BodPod Reliability and Validity: Especially in Male and Female Athletes.
A Literature Review
Research in Exercise Science
BODPOD INFORMATION AND BACKGROUND
The BODPOD is a fairly new form of body fat estimation introduced to the health and fitness world. BODPOD is a shortened term for the formally named air-displacement plethysmography. This tool for body composition estimation is called a two-compartment model, similar to hydrostatic weighing. Hydrostatic weighing is another two-compartment model that was around and used before the BODPOD’s existence. (Fields, Hunter & Goran , 2000) Also ...view middle of the document...
With hydrostatic weighing a person must be submerged numerous times for an accurate estimation to be calculated. Though this convenience in use does not come without a price, the BODPOD has been found in studies to be less valid and reliable when compared to other forms of body fat estimating. (Moon, Eckerson, Tobkin, Smith , Lockwood, Walter , Cramer & Beck, 2009; Collins, Millard-Stafford, Sparling, Snow , Rosskopf, Webb & Omer, 1999; Fields, Wilson, Gladden, Hunter, Pascoe & Goran, 2001; Ballard, Fafara & Vukovich, 2004, Tseh, Caputo & Keefer , 2010) These common discrepancies found among studies regarding the BODPOD would lead one to believe more research needs to be done on the reliability, variability, and validity of this method on athletes and non-athletes alike. Therefore I propose that furthering research be done on the validity and reliability of this machine as well as a development of more precise technology within the BodPod to obtain more accurate readings.
The diagram above shows the anatomy of the BODPOD. This machine is an egg shaped chamber that the patient being tested will sit in. There is a front chamber where the subject sits and a back chamber where the electronics and a diaphragm are located. (Dempster, Aitkens, 1995) The diaphragm moves, which produces pressure changes in both chambers of the machine. The pressure changes, however, are not noticeable to the subjects being tested. (Dixon, Deitrick, Pierce, Cutrufello & Drapeau, 2005; Interdevice Varability, 2005 ) The subjects being tested will enter the chamber with minimal amounts of clothes and usually a cap to cover up the hair. This is so there is as little impedance as possible to the accuracy of the machines results.
As stated previously the reliability and validity or the BODPOD when used as a means to measure body composition has been called into question, this is no different when all the subjects are males. It seems as if many studies show that the BODPOD is a mediocre form of measurement, not terrible, but not spot on. (Moon, 2008; Pribyl, Smith & Grimes , 2011 )
The studies that have been done on the accuracy on the BodPod’s measurements on males seem to be fairly consistent depending on what model or method it is being compared too. One consensus that the studies seemed to come to was that the BodPod consistently underestimated body fat percentages in males. (Dixon, Deitrick, Pierce, Cutrufello & Drapeau, 2005; Collins, Millard-Stafford, Sparling, Snow , Rosskopf, Webb & Omer, 1999) One study done on this was conducted on 61 division 1A athletes, in which the BodPod was compared to Hydrostatic weighing. This particular study showed that the PodBod is a valid form of measurement but it routinely underestimated BF% in all of the football players. (Collins, Millard-Stafford, Sparling, Snow , Rosskopf, Webb & Omer, 1999)
Other studies conducted on collegiate wrestlers yielded similar results to the study...