Consistency of a mobile body composition trailer: a novel portable laboratory assessment?

Objective: The purpose of this investigation was to (i) assess the test-retest reliability and minimum difference (MD) values of air-displacement plethysmography (ADP) and the Siri 3-compartment (3-C) model in a mobile trailer, and (ii) identify any environmental fluctuations in the trailer.

Methods: percent body fat (%BF) was examined in 22 firefighters on two separate days in a climate-controlled mobile trailer using ADP. Total body water was examined in a subset of participants (n = 12) using bioelectrical impedance spectroscopy (BIS) to determine %BF using Siri's 3-C model.

Results: There were no differences in environmental measures (P≥0·138), %BF for ADP (P = 0·276), or %BF for the Siri 3-C model (P = 0·382) between day 1 and day 2. Intraclass correlation coefficient and standard error of measurement values for ADP and the Siri 3-C model were 0·978 and 1·3% and 0·986 and 0·6%, respectively. The MD values were 3·6% and 1·7%, respectively.

Conclusions: These findings indicate that ADP can reliably determine %BF when transported in a climate-controlled mobile trailer. Additional accuracy is achievable with the Siri 3-C model, providing an attractive and promising method to measure body composition in larger scale community-based settings.