Assessment of physical activity among rural Senegalese adolescent girls: influence of age, sexual maturation, and body composition.

PURPOSE: To analyze the level of habitual physical activity and its relationship with age, maturational stage, and growth status in a group of adolescent Senegalese girls. METHODS: Physical activity was assessed for 3 consecutive years in a sample of 40 girls of rural origin. They were 13.3 +/- 0.5 years old at the beginning of the study and belonged to a Sereer community located in the center of Senegal. Minute-by-minute movement counts using accelerometers enabled quantification of levels of physical activity. The assessment was performed during a 4-day period in the first round (1997) and during a 3-day period in 1998 and 1999. Half of the girls were not yet pubescent during the first round, and the whole sample displayed growth retardation in weight and stature, compared with the World Health Organization/National Center for Health Statistics reference. RESULTS: Estimated levels of activity were high, ranging from 1.80 to 1.85 multiples of basal metabolic rate. There was a clear decline in the activity level during the course of study. Schoolgirls were less active than the others. Mature adolescents showed more activity during the night. A weak, but significant and positive correlation existed between body mass index and activity during the day; during the night, there was a positive correlation with fat and lean body mass. CONCLUSION: Factors determining the activity level were intricate but greater maturity and better nutritional status appeared to be positively related to the activity level.