High levels of habitual physical activity in west African adolescent girls and relationship to maturation, growth, and nutritional status: results from a 3-year prospective study.

This study examines energy expenditure and physical activity levels for a sample of 40 adolescent girls of the Sereer ethnic group of rural Senegal. The girls were 13.3 +/- 0.5 years at the start of the study (June 1997) and were followed annually for the next 2 years during puberty. Data collected during each round included: 1) pubertal status (as assessed by breast development and occurrence of menarche); 2) selected anthropometric dimensions (weight, stature, arm circumference, and six skinfolds); and 3) physical activity levels quantitatively assessed using CSA accelerometers. During rounds 1 and 3, activity was also qualitatively reported by direct minute-by-minute observations. A food consumption survey was performed once during the 3(rd) round, using an individual food weighing method. Girls of this sample had high levels of energy expenditure with daily physical activity levels (PALs) ranging from 1.70 to 1.85 multiples of basal metabolic rate. Energy intakes were, on average, sufficient to meet energy and protein requirements, although micronutrient deficiencies were likely to exist. Activity levels declined with age between the 1(st) and 3(rd) rounds. Stepwise regression analyses showed that stature was negatively correlated with both total daily and day-time activity, whereas the body mass index was positively associated with this measure. Pubertal status and subcutaneous fatness were not significant predictors of activity levels. The contribution of these adolescent girls to the everyday tasks of the household was considerable. They spent more than 3 hours 30 minutes per day in domestic duties. Copyright 2001 Wiley-Liss, Inc.