Abstract des Autors

Aim. Assesment of body composition in 2 groups of prepuberal children who practice organized sport activity and free physical activity, respectively. Methods. Subjects were 295 males and 202 females between 7 and 10 years old. Subcutaneous and visceral fat were determined by measuring the thickness of tricipital (TRI) and subscapular (SSC) skindfolds and the waist circumference (CA), respectively. Results. The whole physical activity produces a great decrement of subcutaneous fat of the higher trunk (central subcutaneous fat; SSC, -43% in females, -33% in males), a less decrement of peripheral subcutaneous fat (TRI, -23% in females, -20% in males) and a least decrement of visceral fat (CA, -9% in females, -7% in males). For the males, the minimal requirement of physical activity to produce a change of body composition was 6 hours/week, for the females, 4 hours/week. Linear regression analysis for whole body fat index and time spent in whole physical activity indicates an inverse relationship, non present when the variable is the organized sport activity. Conclusion. In our sample the efficacy of physical exercise becomes evident only after practicing 6 hours/week for the males and 4 hours/week for the females. The organized sport activity alone does not seem sufficient to significantly modify the body composition of prepuberal children.