人体比重― 体脂肪量に関する研究

(1)夏季水泳プール利用による水中体重測定法

抄録

A device for underwater weighing by utilizing a swimming pool was tentatively made, and with it, the weights in water of 111 male students were measured. And from the thus obtained weights in water, the body density was calculated to be compared, for its justification, with those already reported by other workers in the literature. This study aimed at the examination of the body composition of boys in the developing stage. And the points to pay attention in this case were discussed. The principal findings were as follows: 1) The body density obtained by this method from the above mentioned subjects was 1.0724 ± 0.0092 (mean ± standard deviation). This approximately agrees with 1.07, the normal (general) value for the Japanese adolescent males, estimated from the reports in the literature. 2) The residual volume (RV), an important factor determining the body density needs to be measured exactly. The maximal expiratory level which affects RV, is relatively easy to determine in case of the underwater weighing thanks to water pressure. When elementary school children are the subjects of weighing, however, sufficient attention must be paid to avoid danger, because breething needs to be arrested during a time from the attainment of the maximal expiratory level until the end of the weighing. 3) The underwater weighing can be made within 5 seconds after the attainment of the maximal expiratory level of the subject. The body weights in water of the subjects of the present study averaged 3.03±0.578kg (range, 4.25 to 1.60kg.).