Firearm User Network

The following article is based on material by Nick Barringer, PhD.

Nothing ruins a good combat story like a reliable eye witness. Nothing ruins a mostly anecdotal argument like actual science.

Military personnel sometimes complain about the tape test, which is a measure of body composition to assess a person’s lean mass and body fat. The basis of this requirement is spelled out in Department of Defense Instruction Number 1308.3 DoD Physical Fitness and Body Fat Programs Procedures

It is DoD policy that service members shall maintain physical readiness through appropriate nutrition, health, and fitness habits. Maintaining desirable body composition is an integral part of physical fitness, general health, and military appearance. Physical fitness is an important component of the general health of the individual. Comprehensive fitness includes many aspects of a healthy lifestyle.

Physical Fitness Tests assess Service-wide baseline generalized fitness levels and are not intended to represent mission or occupationally specific fitness demands.

Ensure that gender-appropriate body fat standards shall not be more stringent than 18 percent for men and 26 percent for women, and shall not be more liberal than 26 percent for men and 36 percent for women, as measured using circumference-based methods.

In 1981 the Services were directed to develop body composition standards with the three major concerns being: 1) body composition was an integral part of physical fitness 2) body composition is a determinant of appropriate military appearance and 3) body composition is a determinant of general health and well-being of military personnel.

In 1982, in response to the directive developed the following criteria:
a) no skinfold measurements
b) emphasizes circumference measurements at easily locatable anatomic sites
c) not to exceed 4 measurements(excluding height and weight)
d) able to be executed by non-technically trained personnel
e) does not require elaborate or unavailable equipment
f) common equation for all race/ethnic groups
g) measurements should be avoided that require undressing beyond the Army sport ensemble
h) selected equations must have a correlation coefficient of at least 0.80 with hydrostatically determined percent body fat, and a standard error of the estimate not greater than 4.0 % body fat
i) equations should give comparable results in the three major race/ethnic groups

Based on these criteria, a study was carried out at Fort Hood, TX and Carlisle Barracks, PA on 1,194 males and 319 females between 25 Jun and 1 Nov 1984. The Soldiers were hydrostatically weighed and circumference measurements were taken. Based on this study, the Army circumference formula for the tape test was built. When the body fat estimates from the tape test were compared to the “gold standard” of hydrostatic weighing the values provide were an R=0.817 with Standard Error of 4 for men and an R=0.820 and a Standard Error of 3.5 for women. The assessment was also cross-validated in a population of Navy personnel.

In statistics you have the R or correlation coefficient which tells you how well one test correlates to the other with 0 being no correlation and 1 being a perfect correlation. The only way you get 1 is when comparing something to itself so anything 0.80 and above is considered a strong correlation. These tests were 0.81-0.82.

For perspective, the correlation coefficient for asbestos exposure and cancer, particularly mesothelioma, is reported around 0.80, a slightly lower correlation.

Aren’t there better alternatives? In a 2013 Army Times article (“Experts: Tape test has huge margin of error”) they used hydrostatic weighing on 10 Soldiers. The irony is using ten subjects completing hydrostatic weighing in a non-research setting to claim flaws with a test that was developed using hydrostatic weighing of 1,513 Soldiers in a research setting and then
cross-validated using additional Navy personnel, and revalidated by more advanced methods such as Dual-energy X-ray absorptiometry.

All body composition assessments are estimates. The only way to directly measure body fat is to dissect a cadaver, cut out all the fat, and weigh it. Every assessment has its flaws.
For hydrostatic weighing, if you drink a bunch of fluid or just ate a large meal, you would be denser and therefore the extra weight would be interpreted as lean mass and a lower body fat percentage. That is why how the test was administered makes a difference. In a research setting, such as the one used to develop the tape test, the researchers control for things like subject hydration status etc. In the 10 subjects the Army Times assessed we don’t know if these things were taken into account.

Bioelectrical Impedance (BIA), as seen on some types of bathroom scales, estimates body fat based on body water. So hydration status and the quality of the machine can significantly impact the estimate. Skin-fold calipers requires a trained professional with knowledge of the appropriate anatomical sites and technique. The Army used skin-fold calipers in the past but found the tape test to have less variability, be more efficient, and according to Dr.Friedl better serve the Soldier trying to lose weight since intraabdominal fat seems to mobilize more quickly than subcutaneous fat as he reported “waist circumference based military equations are relatively sensitive to changes in criterion-measured body fat for male and female soldiers during basic training and male soldiers during Ranger training”.

The tape test acknowledges that height/weight fails to take body composition into account and was designed to determine if a Soldier is over-fat. It was designed to be an efficient and economical assessment that could be completed by non-technically trained personnel. It was designed to have a strong correlation to recognized “gold standards” in body composition assessment and work for all major ethnicities. Even in the Army Times report from 2013, they did not report that any of the 10 Soldiers failed the tape test that shouldn’t have. So the tape test still did its job. When one takes the original daunting requirements into consideration, actually reads the level of research that went into developing the tape test, and compares it to the fiscal and time costs of other body composition assessments, a tape test is the only sensible answer.

It could be argued a Waist-Hip Ratio is a better assessment as it has been correlated to mortality in formal studies. A simple waist measurement, as used by the Air Force, is simpler still and accomplishes much of the same thing. Regardless, we’d still be using a tape test. Nobody that is actually lean and has appropriate body composition will fail a tape test. If the tape is giving a result you don’t like, fix the cause instead of blaming the test.

For more information on the background of body composition assessments in the military, go to Google Scholar and enter the names of Dr. J.A. Hodgdon, Dr. J.A. Vogel, and Dr. K.E. Freidl. For the cliff notes read Dr. Freidl’s review

Click to access a370158.pdf

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