Correlation between Vital Capacity and Body Size

Vital capacity is affected by age and body size. Most of the regression equations of predicted vital capacity are based on age and body height. In the same age group, vital capacity correlates remarkably with body height. But the vital capacity divided by height correlates remarkably with body size. Body height, body surface area, and the product of chest circumference and sitting height are used as a body size index. The correlations between these indices and vital capacity or the square root of vital capacity in the same age group are investigation. The following became clear after the investigation. The vital capacity predicted by body height is profitable for surpassing body size. The relation between vital capacity and body size is predicted more clearly by body surface area or by the product of chest circumference and sitting height than by body height. When it is predicted by body height alone, the use of the square root of vital capacity is most advisable. Investigated age groups are 6-12, 15 and 18-20 (only females) years old. The similar imvestigation must be persued concerning other age groups.