So I'm trying to figure out my bf% and I'm getting wildly different results. I bought a Fattrack II (http://www.bodybuilding.com/store/acc/fattrack.html) and get fairly inconsistent results. I'm guessing that's primarily technique. I'll get 13%, 25%, 19%, etc. all withing 5 minutes of each other.

Any suggestions for technique? I know some of you are masters out there. I also know I'm pinching the same area because I've got little bruises :rolleyes:

I tried mybodycomp.com (http://www.mybodycomp.com) and healthcentral.com (http://www.healthcentral.com/cooltools/CT_Fitness/bodyfat1.cfm) but those give me slightly different answers too (25% & 23%). Basically nothing is even close to being consistent, and I'm pretty sure it's all my technique.

I'd like to just use the calipers (http://www.bodybuilding.com/store/acc/fattrack.html), but since they're inconsistent I don't think I can trust them yet. Any advice for getting better readings?

The biggest problem is that when I pinch I can't get any traction -- my fingers just kind of slip until I end up with a teeny tiny pinch of skin. (No, my skin isn't wet or anything out of the ordinary)

When I get my camera back (my GF stole it and took it to work!) I'll post some pictures and some AVI's of my pinching technique. Maybe some obvious problem will be visible that way.

i do have the same problem with my fattrack II.
maybe i'm too fat to use such a device (240lbs at 5ft and 9inches) (109kg - 176cm)...?
everytime i try i get totally different measurements.

yesterday i measered myself with myotape and tried to calculate my bodyfat percentage with different websites. here are the somewhat funny results:

mybodycomp (http://www.mybodycomp.com): 33.20%
ability.org (http://www.ability.org.uk/bodyfat.htm): 23.00%
healtcentral (http://www.healthcentral.com/cooltools/CT_Fitness/bodyfat1.cfm): 21.80%
of course is used the same measurements for every site.

is this ridiculous or what?
how can anyone rely on numbers that are so different like these are?
or is it just me?

as i have never worked out before i guess that mybodycomp goes in the right direction...

I just found out that my gym ('http://as.sdsu.edu/arc') has free (for members) body fat measuring and analysis once a week (on Mondays). I think I'll do that instead.

Anybody interested in some barely used calipers? I'll cut a deal for JSF (john stone forums, oooooh, new acronym!) members. If nobody's interested I'll just ebay 'em.

I'm having the same problem. It's telling me that I have 8%bf, shouldn't I have a body like Bruce Lee if that's correct?

Does the non digital caliper work any better?

Does the non digital caliper work any better?
Couldn't tell ya. I'm 99% sure that (at least in my case) this is all operator error - hence having the professional* at my gym do it.

(I'm pretty sure 'professional' means physiology/kiensiology student at my school, since the gym is part of SDSU ('http://as.sdsu.edu/arc'))

I used to have trouble with the fat track but I found a way to make it more consistent and accurate. Instead of putting my hand on the blue button when I'm taking a reading, I get the calipers aligned and clinched, THEN I press down lightly on the button. I found that the button is far too sensitive, and this method leads to more consistent results.

I used to have trouble with the fat track but I found a way to make it more consistent and accurate. Instead of putting my hand on the blue button when I'm taking a reading, I get the calipers aligned and clinched, THEN I press down lightly on the button. I found that the button is far too sensitive, and this method leads to more consistent results. I noticed this same problem the first time I tried. I wasn't even close to my skin and the thing beeped! I'll be posting some pictures later showing my little bruises along with technique to see if I'm doing it correctly or not. Anybody who's got experience with this device: I'd like your input!

I signed up for bodyfat measurement at my gym (http://arc.sdsu.edu) but apparently they fill up really fast. Doing it weekly doesn't look like it'll be possible. I'll have to make that my reality check and use the calipers as my primary method.

UPDATED
Below are some pictures showing technique. You can see overall pictures here ('http://forums.johnstonefitness.com/showthread.php?p=4992').

"Top" portion, pre-pinch:
http://spaz.mootech.net/training/top-pre-pinch.jpg
Then I pinch and my fingers slip until I get this:
http://spaz.mootech.net/training/top-pinch.jpg

"Mid" portion, pre-pinch:
http://spaz.mootech.net/training/mid-pre-pinch.jpg
Then I pinch and the same slippage occurs until I get this:
http://spaz.mootech.net/training/mid-pinch.jpg

I've ommited "Low" portions because it's basically the same. When I did it this time around I got 14.99% BF. Can anybody with a decent eye for that take a look at my current pictures ('http://forums.johnstonefitness.com/showthread.php?p=4992') and say if that's even close to being right? :o

I've got an appointment to get a "professional" BF analysis, but it's not for 2 more weeks! I guess that'll be the real test.

If you look at John's photos, it can give you an idea of what you're.

John was in at somewhere in the 14-15% range in Mar-Apr

Hi Daveo,

I don't think that you're doing this quite correctly. It would appear that you're getting little more than skin with the pinch. Here are a couple of poor quality pics :p of myself doing an abdominal and thigh pinch. BTW, I'm at about 12.2% BF. FWIW, I'd guess by looking at your full body pics that you're prob. in the mid 20's.

I don't think that you're doing this quite correctly. It would appear that you're getting little more than skin with the pinch.
Yeah yeah, that's what I'm trying to get across. Strange though it may sound the skin on my abdomen, thigh, and chest doesn't want to move the way yours does -- it's too tight.

Too much fat maybe? :(

No matter what I do, I can't get a pinch like you have pictured. They might be visible in the full-body shots, but I've got little bruises, so don't think it's lack of effort. Actually, I can get a pinch like you have pictured, just not at the targeted areas :(

If I grab my tricep I can do that. If I grab between the bulk of my bicep and the interior of my elbow I can do that -- several places OTHER than where it's supposed to be done according to the booklet :(

Yeah yeah, that's what I'm trying to get across. Strange though it may sound the skin on my abdomen, thigh, and chest doesn't want to move the way yours does -- it's too tight.

Too much fat maybe? :(

No matter what I do, I can't get a pinch like you have pictured. They might be visible in the full-body shots, but I've got little bruises, so don't think it's lack of effort. Actually, I can get a pinch like you have pictured, just not at the targeted areas :(

If I grab my tricep I can do that. If I grab between the bulk of my bicep and the interior of my elbow I can do that -- several places OTHER than where it's supposed to be done according to the booklet :(

i have exactly the same problem.
maybe this is a question of age...?

i have exactly the same problem.
maybe this is a question of age...?

Possibly, but probably not...

I'm 23, Nate doesn't look too much older (if not younger) than me but he says things work just fine...

Any other ideas?

daveo, did you ever get the calipers to work for you?

I was going to buy them until I read this thread. I tried pinching myself and i can't get anything that looks like, rboit, kind of like rubber man they way he's stretching.

I think the most relialbe way to measure fat is weight-to-volume displacement.

Fill the tub up, and mark the water line with a grease pencil.

Get naked, hop in, lay back, and mark the new water level.

Measure how far apart they are. They enjoy a hot bath.

Do it every month - the leaner you are, the less you'll displace, no matter what you weigh.

Sure, it doesn't tell you what exact percentage you are, but it will show you improvement.

By the way, the leaner you become, the less buoyant you are - remember that next time you go to the pool!

I think the most relialbe way to measure fat is weight-to-volume displacement.

Fill the tub up, and mark the water line with a grease pencil.

Get naked, hop in, lay back, and mark the new water level.

Measure how far apart they are. They enjoy a hot bath.

Do it every month - the leaner you are, the less you'll displace, no matter what you weigh.

Sure, it doesn't tell you what exact percentage you are, but it will show you improvement.

By the way, the leaner you become, the less buoyant you are - remember that next time you go to the pool!

:confused: I'll give this a try, although it does not jive with my once a day measurement. I like to check BF% daily to be sure I'm not losing lean mass.

If only I had a graduated tub! With markings on the side indicating volume, then I'd be sittin pretty. :nod:

daveo, did you ever get the calipers to work for you?

I was going to buy them until I read this thread. I tried pinching myself and i can't get anything that looks like, rboit, kind of like rubber man they way he's stretching. I haven't tried recently. I'm waiting until my professional measurement (on the 23rd) to see how they deal with my skin, and ask questions. At that point I'll re-evaluate the calipers and let y'all know! :nod:

I think the most relialbe way to measure fat is weight-to-volume displacement.

Fill the tub up, and mark the water line with a grease pencil. That'd work if I fit in the tub :o

I'm ~ 6'3", and the tub isn't long enough for me, so I'd have knees and arms hangin out all over the place throwin off my measurements...

I need to buy a house and get a big friggin tub :nod:

I think the most relialbe way to measure fat is weight-to-volume displacement.

Fill the tub up, and mark the water line with a grease pencil.

Get naked, hop in, lay back, and mark the new water level.

Measure how far apart they are. They enjoy a hot bath.

Do it every month - the leaner you are, the less you'll displace, no matter what you weigh.

Sure, it doesn't tell you what exact percentage you are, but it will show you improvement.

By the way, the leaner you become, the less buoyant you are - remember that next time you go to the pool!

What kind of bullshit is this? First a practical issue. You're bath tub, isn't exactly square, so it would be very very difficult to calculate the difference in volume. Second issue, you would have to weigh yourself underwater as well, or there is absolutely no point in doing this. You could be replacing fat with muscle, and displace the same volume. The point is to measure the density of your body. If what you're saying actually worked, don't you think everyone would do it?

just my 2 cents

So I'm not sure how the underwater method works exactly. It seems like you would need to know your actual weight under the water. And that is sort of what this website says below. But, you'll notice that the simplified equation that they present does not require the weight underwater to be known.

the equation is: Percentage of body fat = 495/D - 450

Where D is the density of the body in grams/cm^3, which is just weight/volume. You get the volume of your body by measuring your water displacement. I think they don't need the underwater weight because they are using assumptions for the density of lean tissue and fat tissue perhaps. But it seems this might be an approximate method, where you only need your volume. Anyone else know more?

http://kspark.kaist.ac.kr/BodyFat/Body%20Fat%20from%20Underwater%20Weighing.htm

I used to have trouble with the fat track but I found a way to make it more consistent and accurate. Instead of putting my hand on the blue button when I'm taking a reading, I get the calipers aligned and clinched, THEN I press down lightly on the button. I found that the button is far too sensitive, and this method leads to more consistent results.

I recently bought a fat track II and was getting really frustrated because it would beep before it even touched me. I tried your method and it seems to work great! I am getting really consistent results this way!! Thanks! :claphigh:

So I'm not sure how the underwater method works exactly. It seems like you would need to know your actual weight under the water. And that is sort of what this website says below. But, you'll notice that the simplified equation that they present does not require the weight underwater to be known.

the equation is: Percentage of body fat = 495/D - 450

Where D is the density of the body in grams/cm^3, which is just weight/volume. You get the volume of your body by measuring your water displacement. I think they don't need the underwater weight because they are using assumptions for the density of lean tissue and fat tissue perhaps. But it seems this might be an approximate method, where you only need your volume. Anyone else know more?

http://kspark.kaist.ac.kr/BodyFat/Body%20Fat%20from%20Underwater%20Weighing.htm

http://www.wvc.vlaanderen.be/gezondsporten/voeding/ideaalgewicht/images/fig3.jpg
On this site it is explained: http://www.wvc.vlaanderen.be/gezondsporten/voeding/ideaalgewicht/

The site is in Dutch, but it basically says you need the weight out of the water, and in the water to be able to calculate the density of the body.

How hard do you pinch with the calipers? That's the one thing it doesn't tell you in the "Improve your Measuring" Guide. I mean, the button is obviously too sensitive so you can't use it as a guage of how hard to pinch. When I pinch with my fingers do I pinch until I can't get my fingers any closer together? When I pinch with the calipers do I pinch until I can't get the claws any closer together?

There's gotta be a better way. :mad:

How hard do you pinch with the calipers? That's the one thing it doesn't tell you in the "Improve your Measuring" Guide. I mean, the button is obviously too sensitive so you can't use it as a guage of how hard to pinch. When I pinch with my fingers do I pinch until I can't get my fingers any closer together? When I pinch with the calipers do I pinch until I can't get the claws any closer together?

There's gotta be a better way. :mad:

There is a better way. Check out the Slim Guide body calipers. They pinch automatically with a spring loaded mechanism. You just apply the calipers, let go of the trigger and read the measurement. I've found that readings are very stable and reproduceable. Not sure what they cost new but I got mine for $5 + S&H on ebay.