Decoding endurance performance: integrative genomic and epigenetic insights into the molecular basis of athletic...

Applied genomics in sports performance has rapidly evolved into a multidisciplinary field aimed at elucidating the biological determinants of complex athletic traits, particularly endurance. Endurance performance represents a highly polygenic and multifactorial phenotype, shaped by the dynamic interplay between genetic predisposition and training-induced adaptations. This review provides a comprehensive synthesis of evidence from candidate gene studies, genome-wide association studies (GWAS), and meta-analyses to identify genetic variants consistently associated with endurance-related phenotypes. GWAS and candidate gene approaches have identified over 44 polymorphisms relevant to endurance-oriented sports, with HFE rs1799945 emerging as a strong predictor of endurance ability. Key variants, including ACE rs1799752, CDKN1A rs236448, PPARGC1A rs8192678, and PPARA rs4253778, are highlighted for their roles in modulating critical physiological pathways such as oxygen transport, mitochondrial biogenesis, energy metabolism, and muscle fiber composition. Beyond static genetic variation, this review emphasizes the pivotal contribution of epigenetic mechanisms, including DNA methylation, histone modifications, and non-coding RNAs. In particular, exercise-responsive microRNAs (miR-1, miR-206, miR-21, miR-146, miR-208, and miR-222) are discussed as key regulators of gene expression and molecular adaptation to endurance training. Although more than 200 genetic polymorphisms have been associated with athlete status, only a limited subset demonstrates consistent and replicated associations with endurance athlete status. This underscores the limitations of single-marker approaches and highlights the need for integrative frameworks that incorporate genomics, epigenomics, and transcriptomics. Advancing toward such multi-omics strategies is essential for a more comprehensive understanding of the biological architecture of endurance, and for the development of personalized training interventions aimed at optimizing performance and adaptation.