Bod Pod tests for fat ratio

  • Published
  • By Catherine Cornett
  • Hilltop Times correspondent
HILL AIR FORCE BASE, Utah --  Waking up early to exercise isn't a strange concept for Col. Patrick Higby, commander of the 75th Air Base Wing. So it was no big stretch for him to make an appointment early in the morning so he could head over to the Health and Wellness Center and hop into the Bod Pod.
Though it slightly resembles a futuristic space shuttle with its curved egg shape and round window, the Bod Pod is actually a reliable and easy way to measure the amount of fat present in the body. 

Before entering the Bod Pod, both men and women must first adhere to a few rules in order to make sure their assessment is as accurate as possible. The rules include wearing form-fitting clothing such as Spandex or a Speedo, and also a sports bra for women.
Since not many individuals may own Speedos, HAWC employees also allow PT shorts, as long as they are tucked in, as well as swimsuits, said Jenny McFarland, a member of the 75th Aerospace Medicine Squadron and the Health Promotions manager at the HAWC. 

Before arriving 

Patients are also expected not to exercise or eat for two hours before their Bod Pod assessment and should use the restroom before testing.
Test takers are also required to wear a swim cap, which is provided by the HAWC. The reason for the form-fitting clothing and swim cap is so that the body's volume displacement isn't distorted by loose clothing, said Katherine Purser, a member of the 75th Force Support Squadron.
After the colonel's basic information was entered into the computer, Ryan Burns, an exercise physiologist with the 75th AMDS, began calibrating the machine. The process took around 10 minutes because it was the first time the machine had been used that day, but once done, calibration usually only takes around three to four minutes. 

Once the machine was calibrated, the colonel's mass was measured and he was then able to take a seat inside the inner chamber where his body volume would be measured. 

How it works 

According to the Bod Pod Web site, the machine takes measurements through a process called Air Displacement Plethysmography. The process involves the measurement of the interior volume before the patient is inside and again after the patient is seated inside the chamber. The difference in volume is then subtracted to obtain the patient's body volume. 

"Once the subject's mass and volume are determined, body density is calculated and the relative proportions of fat and fat-free mass are determined," the Bod Pod official Web site said. 

The system is very similar to the hydrostatic test, where body volume is measured by water displacement. The Bod Pod, however, offers a more comfortable test in that the body doesn't have to be completely submerged underwater and the patient doesn't have to force all of the air out of their lungs, explained Burns. 

Instead of having test takers force all of the air out of their lungs, HAWC employees use a predicted thoracic gas volume, or the volume of the air inside the test taker's lungs, throat and mouth.
 
Although Higby has never taken a hydrostatic test, he has done electrostatic testing of his body's mass resistance. He reported that the Bod Pod test was more comfortable, especially since the assessment itself only took around one minute, with two 30 second readings. 

"I think this is going to be a lot more accurate," Col. Higby added as he looked over his results. 

His assessment scored him in the 13 percent to 20 percent body fat range, which was a bit of a surprise, he said. 

"I thought I was going to be in the 21 to 30 percent range," Higby said. 

According to the Bod Pod reading, his body mass is made up of about 32 pounds of fat. 

"I'd like to get rid of 12 pounds of that," the colonel said. To see if he has succeeded, he plans to head back into the Bod Pod in about a year.
Another item of note on the test results is the Resting Metabolic Rate (RMR) value. For the colonel's test, the value was 1,678 kilocalories per day.
"If I'm lying around all day, I shouldn't eat more than that," Higby explained. "Otherwise, I would gain fat." 

After experiencing the Bod Pod and getting his test results, the colonel spared no time in his plans to lose those 12 excess pounds of fat as he took off running past the RV park. 

For those interested in finding out their percent of body fat, RMR, or who just want to start a health regime and pick out some goals, Bod Pod appointments are available from 7 a.m. to 3 p.m. Monday through Friday. The tests are available for anyone with base access, including military dependents, at no cost to the participant. You can make an appointment through the HAWC by calling 777-1215 or calling the fitness center front desk at 777-2762.