way ANOVA, with Dunnett multiple comparison procedure).
‡ Significantly different from the corresponding body composition variables by
HW within the dehydrated state (P 0.05) (repeated-measures one-way ANOVA,
with Dunnett multiple comparison procedure).
Db, body density; %BF, percent body fat; FFM, fat-free mass; HW, hydrostatic
weighing; ADP, air displacement plethysmography; SK, skinfolds.
TABLE 1. Subject characteristics (N 66).
Age (yr) 20.2 2.0
Height (m) 1.73 0.08
Weight (kg) 77.1 13.2
Wrestling experience (yr) 9.0 1.1
Values are expressed as mean SD.
502 Official
http://wweb.uta.edu/faculty/ricard/C...es%20ANOVA.pdf
notice that while all testing methods were impacted by hydration (or more accurately, lack thereof) the hydrostatic weighing and skinfold were only off by 0.2 percent while the air displacement was off by almost a full percentage (0.9)
%BF HW 11.3 hydrated 11.1 dehydrated
%BFADP 11.0 hydrated 10.1 dehydrated
%BFSK 12.4 hydrated 12.2 dehydrated
with this in mind, it would seem logical that overhydration would increase bf% by a similar amount (but I have not seen a study to confirm that).
lol shan my head just exploded reading that.But I got the jist of it .Thankyou
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