Rationale: Soccer training and competition is characterized by a combination of aerobic high-intensity training, endurance and strength training, and team-play components. Current scientific evidence points to a cellular anti-ageing effect of regular endurance training, which may differ from other sport modalities. Effects of soccer on markers of cellular senescence have never been tested. In this study, we measured telomere length and telomerase activity in young and aged soccer athletes, and compared them with untrained age-matched controls.
Methods and results: 140 male young (YS, 21.6±0.5y) and aged (AS, 71.9±0.5y) soccer players and age-matched physically inactive healthy young and aged control subjects (YC, 24.3±0.6y; AC, 70.1±0.7y) were consecutively enrolled in the study (n=35 per group). YS had 5.3±0.3 football training sessions per week and AS 2.3±0.2. YS had a total soccer history of 16.3±0.6y and 6.2±0.6y at high-level, AS a total soccer history of 60.5±1.4y
Peripheral blood samples were taken at least 48h away from training to exclude acute effects. Telomerase activity was measured using telomerase repeat amplification protocols (TRAP assay), in which human embryonic kidney (HEK) cells serve as telomerase positive control. Young soccer athletes had higher mononuclear cell telomerase activity compared to young inactive controls (YS, 130±25 HEK cell equivalents vs. YC, 31±4; p=0.0004). In contrast, aged controls and aged soccer players did not differ with respect to telomerase activity (AC, 86±18 vs. AS, 78±16). Leukocyte telomere length was measured in 40ng genomic DNA isolated to quantify telomere (T) and single (S) copy gene 36b4 DNA before comparing T/S ratios between subjects. The assay showed that aged subjects had significantly shorter telomeres, but soccer athletes did not differ from age-matched controls (T/S: YC, 1.3±0.1; YS, 1.4±0.2; AC, 1.1±0.1; AS, 1.0±0.1; p=0.02 young vs. old). In addition real-time PCR was performed to measure the mRNA expression of senescence-associated markers such as telomere repeat-binding factor (TRF) 2. 18S-corrected TRF mRNA expression was increased in both young and aged soccer athlete groups as compared to physically inactive controls (ddCt method: YC, 1.7±0.4; YS, 5.5±0.9; AC, 1.5±0.3; AS, 4.1±1.1; p=0.0004). Data are mean±SEM, statistics are ANOVA or t-test.
Conclusion: The present study suggests that soccer training induces cellular anti-senescence mechanisms implying positive cardiovascular health effects in the long-term.