Body Fat vs Body Weight

[WillBrink]

Will;

Just picked up a set of the accu measure calipers based on your review, and I was very impressed. My home body fat scale puts me regularly at 7.8 to 8.0%, depending on my hydration levels at the time. When I had my body fat done by caliper (7 point) at a local training center I came out at 9.5%. The accu measure calipers put me right at 9.5% for the price of $8.00. These are great, to give you a general idea of how you are maintaining, gaining or loosing. Thanks a bunch.

As you found, and I said, they are amazingly accurate. $8??? I paid $20!

[Dos Cylindros]

As you found, and I said, they are amazingly accurate. $8??? I paid $20!

Yup, it was like 8.99 with a Mayo body measuring tape thrown in.

[murphy j]

Will, I have friend with an electronic bady fat measuring device. As I understand it, it's used by holding an electrode in each hand between thumb and forefinger and then passes a signal through your body to get a reading to base your body fat off of. Do you have any experience with this type of device? And how accurate is it? Also, if it's not very accurate for overall percentage, is it accurate for establishing a baseline to monitor percentage lost? Thanks.

[bsf]

Will, I have friend with an electronic bady fat measuring device. As I understand it, it's used by holding an electrode in each hand between thumb and forefinger and then passes a signal through your body to get a reading to base your body fat off of. Do you have any experience with this type of device? And how accurate is it? Also, if it's not very accurate for overall percentage, is it accurate for establishing a baseline to monitor percentage lost? Thanks.

He covers resistance-based devices in the video.

[WillBrink]

Will, I have friend with an electronic bady fat measuring device. As I understand it, it's used by holding an electrode in each hand between thumb and forefinger and then passes a signal through your body to get a reading to base your body fat off of. Do you have any experience with this type of device? And how accurate is it? Also, if it's not very accurate for overall percentage, is it accurate for establishing a baseline to monitor percentage lost? Thanks.

BSF beat me to it....see vid.

[murphy j]

BSF beat me to it....see vid.

Roger that. I was lazy and hadn't watched the vid

[Bill Bryant]

I'm not sure who will or will not be encouraged by this, but I'm just adding it to the discussion.

http://www.thefrisky.com/post/246-su...better-in-bed/

[bsf]

Ok. I purchased a MyoTape and Accu-Measure through Amazon. These are the genuine versions, not the fakes. I played with the Accu-Measure until I could get repeatable results. It indicated 12mm at the suprailiac location, which corresponds to 16.8% for me, according to the supplied conversion chart. Now, first response was “WTF?” Quite honestly, I was anticipating ~10% based on a SWAG. Then I immediately considered the analogy of the doofus at the range not hitting squat and complaining about his/her gun or sights. I do not want to be that guy, so I did a little research.

First off, the calipers do not appear to generate accurate thickness measurements on solid test matter. Based on a quick test, it appears my calipers return results that are ~20% greater than actual. Second, based on some internet sleuthing, I determined that the supplied chart is based on the work of A. S. Jackson and M. L. Pollock. I was able to download the article Generalized Equations for Predicting Body Density of Men, British Journal of Nutrition, 1978 by A. S. Jackson and M. L. Pollock.

Though a little heavy on math, I was going to use the Accu-Measure calipers to determine skin fold thickness at 3 locations, and along with some other circumference measurements, use one of the supplied formulas with a high correlation factor to determine my BF%. Well, I ended up skipping that because I am not certain where exactly to measure forearm circumference (any help Will?). I was going to run the formula with both skin fold sum as provided by the Accu-Measure, and a sum corrected by 20%.

Since I am waiting on more info for forearm circumference measurement, I decided to just plug the 3 Accu-Measure mm results for chest, abdomen, and thigh into an online, Jackson & Pollock- based calculator. That returns 10% with uncorrected mm readings, and 8.15% with the corrected mm readings. Now, understand these are based on thickness measurements from a device I already indicated may be very inaccurate. Also, I do not know what formula that online calculator actualy uses.

This is what I take away from this. Though results using the supplied chart may be repeatable, or precise, they are not necessarily even marginally accurate. I would like to utilize DEXA, hydrostatic weighing, or even caliper method performed by a “pro” with good calipers and previously validated results, but I am not laying willing to lay out much $. Even comparing the thickness measurements from my Accu-Measure and a medical- or professional-grade skin fold caliper would be enlightening I believe.

Just some info to consider.

[Hmac]

Body Mass Index is only the most crude of fitness tools. It was developed not as a screen for the general population but for demonstrating degree of obesity in the obese. It has value in the bariatric surgery community, not in the general fitness community.

[WillBrink]

This is what I take away from this. Though results using the supplied chart may be repeatable, or precise, they are not necessarily even marginally accurate.

Key term there...The actual accepted margin of error is 3-4%, and tests have shown they fall within that when tested against multi site high end calipers and water. Generally speaking, the leaner you are, the more that margin comes into play, as there's effectively no major difference between being 25% and 28%, but there is say between 9% and 12%.

Accumeasure type calipers are best for tracking actual progress and not bad for actual numbers, but it aint DEXA.


I will say, many years ago when I was asked to write about the accumeasures, I took one look at the cheapo things and fully expected them to be way off from multi site measurements done using reference calipers (Lang medical calipers) by done by an experienced person, and much to my surprise, accumeasure was dead on.

In my n = 1 testing, much lower margin then the 3-4% considered acceptable.

If you are consistent with them in placement, follow the directions, they are accurate enough for "gubment" work and mostly useful for tracking changes.

If one is really dedicated, getting water dunked, or better yet DEXA scanned, to get accurate numbers of BF% within narrower margins is always a good idea, but having known probably thousands the accu-m and or slimGuide tester, and having used them on a lot of people, a very useful, fairly accurate, cheap, device for tracking changes in BF%.