Bod PodDoes beverage consumption affect results?

Sophia Fong, Megan Magiera, Dinh Nguyen, Shawn Rigdon

IntroductionBody composition testing

•the 2-compartment modelo fat mass = 0.9 grams per cm3

o fat-free mass = 1.10 grams per cm3

•Siri equation:%fat = (495/density) - 450

How does the Bod Pod work?

● Air Displacement Plethysmograph (ADP)○ Density= Mass/Volume○ Weigh subject → mass○ Volume-Pressure changes

in chamber → measure pressure → derive subject volume● Must account for:

○ Average thoracic lung volume○ effect of skin surface area

Image from:http://floridafitnesstesting.com/index.php/qaa.html

Recommended Protocol

● No food or drink within 2 hours of testing

● No vigorous exercise within 2 hours of testing

● Appropriate attire should be as close to bare skin as possible○ Wear swim cap○ Form-fitting swimsuit○ Compression shorts○ Unpadded sports bra○ Remove all other clothing, jewelry, etc.

Hypothesis

• We expected body % fat, volume, and mass to increase while density to decrease due to body absorption of 32 ounces of Gatorade.

Methods• 6 Total Participants: 3 Males and 3 Females

• Age range: 21 - 33

• 2 Tests per participants were collected. Pre-Gatorade and post-Gatorade.

• Pre-Gatorade: Follow recommended protocol:

No food or drinks were to be consumed at least 2 hours before the

• Post-Gatorade: Approximately 16 ounces of Gatorade to be consumed within 5 minutes and another 16 ounces within the next 5 minutes. Wait 25 minutes, then re-test.

Results• With the exception of 2 outliers body % fat, volume,

and mass increased while density decreased (due to density being inversely proportional to volume D=M/V).

• No statistical significance was found (p=0.4)

Results

Results

Results

• 2 Female subjects’ body % fat, volume, and mass decreased while density increased.

Conclusion• Most subjects’ body composition readings POST

Gatorade were what was expected.

• 2 outliers’ body composition readings were the opposite of what was expected.

• Validity of BodPod?o 4 compartment vs 2 compartment models

fat mass, total body water, bone mineral mass, residual

up to 3.5% difference (Withers, R.T. et al, 1998)