Physical fitness and body composition in relation to physical activity in prepubescent Senegalese children

Relationships among estimated body composition, habitual physical activity, and physical fitness were considered in Senegalese children 8.5-13.5 years of age. Anthropometric dimensions (arm and calf circumferences, trunk, and extremity skinfolds, body mass index), four motor performances (dash, standing long jump, throw, grip strength), a step-test (cardiorespiratory fitness), and heart rate (HR) monitoring (physical activity) were collected in 140 children (66 boys and 74 girls). Age and sex had a major effect on indicators of body composition and physical fitness. Height stunting used as an indicator of chronic undernutrition had a remarkable effect on body composition but only a limited influence on physical fitness. Physical activity, represented by percentage of time above the flex-HR (%fHR), did not vary with sex, age, and nutritional status. However, there was a low-to-moderate correlation between %fHR and several body composition indices, grip strength, and cardiorespiratory fitness. Comparisons of children in the upper and lower quartiles of %fHR indicated that better indices of body composition in boys, and better strength and cardiorespiratory fitness in girls were positively associated with a higher level of physical activity. Am. J. Hum. Biol. 10:385-396, 1998. © 1998 Wiley-Liss, Inc.