Chapter 8 Lab
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Assessment of body composition by skinfold measurements is a simple and relatively accurate method of determining the amount of fat and fat-free tissue in a person. It requires minimal equipment and can be used with large numbers of subjects in a field setting. Skinfold measurements can be used in multiple regression “prediction” equations to estimate body composition (body density, percent fat, fat-free weight, fat weight).
The ability to predict body composition from skinfolds is simply based on the fact that fat or fat-free tissues accumulate in relatively predictable patterns in similarly aged individuals of the same gender. Therefore, if specific sites are measured, the measurements will be influenced by the amount of the individual’s adipose or fat-free tissue.
In this laboratory the technique for skinfold measurement will be outlined, and you will use the measurements to predict various aspects of body composition.
- Washable marker
- Tape measure
- Skinfold calipers
- Measure and mark the anatomical sites with a marker. Three sites are to be measured for each gender. Both males and females are measured at the thigh site.2 Males are also measured at the chest3 and abdomen4; females at the triceps5 and suprailium.6
- Take all measurements on the right side of the body.
- Grasp the skinfold of the subject firmly with the thumb and forefinger and pull away from the body.
- Hold the caliper perpendicular to the skinfold. The caliper should be approximately 1 cm away from the thumb and forefinger so that the pressure of the caliper will not be affected.
- Read the skinfold size approximately one to two seconds after the caliper thumb grip has been released.
- Take three measurements per site at least 15 seconds apart to allow the skinfold site to return to normal. If the repeated measurements vary by more than 1 mm, more measurements should be taken. Use the mean of the recorded measurements that are within 1 mm as the representative skinfold value in the equation.
- Calculate body composition characteristics using the worksheet below.
Abbreviations and Equations
DB = body density
FFW = fat-free weight
FW = fat weight
% fat = percent fat
Males (ages 18–61 years)7
DB = 1.1093800 – (0.0008267 (X2)) + (0.0000016 (X2)2) – (0.0002574 (X4))
R = 0.91
SEE = 0.008 kg • L–1
X2 = sum of chest, abdomen, and thigh skinfolds in mm
X4 = age in years
Females (ages 18–55 years)2
DB = 1.099421 – (0.0009929 (X3)) + (0.0000023 (X3)2) – (0.0001392 (X4))
R = 0.84
SEE = 0.009 kg • L–1
X3 = sum of triceps, thigh, and suprailium skinfolds in mm
X4 = age in years
SEE = standard error of estimate, R = multiple correlation coefficient
% fat = (((4.57 / DB) – 4.142) x 100)1
fat weight = body weight x (% fat/100)
fat-free weight = body weight – fat weight
body weight goal = FFW / (1 – (Target % fat / 100))
- Harrison, G. G., Buskirk, E. R., Carter, J. E. L., Johnston, F. E., Lohman, T. G., Pollock, M. L., et al. Skinfold thicknesses and measurement techniques. In Anthropometric Standardization Reference Manual, eds. T. G. Lohman, A. F. Roche, and R. Martorell. Champaign, IL: Human
- Kinetics, pp. 55–70, 1988.
- See video demonstration of measuring the skinfold at a man’s thigh site at http://www.youtube.com/watch?v=HWdcdQ208PA.
- See video demonstration of the chest site at http://www.youtube.com/watch?v=ZH2M0LNn4hk.
- See video demonstration of the abdomen site at http://www.youtube.com/watch?v=J94W4_rL-IY.
- See video demonstration of the triceps site at http://www.youtube.com/watch?v=xJL0ApsuaSo.
- See a video demonstration of the suprailiac site at http://www.youtube.com/watch?v=AJU0wr_KrpI .
- Jackson, A. S., and Pollock, M. L. Practical assessment of body composition. Physician Sportsmed. 13: 76–90, 1985.
Lab adapted from Housh, T., Cramer, J., Weir, J., Beck, T., & Johnson, G. (2009). Physical fitness laboratories on a budget. (pp. 164-166, 169). Scottsdale, AZ: Holcomb Hathaway, Publishers.