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

Summary 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.