Hydrostatic Weighing Questions
Purpose:
1. Write 1 sentence about the purpose of this lab. (1pt)
Methods:
2. Write 1-2 sentences about what you measured. (1pt)
3. What is the general equation for density of an object? What principle did you use
to measure volume? (1pt)
Results/Conclusions:
For full credit make sure to show all calculations
4.
a. Use your vital capacity to calculate a predicted residual volume for
yourself using either formula 26.5 or 26.6 on p358 of your lab notebook.
b. Calculate your body density using your predicted residual volume and
equation 26.8.
c. Using the Siri formula (eq. 26.9) calculate your body fat percentage using
your body density from the predicted RV. (1.5pts)
5.
a. Calculate your body density using your actual measured residual volume
using equation 26.8.
b. Using the Siri formula (eq. 26.9), calculate your body fat percentage using
your body density from this body density (measured RV). (2.0 pts)
6. Using your body density from the measured RV (question 5) calculate your body
fat percentage using the(page 359):
a. Brozek equation
b. Lohman equation
c. Schutte equation
(1.5pts)
7. Select the equation for body fat that you feel is most appropriate for you based on
the populations from which the regression equation was made (see descriptions in
your lab manual) and state why you chose that formula. Calculate the difference
between body fat percentages from your selected formula and all other formulas.
(2.0pts)
8. Calculate your fat mass and your fat-free mass for all four methods used (please
put into tabular format as seen below):
Method
Siri
Brozek
Lohman
Schutte
(2.0 pt)
Fat-Free Mass
Fat Mass
9. Hydrostatic weighing is considered the “Gold Standard” in body composition
analysis. However, the standard error of this method is 2% body fat (as opposed
to 2% of the body fat percentage). Example of the correct way to do it 13%, 1115%. Calculate the range within which your body fat percentage falls for body fat
calculated using the formula you selected in #7. (1pt)
10. Based on this information you have calculated throughout this lab report, what
can you conclude about regression equations and the importance of population in
using these equations? (2pts)