How Length Sizes Affect Body Composition Estimation in Adolescent Athletes Using Bioelectrical Impedance

Area of Science:

• Sports Science
• Biomedical Engineering
• Human Physiology

Background:

• Bioelectrical impedance analysis (BIA) is widely used for body composition assessment in athletes.
• Its accuracy can be compromised in athletes with unique body geometries.
• Dual-energy X-ray absorptiometry (DXA) serves as a reference method for comparison.

Purpose of the Study:

• To investigate the impact of body length dimensions on BIA accuracy for body composition estimation.
• To compare BIA and DXA assessments in male adolescent athletes across three different sports.
• To identify potential correlations between segmental lean body mass differences and body length measurements.

Main Methods:

• Inclusion of 738 male adolescent athletes (mean age 15.8 years) from soccer, basketball, and handball.
• Body composition measured using BIA (InBody 720) and DXA (Lunar Prodigy).
• Statistical analyses included Bland-Altman, paired t-tests, ANOVA, Pearson correlation, and multivariate linear regression.

Main Results:

• BIA consistently underestimated percent body fat and overestimated lean body mass compared to DXA.
• Significant differences between BIA and DXA were larger in handball and basketball players than in soccer players.
• Negative correlations were observed between segmental lean body mass differences and length dimensions, with the lower extremity showing the strongest correlation (r = -0.4).

Conclusions:

• Body length dimensions, particularly lower extremity length, influence the accuracy of BIA for lean body mass estimation in athletes.
• Differences in body composition assessment between BIA and DXA are sport-specific, likely due to variations in body height.
• BIA assessments using InBody 720 require careful interpretation in athletes with extreme body lengths, notably basketball players.