THE SCIENCE BEHIND SPEED: HOW ACTN3 AFFECTS SOCCER PLAYER PERFORMANCE

Abstract

Background: Soccer demands a combination of speed, agility, endurance, and power. While
training and nutrition are crucial, genetic factors, particularly the ACTN3 gene, significantly
influence performance. The ACTN3 gene encodes α-actinin-3, a protein in fast-twitch muscle
fibres essential for power and speed. The R577X polymorphism results in three genotypes: RR,
RX, and XX, each affecting muscle function differently. Understanding these variations can
provide insights into soccer performance. Objectives: This study examines the impact of the
ACTN3 R577X polymorphism on soccer performance attributes such as sprinting, jumping,
endurance, and recovery. It also explores genotype-based training approaches for performance
optimization. Method: A scoping review was conducted following JBI guidelines, searching
PubMed, Web of Science, Scopus, SPORTDiscus, and Google Scholar. Studies on male and
female soccer players analysing ACTN3 R577X polymorphisms and performance outcomes
were included. Results: The RR genotype enhances sprint speed and power; the XX genotype
is linked to higher aerobic capacity (VO₂ max) and endurance, while the RX genotype provides
a balance of power and endurance. RR-genotyped players recover faster. Genetic profiling may
aid in talent identification and personalized training strategies. Conclusion: ACTN3 genotypes
significantly influence soccer performance. Integrating genetic insights into training regimens
can optimize performance and reduce injury risks. Future research should explore genotype
specific training interventions.