Reliability of measurement of oxygen uptake by a portable telemetric system

Summary The purpose of the present study was to check the reliability of measurements of oxygen uptake (VO₂) using a newly developed portable telemetry system. This system (K2) consisted of a face mask, a flow meter, a gas analyser with a transmitter, and a receiver. The total mass for the subject to carry was about 850 g. Three experiments were carried out, firstly to check the reliability and reproducibility of the flow meter and the K2 gas analyser, secondly to check the accuracy of K2 by comparing it with the Douglas bag method (DB), and thirdly to apply K2 to sports activities. In the first experiment, the flow meter was highly accurate up to 180 l·min^–1 with good reproducibility. The measurement error of the gas analyser was less than 2%. In the second experiment, there was no significant difference in the calculated ventilation between K2 and DB. The VO₂ showed no significant difference between K2 and DB with some exceptions. In the third experiment, we succeeded in the measurement of VO₂ during rowing on water. The measurement of VO₂ during running and playing soccer was also possible. It would seem that the present system could well be a powerful tool in the field measurement of VO₂ during various sports activities.