T Nation

Accurate fat measurements?

I have been getting regular 3 site caliper measurements at the gym. I’m down to 17% and looking reasonably lean. OK I don’t have a ripped 6-pack but I’m sure I’m more like 12% not 17!

Does anyone have a more accurate way of getting a fat measurement. Another personal trainer friend of mine thought I looked more like 12% (he didn’t do a measure - this was just from looking at me - but even so…).
Maybe I’m just wishful thinking about what my percentage is… still I’m interested whether others go strictly by what the calipers tell them.

Can I ask why is it so important to know what your fat percentage is when you’re not preparing for a contest? Or are you? I only know my percentage due to my past contest preps. As for calipers, the best way for a somewhat accurate caliper reading is to have the same person perform the test. And this person better be knowledgable with calipers.

No I’m not preparing for a contest. I set myself a goal of 12% that hopefully translates to the “look” that I’m after. I just want to cut down to a certain point and then maintain at that level.

I have been using the same person for my measurements. As to accuracy I’m not in any position to comment.

In reality, accuracy is first not attainable in body composition and it is not necessary. The vast majority of us use one method of body composition, be it skinfolds, bioimpedance or hydrostatic weighing and use it to track our changes. I have done research in the field of body composition and have read over 150 journal articles and texbook chapters that cover this topic. Use a body composition measurement tool to track your progress, but use the mirror as the final judge. If the calipers say that you are 17%, but you want to get a little leaner, shoot for 15%. Just make sure that you have the same guy do the measurements each time. Or better yet, pick up some calipers and learn to do it yourself. Unless you are willing to go through dissection, you will never be 100% accurate. Even if you get to participate in a study like mine that uses a 4 compartment model including a measure of body density from hydrostatic weighing, total body water from deuterium dilution and total body bone mineral from dual energy x-ray absorptiometry, you would only get to do it once. Yes, it is more accurate, but not useful at all. The nubmers don’t matter, it is the changes in the numbers and how you feel when you look into the mirror. For more information on body composition, please use the search engine and look up a post entitled “Why you don’t like your body comp numbers”. It was started by me and should give you some good advice and some more background on what body composition really is. Good luck. Please ask any questions if you have any and if you have trouble finding that post, let me know and I will bump it up for you.

Under Water Weighing (densitometry) is the most accurate way to measure bodyfat, with the exception of DEXA (an X-ray that is 100% accurate). The problem with UWW is that it can be costly ($50-$100) and it is just not convenient. The calipers are the next best thing with a margin of error of +/-7%. The calipers are good because you can use them as more of a before and after tool. If your quad measurement is 20mm one month and 16mm the next, then you can be safe to say you lost some subcutaneous fat and water. A few tips: always measure the exact same spot. Always take 3 measurements at each reference site and use the average, and always use the same person to measure you to ensure consistency. Good luck!

While I agree that if you are striving for accuracy in one test, DEXA is likely to be best, there are still very significant problems. There are 3 manufacturers of DXA machines, different x-ray distribution patterns (fan beam array vs. pencil beam), different software generations and different machine generations. In most, if not all, of the papers that I have looked at which are comparing different DEXA settings, there are significant differences when it comes to % body fat calculation. And this is just comparing DEXA to DEXA. If there is no consistency in a method, how can you accurately compare it to another method. Also, in regard to UWW, there are several problems that make reliability (consistency from measure to measure) very difficult to attain. I say stick with the calipers because they are cheap, easy and reliable. If you want references to support my claim, I’m glad to supply them to you. The only way to accuracy in body comp is a 4 compartment model, I’ve mentioned above. Every single new technique must be compared to a 4 compartment model nowdays or the comparison is really inconclusive.