Table of Contents:
Hydrostatic Under Water Weighing w/ Isadora Williams Olympic Figure Skater
Video taken from the channel: Vivo Phys Evan Matthews
Measuring Body Fat Percentage In Hydrostatic Weight Tank
Video taken from the channel: Odum Idika
Checking My Body Fat% | Does Hydrostatic Weighing Work? | 135lbs Curls
Video taken from the channel: TheSwolefessor
BODY FAT TEST Comparison: Hydrostatic, Skin Fold, DEXA Scan, BIA
Video taken from the channel: Alan Thrall
Hydrostatic Body Fat TestingThe most accurate way!
Video taken from the channel: BodyFatTestofSoCal
Hydrostatic weighing how-to
Video taken from the channel: Hawaii Concussion Awareness and Management Program
Hydrostatic Weighing
Video taken from the channel: Utah State University Extension
By Weighing Yourself Underwater Hydrostatic weighing is a method of determining body fat percentage where you are weighed in and out of water. This relies on some fun math having to do with measuring the density of your body in water. Lean mass (bone, muscle, connective tissue, and organs) is more dense than water, while fat is less dense.
Hydrostatic weighing, also referred to as “underwater weighing”, “hydrostatic body composition analysis”, and “hydrodensitometry” is a technique for measuring the density of a living person’s body. It is a direct application of Archimedes’ principle, that an object displaces its own volume of water.On the tails of the hydrostatic weighing method is a revolutionary body composition weighing method known as the Dexa (DXA) Scan.
This scan from DexaFit is designed to not just measure the amount of body fat you’re carrying, but also tell you where it is in the body. The Dexa Scan is the most accurate method for body composition analysis.“Hydrostatic weighing, also referred to as ‘underwater weighing,’ it is a technique for measuring the density of a living person’s body. It is a direct application of Archimedes’ principle, that an object displaces its own volume of water.Hydrostatic weighing borrows Archimedes’ principle in physics to measure body fat and lean mass through full underwater submergence.
In the case of body composition testing, lean mass is denser than water, while fat mass is less dense than water. Therefore, a person with more fat will weigh less under water than someone with more muscle.Underwater weighing is based upon Archimedes Principle which states that the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object. We can use this principle to determine a person’s percentage of body fat because the density of fat mass and fat-free mass are constant.Hydrostatic weighing, or hydrodensitometry, is the most accurate test used to measure the body composition of a subject till date.
The other terms used for this test are ‘underwater weighing’ and ‘hydrostatic body composition analysis’. It helps determine the body density of a ‘subject’ or human body. Would you like to write for us?-maintaining the increased caloric intake is necessary to maintain the higher body weight The thermal effect of the diet can affect energy balance (Dietary composition) -it takes more energy to digest, absorb, transport, and metabolize protein and carbs. vs. fat.
If each test is performed correctly according to the recommended guidelines, hydrostatic underwater weighing has small percentage error (+/1.5% error), and has been labelled the gold standard assessment of fat mass/fat free mass.Underwater weighing, also known as hydrostatic weighing, is a method of calculating body fat percentage based off body density. Underwater weighing takes place in specially designated pools and/or water tanks designed for hydrostatic measurement. The test is usually only available at universities, research facilities, and some fitness centers.
Hydrostatic weighing is the “gold standard” and the most widely used laboratory procedure for measuring body composition. It is useful to have an assessment such as this when trying to make physical changes because body weight by itself doesn’t tell us how our weight is distributed; how much is lean and how much is fat.Hydrostatic Weighing Hydrostatic weighing, also known as Hydrodensitometry or underwater weighing, is a classic measure of body composition. The test involves the subject being lowered into a water tank until all body parts are emerged, expelling all the air from the lungs, then weighed.Hydrostatic (underwater) weighing is generally regarded as the “gold standard” for body composition assessment.
Because body fat is less dense than water, it increases one’s buoyancy. Fat-free mass is denser than water and causes one to sink. After correcting for residual volume, body density can be calculated based on the underwater weight.Question 11 11. _ is a precise way to measure body fat percentage using underwater weighing. Hydrostatic weighing.
Waist to hip ratio. Bioelectrical impedance analysis. Skinfold measurements.Popularity.
National and international sport professionals who assess body composition prefer ADP to UWW (i.e. hydrostatic weighing), according to a 2013 survey [10]. However, these methods were the least popular compared with the other popular body composition assessment methods, including skinfold assessment, bioelectrical impedance analysis (BIA), and dual energy x-ray.
List of related literature:
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from The Ketogenic Diet: A Complete Guide for the Dieter and Practitioner |
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from Physical Fitness and Wellness: Changing the Way You Look, Feel, and Perform |
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from The Biophysical Foundations of Human Movement |
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from The Encyclopedia of Nutrition and Good Health |
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from The DASH Diet Action Plan: Proven to Lower Blood Pressure and Cholesterol Without Medication |
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from Natural Bodybuilding |
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from Human Biology: An Evolutionary and Biocultural Perspective |
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from Transcend: Nine Steps to Living Well Forever |
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from Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate |
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from Maternal Child Nursing Care |
83 comments
is very easy to measure the volume of the loungs. Stop asking for the obvious stuff.
I stopped at 3:45 to guess you have 4% body fat. OOHHHH, I was close! You come in at 3.5%! Dude, you got a nice, NICE physique for a powerlifter, btw. I mean, I’ve seen some really flabby youtube powerlifters, lol. Anyway, wish I can test my body fat tho. Best video on body fat science!
when some one say i am a natural competing body builder you know they are lyin
Alan you lucky bastard, get to have abs at 20+, also know it’s cause you train your ass off
I feel like it’s impossible to have visible abs and be over 20%
Are you still going to the Game Changer’s 21 day vegan mass building challenge?
Awesome vid!!! Those scales always read higher IMO. I wish you’d tried a bod pod too, I was curious how that compares. I was thinking 17-18% for you.
I actually looked for scientific literature comparing different body composition methods and couldn’t find any. Some random youtuber had to do the work… Thanks my good man.
3% drop is a 3% drop. is not true. Thats only true if its linear and most likely the impedence method is not.
I guessed 18. Only because you look like me.
However, I have zero method so my guess means nothing.
PS, them dudes with the stupid bicep poses at 6:15, can’t hit harder or beat me at arm wrestling.
natural bodybuilder but looks suspeciously like hes on roids xD
I think people are sometimes really dumb when calculating bodyfat. Let me explain: we associate a certain degree of visual leanness to a percentage. What we often forget is to take into account the person’s total bodyweight. My man Alan has a big amount of muscle mass. My guess is in 18%-20%
Hydrostatic 17,8%
DEXA Scan: 22%
Skin fold: 18,6%
Body Scale: 25,7%
Coach 1: 23%
Coach 2: 18% 22%
Do not take gym advice from someone who looks like that with shirt off
Without advanced imaging equipment RV cannot be measured in a human in vivo. It’s often estimated from forced vital capacity, which can be measured using a spirometer. There are (less expensive) stand-alone spirometers that simply report lung volumes, or the pneumotach (or other flow meter equivalent) on an indirect calorimeter (“metabolic cart”) can be used.
Also common is the estimation of RV using the patient’s anthropomorphic data. These equations, as well as the FVC spirometry protocols, are all easily accessible via a simple google search.
Bio-impedance is highly inaccurate; because the machine is essentially subtracting two similar numbers (resistance values), each with large errors, and calculating the percent body fat from the rather small difference between these resistance values (which is comparable in size to the error range), thus the results are highly inaccurate (hence all the questions such as how old, athlete or not, male or female etc. to fiddle the result. If the method of determination was truly accurate no questions would be required.
Three years later, but I do have to wonder if you can measure scale accuracy by doing consecutive weighings. It would be just like one of those companies to have the software detect that the same person is using it twice in a row (highly similar weight, short time between reading) and simply reissue the same number. I’ve got a scale that looks similar to that one, minus the body fact gizmo, and I have to fool it by using a foot to get a dissimilar weight into it before going again. It obviously is resetting as the weight will move slightly in that case.
I have some home body fat scales, different brand, and they measured me as 40% for about a week then it jumped up to 60%. Scales in the gym measure me at 17% so those home scales aren’t just inaccurate they can be inconsistent.
Hello my name is Alberto Montoya, you killed my father. prepare to die.
I have the exact same fat composition as you. Right now my upper body is certainly not looking lean but compared to my lower body it is pretty lean
The only truly accurate way to measure body fat is an autopsy.
You should do a Dexa-Scan. Bro, your in awesome shape, but 3.5% is unhealthy, I would have put you to be a respectable 8-10% really the ideal level of being as low as healthily possible.
I appreciate the experiment.. I guess we will have to just go by the mirror and keep cutting until the body looks sufficient
Aw that’s some bullshit bro. I knew it was a lot lower but I overestimated for the fun of it. Maybe next time I get my 50 cent discount but damm you lean. EDIT: There’s still hope. I may give my 50 cent
if you feel the need to present yourself as a “natural” bodybuilder you ain’t natural boi
Wow..I didnt know bodybuilders drop to 3% in competition thats around aneroxia levels
PSS, why does anyone wanna be 3-6% body fat and useless as a nude mag?
I would say, you do look more like 23-24%. Now, let’s watch your video.
At the university of Physical education I was taught that the water is the most accurate one
Yeah….I would say you are a little chunky. If you just cut out the ice cream, oatmeal & bananas you would naturally loose some of that baby fat
my class had to do an hydrostatic weighing for part of the finals. The guys had to wear bike shorts and the girls had to have their hair down. Very interesting to say the least.
They forget to add the hundredths place. Meaning add a 1 in the front of those readings. So I believe you’ll be at 13.5
The work you put into your videos shows. Always excellent content.
You should asked for a refund.. heck noo! You basically paid 50 dollars to torture yourself I don’t even think I can blow out air that longgg lol That looked hard & y’all guys are super fit! I could just imaging an obese person doing this not easy at all or accurate
6:46 “pro natural bodybuilder” ok dude you’re not fooling anyone stop claiming natty
What’s the difference between a waist trimmer and a sauna belt
Difference from 25 to 17…that’s a 20 lb difference in how much I would need to cut…
Thanks for the advice on that. I had higher reading with skin fold specifically was 7% higher than my bia reading which made me just under unhealthy. that annoyed me as a runner and a person that does weights. My diet needs some more improvement. I will do those same checks as well with mine. I know low muscle mass would be bad for me. I am trying to lose fat and add muscle and doing recomposition. I am still eligible for newbie gains. Have problems with a very high body fat and want to be ready for next years physique competition. I lost 5% on their scale in 8 months but was slightly more hydrated. Is this still legit? If anyone has an answer in why that is so much less than my skin fold. My home scales ranged between 18% (no way lol ) and 24%. I got a dearer one. I am old school in my approach and have been lean before and really miss my good definition doubled body fat because of poor diet and time off. It has not come off since but I gain weight easily. 2% fat loss is gone in 2 years but its disappointing. I had eaten a high salt meal 3g the day before and rode a bike to my appointment
(only 5 minutes)before the measurement was taken. I don’t appear like my body fat is 32%. My hope is I don’t accumulate more and get health issues. I don’t like to gain weight very much. I gain and lose through bulking and cutting as weighing much less would make me underweight. Bmi doesn’t work for me due to build. Bones are very small. I am still in good health but I know there are risks and not impressed with those numbers. Many have tried to tell me gain muscle and then lose. Just wondering now is it true. I do ok maintaining and gaining a few pounds.Its hard to judge on appearance. I am nondescript thick on the legs but no curves and very thin on top but no definition aside from ribs showing and some collarbone and thin arms. I have some fat visible around the back and around the bellybutton. From ribcage up is very bony.
(definition but slightly higher than 25% most likely bunt not 30)but its unsatisfactory for me. I cross checked on a scales I used in january and there was a drop. Reportedly 25% body fat at seven stone 1 5, feet one down from 29%. Trying to hit 19% high enough to be aesthetic and not too thin to be healthy. Its quite confusing. If anyone has an input that would be great.
Alan interesting videos…what was your weight out of boot camp? The scanner was a new one for me..
I’ve been tested with the Bod Pod. There’s a fitness service/assessment organization in Kankakee, IL, that has one. It’s neat. It’s apparently as accurate as the DEXA, but with no radiation exposure.
yeah I want to know
how did you measure her residual lung volume?
PPSSS, that one dude said you got a fat ass at 8:10
PPSSSS, yer great btw.
I have one of those scales, and yes it is pretty nice…
It’s all about trending data not the actual numbers! This is why we have standards in industry and such. So that if you want to regulate say weight classes you need a scale that is repeatable everywhere not necessarily as accurate as possible
If the bathroom scale has lower levels of accuracy, a 3% drop in body fat is NOT a 3% drop in body fat. If it’s consistently producing the same deviation from other BF testing methods, there is a measurable error that can be identified and compensated for, thereby increasing the level of accuracy.
If the scale only has a +/2% accuracy, then a 3% drop could technically be as little as 1% or as much as 5%. Unless you are trying to monitor progress as you drop 15-20% body fat, I strongly believe that something like a DEXA scan is the only relevant way to monitor progress.
Dexa is definitely the most accurate here, if read and calibrated properly. The most accurate ever would be a full body CT. You could calculate every square mm of fat, bone, muscle, air, and collections of stool and water.
What the hell is with these bodyfat percentages?? Now way in hell these guys are that low
Yeah I was measured at 6% when I did mine last year at 194lbs at the same height as you. Watching this confirms my thoughts on the lower than expected reading.
You don’t look like you are 22% fat, or 18%, or 17.8% for that matter. I would say you look like 15% maybe…
There is no way medically he or you could be 1 to 3% body fat dude
Hello Alan. Just wanted to drop a comment to say thank you for the scale information. I’ve been looking for a consistent scale to help getting my weight back down to when I was trying BJJ 4 times a week. The code you provided saved me almost $75 USD. Very much appreciated.
I agree with Alberto. I think he’s spot on. I also think the DEXA scan was the most accurate.
The girls love holding on to my donkey while I take them for a ride.
True..its just consistency that matters…there is no real way to measure fat content
If you see abs, and when you look down while peeing, and your gut doesn’t cover your penis when you look down, while pissing your good. Listen, assume Alan takes gear ( no shaming, he’s a grown man and there’s nothing wrong with cycling) it’s not that clear cut, if cycles properly and diets, he can come in at 205 lean at 6 feet. I don’t see how he’s 184lbs.
For fun, have you tried the US Navy calculation too? I like that method and think it’s accurate. https://www.omnicalculator.com/health/navy-body-fat
I think you should have compared the scale between the active male and the non-active male. Perhaps there are programming adjustments that assume active means someone who just does cardio.
Exactly….. scale is God sent if you keep it just for checking your progress and not getting crazy about the numbers.
All you need are a mirror and scale….You don’t need fancy BF analysis…The BF scale isn’t a bad tool either…
I like this scale. Calipers say I’m 21.8%. This scale (non-athletic) says I’m 19.3%.
I’m not certain but I think she gave the test in correctly, because they were supposed to go belly first, they put their head under water and blow bubbles for and 10 secs then record the data
My gym instructor said, that results also depend on what you ate one or two hours ago, because these machines think, that fat in your stomach from food is a part of your body, skewing results a tad bit.
3% off the fat number would be a better comparison across the scales. 25% to 22% is nowhere near as much improvement as 18% to 15%. (3% of 25 is.75. 3% of 18 is.54.) So if you want to go from 25 to 22, you only need to lose 12% of your starting fat. But to go from 18 to 15, you need to lose 16.67%.
As you get to extremely low bodybuilder percentages you risk your health.
That Alberto guy is really smart in this field…..very impressive with his in depth and clear explanation so simple to understand.
Great video and helpful.
Mahalo-TBD
That’s crazy where u guys BF came out to! How much is Dexa Scan where u guys are at? Our university offers it for $80
the machine was rebellious today, giving gifts of percentage to everyone, but it’s not for me to say
That’s pretty disappointing but it was still really cool! What’s a good cheap option to check for the average guy? Just for in the ballpark reference point of course
I’m late watching this video. But I’m here to show support so keep doing you bruh, I’m proud of you!
She made a huge mistake. You are supposed to go completely underwater. She had you with your face sticking out, which will be extremely inaccurate. Hydrostatic is actually very accurate.
yea i went back to this video based on your video today…yea i remember this video and i was like wth that lady robbed yall money
https://idass.com/collections/body-composition/products/bodystat-1500-touch-screen
I just did a Dexa scan. I’d be interested in seeing how your results will be. Post that video, Sir. It cost me $45 but it’s cool that you may be able to get yours for free.
Fail! Digital scales retain memory of prior weigh ins so they just use the weight stored in memory for consistency.
The results was most definitely faulty but the videos are always informative. Cool experience to watch though
Bruh…what..lmaoo man I honestly don’t know how she even said “3.5” and “1.9” confidently like she should know being around that testing and what not, that it’s completely wack lol
WOW, and that thing is known to give the BEST RESULTS when it comes ta bodyfat percentage. 3.5% my ass, you would be even more vascular (not downtalking you or anything, because it also means you’d be dangerously low in bodyfat)
and 135lb curl was my goal for the longest and was the highest i ever went, LMFAO! And it wasnt 100% strict form, i probably bent my back just a bit to lift it. but im damn proud of it, some people cant even bench that weight! STRICT curl though, i for sure did 125lbs. so i coulda hit 135 strict after like a month, but i wanted to be done with it since 10lb difference for bicep curls takes fucking forever to achieve and im impatient lol..
What’s the point of building muscle if you hide it under 40 lbs of fat?
The scales are BS. You can be 210lbs with a lot of actual body fat and the scale reads 25%. You train, lose some weight, then spend a couple of years building muscle and now 210lbs again, but much better shape. The scale reads 25%.
Oh that’s an easy one. I can tell you exactly what his body fat percentage is. It’s somewhere between 5% and 30%. BAM!
Nice beaver!
Even the time of day of the measuring will affect the results.
More exercising leads to denser bones, affecting the results.
How hydrated you are (and hydration levels compared between tests) must have a large role to play in the results.
I think that most of all, just how much air you exhale each time will vary… skewering the results big-time.
So, really, one must look at it like a poll result… accurate within a range of plus/minus %