Anthropometric models to predict appendicular lean soft tissue in adolescent athletes

Area of Science:

• Sports Medicine
• Human Physiology
• Body Composition Analysis

Background:

• Skeletal muscle (SM) is a key body compartment, primarily within appendicular lean soft tissue (ALST).
• Accurate estimation of SM and ALST is crucial but challenging.
• Developing practical anthropometric models is needed for athletes.

Purpose of the Study:

• To develop and cross-validate anthropometric models for estimating ALST in athletes.
• To compare the accuracy of a body weight (WHt) model and a corrected muscle girth (CMG) model.
• To use dual-energy x-ray absorptiometry (DXA) as the reference method for validation.

Main Methods:

• Developed two ALST prediction equations in 176 athletic boys and 92 athletic girls.
• Measured skinfolds (triceps, thigh, calf) and circumferences (arm, thigh, calf).
• Assessed ALST using DXA; developed WHt and CMG models, cross-validating with regression analysis and agreement metrics.

Main Results:

• The WHt model equation: ALST = -20.338 + 0.199(W) + 3.294(gender) + 14.230(height) + 0.192(age).
• The CMG model equation: ALST = 3.260 + 0.002(height x CTG) + 0.007(height x CAG) + 0.003(height x CCG).
• CMG model showed higher accuracy (R=0.93, SEE=1.80 kg) than WHt model (R=0.91, SEE=2.00 kg); both models demonstrated excellent agreement with DXA.

Conclusions:

• Both developed anthropometric models accurately predict ALST in young athletes.
• These models provide a practical and reliable method for quantifying appendicular lean soft tissue.
• The findings offer valuable tools for sports scientists and clinicians assessing athlete body composition.