[Liz]

What are your favorite methods of measuring body fat with your clients? The skin calipers or the body fat analyzer? I need to buy one and don't know which one is more accurate.

Thoughts?

Liz

[muscletrainerdh-NSCA CPT]

Liz,

Since you're just starting out, I'd get an Accu-measure caliper and refine your caliper skills.

The Lange Calipers are 10 X as expensive and really not that much more accurate.

Also, you can get the accompanying tape measure and learn how to do circumference measures as well.

A book called "Protein Power" has charts in it for simple circumference measure conversions for men and women.

Commercial Bio Electrical Impedance measuring devices (Tanita/Taylor/Omron) have taken great liberties with their interpretation of the BIA body fat measuring method studies and have created devices that are innacurate and inconsistent. Yeah sure they are easy, but are they really measuring the amount of body fat your client has, or how well your client is hydated? My personal preference is to use calipers.

Hope that helps,

Dave

[kelli m]

Liz,

I think the question is not necessarily which is most accurate, but will give a reasonable measure of amount change over time. While skinfolds (7 site)will in MOST cases give you a more accurate reading than a BI reading ( its hard to always follow the prescibed protocol), you must factor in the time required to do this. Remember it is no less than 2 readings per site.

In the fitness world(especially field work) a truly accurate measure is not needed, again only amount of change over time. In the research or medical world, an accurate reading is necessary if the goal is to determine what physiological manifestations occur at a CERTAIN %BF or a BF range..

Also some research by many physiologists both inside and outside of the exercise science community is showing some breadown of some of the accepted density equations. That would effect any instrument or indirect method.

[C Lenart]

If you have the time, I'd definitely go with the skinfolds. According to ACSM, the error rate for skinfolds is 4%. The error rate for BIA is 4% to 5% when performed correctly but the BIA readings are subject to hydration levels. For example, the test protocol for BIA states that the client should:

1. Remove oil and lotions from the skin with alcohol before placing electrodes.

2. Individuals being assessed should avoid eating and should only drink only enough to maintain hydration during the 4 hr before assessment.

3. Exercise should be avoided for 12 hr preceding BIA.



If the client is dehydrated, the amount of fat will be overestimated.

Just my thoughts.

Curt

ACSM Health/Fitness Instructor

[Christina]

Liz,

I use the handheld analyzer. I have a pair of Lange calipers but I do not use them. Here's why: In one of my classes we had to do body fat testing. We used both the handheld and the Lange calipers. Every single one of us were far off the mark with our caliper results. (My body fat came back 26%. I know for a fact that my body fat was in the high teens.) From what I have read, it takes about 100 readings to get really good at using calipers. I would hate to tell one of my clients that they have a certain % of body fat when it is nowhere near accurate. I figure the handheld at least gets me in the ballpark and gives me something to track. I really need to get better at using the Lange calipers.

I know this isn't all that helpful but maybe it will give you something to think about.

Christina

[kelli m]

Liz,

Another thought to ponder against calipers.

Ever try to pinch an extremely overweight person? No need to subject them to furthur distress.

Also some very lean people are difficult to pinch. It seems the more 'membraneous' skin types just are hard to grip.

[Liz]

Thanks again for all of the help! As a matter of fact, I have thought that the assessment portion of training may be intimidating to people... and I don't like the idea of making someone who may already feel insecure, to feel more so. I think I like the idea of the handheld one - even if it may be off, at least it's the machines fault and not mine.

Thanks!
Liz

[megfit]

Hi Liz (and all),

There is an excellent book called "Applied Body Composition Assessment" by Vivian Heyward and Lisa Stolarczyk. I highly recommend it.

I think several people have hit the nail on the head when it comes to assessments. Not only will you have different fitness levels, but you may also have different age levels. My assessment for older adults (80's) was totally different than what I had for younger clients. Plus, I would also explain to clients who were setting up an initial assessment with me over the phone what I did and that it was all subject to what they felt most comfortable with and what was most appropriate. Ask yourself what information do you most need to best help your client.

With that being said, I only ever had a few clients who were obese. Then we just did measurements. For all of them, no matter what measure we used, I emphasized that they were not to compare them with others, but to be able to monitor their changes. This is THE most important point.

I would do a regular re-assessment with clients that included measurements and skinfolds. One client liked to also use his hand-held BIA machine. Because I have a formula calculated into my computer, I would take skinfolds (after playing around, ended up with the three-site again, doing three measures for each spot) and then pluck them into my program. We would then compare the machine with what I had done. Most of the time we were extremely close. Probably because I always instructed him to NOT do cardio before I got there, he was eating well, consistently, and it was 5:30am in the morning.

Some of the last few lectures I've sat in on have all mentioned that if the user gets those 100 skinfolds in, as Christina mentioned, that even the cheap $15 Sportsmart calipers are just as accurate as my EXPENSIVE Langs! Too bad I didn't hear that back in '96, huh?

Margie

[BrianB]

I think that as long as you use the same method each time, and as long as you space out the measurements to no more often than say once a month, you're going to be fine. It doesn't really matter if the number you come up correlates very closely with what their actual body fat is, so long as you're getting a good number relative to the prior measurement (i.e. seeing that they have "lost" body fat, or not).

If they want to know a reasonably close approximation of their actual body fat, the only reasonably accessible and economical tests are BodPod (air displacement) and DEXA, with my preference strongly being toward DEXA if you can get them done in your area without a prescription.