ACTN3 rs1815739 and BDNF rs6265 Polymorphisms May Not Be Associated with Handgrip Strength in Elite Wrestlers

Background/Objectives: Handgrip strength (HGS) is a widely used indicator of upper-limb muscular strength and a practical proxy for neuromuscular performance across both clinical and athletic contexts. Although HGS is heritable, evidence supporting specific genetic contributors in elite athletes remains limited. Thus, the present study investigated the associations of two functional polymorphisms, BDNF rs6265 (p.Val66Met) and ACTN3 rs1815739 (p.R577X), with HGS performance in elite wrestlers, integrating neuromuscular and muscle fiber-related biological pathways. Methods: The present study included 613 subjects (56 elite male wrestlers (mean age: 22.35 ± 5.34 years; training experience: 13.40 ± 3.85 years) and 557 healthy individuals drawn from a public database). HGS measurements were performed using a digital hand dynamometer. Results: Genotyping was performed on DNA extracted from peripheral blood using a high-density single nucleotide polymorphism (SNP) array. Neither BDNF rs6265 nor ACTN3 rs1815739 was significantly associated with HGS in elite wrestlers (p > 0.05), and effect estimates were negligible. In addition, ACTN3 rs1815739 genotype and allele frequencies were comparable between wrestlers and the reference population, indicating no enrichment of this variant in the elite cohort. In this sample of elite male wrestlers, BDNF rs6265 and ACTN3 rs1815739 were not associated with HGS, and ACTN3 rs1815739 was not enriched relative to a national reference population. Conclusions: These findings suggest no detectable effects of single candidate variants on HGS under the current study design in highly trained athletes; however, this interpretation should be made cautiously given cohort-specific limitations and does not preclude their potential contribution within the broader polygenic architecture of strength-related traits. Future research employing larger, well-powered, and multi-cohort designs and polygenic approaches is warranted to further elucidate the genetic basis of strength phenotypes.