Background:
In this prospective, randomized controlled study we assessed effects of moderate-intense supervised exercise training on cellular ageing, cardiovascular and overall health, and workability in middle-aged sedentary women.

Methods:
We randomized 291 healthy, non-smoking sedentary women (45-65 years) to 6 months endurance training (EG, 210 min/week) or wait-list-control (CG, no change of inactive life-style). At baseline and 6-month follow-up we assessed leukocyte telomere length in freshly isolated mononuclear cells (MNC), peak oxygen uptake (VO2peak) by cardiopulmonary exercise testing, pulse wave velocity and work ability index (WAI, by questionnaire). The metabolic syndrome score (MSS) was calculated using the siMS score. Changes within the study period were evaluated by analysis of variance including group randomization, periodontal status, menopause status and the respective baseline values.

Results:
At baseline, groups were well matched for anthropometric and cardiovascular parameters. Adherence to exercise training was 207±17 min/week (98±5%). After intervention, the exercise group improved significantly compared to controls in VO2peak (mean difference: 2.11 ml/min/kg, CI [1.41;2.79], p<0.001), pulse wave velocity (mean difference: -0.37 m/s, CI [-0.62;-0.13], p=0.004), WAI (mean difference: 1.58 points, CI [0.59;2.78], p=0.009) and metabolic syndrome score (mean difference: 0.11 points, CI [0.053;0.175], p<0.001). VO2peak and WAI changes correlated significantly (R=0.201; p=0.002). MSS increased significantly in the CG (0.14 points = 2.85%) but not in the EG (0.01 points). Cellular ageing as measured by telomere length in MNC increased only significantly within the exercise group (EG: Δ=0.055, ±0.26, p=0.034; CG Δ=0.021, ±0.30, p=0.437), but with no significant differences between groups (mean difference: 0.03, CI [-0.04;0.11], p=0.581). However, telomere length at baseline inversely correlated with age (R=-0.121, p=0.045). Individuals with short telomeres at baseline in the exercise- but not in the control group significantly (p=0.003) decreased pulse wave velocity with the 6-month intervention.

Conclusion:
Our results show that a moderate personalized 6-months exercise training in middle-aged previously sedentary women improved established parameters of cardiovascular function, prevented metabolic syndrome progression and improved work ability, but did not have major effects on MNC telomere length. However, telomere length might be predictive for certain exercise-induced vascular adaptations.