Question

The following data were collected on a male Hispanic high school football player:

Weight = 175 lbs. Height = 70 inches Age = 16 years

Method 1: % fat using a published prediction equation for athletes (boys 14-19 years; requires subscapular, abdomen, triceps, and midaxillary skinfolds): 11% body fat

Method 2: % fat using the published 3 girth method (upper arm, abdomen, forearm): 20% body fat

Method 3: % fat using hydrostatic weighing: 16% body fat

Give 3 reasons why there is variability (i.e., error) in the % fat values. BE SPECIFIC. Consider the method of determining body fat and the sites used to predict body fat.  Assume that the technician performed all the measurements and calculations correctly, and that the athlete followed all pretest instructions.  Do NOT state calculation errors or failure to follow pre-test instructions.  

Answer 1

1. The character of the subcutaneous fat in an individual can influence the precision of skin-fold measurements. Which leads to inaccurate result.

2.  Girth method - It does not work well on lean individuals and it lacks high tech appeal. Measuring girths can be a fairly embarrassing form of testing for some clients.

3. Hydrostatic weighing method subjects must completely submerge themselves underwater and expel all of the air in their lungs. This might make the subject anxious or uncomfortable. Which leads to error in calculation of fat.