In Part 2 of this series, we demonstrated the three most practical methods of body composition measurements. In this third and final article, we’ll discuss what you will typically experience and discover when taking the various types of measurements, and address what to consider when selecting what methods you want to use with specific clients.
- Review what science has taught us about the three methods of body composition addressed in this series of articles.
- Understand what experienced hands-on trainers typically encounter when using and comparing these methods.
- Learn how to use these simple and practical methods to help your clients, as well as benefit your bottom line.
The Science of Body Fat Testing
Anthropometric (body composition) assessments are an incredibly important tool for fitness professionals. Equally important is an understanding of the science behind these assessment techniques. We’ll look at some recent research studies investigating the pros and cons of bioelectrical impedance, skinfold assessments and umbilicus (waist) circumference measurements.
After demonstrating the three most practical methods of collecting body comp data in Part 2, we’ll now compare results of each. Sometimes the results of the various types of measurement can yield very similar results, and other times they can be drastically different. If done properly, the results should not be more than a few % in difference. Otherwise, you can assume something was wrong with either the way in which the measurements were taken or how the client prepped for the test.
If you are new to conducting body composition measurements, expect results to vary greatly until you hone your skills and gain more experience.
Practice Makes Perfect
The more practice you acquire taking measurements and talking through the numbers with a variety of clientele, the better you will learn how to communicate the message while enhancing your client's understanding … regardless of the accuracy of the measurements.
What is most important for the client is for them to gain a better understanding of lean mass versus fat mass.
Gain hands-on experience by experimenting with friends, family and clients to be able to speak intelligently about the three methods of measurement addressed in this series. Doing so will hone your skills as a fitness professional and also better assist your clients in reaching their goals. You can use this objective feedback to help drive clients toward their goals by:
- Educating clients to change their perspective
- Using the info to motivate and inspire them to take action
- Simplifying accountability and short-term goals
Some methods are better for certain clients as discussed in Part 1 of this series. I recommend that you read that article first, if you haven’t already.
As a baseline to compare results, I prepped according to the standards already discussed within a 4 hour window, while fasting,for five different methods of body comp tests.
The tests included:
- Handheld Bio-Electrical impedance
- Bod Pod
- 4 padded BEI at Equinox with InBody BEI
Then for true quality control, I went to Cenegenics Anti-Aging Company in Boston to get a Dexa scan done.
The Three Most Practical Methods
Most clients want to lose fat! Utilize these three simple, inexpensive methods to help deliver that result.
Skinfold (caliper) assessment is a popular method for measuring body fat in a gym or health club setting. When using caliper measurements it is important to be consistent with the exact areas of skinfolds measured. For example, all measurements should be taken on the right side of the body for standardization purposes.
Although skinfold measurements take a little more time to perform, a skilled individual can perform this in less than 6 minutes including circumference measurements. There are many skinfold sites and equations to determine body fat based on an individual’s age and gender.
Loenneke et al. (2013), performed a study to evaluate the reliability of two bio-electrical impedance (BIA) devices and compared the results to 3-site skinfold (SKF) readings. Twenty-one college-aged students volunteered for the study. The students had the following measurements taken: height, weight, 3-site skinfold, BIA (using two different devices). The study did not find significant differences between SKF measurements and BIA (accuracy within 2%). The authors concluded that both methods can be viable for measuring body fat percentages and changes over time.
When dealing with a variety of clients, skinfold numbers may reveal lower numbers than both BEI and umbilicus measurements. Once you have enough experience with skinfolds and become more consistent in your technique, they are a superior method over umbilicus and BEI. This will require working outside of your comfort zone to learn this skill, but it will enhance your offering to your client. It makes it easier to explain to your clients what is going on with their bodies and that can play a huge role in changing the way your clients think.
Even if the measurement results are not 100% correct, as long as each measurement technique is consistent to the one taken previously, it is a great method to monitor fat loss progress over the short and long haul. This will positively impact client retention.
The umbilicus measurement is by far the simplest and easiest method to deploy, and also found to be a non-invasive method for those truly uncomfortable getting measured by the calipers. It’s great for trainers who need to collect body comp data on a lot of people in a short amount of time - for example, trainers who instruct small group training or boot camps. It is also an exceptional method for trainers and coaches who perform online or phone training because the client can take their own simple measurement.
Umbilicus measurements are more reliable than skinfolds on a person who has lost a significant amount of fat, are fairly lean or has very loose skin. Alternatively, this is a better method for those who are greatly overweight and the skinfold caliper will not fit.
Obesity, especially abdominal obesity, is associated with a myriad of health risks including cardiovascular disease, cancer, type 2 diabetes, arthritis, pregnancy complications, and shortened life expectancy. Waist circumference measurements help track abdominal obesity and can be used as a method for estimating total body fat, although the accuracy and validity is still in question. An accurate measurement will typically produce a slightly higher fat percentage than skinfold, but about the same as bio-electrical impedance.
As the client stays on your program and changes diet, when re-measurements are done, you can see a correlation between lifestyle behavior and outcome. That is the point you want to get across to your clients. Driving clients to see progress and a slimming of the waistline provides motivation to get more results and to stay training in your program.
According to the National Heart, Lung and Blood Institute (2015), measuring waist circumference is an effective tool to help screen for possible health risks. If fat is most distributed across the waist versus the hips, the individual’s risk for heart disease and type 2 diabetes is elevated. This risk is elevated with a waist circumference greater than 40 inches (102 cm) for men or greater than 35 inches (88 cm) for women. It is important to note, waist circumference is less accurate in determining disease risk in certain situations, such as pregnancy, medical conditions consisting of distension of the abdomen, or for certain ethnic groups and children.
Flegal et al. (2009) investigated the relationship between body mass index, waist circumference, and waist-stature ratio (waist circumference divided by height), with body fat percentage (using DEXA scan) in adults from the National Health and Nutrition Examination Survey (NHANES). The NHANES sample included 12,901 adults. The results were slightly mixed but the overall message was that, “more than 90% of the sample could be categorized to within one category of percentage body fat by each measure.” The researchers concluded that BMI, waist circumference and waist stature ratio perform similarly as indicators of overall body fatness and are more closely related than percentage of body fat (DEXA). “These variables may be an inaccurate measure of percentage body fat for an individual, but they correspond fairly well overall with percentage body fat within sex-age groups and distinguish categories of percentage body fat.”
The actual percentage of body fat may not be entirely accurate by solely measuring waist circumference, but when used as a motivational tool, waist circumference measurement is a highly effective tool.
Bio-Electrical impedance (BEI) has made significant improvements over the past 30 years (Hu, 2008). Improvements in methods and equations continue to improve the accuracy methods of BEI. This is the second-fastest method. It takes less than a minute to program the machine and tap in a client’s information and the test itself takes 30 seconds or so.
Recently a study by Sun et al. (2005) compared BEI to DEXA scans using a large sample of 591 subjects. The study found that BEI overestimated body fat percentage of lean subjects with less than 15% body fat. In these individuals BEI overestimated body fat by 3.03-4.40%. Subjects with greater body fat percentages (greater than 25% body fat), BEI was found to underestimate body fat percentages between 2.7-4.32%. The researchers concluded that BEI is effective for measuring body fat percentage in healthy, normal weight individuals, but the results were less accurate for very lean or obese individuals.
BEI is based on the principle that fat is less efficient as a conductor than lean body tissue. The faster the conduction, the leaner the individual. However, inconsistencies in testing result in a large amount of incorrect information, so standardization is essential.
According to Kyle et al. (2004) BEI is a common, non-invasive, and inexpensive body composition assessment used in healthy individuals and patients alike, but lacks standardization and quality control procedures for all populations/pathologies. BEI enables professionals to determine a person’s fat free mass, body fat percentage, and total body water; however, appropriate equations based on age, sex, and race and established procedures must be followed. Individuals with electrolyte or fluid abnormalities should not be tested using BEI because the data will be skewed. When the client has been properly prepped (as discussed in the previous articles), typically the fat percentage will come out higher than the skinfold test.
Having 4-point contact machines are a lot more expensive. They will provide you more data such as body fat, lean mass, BMI, intra and extra cellular health of the cell. Additionally, different types and brands of BEI devices produce slightly different results, but only by a few percentage points. Be sure to re-measure using the same device.
Watch as Mike D’Angelo shares the results of various body composition measurements, including DEXA scan, BEI, circumference measurements, etc.
If not properly prepped, there can be drastic results among these methods of body composition measurements, particularly when performed without following the recommended guideline and procedures. To get accurate and dependable results the simple guidelines identified in the previous articles and videos should be followed. When they are, the results are similar enough to use the data to help your clients
At the end of the day, clients want results. Initially testing and then retesting is where the true value is. When you can show clients clear progress from being on your program, it makes it very easy to sell more training and retain clients longer!
When you deliver data-driven results to your clients, building your business is easy. That is why tracking outcomes become your greatest retention and referral tool particularly for fat loss clients.
Loenneke, J.P., Barnes ,J.T., Wilson, J.M., Lowery, R.P., Isaacs, M.N. & Pujol, T.J. (2013). Reliability of field methods for estimating body fat. Clin Physiol Funct Imaging, 33(5), 405-8. doi: 10.1111/cpf.12045. Epub 2013 May 3.
National Heart, Lung and Blood Institute. https://www.nhlbi.nih.gov/health/educational/lose_wt/risk.htm. Accessed August 12, 2015.
Flegal, K.M., Shepherd, J.A., Looker, A.C., Graubard, B.I., Borrud, L.G., Ogden, C.L., Harris, T.B., Everhart, J.E. & Schenker, N. (2009). Comparisons of percentage body fat, body mass index, waist circumference, and waist-stature ratio in adults. Am J Clin Nutr., 89(2),500-8. doi: 10.3945/ajcn.2008.26847. Epub 2008 Dec 30.
Hu, F. (2008). Obesity Epidemiology. Oxford Press: Oxford, New York.
Sun, G., French, C.R., Martin, G.R., Younghusband, B., Green, R.C., Xie, Y.G., Mathews, M, Barron JR, Fitzpatrick, D.G,. Gulliver, W., & Zhang, H. (2005). Comparison of multifrequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for assessment of percentage body fat in a large, healthy population. Am J Clin Nutr., 81(1),74-8.
Kyle, U.G., Bosaeus, I., De Lorenzo, A.D., Deurenberg, P., Elia, M., Gómez, J.M., Heitmann, B.L., Kent-Smith, L., Melchior, J.C., Pirlich, M., Scharfetter, H., Schols, A.M., & Pichard, C. (2004). Composition of the ESPEN Working Group. Bioelectrical impedance analysis--part I: review of principles and methods. Clin Nutr., 23(5),1226-43.
Kyle, U.G., Bosaeus, I,. De Lorenzo, A.D., Deurenberg, P., Elia, M., Gomez, J,. Lilienthal Heitmann, B., Kent-Smith, L., Melchior, J.C., Pirlich, M., Scharfetter, H., M W J Schols, A., Pichard, C. (2004). ESPEN. Bioelectrical impedance analysis-part II: utilization in clinical practice. Clin Nutr., 23(6), 1430-53.
Kyle, U.G., Bosaeus, I., De Lorenzo, A.D., Deurenberg, P., Elia, M., Gómez, J.M., Heitmann, B.L., Kent-Smith, L., Melchior, J.C., Pirlich, M., Scharfetter, H., Schols, A.M., & Pichard, C. (2004). Composition of the ESPEN Working Group. Bioelectrical impedance analysis--part I: review of principles and methods. Clin Nutr., 23(5), 1226-43.