Analysis of the impact of FTO (rs9939609) gene variants on anaerobic performance and body composition in active male adults: a preliminary study

Abstract

Genetic variations can influence individual differences in sports performance by affecting energy metabolism, body composition, and adaptation to training. Among these genetic variants, FTO rs9939609 is particularly relevant due to its contribution to the regulation of body fat and appetite, with potential downstream effects on physical performance. This study examined whether the FTO rs9939609 variant was associated with aerobic endurance (Yo-Yo Intermittent Recovery Test Level 2) and anaerobic sprint performance (30 m sprint), and whether body mass index (BMI) was related to these outcomes. Sixty healthy, physically active males (18–22 years) underwent genotyping from buccal epithelial DNA samples and completed a six-week structured training program combining continuous running and whole-body muscular endurance circuit training. Performance was measured before and after training, and BMI was recorded. Genotype groups (A/A, A/T, T/T) were compared using ANOVA and ANCOVA controlling for BMI, height, and weight, and obesity risk was analyzed under dominant and recessive models using Fisher’s exact test. No significant differences were found between genotypes for aerobic or anaerobic performance, and adjusting for anthropometric covariates did not alter this null result. Mean BMI was descriptively similar across genotype groups, and obesity odds did not differ significantly across genotypes; the T/T genotype was rare (n=4) and no T/T participants were classified as obese. No statistically significant associations were detected between FTO rs9939609 genotype and the assessed performance outcomes. in this sample. These findings should be considered preliminary given the small sample size and the limited number of T/T participants (n=4), which restrict the ability to detect modest genotype-related differences.