For decades, we've chalked up elite athletic performance to genetics—born sprinters, naturally powerful muscles, limb lengths, but emerging research is flipping the script. A growing body of evidence now points to epigenetic, especially DNA methylation, as a powerful driver of athletic adaptation—often outweighing fixed genetic code.
The science
High-Intensity Resistance Training
A 2025 SportRxiv preprint compared long-term strength athletes (≥ 5 years of heavy resistance training) with untrained controls, analysing saliva DNA methylation patterns. The powerlifters and strength athletes showed distinct methylation signatures—in other words, training left clear molecular marks, separate from innate genetic differences, proving that training may override general genetic predispositions.
Endurance vs. Resistance Athletes
In a landmark study published in BMC Biology, researchers found that endurance-trained athletes (with ≥15 years of training) had different methylation patterns in genes like MYH7 and MYL3 (slow-twitch fibre genes) compared to resistance athletes and untrained individuals. Lower promoter methylation of these genes corresponded with elevated expression in endurance athletes—while transcription regulators like PGC-1α, FOXO3, and CREB5 showed higher methylation in the same group. Those baseline methylation landscapes correlated with how genes responded to acute exercise.
Muscle Memory: Epigenetic Adaptation that Lingers
Chronic training—whether endurance or resistance—creates long-lasting “molecular memory.” A seminal resistance-training methylome dataset. A slightly older study demonstrated that key anabolic genes such as UBR5, RPL35a, HEG1, and PLA2G16 became hypomethylated following training—and stayed that way even through periods of detraining. When retraining began, these genes reactivated with greater vigour, driving muscle growth faster than the original training phase – a phenomenon we often call “muscle memory”
Epigenetics: Environment Meets Performance
A comprehensive review of exercise-induced epigenetic changes highlights that aerobic exercise generally reduces promoter methylation (thereby increasing expression) in genes supporting mitochondrial function, glucose metabolism, and endurance, while resistance training shifts methylation patterns toward anabolic and hypertrophy pathways. Both pathways create a transcription-ready muscle phenotype best suited to the specific training stimuli regardless of the persons inherited genotypes.
The Key Takeaways:
Training may be able to Override Genetic Predispositions
Even athletes with less favourable physiological genes can remodel their gene regulatory landscape through targeted training, effectively re-tuning expression.
Personalised Training Based on Epigenetic Profile
If endurance and resistance athletes carry distinct methylation imprints, future protocols could tailor training to one’s epigenetic state—maximising adaptation.
Epigenetics explain “muscle memory”
A single training intervention can lead to lasting molecular changes that boost adaptability later—meaning a stronger come-back and smarter progression.
Reframing Athletic Potential
Far from being purely genetic lottery winners, elite athletes may be showcases of epigenetic transformation, with their training histories sculpting performance-relevant gene expression. DNA methylation patterns adapt to the demands placed on muscles—creating a dynamic molecular foundation for enduring physical performance.
Genetics provides the hardware, but epigenetics writes the software.
The interplay of training, diet, recovery, and environment orchestrates which genes are activated—or silenced—to drive athletic excellence.
A Glimpse at Future Avenues
· Epigenetic biomarkers to monitor training readiness and adaptation.
· Targeted epigenetic interventions (e.g. nutrition, training cycles) to optimise performance windows.
· Epigenomic studies comparing elite athletes across disciplines, uncovering signatures that transcend traditional genetic variation.
· Targeted supplementation to alter epigenetic expression, one study showed that creatine monohydrate caused distinct epigenetic changes.
Conclusion
Genetics may set the table and give athletes a head start that is for sure, but it’s epigenetics that serves the meal. As these recent studies show, DNA methylation—and broader epigenetic reprogramming—may play an outsized role in athletic success. By recognising and harnessing these epigenetic phases coaches and athletes alike can shift the narrative—moving from inherited fate to empowered transformation.
References
Collins, C., Puras, A and Brown, J (2025). DNA Methylation Signatures Diverge Between Endurance and Resistance Trained Athletes, researchhub, 10.55277/researchhub.smvkzbhy.2
Collins, C.,& Puras,A. (2025). Creatine Monohydrate Use Is Associated with Performance-Enhancing DNA Methylation Patterns. SportRχiv, https://sportrxiv.org/index.php/server/preprint/view/554
Collins, C.,& Puras,A. (2025).High-Intensity Resistance Training Is Associated with Epigenetic Reprogramming & Distinct Salivary DNA Methylation Patterns. SportRχiv. https://sportrxiv.org/index.php/server/preprint/view/549
Collins, C., & Heasman, A. (2022). Born Equal: Can genetics make the perfect athlete. SportRχiv, https://sportrxiv.org/index.php/server/preprint/view/187
Geiger, C., Needhamsen, M., Emanuelsson, E.B. et al. DNA methylation of exercise-responsive genes differs between trained and untrained men. BMC Biol 22, 147 (2024). https://doi.org/10.1186/s12915-024-01938-6
McCabe K, Collins C. Can Genetics Predict Sports Injury? The Association of the Genes GDF5, AMPD1, COL5A1 and IGF2 on Soccer Player Injury Occurrence. Sports (Basel). 2018 Mar 5;6(1):21. doi: 10.3390/sports6010021. PMID: 29910325; PMCID: PMC5969195.
Seaborne, R. A. et al. Methylome of human skeletal muscle after acute & chronic resistance exercise training, detraining & retraining. Sci. Data. 5:180213 doi: 10.1038/sdata.2018.213 (2018)
