PULMONARY VENTILATION AS AN INDEX OF ENERGY EXPENDITURE

Abstract

1. If, over a considerable range of human activity, it is possible to predict energy expenditure by measurement of ventilation alone, then field surveys can be considerably simplified by reduction of laboratory work; elimination of most of the gas analyses allows more subjects to be studied.2. Analysis of the results from two field surveys shows that this method of prediction can be utilized with very little increase in error.3. For each subject in these two surveys a regression line was drawn through the origin using 6 points of determined rates of ventilation and of energy expenditure to calculate the regression coefficient; these rates were reasonably far from zero, e.g. at about 7‐8 kcal./min.4. Subsequently, prediction of energy output from ventilation alone, using these regression lines, gave an additional error of only about 5 per cent.5. This technique is not valid when ventilation is low or high and should be restricted to the range of 15‐50 1./min.6. The application of this procedure in field studies of energy expenditure is discussed.