BACKGROUND
Telomere length (TL) is a marker of cellular health and aging. Physical exercise has been associated with longer telomeres and, therefore, healthier aging. However, results supporting such effect vary across studies.
OBJECTIVE
Our aim was to synthesise existing evidence on the effect of different modalities and duration of physical exercise on TL.
METHODS
We performed an umbrella review and meta-analysis. Data sources included PubMed, Embase, Web of Sciences, Cochrane Library, and Scopus. We selected systematic reviews and meta-analyses of randomised and non-randomised controlled clinical trials evaluating the effect of physical exercise on TL.
RESULTS
Our literature search retrieved 12 eligible systematic reviews, five of which included meta-analyses. We identified twenty-two distinct primary studies to estimate the overall effect size of physical exercise on TL. The overall effect size was 0.2780 (95% CI: 0.118; 0.439), with a heterogeneity test value (Q) of 43.08 (p=0.0031) and I² coefficient of 51.3%. The number of weeks of intervention explained part of this heterogeneity (Q_B=8.25; p=0.0041), with higher effect sizes found in studies with an intervention of less than 30 weeks. Exercise modality explained additional heterogeneity within this subgroup (Q_B=10.28, p=0.016). The effect sizes were small for aerobic exercise and endurance training, and moderate for High-Intensity Interval Training.
CONCLUSIONS
Our umbrella review and meta-analysis detected a small-moderate positive effect of physical exercise on TL, which seems to be influenced by the duration and type of physical exercise. High quality studies looking into the impact of standardised, evidence-based physical exercise programmes on TL are still warranted.
CLINICALTRIAL
PROSPERO CRD42024500736