Question: Calculating Percent Body Fat from Skinfold Measurements Instructions: Calculate the body density from each of the two client's skinfold assessments performed using the appropriate equation. Then use body density to calculate % body fat for each client. (HRPFBox 4.3 pg 69.) Compare the client's assessments outcome to normative values. (Table 4.2 & 4.3).

Calculating Percent Body Fat from Skinfold Measurements Instructions: Calculate the body density from each of the two client's skinfold assessments performed using the appropriate equation. Then use body density to calculate % body fat for each client. (HRPFBox 4.3 pg 69.) Compare the client's assessments outcome to normative values. (Table 4.2 & 4.3). Client #1: 28-year-old white male Chest: 11mm Midaxilla: 16mm Triceps: 12mm Subscapular: 18mm Abdomen: 21mm Suprailiac: 15mm Thigh: 16mm Client #2: 39-year-old black female Chest: 20mm Midaxilla: 24mm Triceps: 18mm Subscapular: 26mm Abdomen: 34mm Suprailiac: 38mm Thigh: 31mm MALES Seven-Site Formula (Chest, Midaxilla, Triceps, Subscapular, Abdomen, Suprailiac, Thigh) Body density (g/ml) = 1.112 -0.00043499 x sum of seven skinfolds) + (0.00000055 x [sum of seven skinfolds]2) – (0.00028826 x age) g/ml = 1.112 – (0.00043499 x _109__) + (0.00000055ⓇL_109_12-(0.00028826 x _28__) = _1.063_ (sum of skinfolds) (sum of skinfolds) (age) FEMALES Seven-Site Formula (Chest, Midaxilla, Triceps, Subscapular, Abdomen, Suprailiac, Thigh) Body density (g/ml) = 1.097 - (0.00046971* sum of seven skinfolds) + (0.00000056 x [sum of seven skinfolds]2 – (0.00012828 x age) = 1.097 – (0.00046971Ⓡ_191__) +(0.00000056 XL_191_12) -(0.00012828 _39__) = _1.08_ g/ml (sum of skinfolds) (sum of skinfolds) (age) Calculating Percent Body Fat from Body Density Refer to the table below (from ACSM book) to use the body density in the appropriate equation based on the age, gender, and race of the individual. (Note: Population-specific formulas don't exist for all ethnic or age groups; use the formula for whites of the appropriate age and gender if there is no population-specific formula appropriate for your client.) An alternative is to use an online calculator in which the skinfold measurements are used to estimate body fat % (there is one at the website linear- software.com that works well). Body density (from formula above): % (convert from decimal) Client #1: Percent body fat = (from table below) (body density) Client #2: Percent body fat = (from table below) (body density) (from table below) . % (convert from decimal) (from table below) Client #1: Client #2: % % (classification from HRPF Table 4.2) (classification from HRPF Table 4.3) Table 4.3 (ACSM's Guideline for Exercise Testing and Prescription 10th edition) POPULATION (Race) White AGE 17-19 SEX Male Female Male Female Male % BODY FAT EQUATION (4.99/Db) - 4.55 (5.05/Db) - 4.62 (4.95/Db) - 4.50 (5.01/Db) - 4.57 (4.37/Db) – 3.93 20-80 Black 18-32 Hispanic American Indian Japanese Native 24-79 20-40 18-60 18-48 Female Female Female Male Female (4.85/Db) - 4.39 (4.87/Db) - 4.41 (4.81/Db) - 4.34 (4.97/Db) - 4.52 (4.76/Db) - 4.28 SPECIAL POPULATIONS: Obese Anorexic Resistance trained athlete 17-62 15-30 20-28 29-41 19-23 17-25 Male Female Male Female Male Female (5.00/Db) - 4.56 (5.26/Db) - 4.83 (5.21/Db) - 4.78 (4.97/Db) - 4.52 (5.12/Db) - 4.68 (4.95/Db) - 4.50 Endurance athlete Formulas to know: Fat Mass = (Total body mass) x (% BF / 100) Fat Free Mass (Lean Body Mass) = Total body mass – Fat mass Desired Body Fat % (Gain or Loss) = Fat Free Mass/(1 - desired body fat %**) ** desired body fat % needs to be in decimal form: 12% would be 0.12.