Lab 3 Skinfold Estimations of Body Composition

Skinfold Measurement Is simple and relatively accurate Requires a minimal amount of equipment Can be used with a large number of subjects in a field setting Produces results within 3 to 5 percent of underwater weighing

Principle Behind Skinfold Measurement Fat or fat-free tissues accumulate in relatively predictable patterns. If specific sites are measured, the size of such measurement will be influenced by the amount of the individual’s fat or fat-free tissue.

Equations/Calculations Slide 1 Males (ages 18-61) DB = – ( (X 2 )) + ( (X 2 ) 2 ) – ( (X 4 )) R = 0.91 SEE = kg ∙ L -1 X 2 = sum of chest, abdomen, and thigh skinfolds in mm X 4 = age in yrs

Equations/Calculations Slide 2 Females (ages 18-55) DB = – ( (X 3 )) + ( (X 3 ) 2 ) – ( (X 4 )) R = 0.84 SEE = kg ∙ L -1 X 3 = sum of triceps, thigh, and suprailium skinfolds in mm X 4 = age in yrs

Equations/Calculations Slide 3 % FAT = (((4.57 / DB) – 4.142) x 100) Fat Weight = Body Weight x (% FAT / 100) Fat-Free Weight = Body Weight – Fat Weight Body Weight Goal = FFW / (1 – (Target % FAT / 100))

Skinfold Estimation Example pound 22 year-old male Skinfold measures: Chest = 10 mm Abdomen = 20 mm Thigh = 15 mm Target % FAT = 10

Example 1, Slide 2 DB = – ( (45)) + ( (45) 2 ) – ( (22)) = kg · L -1

Example 1, Slide 3 % FAT = (((4.57 / ) – 4.142) x 100) = 11.1 Fat Weight = 170 x (11.1 / 100) = Fat-Free Weight = 170 – = Body Weight Goal = / (1 – (10 / 100)) = 168

Skinfold Estimations Example pound 22 year-old female Skinfold measures: Triceps = 12 mm Thigh = 17 mm Suprailium = 18 mm Target % FAT = 15

Example 2, Slide 2 DB = – ( (47)) + ( (47) 2 ) – ( (22)) = kg · L -1

Example 2, Slide 3 % FAT = (((4.57 / ) – 4.142) x 100) = 20.7 Fat Weight = 140 x (20.7 / 100) = Fat-Free Weight = 140 – = Body Weight Goal = / (1 – (15 / 100)) = 131