The Relationship Between BMI and Body Composition in Exercise-trained Men and Women

Introduction: The notion that individuals with a low body mass index (BMI) exhibit higher body fat percentages than those with a higher BMI is popular within the fitness industry. This is often referred to as the “skinny- fat” phenotype. The purpose of this cross-sectional investigation was to examine the relationship between BMI and body composition in a group of male and female resistance- and endurance-trained individuals. Methods: One hundred and fifteen exercise-trained individuals (n = 57 male, n = 58 female) were assessed for body composition via the Bod Pod®. Body weight, lean body mass, fat mass and BMI was ascertained. The relationship between BMI and body fat percentage were assessed with correlations.Results: Males had statistically greater (p < 0.05) height, body weight, lean body mass, and BMI compared to females. Furthermore, males had significantly lower (p < 0.05) fat mass and body fat percentage than females. Moreover, there was a moderately positive correlation (r = 0.5069 male, p < 0.001; r = 0.5196 female, p < 0.001) between BMI and body fat percentage.Conclusions: There is a moderately positive relationship between BMI and body fat percentage in strength- and endurance-trained individuals. Furthermore, individuals with a higher BMI also tended to have a greater body fat percentage.