Agreement Between Methods to Estimate Residual Lung Volume: A Methodological Investigation

Claire Mills*, Mark De Ste Croix and David James

Agreement Between Methods to Estimate Residual Lung Volume: A Methodological Investigation.

Hydrostatic weighing can be demanding on the participant even after an initial period of
familiarisation.1-3 For instance, the weighing procedure requires the participant’s cooperation whilst totally submerged in water. Being submerged can be a daunting experience for participants, particularly as they are required to exhale maximally whilst keeping as still as possible in a crouched seated position. In other words, this apprehension can result in the deliberate retention of surplus air in the lungs, thereby influencing measurement results, making collected data unreliable.

On the third cycle the primary investigator asked the participant to take a maximal inhalation immediately followed by a maximal exhalation.  Once submerged, the primary investigator took the measurement of the participant’s body mass in water (kg) from the wall mounted digital weighing scale adjacent to the hydrostatic weighing tank. Following the measurement reading, the primary investigator rapped loudly on the side of the tank thereby instructing the participant to return to the surface.
Once underwater and keeping as still as possible the participant exhaled maximally. The primary investigator watched for the ending of exhalation bubbles and took the measurement of the participant’s body mass in water (kg) from the wall mounted digital weighing scale adjacent to the hydrostatic weighing tank. Following the measurement, the primary investigator rapped loudly on the side of the tank instructing the participants to return to the surface.

Results from the pre-submersion exhalation technique revealed that four participants were unable to successfully carry out a single attempt and the remaining participants were only able to complete a mean average of four underwater weighing attempts.

Sport Exerc Med Open J. 2017; 3(1): 20- 23. doi: 10.17140/SEMOJ-3-143