Skinfold Measurements
Measuring skinfold thickness is one of the most frequently performed tests to estimate %BF. This quick, noninvasive, inexpensive method can provide a fairly accurate assessment of %BF. The value obtained by skinfold measurement is typically within 3.5% of the value measured with underwater weighing (30). Skinfold measurement is based on the assumption that, as a person gains adipose tissue, the increase in skinfold thickness is proportional to the additional fat weight.
Because of the widespread use of skinfold measurement, fitness professionals should master the skills involved. Accurately assessing skinfold thickness requires the correct performance of several steps: locating the skinfold site, pinching the skinfold away from the underlying tissue, measuring with the caliper, and choosing the proper equation. The following sections address each of these concerns.
Locating the Skinfold Site
It is critical to accurately determine the site of the skinfold measurement. To increase the accuracy of the measurement, especially for the inexperienced technician, the site should be located and then marked with a washable marker. This helps ensure that the calipers are placed in the correct position each time the skinfold is measured. All skinfold measurements should be taken on the right side of the body unless otherwise specified. Refer to table 8.4 and figure 8.1 for some of the most commonly used measurement sites. For a more complete description of determining skinfold sites, refer to the Anthropometric Standardization Reference Manual (22). Measuring skinfolds immediately after exercise should be avoided because exercise can shift fluid volume, leading to inaccurate results.