Bioelectric impedance analyses for young male athletes: A validation study.

BACKGROUND: Adolescence is characterized by a rapid and erratic growth period. Many factors completely change in growth period up to 20 years of age, with a very slight alteration during the later years of life. Bioelectric impedance analyzers (BIA) are used in estimating the total and segmental body composition compartments. OBJECTIVE: To determine the validity of different BIAs for young male athletes. METHODS: Sixty-one young male athletes (basketball, football, handball, swimming, and skiing) participated in the study. The validity of Tanita 401A (TANITA), Jawon Segmental Body Composition Analysers model AVIS 333 Plus (AVIS), and Biodynamics Model 310e (BIODYNAMICS) was tested by Bland & Altman analysis and heteroscedasticity, providing the gold standard criterion method, hydrostatic weighing (HW) for body density (D b), body fat percentage (%BF), and lean body mass (LBM). RESULTS: BIA models used for predicting body composition, except for %BF of TANITA, are valid and in accord with HW for young male athletes. TANITA had significantly lower %BF (5.75 ± 2.95%) and higher LBM (62.12 ± 7.53 kg), compared to HW (10.79 ± 4.17 %BF and 58.80 ± 7.38 kg LBM). Percent BF of BIODYNAMICS and AVIS results were significantly higher (2.04% and 3.3% respectively) than %BF of HW. CONCLUSION: Prediction of body composition compartments of young male athletes using BIA models is valid except for %BF by TANITA. LBM values of HW and BIA models can be used interchangeably. However, these BIA softwares do not have specific options concerning athletic status for the growing age and sex group to clarify population specificity in adolescent male athletes. Therefore, using the same BIA model is recommendable in following up training regimen and nutritional status, in order to avoid underestimating or overestimating the body composition compartments. [ABSTRACT FROM AUTHOR]