Leukocyte telomere length is preserved with aging in endurance exercise-trained adults and related to maximal aerobic capacity

Telomere length (TL), a measure of replicative senescence, decreases with aging, but the factors involved are incompletely understood. To determine if age-associated reductions in TL are related to habitual endurance exercise and maximal aerobic exercise capacity (maximal oxygen consumption, VO₂max), we studied groups of young (18-32 years; n = 15, 7 male) and older (55-72 years; n = 15, 9 male) sedentary and young (n = 10, 7 male) and older (n = 17, 11 male) endurance exercise-trained healthy adults. Leukocyte TL (LTL) was shorter in the older (7059 ± 141 bp) vs. young (8407 ± 218) sedentary adults (P < 0.01). LTL of the older endurance-trained adults (7992 ± 169 bp) was ∼900 bp greater than their sedentary peers (P < 0.01) and was not significantly different (P = 0.12) from young exercise-trained adults (8579 ± 413). LTL was positively related to VO₂max as a result of a significant association in older adults (r = 0.44, P < 0.01). Stepwise multiple regression analysis revealed that VO₂max was the only independent predictor of LTL in the overall group. Our results indicate that LTL is preserved in healthy older adults who perform vigorous aerobic exercise and is positively related to maximal aerobic exercise capacity. This may represent a novel molecular mechanism underlying the “anti-aging” effects of maintaining high aerobic fitness.