A Systematic Review and Meta-analysis Highlights a Link Between Aerobic Fitness and Telomere Maintenance.

Cardiorespiratory fitness declines with aging and is a major risk factor of cardiometabolic diseases and early death. Although the benefits of regular exercise are well established, whether maximal oxygen uptake (VO2max) is associated with biological aging remains unclear. Given that telomere shortening is a hallmark of aging, the purpose of this systematic review and meta-analysis was to determine the association between VO2max and telomere length. Articles were retrieved from PubMed, Scopus, and ScienceDirect and deemed eligible if they: (i) involved human participants with relatively low and high VO2max values objectively assessed by pulmonary analysis; (ii) quantified telomere length using an established technique; and (iii) were peer-reviewed journal articles written in English. Relative to individuals with below-average VO2max based on age- and sex-adjusted norms, fit participants with relative VO2max values in the 70th percentile or higher possessed longer telomeres (standardized mean difference [95% confidence interval {CI}]: 0.36 [0.14-0.59], p = .002). A similar difference was observed between individuals with below-average VO2max and those above the 90th percentile (0.28 [0.03-0.53], p = .03). However, no statistically significant telomere length differences were observed between individuals in the 70th to 90th percentile compared to those above the 90th (-0.08 [-0.40 to 0.24], p = .62). The findings provide evidence linking metabolism to telomere biology. They encourage individuals to regularly engage in endurance exercise to attenuate telomere attrition and promote healthy biological aging. Importantly, the results suggest that extensive endurance training may not be required to protect the telomeres, rather moderate amounts of training may be sufficient to reach more achievable VO2max targets.