Body Mass Index and Sport Type as Predictors of Strength, Power, and Agility in Adolescent Athletes: A Cross-Sectional Study

Abstract

This Body Mass Index (BMI) is a commonly used anthropometric measure in youth athletic evaluations. However, its utility in predicting physical performance outcomes among trained adolescent athletes remains unclear, especially when considering the influence of sport type. This study aimed to examine the interrelationships between BMI and key physical performance attributes—upper body strength, lower body strength, lower body power, and agility—in adolescent athletes. A secondary objective was to compare performance profiles between contact and non-contact sport athletes and evaluate BMI’s predictive utility. A cross-sectional study was conducted with 198 adolescent athletes (mean age 15.19 ± 1.33 years) from contact (boxing, wrestling, soccer) and non-contact (track and field, Chinese martial arts) sports. Anthropometric data and physical performance metrics were collected, including 1RM bench press, 1RM squat, standing long jump, and T-agility test. Correlation and regression analyses evaluated BMI’s association with performance outcomes. Independent sample t-tests assessed group differences by sport type. BMI was moderately associated with upper body strength (r = 0.41) and weakly with lower body strength (r = 0.31) but showed no significant relationship with lower body power or agility (p > 0.2). Regression models indicated that BMI accounted for 16.8% of the variance in upper body strength and 9.9% in lower body strength. Contact sport athletes exhibited significantly greater strength and power than non-contact athletes (p < 0.05), but no significant group differences in agility or BMI were observed. While BMI may serve as a partial proxy for upper-body strength in adolescent athletes, it lacks sensitivity for evaluating agility and power. Sport type appears to be a stronger determinant of performance profiles than BMI. These findings suggest that BMI should not be used in isolation for athletic talent identification or performance prediction. Sport-specific and functional assessments are recommended to guide training and development in youth sports.