While the AMPD1 C34T genotype was not associated with athlete status, the CC genotype was associated with greater rugby union playing time per appearance in forwards, and the CT genotype was associated with superior performance in elite distance runners.
Key Findings
Results
AMPD1 C34T genotype and allele frequencies did not differ between athletes and non-athletes or between athlete groups.
Participants included 621 elite male rugby union athletes, 666 elite/sub-elite male and female distance runners, and 1029 male and female non-athletes, all of European ancestry.
Genotype and allele frequencies were compared using χ² tests.
No statistically significant differences were observed between any athlete group and non-athletes.
No differences were found between the distance runner and rugby union athlete groups.
Results
Distance runners with the CT genotype in the elite and elite male subgroups were up to 5% faster than CC and TT homozygotes.
Run time comparisons were performed across all distance runners using Kruskal-Wallis H, Mann-Whitney U, one-way ANOVA, and t-tests.
Benjamini-Hochberg correction was applied for multiple comparisons.
In all distance runners combined, run times did not differ between genotypes.
The CT heterozygote advantage of up to 5% faster times was observed specifically in the elite and elite male subgroups.
This suggests a possible heterozygote advantage for endurance performance at the elite level.
Results
Rugby union participants with the CC genotype played 13% longer per appearance than those with the CT genotype.
Playing time per appearance was used as the performance metric in rugby union athletes.
The CC genotype was associated with greater playing time compared to the CT genotype across all rugby union participants.
This 13% difference in playing time per appearance was identified in the overall rugby union cohort of 621 elite male athletes.
Statistical analyses included Kruskal-Wallis H and Mann-Whitney U tests with Benjamini-Hochberg correction.
Results
Rugby union forwards and front five players with the CC genotype played 13% and 26% longer per appearance, respectively, than T-allele carriers.
Positional subgroup analyses were conducted within the rugby union cohort.
Forwards with the CC genotype played 13% longer per appearance than T-allele carriers.
Front five players (a subset of forwards) with the CC genotype played 26% longer per appearance than T-allele carriers.
These findings suggest the CC genotype may confer a positional performance advantage particularly in high-intensity, repeated-effort forward positions.
Results
Front five T-allele carriers made 75% more clean breaks than front five players with the CC genotype, despite playing for a shorter time.
Clean breaks were assessed as an additional performance metric in positional subgroups.
Despite playing less time per appearance, front five T-allele carriers outperformed CC homozygotes on this specific metric by 75%.
The authors noted this finding 'should be interpreted cautiously.'
This contrasting result adds complexity to the interpretation of T-allele effects in forwards.
Methods
Genotyping was performed on participants of European ancestry using real-time PCR with TaqMan reagents.
The AMPD1 C34T polymorphism is identified by rs17602729.
All participants were confirmed to be of European ancestry.
The total study sample comprised 2316 individuals across three groups: 621 rugby union athletes, 666 distance runners, and 1029 non-athletes.
The distance runner group included both male and female elite and sub-elite participants.
What This Means
This research examined whether a specific genetic variant called AMPD1 C34T (a change in the gene that controls an enzyme involved in energy metabolism during exercise) influences athletic ability and performance. The study looked at over 2,300 people including elite rugby union players, competitive distance runners, and non-athletes, all of European descent. The researchers found that simply having or not having this genetic variant did not determine whether someone became an elite athlete — the variant was equally common among athletes and non-athletes alike.
However, when the researchers looked more closely at actual performance within athletes, some interesting patterns emerged. In distance running, athletes who carried one copy of each version of the gene (called heterozygotes, or CT genotype) tended to run up to 5% faster than those with two copies of either version, but only among the most elite runners. In rugby union, players with two copies of the 'C' version of the gene (CC genotype) spent significantly more time on the field per game — about 13% more overall, and up to 26% more among front five forwards — suggesting coaches may have favored them for longer periods. Conversely, front five players carrying the 'T' version made 75% more clean breaks, though this result was flagged by the authors as needing cautious interpretation.
This research suggests that the AMPD1 C34T variant does not act as a simple 'gateway' gene that determines athletic potential, but may subtly influence certain aspects of performance once athletes reach elite level. The findings are complex and sometimes point in different directions depending on sport and position, highlighting that athletic performance is shaped by many genetic and non-genetic factors working together rather than any single gene variant.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Martin D, Stebbings G, Heffernan S, Erskine R, Antrobus M, Brazier J, et al.. (2026). Does the AMPD1 C34T Polymorphism Influence Physical Performance in Elite Athletes?. Genes. https://doi.org/10.3390/genes17080935