Determining energy costs of agricultural activities by respirometer and energy balance techniques

Abstract

Eighteen Guatemalan agricultural workers who had received an excellent diet for 3 years prior to the study were investigated in regard to body composition, energy cost of work of 37 agricultural activities, dietary intake, time-motion studies, and energy balance. A detailed description of the methodology used and of the results obtained is presented. The subjects' body composition was normal, except for only two relatively obese individuals. However, muscle mass was smaller than that determined in a group of normal military academy students. The energy cost of work of the various activities measured agreed with published values from both developed and developing countries, except for the results published from India, which were lower. Caloric balance was, on the average, –138 kcal/day, and mean weight loss, –29 g in 3 days. In 14 of the 18 subjects studied, there was a high correlation between pulse taken for 15 sec after the end of each activity and oxygen consumption. In general, respiratory minute volume agreed better with Vo₂than pulse, following an essential linear regression, except in severe exercise situations.