title: Reliability of air displacement plethysmography.
abstract: The purpose of this study was to examine the reliability of an air displacement plethysmography device (BOD POD) over trials performed on 3 different days. Subjects consisted of 24 healthy adults (8 men, 16 women), ages 18-38 years, with body weights 46.8-93.6 kg, body mass indexes of 19.1-30.1 kg x m(-2), and percentage body fats (BF) of 7.9-43.1%. Two estimates of BF were performed on 3 days. Paired t-tests revealed no significant within-day differences in body volume (BV), thoracic gas volume (V(TG)), body density (BD), and BF. Correlations between the two V(TG) measures on a day were r = 0.86 for day 1, r = 0.93 for day 2, and r = 0.96 for day 3. BF estimates within a day had high correlations of r = 0.98. Significant differences were found between days for measures of BV, V(TG), BD, and BF. These results indicate a high reliability for within-day estimates of BF and significant differences in between-day estimates of BF using air displacement plethysmography. Reliability of BF may be increased by requiring subjects to practice the procedure for V(TG) measurement.
authors.affiliation: Department of Health, Exercise, & Rehabilitative Sciences, Winona State University, Minnesota 55987, USA. danderson@winona.edu
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000388:Air; D001823:Body Composition / Q000502:physiology*; D001824:Body Constitution / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010991:Plethysmography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity