Study on Breath-Holding Test.

(I) Comparison of the results obtained under ordinary and under-water conditions

Abstract

1. Breath-holding test was applied both under ordinary and under-water conditions to the same subjects, and the breath-holding time, CO₁ content and O₂ content of the alveolar air were determined in each subject
2. For collecting the sample of the alveolar air, a modified collecting tube was designed, making it more suitable for a field work.
3. In primary school children, the breath-holding time increases with the age both under ordinary and under-water conditions. The longer breath-holding time is accompanied with increased CO₂ content of the alveolar air after the test.
4. Generally speaking, breath can be held longer under ordinary conditions than under the water. Here also the longer breath-holding is accompanied with greater CO₂ content of the alveolar air after the test.
5. The age difference in the breath-holding time may be due to the sensitivity and/or the volitional effort of endurance.
6. For the shorter endurance in the. under-water breath-holding, not only psychological, but also technical factors on the part of the tested subject may be responsible.