Energy expenditure of male farmers in dry and rainy seasons in Upper-Volta.

1. Thirty Mossi male farmers from Upper-Volta were investigated, twenty-three in the dry season (March-April) and sixteen in the rainy season (July-August), eight of them being studied twice. A 48 h time-and-motion study was carried out and the daily energy expenditure was computed. 2. The mean height was 1.70 m and the mean weight 58.5 kg. The averaged percentage of body fat calculated from skinfold thickness was 10. 3. During the dry season the subjects could be classified as very moderately active with an energy output of 10.0 MJ (2410 kcal)/d. By contrast, with an energy expenditure of 14.4 MJ (3460 kcal)/d, they were considered as exceptionally active in July-August when performing the agricultural work. 4. In this study we measured the intensity of physical work in a society where human labour is still the main tool of production. The determination of seasonal variations in energy expenditure may be useful to assess the nutritional requirements in arid zones of West Africa.