BERTHOUZE, S. E., P. M. MINAIRE, J.-C. CHATARD, C. BOUTET, J. CASTELLS, and J.-R. LACOUR. A new tool for evaluating energy expenditure: the “QAPSE” development and validation. Med. Sci. Sports Exerc., Vol. 25, No. 12, pp. 1405–1414, 1993. The objective of this study was to design and validate a working tool for the objective evaluation of daily energy expenditure (DEE) by means of a simple, noninvasive method: the QAPSE (Saint-Etienne Physical Activity Questionnaire), a questionnaire about physical activity (PA) over a period of 7 d (168 h). This eight-page questionnaire is designed to provide a complete picture of the subject's habitual PA without any restriction concerning the activities investigated, nor any specialization in relation to health components. It investigates the five areas of PA during daily life: work or way of keeping occupied, leisure activity (sports and nonsports activities), housework, basic everyday activity, moving about from place to place. Assessment of physical activity was conducted in 115 healthy volunteer subjects of both sexes aged 20–88. The values of mean habitual daily energy expenditure (MHDEE) obtained varied between 6,510 and 24,331 kj.d-1. The MHDEE were in agreement with the data reported in the literature for various groups differing in respect to level of activity, sex, and age. The study demonstrated the reproducibility of the QAPSE (r = 0.997; N = 20; P < 0.0001). Its validity was tested in a comparative study between MHDEE and caloric intake (r = 0.576; N = 20; P < 0.01).