Int J Sports Med
DOI: 10.1055/a-1179-6236
Physiology & Biochemistry

Fat-free Mass Bioelectrical Impedance Analysis Predictive Equation for Athletes using a 4-Compartment Model

Catarina N Matias
1  Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Portugal
,
2  Department of Biomedical and Neuromotor Science, University of Bologna, Bologna, Italy
,
Diana A. Santos
1  Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Portugal
,
Henry Lukaski
3  Department of Kinesiology and Public Health Education, Hyslop Sports Center, University of North Dakota, Grand Forks, United States
,
Luís B. Sardinha
1  Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Portugal
,
Analiza M. Silva
1  Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Portugal
› Author Affiliations

Abstract

Bioelectrical impedance analysis equations for fat-free mass prediction in healthy populations exist, nevertheless none accounts for the inter-athlete differences of the chemical composition of the fat-free mass. We aimed to develop a bioimpedance-based model for fat-free mass prediction based on the four-compartment model in a sample of national level athletes; and to cross-validate the new models in a separate cohort of athletes using a 4-compartment model as a criterion. There were 142 highly trained athletes (22.9±5.0 years) evaluated during their respective competitive seasons. Athletes were randomly split into development (n=95) and validation groups (n=47). The criterion method for fat-free mass was the 4-compartment model. Resistance and reactance were obtained with a phase-sensitive 50 kHz bioimpedance device. Athletic impedance-based models were developed (fat-free mass=− 2.261+0.327*Stature2/Resistance+0.525*Weight+5.462*Sex, where stature is in cm, Resistance is in Ω, Weight is in kg, and sex is 0 if female or 1 if male). Cross validation revealed R2 of 0.94, limits of agreement around 10% variability and no trend, as well as a high concordance correlation coefficient. The new equation can be considered valid thus affording practical means to quantify fat-free mass in elite adult athletes.



Publication History

Received: 00 00 2020

Accepted: 05 May 2020

Publication Date:
07 August 2020 (online)

© Georg Thieme Verlag KG
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