[Comparison between methods to estimate total body fat mass in triathletes: dual X-ray absorptiometry, bioelectrical...

Introduction: the estimation of body fat mass (FM) can be performed using different methods. Although Dual-Energy X-ray Absorptiometry (DXA) is considered the reference technique due to its precision and reproducibility, its high cost and limited accessibility restrict its widespread use. Moreover, its application requires standardized hydration conditions and trained personnel, which makes its implementation difficult in field settings or for frequent assessments of athletes. More accessible methods, such as Bioelectrical Impedance Analysis (BIA) and Anthropometry (ANT), present validity limitations when applied to Mexican athletes. Objective: to compare the body fat mass of Mexican triathletes obtained by BIA and ANT versus DXA, in order to evaluate the reliability of the equations used in these methods. Materials and methods: an exploratory, observational, cross-sectional study was conducted with 30 Mexicans triathletes (10 women, 20 men), between 18 and 40 years of age, who met the inclusion criteria were studied. The BIA equation used was Macias (2007) and the anthropometric equations were those of Durnin & Womersley with Siri. Results: different average values of body fat percentage were obtained in the methods used (DXA 24.91 %; BIA 22.18 %; ANT 21.83 %), but they did not present significant differences (one-way ANOVA, post hoc Scheffe & Bonferroni, p > 0.05). A positive correlation was obtained between DXA and the other methods (BIA r = 0.697, ANT r = 0.876, p > 0.05), with anthropometry being the strongest. Conclusions: the methods used estimate different values of body fat percentage in the studied population, but without statistically significant differences. The method that showed the best results in the studied population when compared to DXA was the anthropometric method.