Body Composition Analysis Methods in Adolescent Athletes: A Systematic Review.

Body composition analysis in adolescent athletes is critical for assessing fat mass percentage and fat-free mass. However, measurement inaccuracies can compromise results. Additionally, there is a lack of reliable reference methods to evaluate the accuracy of field measurement techniques. This review evaluates the reliability and validity of methods in adolescent athletes and provides evidence-based recommendations for best practice. The search (Pubmed and Scopus) followed Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines and PICO criteria related to adolescent athletes in bioelectrical impedance analysis, dual-energy X-ray absorptiometry, air displacement plethysmography and skinfold thickness measurements. Thirty-one studies out of 4,408 records met the eligibility criteria. Estimating fat mass percentage and fat-free mass in adolescent athletes is moderately reliable and valid. Dual-energy X-ray absorptiometry is often regarded as the criterion standard particularly for validating equations in bioelectrical impedance analysis and skinfold measurements. Its assumptions regarding tissue density and confounding factors limit precision. Air displacement plethysmography and hydrostatic weighing are limited in athletes with extreme body mass or atypical fat distribution. Recent calculation formulas validated for adolescents are rare and inadequate for athletes. In summary, two- and three-compartment models reflect reduced accuracy in adolescent athletes, making four-compartment models preferable. Field methods like bioelectrical impedance analysis and skinfolds require further validation due to the lack of reliable reference methods in this specific population.