We conducted a systematic review and meta-analysis to assess the effects of lifestyle intervention on telomere length (TL).Four databases were searched for studies reporting TL in leukocytes, before and after a lifestyle intervention. We computed random-effects meta-analysis on TL within intervention and control group after versus before intervention, and on changes in TL between groups. Sensitivity analyses and Meta-regression were conducted.We included 20 studies in the systematic review (2995 participants, mean 50.3 years old, 77% women, 2045 following an intervention and 950 controls) and 19 in the meta-analysis. TL were similar at baseline between intervention and control groups. The physical activity ± diet group had an increase in TL (Effect size 0.17, 95%CI 0.03-0.31, p = 0.020) using changes within the intervention group, whereas TL shortened in the control group (-0.32, -0.61 to -0.02, p = 0.037). TL was longer in the physical activity ± diet intervention group (0.24, 0.08-0.40, p = 0.004) compared to controls after the intervention. Sensitivity analysis gave similar results. Meta-regressions demonstrated that combining strength and endurance exercise increased TL more than endurance alone or strength alone.A lifestyle intervention with physical activity ± diet can increase telomere length, independently of population characteristics or baseline TL.
