Muscle Hypertrophy Improvement Test Based on Body Mass Index (BMI) and Body Fat Percentage

Muscle hypertrophy plays a crucial role in supporting physical performance, metabolism, and overall health. Even though Body Mass Index (BMI) and body fat are commonly used health indicators, their role in predicting muscle hypertrophy remains underexplored. The purpose of this study is to explore the connection between BMI, body fat, and muscle hypertrophy in physically active individuals. Using a descriptive quantitative design with a correlational approach, the study involved 40 purposively selected students from a total of 126 enrolled in a Sports Coaching specialization program. Data were collected using Bioelectrical Impedance Analysis (BIA) to measure BMI and anthropometric measurement of quadriceps muscle to assess muscle hypertrophy. Spearman correlation analysis revealed a very strong and statistically significant relationship between BMI and muscle hypertrophy (r = 0.970, p = 0.000). These results suggest that individuals with higher BMI tend to experience greater muscle hypertrophy, possibly due to their initial body mass composition. Even though BMI does not distinguish between fat and muscle hypertrophy, this study highlights its potential as a practical predictor in fitness program planning when complemented with body fat analysis. The findings contribute theoretically by supporting existing anthropometric models and offer practical insights for fitness and rehabilitation professionals. However, limitations such as the small sample size and the specific population studied restrict the generalizability of the findings. Future research should include more diverse populations and adopt longitudinal designs to examine long-term changes in muscle hypertrophy, BMI, and body fat, while also considering additional factors such as genetics, diet, and activity level. This study contributes to a deeper understanding of the connection between BMI, body fat, and muscle hypertrophy, and encourages more comprehensive evaluation models in health and fitness strategies.