Longer leukocyte telomeres are associated with ultra-endurance exercise independent of cardiovascular risk factors.
Level 4 - case-series / case-control
Cross-sectional observational study comparing ultra-marathon runners to healthy controls
PubMed 23936000 · doi:10.1371/journal.pone.0069377
What was done
Leukocyte telomere length (T/S ratio) was measured using real-time quantitative PCR in 67 male ultra-marathon runners and 56 apparently healthy male controls. Differences in telomere length were evaluated using age-adjusted models and models further adjusted for cardiovascular risk factors and markers of inflammation/adhesion molecules.
What was found
Ultra-marathon runners had 11% longer leukocyte telomeres than controls in age-adjusted analyses (runners: T/S ratio = 3.5 ± 0.68 vs controls: 3.1 ± 0.41; β = 0.40, SE = 0.10, P = 1.4 × 10(-4)). The difference remained statistically significant after adjustment for cardiovascular risk factors (P = 2.2 × 10(-4)), which the authors estimated as translating to a 16.2 ± 0.26 year difference in biological age and a 324–648 base pair difference. Neither traditional cardiovascular risk factors nor markers of inflammation/adhesion molecules explained the difference.
Why it matters
This study provides evidence that chronic ultra-endurance exercise is associated with longer leukocyte telomeres rather than accelerated cellular aging, independent of standard cardiovascular risk factors.
Limits
The cross-sectional design prevents causal inference and cannot exclude selection bias or residual confounding (such as unmeasured lifestyle or genetic factors). The sample size was modest (n = 123) and limited strictly to males. Telomere length was measured only in leukocytes rather than multiple tissue types.
Cited by
- supports The relationship between exercise volume/intensity and telomere length is non-linear, with marathon runners exhibiting only slightly longer telomeres than moderate regular runners.