Effect of short schemes on body composition measurements using Air-Displacement Plethysmography

BACKGROUND: Air-displacement plethysmography (ADP) is becoming a popular method to assess body composition. Several studies have shown certain types of clothing can affect measurements of body density, however no study has specifically investigated the effect of cotton gym shorts and spandex bicycle shorts on body density. METHODS: Thirty-seven males (23.0 ± 3.2 yr., 177.3 ± 5.4 cm., 74.8 ± 7.5 kg.) and thirty-eight females (23.7 ± 5.3 yr., 163.6 ± 8.4 cm., 57.1 ± 7.0 kg.) had their body density measured by ADP in three clothing schemes: 1) a tight fitting Speedo(® )swim suit (criterion measure), 2) cotton gym shorts, and 3) spandex bicycle shorts. The clothing was provided by the University of Oklahoma Body Composition Laboratory and the testing schemes were performed in random order. RESULTS: The regression of body density by the criterion measure against body density while wearing cotton gym shorts for the entire group (y = 0.001 + 0.991x, SEE = 0.003 g/cm(3)) and the females (y = 0.059 + 0.934x, SEE = 0.003 g/cm(3)) did not significantly deviate from the line of identity. However in males the regression significantly deviated from the line of identity (y = 0.052 + 0.944x, SEE = 0.002 g/cm(3)). Body density by the criterion measure and body density while wearing spandex bicycle shorts did not significantly differ from the line of identity for the entire group (y = -0.018 + 1.013x SEE = 0.003 g/cm(3)), in males (y = -0.002 + 1.001x, SEE = 0.003 g/cm(3)), or females (y = 0.073 + 0.925x, SEE = 0.003 g/cm(3)). Residual plot analysis revealed no group or gender bias in either the cotton gym shorts or in the spandex bicycle shorts. CONCLUSION: It would appear bicycle spandex shorts are an acceptable alternative to a Speedo(® )like swim suit, however we advise that subjects adhere to the strict clothing protocol that is recommended by the manufacturer.